CN104170116A

CN104170116A - Lithium coin cell construction to mitigate damage from ingestion

Info

Publication number: CN104170116A
Application number: CN201380014393.5A
Authority: CN
Inventors: 郭敬东; 黄维炜
Original assignee: Eveready Battery Co Inc
Current assignee: Edgewell Personal Care Brands LLC
Priority date: 2012-01-13
Filing date: 2013-01-14
Publication date: 2014-11-26
Also published as: WO2013106821A1; EP2803096A1

Abstract

An electrochemical coin cell that includes an anode, and an anode terminal with a closed end that is configured as an electronic conductor and comprises a material that is resistant to reactions forming hydrogen gas during exposure to a saliva-containing solution. The cell further includes a cathode, and a cathode terminal that includes a closed end that is configured as an electronic conductor and comprises a material that is resistant to metallic dissolution and reactions forming oxygen gas during exposure to the saliva-containing solution.

Description

In order to alleviate the lithium battery structure of the infringement causing because of picked-up

Technical field

The present invention relates in general to the structure that is used in the electrochemical cell (cell) in battery pack (battery) application.More specifically, the present invention relates to the use of the terminal material (shell or crust) that nominal open circuit voltage is greater than the electrochemical cell of 1.23V, this nominal open circuit voltage is for water (H ₂o) the theoretical voltage window of electrolysis.One aspect of the present invention is 3V lithium electrochemical cells (for example, the Li-MnO in button or buckle structure ₂and Li-CF _x) the use of terminal material, in order to alleviate infringement tissue being caused when the accidental ingestion.

Background technology

In the past few years, the event of children and the elderly's accidental ingestion battery pack (especially button cell) presents frequency growth.Children also use electronic toy and the device of being powered by baby battery group more and more.And some is used as baby battery group as pill and the Case Report of wrong picked-up about the elderly's mistake recently.

In some cases, the battery pack of absorption has resided in oesophagus, causes the electrochemistry between battery pack and tissue to interact.As manufacture at national electronics association (NEMA) and American National Toxicological Research center (NCPC) combine in letter to be reported, cause the cell reaction of body fluid from the electric current of the battery pack of absorption.A kind of product of reaction is the formation of oxide, and it can cause alkaline ablation and the perforation of oesophagus.In addition, due to compared with other button cell chemical actions, lithium battery has larger diameter and the voltage of increase, so the injury risk relevant to lithium battery is higher.But, absorb relevant electrolysis to battery pack and cause that injury Mechanism of Electrochemistry behind imperfectly understands in the art.

For example, United States Patent (USP) 5,069,989 have described a kind of alkaline battery Battery pack design of the corrosion of acidic gastric juice to positive electrode while being intended to avoid finding under one's belt.Particularly, proposed the anticorrosion container that is made up of the stainless steel with the chromium that is greater than 23%, preferred embodiment, for to have nickel coating on positive electrode, is intended to prevent that six chromium (hexachrome) ion from discharging from stainless steel.

In addition, the relevant issues that prior art solves are devoted to the effect of mitigate corrosion.As used herein, corrode at least one composition that refers to harmful electrochemical reaction of passive generation in environmental condition and relate to battery, according to design, this composition was not intended to originally as active material.Perhaps the modal example of corrosion comprises typically because of the adverse reaction of oxidation to battery case.

Especially, United States Patent (USP) 5,478,670 disclose the use that comprises senior erosion-resisting stainless positive electrode, and the content of its spot corrosion index based on chromium, molybdenum and nitrogen calculates.Under the voltage of 2.0-2.8 volt, in organic bath, this container material alleviates the corrosion of the inside along anodal container being caused by anodizing of aluminium.So, the needs to coated with aluminum on the inside of electrode shell are eliminated in the use of certain material.

Therefore, desirable be to provide a kind of Electrochemcial cell structures, it can alleviate or delay injury tissue being caused because of accidental ingestion battery.It is also preferred that, develop these new button cell structures and do not damage the basic function of battery.For the method that designs, manufacture and/or sell such button cell, and for to eliminate the mode relevant with the danger of accidental ingestion, to use the method for battery same be desirable.

Summary of the invention

One aspect of the present invention is to provide a kind of electrochemical cell, it comprises anode, negative electrode, electrolyte and anode terminal, this anode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of anode terminal and openend, the closing end of anode terminal is configured to electrical conductivity body, and is included in the material being exposed to containing the reaction of opposing formation hydrogen during body fluid solution.Electrochemical cell also comprises cathode terminal, cathode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of cathode terminal and openend, the closing end of cathode terminal is configured to electrical conductivity body, and is included in and is exposed to containing resisting dissolving metal during body fluid solution and forming the material of reaction of oxygen.Battery is also included in liner that arrange and that sealing is provided between anode terminal and cathode terminal, and is arranged in the dividing plate between anode and negative electrode.

Another aspect of the present invention provides a kind of electrochemistry button cell, it comprises anode, negative electrode, electrolyte and anode terminal, this anode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of anode terminal and openend, the closing end of anode terminal is configured to electrical conductivity body, and is included in the material being exposed to containing the reaction of opposing formation hydrogen during body fluid solution.Electrochemistry button cell also comprises cathode terminal, cathode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of cathode terminal and openend, the closing end of cathode terminal is configured to electrical conductivity body, and is included in and is exposed to containing resisting dissolving metal during body fluid solution and forming the material of reaction of oxygen.Battery is also included in liner that arrange and that sealing is provided between anode terminal and cathode terminal, and is arranged in the dividing plate between anode and negative electrode.Battery has total cell height of total battery external diameter and the about 0.5-10mm of about 5-25mm.

Another aspect of the present invention provides a kind of electrochemical cell, it comprises electrolyte and anode terminal, this anode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of anode terminal and openend, the closing end of anode terminal is configured to electrical conductivity body and is included in be exposed to the material that forms the reaction of hydrogen containing opposing during body fluid solution.Electrochemical cell also comprises cathode terminal, cathode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of cathode terminal and openend, the closing end of cathode terminal is configured to electrical conductivity body, and is included in and is exposed to containing resisting dissolving metal during body fluid solution and forming the material of reaction of oxygen.Battery is also included in liner that arrange and that sealing is provided between anode terminal and cathode terminal.Battery also comprises and is arranged to the anode that is electrically connected with anode terminal and is arranged to the negative electrode being electrically connected with cathode terminal, and its Anodic further comprises the material that is selected from the group that comprises lithium and lithium alloy, and negative electrode further comprises manganese dioxide.Electrochemical cell also comprises the dividing plate being arranged between anode and negative electrode.

Other aspect of the present invention provides a kind of electrochemistry button cell, it comprises electrolyte and anode terminal, this anode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of anode terminal and openend, the closing end of anode terminal is configured to electrical conductivity body and is included in be exposed to the material that forms the reaction of hydrogen containing opposing during body fluid solution.Electrochemistry button cell also comprises cathode terminal, cathode terminal comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of cathode terminal and openend, the closing end of cathode terminal is configured to electrical conductivity body, and is included in and is exposed to containing resisting dissolving metal during body fluid solution and forming the material of reaction of oxygen.Battery is also included in liner that arrange and that sealing is provided between anode terminal and cathode terminal.Battery also comprises and is arranged to the anode that is electrically connected with anode terminal and is arranged to the negative electrode being electrically connected with cathode terminal, and its Anodic further comprises the material that is selected from the group that comprises lithium and lithium alloy, and negative electrode further comprises manganese dioxide.Electrochemistry button cell also comprises the dividing plate being arranged between anode and negative electrode.Electrochemistry button cell comprises total cell height of total battery external diameter and the about 0.5-10mm of about 5-25mm in addition.

Those skilled in the art are by being further understood that with reference to specification, claims and accompanying drawing and understanding these and other features of the present invention, advantage and object.

Brief description of the drawings

In figure:

Fig. 1 is the schematic diagram that is immersed in the lithium button cell in body fluid solution;

Fig. 2 is according to the three-dimensional cutaway view of the lithium-manganese dioxide buckle type electrochemical battery of an embodiment;

Fig. 3 is the two-dimentional cutaway view of the electrochemistry button cell shown in Fig. 2;

Fig. 4 is depicted under 3V DC to be immersed in the Faradaic current of the disc electrode pair in synthetic body fluid as the curve chart of the function of time;

Fig. 4 A is depicted under 3V DC to be immersed in the pH of the disc electrode pair in synthetic body fluid as the curve chart of the function of time;

Fig. 5 describes to have the pH that is immersed in the lithium CR2032 battery pack of synthesizing the nickel coating electrode in body fluid as the curve chart of the function of time;

Fig. 5 A describes to have the Faradaic current that is immersed in the lithium CR2032 battery pack of synthesizing the nickel coating electrode in body fluid as the curve chart of the function of time;

Fig. 5 B describes to have the closed circuit voltage (CCV) that is immersed in the lithium CR2032 battery pack of synthesizing the nickel coating electrode in body fluid as the curve chart of the function of time;

Fig. 6 describes to have the pH that is immersed in the lithium CR2032 battery pack of synthesizing stainless steel model 316 positive electrodes in body fluid as the curve chart of the function of time;

Fig. 6 A describes to have the CCV that is immersed in the lithium CR2032 battery pack of synthesizing stainless steel model 316 positive electrodes in body fluid as the curve chart of the function of time;

Fig. 7 describes to have the pH that is immersed in the lithium CR2032 battery pack of synthesizing stainless steel model 430 positive electrodes in body fluid as the curve chart of the function of time;

Fig. 7 A describes to have the CCV that is immersed in the lithium CR2032 battery pack of synthesizing stainless steel model 430 positive electrodes in body fluid as the curve chart of the function of time;

Fig. 8 describes to have the pH that is immersed in the lithium CR2032 battery pack of synthesizing stainless steel model 304 positive electrodes in body fluid as the curve chart of the function of time;

Fig. 8 A describes to have the CCV that is immersed in the lithium CR2032 battery pack of synthesizing stainless steel model 304 positive electrodes in body fluid as the curve chart of the function of time;

Fig. 9 describes to have the pH of lithium CR2032 battery pack of stainless steel model 304 positive electrodes that are immersed in synthetic body fluid and 55wt%Cu – 32wt%Sn – 12wt%Zn alloyed negative electrodes as the curve chart of the function of time;

Fig. 9 A describes to have the CCV of lithium CR2032 battery pack of stainless steel model 304 positive electrodes that are immersed in synthetic body fluid and 55wt%Cu – 32wt%Sn – 12wt%Zn alloyed negative electrodes as the curve chart of the function of time;

Figure 10 describes to have the pH that is immersed in the lithium CR2032 battery pack of synthesizing the titanium positive electrode in body fluid as the curve chart of the function of time;

Figure 10 A describes to have the CCV that is immersed in the lithium CR2032 battery pack of synthesizing the titanium positive electrode in body fluid as the curve chart of the function of time;

Figure 11 describes to have the pH of lithium CR2032 battery pack of Nintaus's electrode of being immersed in synthetic body fluid and nickel negative electrode as the curve chart of the function of time;

Figure 11 A describes to have the CCV of lithium CR2032 battery pack of Nintaus's gate terminal of being immersed in synthetic body fluid and nickel negative electrode as the curve chart of the function of time;

Figure 12 describes to have the pH of lithium CR2032 battery pack of Nintaus's electrode of being immersed in synthetic body fluid and 55wt%Cu – 32wt%Sn – 12wt%Zn alloy electrode as the curve chart of the function of time;

Figure 12 A describes to have the CCV of lithium CR2032 battery pack of Nintaus's gate terminal of being immersed in synthetic body fluid and 55wt%Cu – 32wt%Sn – 12wt%Zn alloyed negative electrodes as the curve chart of the function of time;

Figure 13 describes to have the pH of lithium CR2032 battery pack of Nintaus's electrode of being immersed in synthetic body fluid and model 304 stainless steel negative electrodes as the curve chart of the function of time;

Figure 13 A describes to have the CCV of lithium CR2032 battery pack of Nintaus's gate terminal of being immersed in synthetic body fluid and model 304 stainless steel negative electrodes as the curve chart of the function of time;

Figure 14 describes to have the pH of lithium CR2032 battery pack of the model S32750 two phase stainless steel positive electrode that is immersed in synthetic body fluid and nickel negative electrode as the curve chart of the function of time;

Figure 14 A describes to have the CCV of lithium CR2032 battery pack of the model 2S32750 two phase stainless steel positive electrode that is immersed in synthetic body fluid and nickel negative electrode as the curve chart of the function of time;

Figure 15 be describe to have the model S32750 two phase stainless steel positive electrode that is immersed in synthetic body fluid and and the pH of the lithium CR2032 battery pack of 55wt%Cu – 32wt%Sn – 12wt%Zn alloyed negative electrodes as the curve chart of the function of time;

Figure 15 A describes to have the CCV of lithium CR2032 battery pack of the model S32750 two phase stainless steel positive electrode that is immersed in synthetic body fluid and 55wt%Cu – 32wt%Sn – 12wt%Zn alloyed negative electrodes as the curve chart of the function of time;

Figure 16 describes to have the pH of lithium CR2032 battery pack of the model S32750 two phase stainless steel positive electrode that is immersed in synthetic body fluid and model 304 stainless steel negative electrodes as the curve chart of the function of time; And

Figure 16 A describes to have the CCV of lithium CR2032 battery pack of the model S32750 two phase stainless steel positive electrode that is immersed in synthetic body fluid and model 304 stainless steel negative electrodes as the curve chart of the function of time.

Embodiment

Be different from pay close attention to corrosion reaction, particularly those are believed to occur in the thing (as disclosed in prior art) in the sour environment of stomach, inventor finds that the injury being caused by the button batteries of taking in occurs because battery resides in esophagus, in esophagus, battery can be exposed to body fluid for a long time.Be actually the neutral aqueous solution that mainly comprises water at body fluid, the impact that alleviates the body fluid electrolysis occurring in the time that the terminal of resident battery pack produces voltage is necessary, as will be described in more detail below in.Inventor also determines at button cell packet size large (, the battery pack of total about 5-25mm of battery external diameter and total about 0.5-10mm of cell height, such as CR2016, CR2032 etc.) and/or children or the less people's of other esophagus diameters situation under, this phenomenon is especially serious.

Therefore, looking back the present invention afterwards of possible electrochemical reaction is understood best.Key reaction is the electrolysis of water, because there is following factors: (a) button cell supply DC voltage itself ,～3VOCV (open circuit voltage); (b) ionic conduction medium (body fluid) jointed anode (+) and negative electrode (-) terminal; And (c) these two terminals and body fluid conducting path complete the closed circuit for electrolytic cell.If the voltage supply of electrolytic cell is enough high, consequently overcome the 1.23V thermodynamics voltage window of polarization and water electrolysis, will there is so electrochemical reaction.In fact,, than the electrolysis being associated with the picked-up of alkaline battery, the cell reaction being associated with the picked-up of lithium battery may be more serious.This is much higher in the situation that (voltage difference between cell voltage and theoretical water electrolysis voltage 1.23V) being the in the situation that of 3V lithium battery than at 1.5V alkaline battery because actuating force (the 1.5V-1.23V=0.27V in the situation that 3.0V-1.23V=1.77V contrasting at alkaline battery at lithium battery in the situation that).

Notably, the nomenclature of electrolytic cell is contrary with the nomenclature for battery pack.Therefore, term " anode " (positive terminal) refers to stand the electrode of oxidation reaction, and term " negative electrode " (negative terminal) refers to stand the electrode of reduction reaction.And, it should be noted that electrolysis need to apply voltage, and so with typically under environmental condition abiogenous corrosion form direct contrast.

Fig. 1 helps to show discussed cell reaction.The Li-MnO of simulation ₂buckle type electrochemical battery 6 is immersed in body fluid solution 5.The key reaction occurring when showing the battery with these same parts by accidental ingestion and residing in people's esophagus, although battery electrode is shown as discrete parts.Particularly, battery 6 is worked under about 3V DC, and comprises button cell crust (for example, positive electrode container) 12, button cell shell (for example, negative electrode container) 20, anode 40 and negative electrode 50.Anode 40 and negative electrode 50 are included as its material of selecting special with the compatibility of the electrochemical reaction of expection; For example, x Li+MnO ₂→ Li _xmnO ₂, wherein Mn is along with lithium ion enters lattice and experiences reduction.

The outer surface of button cell crust 12 is as negative terminal (negative electrode in electrolytic cell), and the outer surface of button cell shell 20 is as positive terminal (anode in electrolytic cell).By accepting electronics and at button cell crust 12, hydrogen evolution reaction occurs from battery anode 40, at this moment anode 40 comprises lithium.In button cell shell 20 (anode in electrolytic cell) part, the multiple reaction being oxidized such as dissolving metal, oxygen evolution and possible chloride occurs and competition each other.Neutral charge in body fluid solution 5 keeps to reciprocal motion towards motion and the cation 7 of button cell shell 20 (anode terminal) from battery crust 12 (negative terminal) by anion 8.Along with being oxidized from the metal of button cell shell 20, it loses electronics and gives battery pack negative electrode 50 (being now manganese dioxide).Fundamentally, the end product at button cell shell 20 places depends on its electromotive force, and pH is the anode of combination and the result of cathode reaction.And pH has reacted the real-time product generating in the reaction zone between esophagus and button cell; Therefore, pH localizes, and must not the be liquid solution reflection of pH value of (, the remainder of not contiguous reaction zone in body fluid).

In the time that 3V lithium button cell is immersed in neutrality or alkaline body fluid solution, the possible electrochemical reaction on button cell crust 12 (cathode terminal) is as follows.Please note that body fluid is normally neutral.

(1)2H ₂O+2e ^-→H ₂↑+2OH ^-?E _o＝－0.83V

(2)O ₂+2H ₂O+4e ^-→4OH ^-?E _o＝－0.4V

Typically, reaction (1) accounts for leading and because the solubility of oxygen in water is limited body fluid in the concentration of oxygen too low.No matter which kind of mode, product hydroxyl ion (, OH ^-) the pH value of body fluid is increased, may reach the point that can cause the ablation of esophagus alkali.

Sometimes, body fluid can be actually acidity.In this case, the reaction at button cell crust 12 places performance is as follows:

(1a)2H ⁺+2e ^-→H ₂↑?E _o＝－0.0V

(2a)O ₂+4H ⁺+4e ^-→2H ₂O?E _o＝1.23V

Under any circumstance, there is high hydrogen and separate out the selection of the material at the negative terminal place of overpotential (overpotential) and leading reaction will be changed to (1a) and (2a) from (1) and (2) being used in.Such beneficial effect is the hydroxy formation that reduces or eliminate the local alkali ablation that can cause esophageal tissue.

When 3V lithium button cell is immersed in body fluid solution 5 and when shell 20 comprises nickel along its surface at least in part, the possible electrochemical reaction on button cell shell 20 (anode terminal) is as follows.

(3)4OH ^-－4e ^-→O ₂↑+2H ₂O

(4)Ni－2e ^-+2OH ^-→Ni(OH) ₂

Reaction (4) accounts for leading conventionally, makes the metal ingredient in button cell shell 20 be tending towards being oxidized.In fact, the nickel plating typically of lithium electrochemical button cell shell, as illustrated by the oxidation of nickel in reaction (4).For example, if button cell shell 20 comprises other metals (, stainless steel), the iron in these alloys may be by similarly to react oxidation.Once the metal surface of button cell shell 20 is passivated (, by form intensive oxide-film in bare metallic surface), oxygen evolution reaction (3) may account for leading (if voltage is enough high).

In addition, as below (3a) and (4a) as shown in, if ferrous metals (steel of some types conventionally) is exposed, especially (for example there is to a certain extent hydroxide, by above-mentioned competitive reaction) time and/or in sour environment (for example, via body fluid), the dissolving of metal shell 20 is also a kind of possible result.

(3a) Fe-2e ^-→ Fe ²⁺(in acidic intermedium)

(4a) Fe-2e ^-+ 2OH ^-→ Fe (OH) ₂(in alkaline medium)

The cathodic process of reaction (1) to (2a) can complete electrolytic cell 6 depicted in figure 1 with any combination of the anodic process that reacts (3) to (4a).For example, the combination of (1) and (3) causes cell reaction in following water (, hydrolysis):

(5)2H ₂O→H ₂↑+O ₂↑?ΔE _o＝－1.23V

Note that cell reaction (5) has the thermodynamic potential of 1.23V, and Δ E _onegative sign represent reaction be not spontaneous.Therefore, need at least DC power supply of 1.23V to start and maintain reaction (5), and as shown in Figure 1, button cell 6 is supplied 3V DC.

In addition, if the amount of the sodium chloride in body fluid (NaCl) is relatively high, can there is cell reaction below, instead of reaction (5) (previous discussion):

(6)2NaCl+2H ₂O→Cl ₂↑+H ₂↑+2NaOH

In reaction (6), one of product is NaOH (NaOH), another contributor and the potential alkaline solution of high pH that can ablation tissue.

In a word, the traditional electrochemistry button cell 6 shown in Fig. 1 and with the reaction (1) to (6) being associated in its immersion body fluid 5 show hydroxide ion by certain repeatedly electrolysis form.Therefore, although reaction and pH value corresponding affected to meeting highly localize, and if not measuring the pH value of the in question parts of next-door neighbour is difficult to discover, but the ablation that button cell causes while surprisingly residing in esophagus and injury may be caused by the high body fluid pH value producing in these courses of reaction.In other words, because the mass transportation limit in esophagus, the people with resident button cell can stand for organizing different pH values from the interactional tissue of button cell shell 20 (positive terminal) and with button cell crust 12 (negative terminal) is interactional, wherein, because liquid is in intraesophageal diffusion-restricted, in the face of the solution of negative terminal (, the button cell crust 12 in Fig. 1) has higher pH value.

Aspect some of the present invention and basic conception thereof, comprise that body fluid and/or the aqueous solution based on body fluid, body fluid can be expressed as following composition: 0.4g KCl, 0.4g NaCl, 0.906g CaCl ₂, 0.560g Na ₃pO ₄12H ₂o, 2ml 10%H ₃p0 ₄, 0.0016g Na ₂s, 1g urea, and surplus is deionized water, in order to make 1 liter of solution.Although this formula is intended to approach mankind's body fluid with standardized way, little difference and/or actual mankind's body fluid can be used as substitute, although will notice in time in this case and the deviation of representative formula.

A first aspect of the present invention is considered to alleviate or eliminated destructive Mechanism of Electrochemistry by the suitable selection of material and battery design, and this mechanism can cause injury because of the mistake picked-up of button cell.For example,, for hindering according to outside, the new combination of materials of button cell of the present invention or preventing that these reactions from occurring.Selecting these combinations of materials to alleviate or eliminating these electrochemical reactions is complicated work, needs thoroughly to understand to reaction and injures the principal element that mechanism exerts an influence.In addition, selection can not be random, and must proper cost and the simplification of considering intrinsic chemical compatibility, high speed and high yield manufacturing technology of battery pack industry.

In one embodiment, weakened on the button cell crust 12 in Fig. 1 the reaction (1) and (2) that occur according to electrochemistry button cell disclosed by the invention, or (1a) with (2a) in the possibility of cathodic process.The basic test of the combination of materials that these novel batteries are quoted is supported this conclusion.For example, employing has positive pole and the negative terminal material for the button cell of the high overpotential of (1) and (2) and reaction (1a) and (2a), and/or increases overpotential (the M – ne for burning ^-→ M ⁿ⁺, wherein M refers to the metal material for positive terminal surface) weaken or eliminate these electrochemical reactions, keep other factors constant, comprise come from button cell self～3V DC.

Another method is to select battery electrode material, its under 3V DC, immerse body fluid in time can be easy to dissolve, analyse oxygen and produce insoluble non-hydroxide product (at least moderate on).The formation of this insoluble non-hydroxide product will preferentially or uniquely occur, and suppress thus above harmful hydroxy reaction of paying close attention to.In this method; should provide enough selected materials to guarantee that base material (; be easy to the material of electrolysis) in the essence period (the wherein still voltage higher than ideal or safe level in output of button cell, 2.8 volts or 2.0 volts typically), do not expose.

In another embodiment, the material of selecting can be wrapped by (cladded), applies (coated) or be deposited on battery, or rather, being wrapped by, applying or be deposited on battery may be exposed on the surface in body fluid in the situation of accidental ingestion.The formation of this coating must be complete, uniform, even if because little slight crack, pin hole or other flaws also may provide sufficient reaction site for the adverse reaction that the base material along lower floor occurs.If if do not form complete covering or coating original position degeneration (that is, reacting etc. because of anodic bias, with body fluid), so this coating will not be suitable.Fundamentally, should carry out actual experiment, although have because inventor has been found that the parts of being made up of proof gold the attribute that the present invention is desirable, that the gold plating of 1.4 microns (approximately 56 microinch) may be not enough to provide is consistent, performance repeatably.

As the whole specification of this paper uses, whether no matter be about male or female container, term " covering " or " coating " refer to the continuous individual material layers without any pin hole or other flaws in essence.Therefore,, as limiting examples, cover titanium stainless steel and will comprise the discontinuous layer that for example, attaches to the titanium at the stainless steel-based end by variety of way (, machinery, chemistry, adhesion, welding etc.).In addition, can realize the selection of the substrate to being adapted to preferably specific manufacturing process such as these the use of clad material.In addition, as limiting examples, selected clad material may have desirable overpotential and other characteristics (as illustrated in whole specification) of anti-electrolytic vessel, and substrate may have magnetic.Significantly, clad material with respect to the orientation of substrate by such: the outside that makes parts/container is with consistent in this illustrated the present invention, meanwhile, substrate will can be compatible and do not react with battery active material and electrolyte towards inner part.

Obviously, the use of clad material will produce exposed edge, and for example, ora terminalis 23 as shown in Figures 2 and 3, may expose in undesired mode comprising the cross section of coating and substrate.In this case, can apply sealant to stop any adverse reaction.For example, can be around wheel rim and packing ring district coated polymer sealant (the more preferably curable sealant of UV) cover the edge of exposure.

Fig. 2 and 3 has described for a layout of electrochemistry button cell 10 that is very suitable for aspect of the present invention and embodiment, although button cell 10 can be taked various alternative orientation and the layout of parts.And shown in accompanying drawing with concrete device described herein and technique be the illustrative embodiments of defined inventive concept in appended claims.Therefore, the clear and definite size relevant to embodiment disclosed herein and physical characteristic are not counted as restriction, except following situation: this size and characteristic are intrinsic in order to produce the reaction wanted.

(electrochemistry button cell 10 comprises anode terminal 12, battery case or crust), anode terminal 12 comprises closing end 13, has the openend 14 of ora terminalis 15, and the sidewall 16 (Fig. 2 and 3) extending between closing end 13 and openend 14.In the nomenclature of battery pack, anode terminal 12 is as the negative electrode of button cell 10.And anode terminal 12 comprises resisting the electrically conductive material that forms the electrochemical reaction of hydrogen in being for example exposed to, containing body fluid solution (, body fluid solution 5).For example, anode terminal 12 can be by titanium, titanium alloy, copper-tin-zinc alloy (40-65wt%Cu, 30-45wt%Sn and 4-15wt%Zn), nickel metal, stainless steel, or has high hydrogen and separate out the another kind of electric conductor of overpotential and make.In addition, can be selected as having with respect to standard hydrogen electrode (SHE) onset potential of separating out for body fluid hydrogen (onset potential) to the scope of-1.96V at approximately-0.66V for the material of anode terminal 12.Preferably, the material of selecting for anode electrode 12 has the onset potential of separating out for body fluid hydrogen with respect to be starkly lower than-0.66V of SHE approach-1.96V.

Alternatively, the outer surface 17 of anode terminal 12 can be plated, coating, sputter, coated or be otherwise coated with any metal in these metals.If outer surface 17 covers by this way, anode terminal 12 can comprise be enough magnetic to promote produce in enormous quantities (for example, rely on and adopt the magnetic drive of robot to pick up the method for putting (pick-and-place) autofrettage) material surplus (for example, model 430 stainless steels).Be by another benefit of plating, coating, sputter or coated titanium metal or titanium alloy structure outer surface 17: than manufacturing anode terminal 12 by these compared with expensive material completely, need these less materials to separate out at hydrogen the increase that realization is wanted aspect overpotential.

(electrochemistry button cell 10 as shown in Figures 2 and 3 also comprises cathode terminal 20, battery case), cathode terminal 20 comprises closing end 21, has the openend 22 of ora terminalis 23, and the sidewall 24 extending between closing end 21 and openend 22.Cathode terminal 20 is as the positive electrode of button cell.In addition, cathode terminal 20 comprises resisting and in being exposed to containing body fluid solution, forms the dissolving metal of oxygen and the electrically conductive material of electrochemical reaction.Particularly, cathode terminal 20 can be by titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold, boron-doped diamond, or dissolving metal when anti-anodic bias and preferably have high oxygen and separate out the another kind of electric conductor of overpotential and make.Closing end 21 also can have following composition, comprise: titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold, boron-doped diamond, or dissolving metal when anti-anodic bias and the another kind of electric conductor that preferably there is high oxygen and separate out overpotential.In addition, can be selected as having with respect to SHE the onset potential for the reaction of body fluid Anodic to the scope of+2.4V at approximately+0.6V for the material of cathode terminal 20.Preferably, the material of selecting for cathode electrode 20 has the onset potential for the reaction of body fluid Anodic apparently higher than+0.6V approach+2.4V with respect to SHE.

According to an embodiment, closing end 21 comprises model 2 titanium surpluses.In other embodiments, closing end 21 comprises model S32750 two phase stainless steel or golden surplus.In addition, the outer surface 25 of closing end 21 can have the figure layer, coating, coating or other coverings that comprise in essence titanium, titanium alloy, titanium nitride, model 304 stainless steels, model S32750 two phase stainless steel or gold.If outer surface 25 is plated, sputter, coating, coated or other covering by this way, cathode terminal 20 can comprise be enough magnetic to promote produce in enormous quantities (for example, rely on and adopt the magnetic drive of robot to pick up the method for putting autofrettage) material surplus (for example, model 430 stainless steels).With being plated, another benefits of the outer surface 25 structural closure ends 21 of coating, sputter or coated titanium, gold or other suitable noble metals is: than completely by these compared with expensive material making end 21, need these less materials for realizing the increase of wanting aspect oxygen evolution overpotential.

The another kind of criterion that is used for the effect of evaluating proposed material is the anode polarization scanning at body fluid, especially with reference to nickel-containing material (this suffers aforesaid harmful electrolysis when being appreciated that and being exposed to body fluid under the voltage that is greater than 2.0 volts).What want is under 0.6 volt, to have the 0.05mA/cm of being less than during anode polarization ²the material of electric current, more preferably there is the 0.03mA/cm of being less than ²the material of electric current.For comparison purposes, nickel-containing material has the 0.86mA/cm of being less than under 0.6 volt ²electric current, and proof gold only has 0.03mA/cm ²electric current.Significantly, gold-plated substrate presents different performance level (under 0.6 volt, from 0.05mA/cm ²to 0.52mA/cm ²), further confirm thus: showing that according to the durability of plated material, before the conclusion as candidate material of the present invention, it is useful doing true test with plated material.

Although localization pH level is considered to cause the reason of the injury being caused by the battery of taking in, but result of the test has shown it is only the effect that the measurement of pH value may be not enough to the solution of definite any proposal.Inventor has determined that pH value changes experimental condition sensitivity, and experimental condition comprises the amount of the body fluid of surface area, the appearance of the exposure of anode and cathode terminals, and the method for pH measurement mechanism and position.Therefore,, while consideration when only relatively in the situation that, it is all the most useful that any pH measures.What at present, inventor did not know to have any announcement absorbs for button type battery the standard clinical method of testing that the impact of human body is simulated or quantized.

While being placed in body fluid for assessment of " activity " battery, between terminal, another device of harmful electrolysis activity is that metal to being dissolved into body fluid solution quantizes.As an example, can be used to determine the existence of metal types according to the elementary analysis of inductively coupled plasma (ICP) mass spectrography.In the same way, this quantitative measurment is being also useful aspect the usefulness of definite coating or clad material.

Button cell 10 also comprises liner 30, and liner 30 provides the sealing between anode terminal 12 and cathode terminal 20 (Fig. 2 and Fig. 3).Liner 30 is made up of non-conductive highly elastic material conventionally, can be for providing compression seal between anode terminal 12 and cathode terminal 20.Stability, its elasticity and its anti-cold flow properties that also must exist at electrolyte with reference to it for the material of liner 30 are selected.Suitable material for liner 30 comprises following: nylon, polytetrafluoroethylene, fluorinated ethylene propylene (FEP), chlorotrifluoroethylene, perfluoroalkoxy, polyvinyls, polyethylene, polypropylene, polystyrene, and polysulfones etc.

Electrochemistry button cell 10 also comprises electrolyte 34.As those skilled in the art understand, various materials can be used in electrolyte 34.For example, electrolyte 34 can comprise the composition that has at least one and be dissolved in the lithium salts in organic solvent or ORGANIC SOLVENT MIXTURES.Comprise trifluoromethanesulfonic acid lithium (lithium trifluoromethanesulfonate), fluoroform sulfimide lithium (lithium trifluoromethanesulfonimide), lithium perchlorate (lithium perchlorate), LiBF4 (lithium tetrafluoroborate), lithium hexafluoro phosphate (lithium hexafluorophosphate) or its combination for the suitable salt being used in lithium button cell.The machine that the common are solvent being used in lithium button cell is propylene carbonate and 1,2-dimethoxy-ethane.

Electrochemical cell 10 also has anode 40, and it is set to be electrically connected with anode terminal 12.As those skilled in the art understand, anode 40 can comprise various alkali metal and the alloy with aluminium or magnesium thereof, if this composition is suitable for use as the words of the anode in electrochemical cell.In one embodiment, anode 40 mainly comprises lithium material, and it is adapted at having in the electrochemical cell of the negative electrode being mainly made up of manganese dioxide as anode.Electrochemical cell 10 also comprises negative electrode 50, and negative electrode 50 is configured to be electrically connected with cathode terminal 20.As those skilled in the art understand, negative electrode 50 can be made up of the various materials that are suitable for use as the negative electrode in lithium-based electrochemical battery.In one embodiment, negative electrode 50 is mainly made up of manganese dioxide.

Electrochemistry button cell 10 also comprises dividing plate 38, and it is arranged between anode 40 and negative electrode 50 for insulation is therebetween provided.Dividing plate 38 can be made up of any material in various polymeric materials, and for example, it provides the electric insulation between anode terminal 12 and cathode terminal 20.For example, dividing plate 38 can be by thickness～polypropylene or the polyethylene non-woven membrane of 20-60 μ m form.

As Fig. 2 and 3 also illustrates, electrochemical cell 10 can be constructed to have button or the button cell structure of total battery external diameter 54 and total cell height 58.The size of total can have～5-25mm of battery external diameter 54, total cell height 58 can be～0.5-10mm.Conventionally understand and there is the button of these sizes or button cell most probable and reside in esophagus because of accidental ingestion.For example, electrochemical cell 10 can be made by the CR2016 structure of International Electrotechnical Commission (IEC) definition, and its total battery external diameter 54 has the diameter of 20mm, and total cell height 58 has the thickness of 1.6mm.

Another embodiment of the invention relates to a kind of initial open circuit voltage and exceedes 2.0 volts, more preferably exceedes the anti-electrolysis lithium primary cell (primary cell) of 2.8 volts.Alternatively, lithium primary cell has the rated voltage of approximately 3.0 volts and/or 2.8 volts.The surface of the parts of the outer exposed of this battery by comprise have necessary Hydrogen over potential and/or and cell reaction, be especially exposed to the material of other characteristics that harmful electrolysis (as mentioned above) under body fluid is relevant.Be applicable to present embodiment in all supplementary features, parts and the characteristic described above in previous paragraphs.

Another embodiment of the invention relates to a kind of open circuit voltage and exceedes 2.0 volts, more preferably exceedes the electrochemical cell of 2.8 volts.Alternatively, lithium primary cell has the rated voltage of approximately 3.0 volts and/or 2.8 volts.The outer surface of the outside of the exposure of battery, especially negative electrode container and positive electrode container comprises the other materials that does not make hydroxide develop and/or otherwise cause aqueous solution electrolysis.For example for one of negative, positive external container or both materials have necessary Hydrogen over potential and/or and cell reaction, be especially exposed to the material of other characteristics that harmful electrolysis (as mentioned above) under body fluid is relevant.All supplementary features, parts and characteristic are applicable to present embodiment as described above.

Another aspect of the present invention relates to the structure of anti-electrolysis button cell and/or the method for manufacture.The method comprises provides the negative electrode active material that comprises lithium, and described material is placed in the conductive container of independent two halves and before the two halves that hermetic seal conductive container, provides the liquid organic electrolyte of non-water to form battery pack.The composition of two halves conductive container be selected as having necessary Hydrogen over potential and/or and cell reaction, be more specifically exposed to the material of other characteristics that harmful electrolysis (as mentioned above) under body fluid is relevant.

Another aspect of the present invention is providing and/or manufacturing of anti-electrolytic cell, with the injury of avoiding being associated with the picked-up of described battery pack, and for avoiding being absorbed by battery pack the method for the injury causing.In these areas, can provide any above-mentioned battery pack design and structure.Core is that method of the present invention comprises to be manufactured anti-electrolytic cell and provide described battery pack for selling and/or consumer.

As used in whole specification, two phase stainless steel is any dual phase steel with ferrite and austenite crystal kernel structure.To any standard that be estimated to be with reference to being announced by the ASTM world (ASTM International) of quoting of concrete model, unless the article pointed out up and down certain other reference known to the skilled of field of metallurgy.

In view of above-mentioned and be included in all information in following instance, the electrochemistry button cell with any combination of following characteristics is expected:

Anode, is more preferably set to the anode being electrically connected with anode terminal;

Anode comprises the material that is selected from the group that comprises lithium and lithium alloy;

Negative electrode, is more preferably set to the negative electrode being electrically connected with cathode terminal;

Negative electrode comprises manganese dioxide;

Electrolyte, more preferably comprises the electrolyte that can promote electrochemical reaction, produce the non-water material of the rated voltage that exceedes the open circuit voltage of at least 2.8 volts or 3.0 volts;

Liner, is more preferably arranged between anode terminal and cathode terminal and the liner of sealing is therebetween provided;

Be arranged on the dividing plate between anode and negative electrode, the electric insulation between anode and negative electrode is more preferably also provided;

Between 5 and 25mm between total battery external diameter, and between 0.5 and 10mm between total battery outside high;

Anode terminal, it comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of anode terminal and openend, the wherein closing end of anode terminal: (a) be configured to electrical conductivity body, and be included in and be exposed to the material that forms the reaction of hydrogen containing opposing during the solution of body fluid, and/or (b) be included in fact and be exposed to the electrical conductivity body that forms the reaction of hydrogen containing opposing during the solution of body fluid;

Cathode terminal, it comprises closing end, has the openend of ora terminalis, and the sidewall extending between the closing end of anode terminal and openend, the closing end of cathode terminal: (a) be configured to electrical conductivity body, and be included in and be exposed to the material of resisting dissolving metal during the solution containing body fluid and forming the reaction of oxygen, and/or (b) be included in fact and be exposed to the electrical conductivity body of resisting dissolving metal during the solution containing body fluid and forming the reaction of oxygen;

Wherein, the closing end of anode terminal comprises or is included in fact the material being exposed to containing the tangible hydrogen of tool is separated out overpotential during the solution of body fluid, and more preferably, the material that wherein the tangible hydrogen of tool is separated out overpotential during being exposed to containing the solution of body fluid has with respect to standard hydrogen electrode at approximately-0.66V to the onset potential for separating out containing the solution hydrogen of body fluid in the scope of-1.96V;

Wherein, the material that the closing end of anode terminal comprises or comprise in fact conduction electron and opposing forms the reaction of hydrogen during being exposed to containing the solution of body fluid, and more preferably, the material that wherein the tangible hydrogen of tool is separated out overpotential during being exposed to containing the solution of body fluid has with respect to standard hydrogen electrode at approximately-0.66V to the onset potential for separating out containing the solution hydrogen of body fluid in the scope of-1.96V;

Wherein, the closing end of cathode terminal comprises or is included in fact and is exposed to the material of resisting dissolving metal the tangible oxygen evolution overpotential of tool during the solution containing body fluid, and more preferably, wherein there is with respect to standard hydrogen electrode the onset potential to the anode reaction for the solution containing body fluid in the scope of+2.4V at approximately+0.6V at the material of resisting dissolving metal the tangible oxygen evolution overpotential of tool during the solution being exposed to containing body fluid; Wherein, the material that the closing end of cathode terminal comprises or comprise in fact conduction electron and opposing causes the reaction of dissolving metal and formation oxygen during being exposed to containing the solution of body fluid, and more preferably, wherein there is with respect to standard hydrogen electrode the onset potential to the anode reaction for the solution containing body fluid in the scope of+2.4V at approximately+0.6V at the material of resisting dissolving metal the tangible oxygen evolution overpotential of tool during the solution being exposed to containing body fluid;

Wherein, the closing end of anode terminal comprises in fact titanium, titanium alloy, nickel metal, stainless steel or copper-tin-zinc alloy, and this copper-tin-zinc alloy comprises 30 to 45% tin and 4 to 15% zinc alloy element by weight;

Wherein, the closing end of cathode terminal comprises in fact the material being selected from containing the group of titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold and boron-doped diamond;

Wherein, the closing end of cathode terminal comprises in fact titanium, model 304 stainless steels, model S32750 two phase stainless steel or gold No. 2; And

Wherein, the closing end of cathode terminal also comprises and comprises in fact stainless steel or the stainless substrate of magnetic, and and the outer surface that comprises titanium, titanium alloy or titanium nitride in fact.

In addition, in view of above-mentioned and be included in the information in following instance, the electrochemistry button cell with any combination of following characteristics is expected:

Internal part, it comprises anode, dividing plate and negative electrode, can in nonaqueous electrolyte, produce the output open circuit voltage of at least 2.8 volts;

Flat cylindrical vessel, it encapsulates described internal part, has the outer height between external diameter between 5 to 25 millimeters, 0.5 to 10 millimeter, and this container comprises that electrically insulating substrate's shield is placed in anode terminal shell and cathode terminal shell therebetween;

Wherein, anode terminal shell has and keeps the inner surface that electrically contacts with anode, and is included in and is exposed to the outer surface that forms the material of the reaction of hydrogen containing opposing during the solution of body fluid;

Wherein, cathode terminal shell has the inner surface that contact with cathodic electricity of maintenance, and is included in and is exposed to the outer surface of resisting the material of the reaction of dissolving metal and formation oxygen during the solution containing body fluid;

Wherein, anode comprises the active material that comprises in fact lithium or lithium-base alloy, and negative electrode comprises the active material containing manganese dioxide;

Wherein, the outer surface of anode terminal shell has with respect to standard hydrogen electrode at approximately-0.66V to the onset potential for separating out containing the solution hydrogen of body fluid in the scope of-1.96V;

Wherein, the outer surface of anode terminal shell is selected from the group that comprises titanium, titanium alloy, nickel metal, stainless steel and copper-tin-zinc alloy, and this copper-tin-zinc alloy comprises 30 to 45% tin and 4 to 15% zinc alloy element by weight;

Wherein, the outer surface of cathode material shell has with respect to standard hydrogen electrode the onset potential to the anode reaction for the solution containing body fluid in the scope of+2.4V at approximately+0.6V;

Wherein, the outer surface of cathode terminal shell is selected from the group that comprises titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold and boron-doped diamond;

Wherein, the outer surface of cathode terminal shell is selected from the group that comprises No. 2 titaniums, model 304 stainless steels, two phase stainless steel and gold; And

Wherein, two phase stainless steel is ASTM model S32750.

In addition, in view of above-mentioned and be included in the information in following instance, the method that manufacture has the buckle-shaped battery pack of any combination of following characteristics is expected, wherein buckle-shaped battery pack has the external diameter of 5-25 millimeter and the outer height of 0.5-10 millimeter, the anti-electrolysis in the time that it is placed in the aqueous solution at first with neutral pH of this buckle-shaped battery pack, described feature is:

Arrange in the container inside with anode terminal the anode material that comprises lithium or lithium alloy, the material that wherein the whole outer surface of anode terminal forms the reaction of hydrogen by opposing in the time that the battery of finally making is submerged is made;

Arrange cathode material in the container inside with cathode terminal, wherein the whole outer surface of cathode terminal is made with the material of the reaction that forms oxygen by resist dissolving metal in the time that the battery of finally making is submerged;

By dividing plate and insulating cell is placed between anode and negative electrode and airtight container to form the battery of finally making;

Wherein, the outer surface of anode terminal is selected as having in the time that the battery of finally making is submerged with respect to standard hydrogen electrode at approximately-0.66V to the onset potential of separating out for hydrogen in the scope of-1.96V;

Wherein, the outer surface of cathode terminal is selected as having in the time that the battery of finally making is submerged with respect to standard hydrogen electrode at approximately+0.6V to the onset potential for anode reaction in the scope of+2.4V;

Wherein, the outer surface of cathode terminal is selected from the group that comprises titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold and boron-doped diamond;

Wherein, the outer surface of cathode terminal is selected from the group that comprises No. 2 titaniums, model 304 stainless steels, two phase stainless steel and gold;

Wherein anode terminal is made up of clad material; And

Wherein cathode terminal is made up of clad material.

Finally, in view of above-mentioned and be included in the information in following instance, the buckle-shaped battery pack with any combination of following characteristics is expected, wherein buckle-shaped battery pack has the external diameter of 5 to 25 millimeters and the outer height of 0.5 to 10 millimeter, this buckle-shaped battery pack its be placed into have at first 7.0 or the aqueous solution of less initial pH in time anti-electrolysis, described feature is:

The exposed surface of anode terminal comprises in fact titanium, titanium alloy, nickel metal, stainless steel, contains by weight the copper-tin-zinc alloy of 30 to 45% tin and 4 to 15% zinc alloy element, or its combination;

The exposed surface of cathode terminal comprises in fact titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold, boron-doped diamond, No. 2 titaniums, model 304 stainless steels, model S32750 two phase stainless steel or its combinations; And

Also comprise the active material of positive electrode with lithium and the active material of cathode with manganese dioxide.

Character of the present invention, its purposes and advantage are further illustrated in following instance, and these examples compare the new battery of the result of the electrolysis test of traditional electrical chemical cell and inventor's structure.These new batteries are example of the present invention and the discovery that has reflected inventor: cause the electrochemical mechanism that is absorbed and stationed the damage causing by unexpected button cell in esophagus.

example 1

For the model of electrode, build desk-top electrolysis tank (bench-top electrolysis cell) for the object of assessment pH value and electric current generation, it is the function of time that pH value and electric current produce, this model be used in anode and the cathode terminal material in traditional electrical chemical cell and be configured to the terminal of example of the present invention consistent.Be prepared as respectively discoidly in order to the positive and negative electrode of the negative electrode and positive electrode terminal of analog electrical chemical cell, there is separately the 3.5cm of estimating ²exposed area.This area approximates the external area of CR20xx (for example, CR2032, CR2016 etc.) lithium electrochemical button cell structure.For test, the assembly that circular electrode is constructed to face with each other.Then two-layer separator material is positioned between circular electrode, and changes to measure pH near test period pH probe is placed in negative electrode.

Then, the electrode assemblie completing is dipped in synthetic body fluid solution, and this synthetic body fluid solution is prepared from following ingredients: 0.4g KCl, 0.4g NaCl, 0.906g CaCl ₂, 0.560gNa ₃pO ₄12H ₂o, 2ml 10%H ₃p0 ₄, 0.0016g Na ₂s, 1g urea, and surplus is deionized water, in order to make 1 liter of synthetic body fluid solution.The chloride concentration of this synthetic body fluid solution equals 0.03M chloride solution.Then utilize EG & G 273A pressurizer to apply 3.0V DC voltage to electrode pair and start electrolysis.Do not adopt to stir and assist mass transfer, the position of pH probe is kept constant, and test has been carried out approximately 80 minutes.

Table 1 has below been listed the electrode pair that lower test is set at this.Ni (+)/Ni (-) is to being chosen to be control, because typical Li-MnO ₂electrochemical cell adopts anode and the cathode terminal with nickel plating.About reaction (3) and (4), titanium and model 304 stainless steel positive electrodes are chosen as these opposing anodic decomposition and have hyperoxia the material of separating out overpotential.Other benchmark tests and theory analysis have shown that copper-tin-zinc alloy (40-65wt%Cu, 30-45wt%Sn and 4-15wt%Zn) also can stop or alleviate harmful cell reaction as negative electrode.Copper-tin-zinc alloy in this test is the form of plating (electroplating the trade mark of composition for certain Umicore Galvanotechnik Gmbh ' s (a/k/a Umicore plating)) steel, plating has following general composition: 55wt%Cu, 32wt%Sn and 12wt%Zn.

Table 1

Referring to Fig. 4, shown ampere (A) electric current as elapsed-time standards (minute) function, it is dipped in synthetic body fluid solution for the electrode pair in table 1 and stands the each electrode after 3.0V DC.As shown in Figure 4, control right Faradaic current for Ni (+)/Ni (-) and be stabilized in rapidly 22-25mA.After having tested, it is green that solution is, and has some white precipitates, represents nickel ion and some nickel oxide of dissolving.As shown in Figure 4 A, the pH with the body fluid solution of Ni (+)/Ni (-) electrode rises to rapidly maximum pH level～13, shows that body fluid has high alkalinity and possibility ablation tissue.

On the contrary, as shown in Figure 4, be obviously reduced to and be less than 1mA for the Faradaic current of Ti (+)/plating 55wt%Cu – 32wt%Sn – 12wt%Zn steel alloy (-) electrode pair.After having tested, keep limpid for the solution of this test.In fact, as shown in Figure 4 A, after testing 60 minutes, the pH with the body fluid solution of Ti (+)/plating 55wt%Cu – 32wt%Sn – 12wt%Zn steel alloy (-) electrode pair is only elevated to slightly～7.5 pH level.Therefore, in this test, the use of this electrode system in electrochemistry button cell 10 significantly weakened electrolysis.

For its part, 304 stainless steels (+)/plating 55wt%Cu – 32wt%Sn – 12wt%Zn steel alloy (-) electrode pair has reduced Faradaic current, lower than the Faradaic current of seeing for Ni (+)/Ni (-) electrode pair, higher than Ti (+)/plating 55wt%Cu – 32wt%Sn – 12wt%Zn steel alloy (-) electrode pair (Fig. 4).Solution for this electrode pair has comprised brown precipitation, may represent that the stainless iron in self-electrode decomposes.Fig. 4 A also illustrates obviously rise to the duration testing～13 pH level of the pH that test has the body fluid solution of 304 stainless steels (+)/plating 55wt%Cu – 32wt%Sn – 12wt%Zn steel alloy (-) electrode pair after 80 minutes.That is to say, for the pH growth rate of 304 stainless steels (+)/plating 55wt%Cu – 32wt%Sn – 12wt%Zn steel alloy (-) electrode pair lower than Ni (+)/Ni (-) electrode pair.Therefore, the use of this system in electrochemistry button cell 10 may postpone the growth of pH value of solution because of electrolysis, behaves and provides the more time to accept to absorb with unexpected button cell the medical rescue being associated potentially.

example 2

In this example, for the model that is immersed in the electrode that is connected to true lithium electrochemical button cell (CR2032) in synthetic body fluid solution (in similar example 1), the object of falling for assessment pH value and closed circuit voltage (CCV) and built desk-top electrolysis tank, it is the function of time that pH value and closed circuit voltage (CCV) fall.Reducing (marginal decrease) for the limit of the battery CCV to fixed electrode configuration may represent to alleviate the system of esophagus damage.Similarly, changing in the limit of test duration and body fluid pH value of solution afterwards the esophagus that also may indicate alleviating because of the electrolysis of battery pack/tissue damages.

The electrode material of studying in this example is listed in table 2 as follows.

Table 2

In table 2, listed material is cut into little bar shaped (0.156 inch × 1 inch) and is provided as electrode use.Note that the configuration with nickel positive and negative electrode in example 2 is used as control, because typical lithium electrochemical button cell is manufactured with nickel plating stainless steel casing and crust.In addition, synthetic body fluid is to prepare according to general formula used in example 1.

Comprise two electrode strips that immerse 0.3125 inch of body fluid solution with electrolysis tank in this example.Distance between electrode is set to～and 0.5 inch.The total amount that is used in the body fluid in this groove is 5ml.Be connected to for the electrode of each test configurations (referring to table 3 below) the lithium CR2032 button cell that do not discharge, this button cell is as the power supply of the electrolysis of body fluid.Utilize DAQ book 56 data acquisition systems to measure cell voltage.At test period, the near surface that healthy and free from worry (Corning) pH meter (model 350) with micro-pH probe (from the Accumet catalogue #S-55500-45 of Cole-Parmer) is placed on negative electrode records the pH of body fluid.Initial cells OCV is～3.2-3.3V, and synthetic body fluid has initial pH level～6.

In this example, near each electrode pair of the tested synthetic body fluid solution (pH～12) that has finally produced obvious alkalescence negative electrode, test time is set at about 90 minutes.These electrode pairs of minor variations have only occurred near tested pH value of solution level negative electrode, and test has been carried out more of a specified duration, has at least duration of 5-6 hour.After the test of carrying out for specific electrode configuration completes, new electrode group, body fluid solution (5ml), and CR2032 button cell is used to next round.Table 3 below provides the summary of electrode, pH value of solution (at 15,90 and 400 minutes) and the battery CCV (at 90 and 400 minutes) of test.And in table 3, " n " combines tested number of times corresponding to specific electrode.

Table 3

As shown at table 3 and Fig. 5,5A and 5B, the control CR2032 lithium button cell one with nickel coating electrode (Ni (+)/Ni (-)) is immersed in synthetic body fluid and has experienced obvious electrolysis.Near the pH level of body fluid negative electrode is in the time that test starts～5.7, and after 15 minutes, increase to rapidly 12.2 pH level (Fig. 5).Therefore, the duration of test, the pH horizontal stable of solution and maintenance are relatively constant.Control right Faradaic current for Ni (+)/Ni (-) is 3.2mA in the time that test starts, and after 20 minutes, increases to 4mA, and remains on 4mA (Fig. 5 A) duration of test.

Although in this example for the Faradaic current level (4mA) of Ni (+)/Ni (-) electrode pair lower than shown in Fig. 4 of example 1 for Ni (+)/Ni (-) test electrode to the Faradaic current level (22-25mA) of seeing, but the result of this example represents obvious electrolysis.In fact, near the gas evolution (hydrogen) negative electrode is observed in test at the very start.And near the solution after having tested positive electrode presents green, may represent that nickel cation forms.In addition, positive electrode itself is obviously corroded, and has large greeny precipitation, may be Ni (OH) ₂.And Fig. 5 B shows for the closed circuit voltage (CCV) of Ni (+)/Ni (-) electrode pair of test in this example and is slightly brought down below the level of 3.0V and was brought down below the level of 2.8V within a few minutes of test within 30 minutes of test.

And please note for the difference between the Faradaic current level of control Ni (+)/Ni (-) electrode pair of testing at this example and in the previous example shown in Figure 4 and 5 A and can explain by the difference between the electrode surface areas between test.In example 1 (Fig. 4), negative electrode surface area is～3.5cm ²(circular electrode), and in the test of summarizing in example 2, electrode surface areas is～0.67cm ²(strip electrode).In example 2, the size of the part of the immersion body fluid of the strip electrode of general introduction is 0.008 inch of (in) (thick) × 0.156 inch (wide) × 0.3125 inch (length), forms 0.67cm ²(0.156in × 0.3125in × 2+0.3125in × 0.008in × 2+0.156in × 0.008in × 1=0.104in ²; And 0.104in ²× 2.54cm ²/ in ²=0.67cm ²) exposed surface area.Therefore, in the test of describing in detail in example 1, more electrode surface areas contacts with synthetic body fluid, and thereby slightly high for these test Faradaic current levels.

Fig. 6 and 6A (and table 3) show the result of the electrolysis test of the lithium CR2032 battery with stainless steel model 316 (SS316) positive electrode and nickel, stainless steel model 430 or stainless steel model 304 negative electrodes.Similarly, Fig. 7 and 7A show the result of the electrolysis test of the CR2032 battery with stainless steel model 430 (SS430) positive electrode and stainless steel model 304 negative electrodes.Especially, Fig. 6 and 7 has illustrated that pH level all increases for all in SS316 positive electrode in this group and SS430 electrode pair, but and unlike controlling Ni (+)/Ni (-) electrode pair fast (compared with Fig. 5).But pH level all increased to pH level more than 11 for all in described electrode pair in 40-50 minute of test, showed synthetic body fluid electrolysis.In addition, Fig. 6 A shows and during test time, reduces with the CCV of the battery of SS316 positive electrode test, but less than for the viewed degree of Ni (+)/Ni (-) electrode pair (compared with Fig. 5 B).And, Fig. 7 A show CCV with the battery of SS430 positive electrode test during test time to reduce with the comparable ratio of the ratio of Ni (+)/Ni (-) electrode pair.Thereby generally speaking, with regard to postponing body fluid pH increase, as positive electrode material, stainless steel model 316 and 430 provides some benefits than nickel plating.Correspondingly, increase with pH this delay being associated and can the more time seek medical rescue after button cell accidental ingestion to people.

As Fig. 8,8A, 9 and 9A (and table 3) as shown in, have the electrolysis test generation of lithium CR2032 battery of stainless steel model 304 (SS304) positive electrode and nickel, stainless steel model 430, stainless steel model 304 or 55wt%Cu – 32wt%Sn – 12wt%Zn alloyed negative electrodes and Fig. 6,6A, 7 and 7A shown in for SS316 and the similar result of SS430 positive electrode system.Fig. 8 and 9 shows pH level and increases (referring to table 3) for all in the right combination of the SS304 positive electrode of testing in this group, but and fast unlike Ni (+)/Ni (-) control group shown in Fig. 5.Similarly, Fig. 8 A and 9A show and reduce at whole test time with the CCV of the battery of SS304 positive electrode test, but less than for the viewed degree of Ni (+)/Ni (-) electrode pair.

In addition, for the pH value of solution level of all SS304 positive electrode groups of testing, until the pH level that is just elevated to at least 15 minutes more than 9 (Fig. 8 and 9) of test.After this is different from test 15 to a certain extent, pH increases to rapidly the more than 11 SS316 positive electrode of (referring to Fig. 6 and 7 test groups---SS316 (+)/SS304 (-), SS316 (+)/Ni (-), second take turns and SS430 (+)/SS304 (-)) of pH level and several results of just test group of SS430.For example, second take turns the configuration of SS316 positive electrode and nickel negative electrode and be configured in test with SS430 positive electrode and SS304 negative electrode and only within 15 minutes, produce pH level～11.5 afterwards.Therefore, SS304 positive electrode button system is to present to be slightly better than the button cell system with SS316 or SS430 positive electrode, and is much better than to have the button cell system of nickel positive electrode.

Finally, Figure 10 and 10A (and table 3) have described to have the electrolysis test result of the CR2032 lithium button cell that immerses the titanium positive electrode (Ti (+)) in synthetic body fluid.For this test group, titanium positive electrode means the coating that titanium is used as positive button battery case itself or is used as the outer surface of this shell.As shown in figure 10, for all button cells as positive electrode material test with titanium, do not increase to more than 7 at the pH of the body fluid of the near surface of negative terminal.Thereby titanium slows down the electrolysis of synthetic body fluid as the positive electrode in the configuration of lithium button cell.In fact,, the duration that these are tested, approximately 400 to 500 minutes, the pH level in synthetic body fluid kept below pH level 7 and higher than pH level 4.Because many common food are acid, there is pH level (for example, the cherry pH=3.2-4.0 lower than 4; Apple pH=2.9-3.3), near the truth that the body fluid pH of some tests in these tests is parked in 4 is not important focus.

Similarly, Figure 10 A has illustrated lithium button cell not obvious reduction of CCV after immersing synthetic body fluid with the configuration of Ti (+) electrode.After testing many hours, these batteries with titanium positive electrode keep 3.1V---start only to reduce 0.1V from test.As before, these results show that titanium is used as positive electrode and alleviates the esophagus damage because of the accidental ingestion of button batteries.

example 3

In this example, for the model of electrode that is immersed in the true lithium electrochemical button cell (CR2032) being connected in synthetic body fluid solution, the object of falling for assessment pH value and closed circuit voltage (CCV) and again adopt desk-top electrolysis tank, it is the function of time that pH value and closed circuit voltage (CCV) fall.What use with example 2 for the test configurations of this example and body fluid solution is identical.

Electrode material in this test is listed in table 4 as follows.The various combinations of these materials are configured and stand desk-top test in the previous mode of describing for example 2 of reference.At this, gold and two-phase stainless steel pattern number S32750 are selected as positive electrode candidate material, because in the time configuring with test chart and be subject to anodic bias, before observing obvious levels of current, they show high onset potential.Model S32750 (for example, is made up from AB Sandovik iron and steel of Avesta Polarit AB through license ) two phase stainless steel has following typical composition: Fe – 0.02%C – 0.27%N – 25%Cr – 7%Ni – 4%Mo.Model S32570 stainless " two-phase " aspect is ferrite/austenite micro-structural (having high strength and corrosion resistance in many environment) of its disome.

Table 4

Table 5 below provides the summary of the result of six kinds of combinations of the positive and negative electrode material of tests column in table 4.For comparison purposes, table 5 also comprises the result of the test in early stage of Ti (+)/Ni (-) that the favourable control electrode of conduct in example 2 is right and Ni (+)/Ni (-) electrode pair.In addition, in synthetic body fluid solution, there is Nintaus's electrode for being immersed in, have the lithium CR2032 battery pack of nickel, plating 55wt%Cu-32wt%Sn-12wt%Zn steel alloy and model 304 stainless steel negative electrodes, Figure 11 to Figure 13 A has described as the closed circuit voltage of the function of time with as the pH level of the function of time.Similarly, in synthetic body fluid solution, there is model S32750 two phase stainless steel positive electrode for being immersed in, have the lithium CR2032 battery pack of nickel, plating 55wt%Cu-32wt%Sn-12wt%Zn steel alloy and model 304 stainless steel negative electrodes, Figure 14 to Figure 16 A has described as the closed circuit voltage of the function of time with as the pH level of the function of time.

Table 5

Table 5 and Figure 11 to Figure 13 A have illustrated that the lithium battery of the synthetic body fluid submergence of the CR2032 configuration with Nintaus's electrode does not almost have after accidental ingestion, to cause the product sign of esophagus damage.The pH level of observing at these test periods is usually less than pH=8.Only Au (+)/Ni (-) electrode pair reaches the level of about pH=8.2 in the time exposing approximately～35 minutes, continues blink until expose～45 minutes.Slightly reduce at the test period battery pack CCV for Au (+) electrode, represent carrying out during some react on body fluid submergence.But it shows at the oxygen evolution at Au (+) electrode place and to separate out at the hydrogen at negative electrode place be primary reaction (primary reaction), not that potential damaging hydrogen forms reaction.

The result of the test of carrying out as positive electrode with model S32750 stainless steel is also illustrated in Figure 14 to Figure 16 A and table 4 above.S32750 (+)/plating 55Cu-32Sn-12Zn steel alloy (-) electrode pair behaves oneself best, and during immersing synthetic body fluid solution, has and is no more than the pH level of pH=8 and reducing of CCV minimum.Another two electrode pairs (S32750 (+)/Ni (-) and S32750 (+)/SS304 (-)) the most of the time of immersing test duration conventionally have lower than the pH level of pH=10 and rest near pH=9 (, alkalescent) or below.Reduce than observing slightly large CCV for S32750 (+)/plating 55Cu-32Sn-12Zn steel alloy (-) electrode pair for these electrode pairs.

After the test time for S32750 (+)/SS304 (-), S32750 (+)/Ni (-) and S32750 (+)/plating 55Cu-32Sn-12Zn steel alloy (-) electrode pair, synthetic body fluid solution colour presents redness or brown, may represent the dissolving metal of S32750 electrode itself.In view of these results, solution observed data after test, and the electrochemical reaction (1) of general introduction is before to (6), these electrode pairs stand anodic solution and oxygen evolution most probably, but do not form the hydroxide ion that can cause esophagus damage.On the contrary, solubilizing reaction shows as the chloride, phosphate and/or the sulfide that produce containing non-hydroxide.Thereby, S32750 should weaken as the positive electrode in lithium button cell or alleviation and unexpected button cell absorb be associated damage mechanism.Advantageously, model S32750 stainless steel is magnetic, becomes good positive electrode material select from the position of button cell manufacturability.

example 4

In this example, the various different materials of describing in utilization as table 6A below and 6B build full-scale CR2016 battery, wherein independently experiment of each table representative.Unless noticed reverse situation, run through all batches of groups and use identical parts, material and size, can compare between the battery that makes to build in this example.Similarly, adopt instrument, method and the body fluid solution identical with previous example.Goldleaf is buied from Sigma Aldrich, and plated material obtains from Electro-spec.Two-phase stainless steel pattern number for this example is the SS2507 from AvestaPolarit (ASTM S32750).As above noting, criticize the object of the comparison of group for the difference of only considering in this example, pH value has directive significance.And, especially in regard to the result of showing in 6A, be considered to some variation and be observed because being difficult to obtain consistent pH measurement.In view of these difficulties, further after improvement, be implemented in the method opinion in the second experiment shown in table 6B.And, in table 6A and 6B, several reproducible results are omitted (for succinct object, there is batch group of identical positive and negative shell), and the in the situation that of table 6B, one of repeat in batch group to comprise two-phase (+)/SS304 (-) batch of group, wherein problem occurs in the uniformity of the structure of battery and the pH of synthetic body fluid.

Table 6A

Table 6B

Generally speaking, be considered through the battery compared with long a period of time with neutrality or acid ph value the candidate that the present invention is outstanding.Because of the shortcoming of electroplating technology of finding, all gold-plated batch of groups and " controls " nickel are criticized group and are showed poorly, reach high pH (>10) within about ten minutes.By contrast, even if being coupled to nickel negative electrode, two phase stainless steel also proves strong candidate.This result is somewhat unexpected, but easily adapts to show fabulous prospect with regard to high speed manufacture view with regard to two phase stainless steel and nickel-plated steel.As illustrated in existing example, titanium also proves promising material.

In a word, the impact relevant to harmful electrolysis causing because of the accidental ingestion of battery advantageously alleviated or weakened to electrochemistry button cell 10.Should be understood that have benefited from other types of the present invention battery (for example, the battery with the nominal open circuit voltage that is greater than 1.23V, comprises the lithium ion electrochemical cells with open circuit voltage more than 4V) can adopt different anodes and negative electrode chemical composition and/or various geometry.

Although describe the present invention in detail according to specific embodiment, but those skilled in the art can carry out various improvement and change to them not departing under real situation of the present invention.Thereby the scope of claims should not be subject to illustrating details and the means restriction of embodiment shown here.

Claims

1. an electrochemistry button cell, comprising:

Comprise the internal part of anode, dividing plate and negative electrode, can in nonaqueous electrolyte, produce the output open circuit voltage of at least 2.8 volts;

Flat cylindrical vessel, it encapsulates described internal part, and described flat cylindrical vessel has the external diameter between 5 to 25 millimeters, and outer height between 0.5 to 10 millimeter, described container comprises anode terminal shell and cathode terminal shell, and electrically insulating substrate's shield is placed between anode terminal shell and cathode terminal shell;

Wherein, described anode terminal shell has inner surface and outer surface, and this inner surface keeps electrically contacting with described anode, and this outer surface is included in and is exposed to the material that forms the reaction of hydrogen containing opposing during the solution of body fluid; And

Wherein, described cathode terminal shell has inner surface and outer surface, and this inner surface keeps contact with described cathodic electricity, and this outer surface is included in and is exposed to the material of resisting the reaction of dissolving metal and formation oxygen during the solution containing body fluid.

2. electrochemical cell according to claim 1, wherein, described anode comprises the active material that comprises in fact lithium or lithium-base alloy, and described negative electrode comprises the active material that comprises manganese dioxide.

3. electrochemical cell according to claim 1, wherein, the outer surface of described anode terminal shell has with respect to standard hydrogen electrode at approximately-0.66V to the onset potential for separating out containing the solution hydrogen of body fluid in the scope of-1.96V.

4. electrochemical cell according to claim 3, wherein, the outer surface of described anode terminal shell is selected from and comprises titanium, titanium alloy, nickel metal, stainless steel, and contains by weight the group of the copper-tin-zinc alloy of 30 to 45% tin and 4 to 15% zinc alloy element.

5. electrochemical cell according to claim 3, wherein, the outer surface of described cathode material shell has with respect to standard hydrogen electrode the onset potential to the anode reaction for the solution containing body fluid in the scope of+2.4V at approximately+0.6V.

6. electrochemical cell according to claim 5, wherein, the outer surface of described cathode terminal shell is selected from the group that comprises titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold and boron-doped diamond.

7. electrochemical cell according to claim 5, wherein, the outer surface of described cathode terminal shell is selected from the group that comprises No. 2 titaniums, model 304 stainless steels, two phase stainless steel and gold.

8. electrochemical cell according to claim 7, wherein, described two phase stainless steel is ASTM model S32750.

9. a method of manufacturing buckle-shaped battery pack, described buckle-shaped battery pack has the external diameter of 5 to 25 millimeters and the outer height of 0.5 to 10 millimeter, the anti-electrolysis in the time that it is placed in the aqueous solution at first with neutral pH of described buckle-shaped battery pack, described method comprises:

Arrange in the container inside with anode terminal the anode material that comprises lithium or lithium alloy, the material that the whole outer surface of wherein said anode terminal forms the reaction of hydrogen by opposing in the time that the battery of finally making is submerged is made;

Arrange cathode material in the container inside with cathode terminal, the whole outer surface of wherein said cathode terminal is made with the material of the reaction that forms oxygen by resist dissolving metal in the time that the battery of finally making is submerged;

Dividing plate and insulating cell are placed between anode and negative electrode and seal described container to form the battery of finally making.

10. method according to claim 9, wherein, the outer surface of described anode terminal is selected as, and has with respect to standard hydrogen electrode at approximately-0.66V to the onset potential of separating out for hydrogen in the scope of-1.96V in the time that the battery of finally making is submerged.

11. methods according to claim 9, wherein, the outer surface of described cathode terminal is selected as, and has with respect to standard hydrogen electrode at approximately+0.6V to the onset potential for anode reaction in the scope of+2.4V in the time that the battery of finally making is submerged.

12. 1 kinds of battery pack that method according to claim 9 is made.

13. battery pack according to claim 12, wherein, the outer surface of described cathode terminal is selected from the group that comprises titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold and boron-doped diamond.

14. battery pack according to claim 12, wherein, the outer surface of described cathode terminal is selected from the group that comprises No. 2 titaniums, model 304 stainless steels, two phase stainless steel and gold.

15. methods according to claim 9, wherein, described anode terminal is made up of clad material.

16. methods according to claim 9, wherein, described cathode terminal is made up of clad material.

17. 1 kinds of buckle-shaped battery pack, described buckle-shaped battery pack has the rated voltage of at least 3.0 volts, the external diameter of 5 to 25 millimeters and the outer height of 0.5 to 10 millimeter, described buckle-shaped battery pack its be immersed in completely have 7.0 or the aqueous solution of less initial pH in time anti-electrolysis, described buckle-shaped battery pack comprises:

The exposed surface of anode terminal, comprises in fact titanium, titanium alloy, nickel metal, stainless steel, by weight containing the copper-tin-zinc alloy of 30 to 45% tin and 4 to 15% zinc alloy element, or its combination; And

The exposed surface of cathode terminal, comprises in fact titanium, titanium alloy, titanium nitride, tantalum, niobium, stainless steel, gold, boron-doped diamond, No. 2 titaniums, model 304 stainless steels, model S32750 two phase stainless steel, or its combination.

18. battery pack according to claim 17, also comprise the active material of positive electrode with lithium and the active material of cathode with manganese dioxide.