KR20120118721A - Electrode assembly and electrochemical device comprising the same - Google Patents

Abstract

PURPOSE: An electrode assembly is provided to solve problems of reduction of cycle life time and capacity of a battery due to a solid electrolyte interface layer heterogeneously formed on the surface of a negative electrode. CONSTITUTION: An electrode assembly(200) comprises a positive electrode, a negative electrode, and a separator, and comprises unit comprising lithium metal. The unit comprising lithium metal is electrically connected to the negative electrode. The negative electrode and the unit comprising lithium metal are connected to a resistor(150). The resistor is conductive metal having a resistance size to charge a battery with an initial self-charging rate of 0.01-1 C-rate. The unit comprising lithium metal is a thin film comprising lithium metal.

Description

Electrode assembly and electrochemical device comprising the same

The present invention relates to an improved electrode assembly and an electrochemical device comprising the same.

Recently, miniaturization and lighter weight of electronic equipment have been realized and use of portable electronic devices has become common, so researches on lithium secondary batteries having high energy density have been actively conducted.

A lithium secondary battery is prepared by using a material capable of inserting and detaching lithium ions as a negative electrode and a positive electrode, and filling an organic or polymer electrolyte between the positive electrode and the negative electrode, and lithium ions can be inserted and removed from the positive electrode and the negative electrode. Electrical energy is generated by oxidation and reduction reactions.

Lithium secondary batteries are also called rocking chair batteries because lithium ions reciprocate the positive and negative poles like a rocking chair to transfer energy. The surface and the electrolyte react to form a solid electrolyte interface (SEI) layer.

In the case of the conventional lithium secondary battery, a transition metal compound in which lithium is inserted, such as LiCoO ₂ , LiMnO ₄ , or LiNiO ₂ , is used as a positive electrode active material, and a graphite capable of intercalating or deintercalating lithium is used as a negative electrode active material. The battery is manufactured using a carbon material such as amorphous carbon or low crystalline carbon.

In the case of the secondary battery using the carbon material, a passivation film (SEI) is formed on the surface of the carbon anode during the initial charging of the battery according to the reaction of the organic solvent and lithium ions. The more stable it is formed, the higher the safety and reversibility of the carbon anode lattice structure, ultimately improving the charge and discharge cycle life of the cell.

However, the formation of the passivation film leads to the consumption of lithium ions, resulting in a decrease in battery capacity and an initial charge / discharge irreversible capacity, which in turn impedes the improvement of the energy density of the battery and the charging of an external current to generate a stable passivation film in the manufacturing process. The process is necessary.

In order to improve this, there are a variety of methods for conventional lithiation of the carbon anode, but the process is very difficult.

An object of the present invention is to provide an electrode assembly that can solve the problems of the prior art as described above to solve the problem of cycle life and capacity degradation of the battery due to the non-uniformly formed SEI layer on the surface of the negative electrode.

In addition, another object of the present invention to provide an electrochemical device comprising the electrode assembly.

A further further object is to provide a medium to large electrochemical device made by connecting a plurality of the electrochemical device.

In order to solve the above problems, the electrode assembly according to the embodiment of the present invention is characterized by including a positive electrode, a negative electrode, a separator, and comprises a means containing lithium metal.

The means comprising the lithium metal is characterized in that it is electrically connected with the cathode.

Means comprising the negative electrode and the lithium metal is characterized in that connected by a resistor.

In addition, the resistor is characterized in that the conductive metal having a resistance size so that the initial self-charging rate of the battery including the electrode assembly can be charged at a rate of 0.01 ~ 1 C-rate.

In addition, the resistor is characterized in that the conductive metal having a resistance size so that the initial self-charging rate of the battery including the electrode assembly can be charged at a rate of 0.01 ~ 0.1 C-rate.

In addition, the resistor is characterized in that at least one conductive metal selected from the metal having a resistance size of 10mΩ ~ 100mΩ.

The means containing lithium metal is characterized in that the thin film containing lithium metal.

In addition, the means including the lithium metal is characterized in that it comprises a lithium metal on the porous sheet,

The means including the lithium metal is characterized in that a thin film of lithium metal laminated on the porous sheet.

In addition, the amount of lithium metal included in the means including the lithium metal may be the same as the irreversible capacity of the negative electrode material used,

The amount of lithium metal included in the means comprising the lithium metal is characterized in that the amount is less than 5% less than the irreversible capacity of the negative electrode material used.

On the other hand, the means containing the lithium metal is characterized in that it is connected to a plurality of electrode assemblies.

In addition, the lithium metal means and the plurality of electrode assemblies are characterized in that connected to the negative electrode of each electrode assembly,

The electrode assembly may be formed of any one structure selected from a stack type, a jelly roll type, and a stack / fold type stack-z-fold type structure.

In another aspect, the present invention provides an electrochemical device including the electrode assembly in order to solve another problem.

In addition, the electrochemical device may be a lithium secondary battery.

Furthermore, the present invention provides a medium-large battery pack including the plurality of electrochemical devices.

The medium-large battery pack includes a power tool; An electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV); Electric two-wheeled vehicles including E-bikes and E-scooters; Electric golf carts; Electric trucks; It is used as a power source for any one or more medium-large devices selected as an electric commercial vehicle or a power storage system.

When electrically connecting a conductive means including a lithium metal, such as a lithium metal thin film or a lithium metal-coated porous sheet, such as an electrode assembly according to the present invention to the negative electrode, the first charge of the lithium secondary battery proceeds in itself within the battery In this way, in the battery manufacturing process, the battery activation process for forming the SEI film on the negative electrode surface can be omitted, thereby simplifying the manufacturing process.

In addition, the lithium supplied to the negative electrode from the conductive means including the lithium metal connected to the negative electrode prevents a decrease in capacity of the battery due to the irreversible capacity of the conventional negative electrode, thereby increasing the cycle life and capacity of the battery, and improving the high temperature storage performance. It has an effect.

1 is a schematic view of the side of the electrode assembly structure according to an embodiment of the present invention,
2 is a schematic view of a side view of an electrode assembly structure of a structure in which a plurality of electrode assemblies and a means including lithium metal are connected according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, "comprise" and / or "comprising" specifies the presence of the mentioned shapes, numbers, steps, actions, members, elements and / or groups of these. It is not intended to exclude the presence or the addition of one or more other shapes, numbers, acts, members, elements and / or groups.

The present invention can omit the activation process for forming the SEI film on the negative electrode surface in the battery manufacturing process by electrically connecting a conductive means including lithium metal to the negative electrode of the electrode assembly consisting of a positive electrode, a negative electrode, and a separator, irreversible The present invention relates to an electrode assembly and an electrochemical device including the same, which improve a reduction in energy density and cycle life due to a decrease in capacity.

Conventional electrochemical devices, particularly lithium secondary batteries, comprise an electrode assembly composed of a separator interposed between a positive electrode, a negative electrode, a positive electrode and a negative electrode and a non-aqueous electrolyte.

As described above, in the conventional electrode assembly, a passivation film (SEI) is formed on the surface of the carbon anode during initial charging of the battery according to the reaction of the organic solvent and lithium ions, but a separate process is required to form the same. The formed SEI film is also difficult to be formed uniformly and stably, and the lithium ions of the positive electrode are consumed to form the passivation film, there is a problem of reducing the capacity of the battery and increase the initial charge-discharge irreversible capacity.

Accordingly, the present invention provides an electrode assembly 200 in which a conductive means 240 including lithium metal is electrically connected to the negative electrode tab 220 as shown in FIG. 1 to provide a source of SEI formed on the surface of the cathode. To provide a lithium ion source from the conductive means comprising the lithium metal. In addition, the negative electrode tab 220 and the conductive means 240 including lithium metal were connected to the resistor 150 to enable self charging.

When connecting the conductive means 240 containing lithium metal to the negative electrode tab 220 as described above, like the half-cell, the negative electrode tab 220 in the conductive means 240 containing lithium metal. Lithium ions are continuously moved to the cathode through) so that a separate formation process is not required to form a film on the surface of the cathode, and the lithium ion for SEI formation also includes a conductive means including lithium metal other than the anode. ), It is possible to significantly lower the irreversible capacity of the battery.

On the other hand, the electrode assembly according to the present invention may be connected to the conductive means 240 and the negative electrode tab 220 containing a lithium metal to the resistor 150.

As such, by connecting the conductive means 240 including the lithium metal and the negative electrode tab 220 to the resistor 150, the movement amount or the moving speed of lithium ions from the conductive means to the negative electrode can be adjusted.

As such, the effect of forming a stable SEI layer by controlling the movement speed of the lithium ions according to the resistance of the resistor is thus generated, such as the formation of an unstable SEI layer during rapid charging, or the deposition of lithium at the cathode, and the formation of an uneven SEI layer. Problems can be prevented.

The resistor 150 for controlling the moving speed of lithium ions is not particularly limited as long as it is a conductive means including lithium metal. Specifically, for example, a lithium metal thin film or a porous sheet coated with lithium metal may be used according to an embodiment of the present invention, but is not limited thereto.

However, the resistor 150 may be a conductive means having a resistance size that the initial self-charging rate of the battery is charged at a rate of 0.01 ~ 1 C-rate, more preferably the battery at a rate of 0.01 ~ 0.1 C-rate It may be a metal having a size of a resistor to enable the charge.

The specific resistance may vary depending on the use, capacity, size, etc. of the battery, and may be a resistor that allows the initial self-charging rate to be charged at a rate of 0.01 to 1 C-rate based on the conditions described above. It costs.

As such, by adjusting the resistance of the resistor 150, the moving speed of the lithium ions supplied from the means 240 including the lithium metal to the cathode through the negative electrode tab 220 may be adjusted.

If the resistance value of the resistor is too large, and the initial self-charging rate of the battery is less than 0.01 C-rate, the charging may be difficult to proceed or may be very slow, which is not preferable. On the contrary, the resistance of the resistor is too small. When the initial self-charging rate of exceeds 1 C-rate, charging may proceed rapidly, resulting in unstable SEI layer formation and lithium precipitation.

In the present invention, even if the means including the lithium metal is connected to the cathode through the resistor, the other performance of the battery is not impaired, or the thickness of the battery is not increased.

In addition, the position in the battery of the means containing the lithium metal is not particularly limited, and may be located in any space inside the battery and connected to the negative electrode. For example, as shown in FIG. 1 or FIG. 2 showing an embodiment of the present invention, the electrode assembly may be interposed thinly on either side of the electrode assembly (FIG. 1), and in the case of multiple electrode assemblies (FIG. 2). Is interposed thinly between the electrode assembly may reduce the increase in volume of the battery, but is not limited thereto.

Since the connection of the resistor may proceed at the same time by using a method such as welding when connecting the negative terminal from the electrode assembly, no additional process is required.

According to one embodiment of the present invention, the conductive means including the lithium metal may be a thin film made from lithium metal powder, the thickness is not particularly limited and can be appropriately adjusted according to the desired use. However, as described below, it is preferable to adjust the thickness of the lithium metal to include a predetermined lithium content.

In the case of lithium metal is not easy to handle in the air, it may be preferable to use a thin film prepared by the rolling method under a certain condition, but is not particularly limited thereto.

In addition, according to an embodiment of the present invention, the means including the lithium metal may be a coating of lithium metal on the porous sheet. Here, the porous sheet is an olefin-based polymer used in a separator of a conventional lithium secondary battery, and examples thereof include PE and PP, but are not limited thereto.

In addition, according to an embodiment of the present invention, the means including the lithium metal may be a laminate of a thin film of lithium metal on the porous sheet. The porous sheet is the same as mentioned above, and the thin film of lithium metal may be a laminate prepared by a method such as a laminate on the porous sheet, but is not limited thereto.

The amount of lithium metal included in the means including the lithium metal may be less than or equal to less than 5% by weight of the irreversible capacity of the negative electrode material used.

This is for separately supplying the lithium content corresponding to the irreversible capacity consumed in the negative electrode by means including lithium metal, and even if the lithium content is supplied in excess of the irreversible capacity including a large amount of lithium metal, its effectiveness is not large, but the remaining lithium This is because ions can form dendrites on the negative electrode, which may degrade the performance of the battery. In addition, in the case of containing less lithium metal by 5 wt% or more than the irreversible capacity of the negative electrode material, the lithium ion is not sufficiently provided to the negative electrode, so that it is difficult to stably and evenly form the SEI film on the negative electrode surface, and to prevent the irreversible phenomenon of the battery. Because it is difficult.

In this case, the irreversible capacity of the negative electrode may vary depending on the negative electrode material used, but since the irreversible capacity according to the carbon material used is somewhat obvious to those skilled in the art, it is included in the means including lithium metal according to the negative electrode material used. The amount of lithium metal can be predetermined.

In the present invention, a carbon material used as a conventional negative electrode active material is used. The carbon material is selected from the group consisting of natural graphite, artificial graphite, fibrous graphite, amorphous carbon and graphite coated with amorphous carbon. It may be abnormal.

The electrochemical device according to the present invention can induce self-charging of the lithium metal into the carbon anode due to the voltage difference after the electrolyte is injected by adding the lithium metal-containing means electrically connected to the anode through the resistor, It is possible to induce stable formation of the passive film by controlling the self-charging rate by controlling the resistor, and the manufacturing process can be simplified by eliminating the activation process for forming the passive film in the manufacturing process.

Meanwhile, according to the embodiment of the present invention, as shown in FIG. 2, the means including the lithium metal 340 may be connected to the plurality of electrode assemblies 300a and 300b. Here, the conductive means 340 including the lithium metal and the plurality of electrode assemblies are connected to the negative electrode tabs 320a and 320b of the respective electrode assemblies. That is, even if a plurality of electrode assemblies are included, since they are electrically connected to the cathodes in each electrode assembly, only one means containing lithium metal may be used.

According to an embodiment of the present invention, the shape or configuration of the electrode assembly is not particularly limited and all of the electrode assemblies of the known configuration may be applicable, for example, a bicell (Bi) on a continuously cut separator film. Stack & Foldable Electrode Assembly manufactured by folding in one direction when Cross-Cell and Full-Cell are crossed, Stack & Folded Electrode Assembly manufactured by folding only Bicell on the separation film Stack and folding electrode assemblies manufactured by folding only full cells on the separation film; Z-shaped stack and folding electrode assemblies manufactured by folding the bi-cells or full cells in a zigzag direction with a separation film, and the bi-cells or full cells. Stack & z-fold type electrode assembly for continuous folding in the same direction, anode and cathode on long cut separator film Electrode assembly prepared by folding in a cross-laid state, a positive electrode plate, a separator, a jelly-roll type electrode assembly prepared by winding in one direction in a state arranged in the order of the negative electrode, and stacked electrode assembly may be applied, but is not limited thereto. no.

The structure of the electrode assembly is not particularly limited, and furthermore, a plurality of electrode assemblies may be connected and used, and of course, the number may be appropriately adjusted according to the use thereof.

In addition, the present invention provides an electrochemical device comprising an electrode assembly having the above structure.

The electrochemical device according to the present invention includes all devices that undergo an electrochemical reaction, and specific examples thereof include all kinds of primary and secondary batteries. In particular, a lithium secondary battery is preferable, and the lithium secondary battery includes a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery or a lithium ion polymer secondary battery.

In addition, it is possible to provide a medium-large battery pack including a plurality of electrically connected with the electrochemical device.

These medium and large battery packs may be used in medium and large devices, and preferred examples of the medium and large device include a power tool; An electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV); Electric two-wheeled vehicles including E-bikes and E-scooters; Electric golf carts; Electric trucks; Although an electric commercial vehicle or the system for electric power storage is mentioned, It is not limited only to these.

The method of manufacturing the electrochemical device of the present invention may use a conventional method known in the art, for example, is prepared by injecting a non-aqueous electrolyte after assembling through a separator between the positive electrode and the negative electrode. .

At this time, the positive electrode and the negative electrode according to the present invention are prepared according to the conventional methods known in the art, the electrode slurry including the electrode active material, that is, the positive electrode active material and the negative electrode active material, and apply the prepared electrode slurry to each current collector Thereafter, the solvent or the dispersion medium may be removed by drying or the like to bind the active material to the current collector, and may also be produced by binding the active material. In this case, a small amount of a conductive agent and / or a binder may be optionally added.

The negative electrode may be formed by appropriately selecting and blending an additive including, for example, a conductive agent, a binder, a filler, a dispersant, an ion conductive agent, and a pressure enhancer, to the powder containing the negative electrode active material.

Examples of the conductive agent include graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, and the like. Examples of the binder include polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, and the like. There are, however, any one included in a conventional negative electrode active material can be used and is not particularly limited.

A mixture of the negative electrode active material and various additives is added to a solvent such as water or an organic solvent to slurry or paste. The obtained slurry or paste can be applied to an electrode support substrate using a doctor blade method or the like, dried and then rolled into a roll or the like to produce a cathode.

In addition, the positive electrode may be a conventional positive electrode active material such as lithium manganese such as LiCoO ₂ , LiNiO ₂ , LiClO ₄ , LiCF ₃ SO ₃ , LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiN (CF ₃ SO ₂ ) _2, or LiMn ₂ O ₄ . It can be prepared by adding a conductive agent, a binder, or the like to a positive electrode active material such as a lithium intercalation material such as an oxide, a lithium cobalt oxide, a lithium nickel oxide, a lithium iron oxide or a composite oxide formed by a combination thereof. have.

As the conductive agent, any electronically conductive material which does not cause chemical change in the battery constructed can be used. For example, carbon black, such as acetylene black, Ketjen black, Farnes black, and thermal black; Natural graphite, artificial graphite, conductive yarn fibers, and the like can be used. Carbon black, graphite powder and carbon fiber are particularly preferable.

As the binder, any one of a thermoplastic resin and a thermosetting resin may be used, or a combination thereof may be used. Among these, polyvinylidene fluoride (PVdF) or polytetrafluoroethylene (PTFE) is preferable.

In addition, isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, etc. can be used as a dispersion medium.

The metal material for the current collector is a metal having high conductivity, and there is no limitation in use as long as it is a metal that can be easily adhered to the paste of the material. Non-limiting examples of the positive electrode current collector is a foil produced by aluminum, nickel or a combination thereof, and non-limiting examples of the negative electrode current collector by copper, gold, nickel or copper alloy or a combination thereof Foils produced.

The electrolyte solution that can be used in the present invention is a salt having a structure such as A + B-, A + includes an ion composed of an alkali metal cation such as Li +, Na +, K + or a combination thereof, and B-is PF _6- , BF ₄ -, Cl-, Br-, I-, ClO _4- , ASF _6- , CH ₃ CO _2- , CF ₃ SO _3- , N (CF ₃ SO ₂ ) _2- , C (CF ₂ SO ₂ ) _3- Salts containing ions consisting of anions or combinations thereof such as propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide , Acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (EMC), gamma butyrolactone (γ-butyrolactone) or their Some are dissolved or dissociated in an organic solvent composed of a mixture, but are not limited thereto.

The separator may use a porous separator that blocks internal short circuits of both electrodes and impregnates the electrolyte, and non-limiting examples thereof include a polypropylene-based, polyethylene-based, and polyolefin-based porous separator.

The external shape of the electrochemical device, preferably a lithium secondary battery, produced by the above method is not limited, and is preferably, for example, a cylindrical, square or pouch type of can.

The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, and the following examples can be modified in various other forms, and the scope of the present invention is It is not limited to an Example. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art.

Example

1-1. Preparation of Electrode Assembly

As a cathode active material, _{Li (Ni 1/3 Co 1} /3 Mn 1/3) O 94% by weight of the ₂ and LiMnO mixed positive electrode active material a mixture of _2, and Super-P (conductive agent) 3.5% by weight, PVdF (binder) 2.5 wt% was added to NMP (N-methyl-2-pyrrolidone) as a solvent to prepare a positive electrode mixture slurry, followed by coating, drying and pressing on aluminum foil to prepare a positive electrode, and using artificial graphite as a negative electrode active material. 94% by weight of artificial graphite, 1% by weight of Super-P (conductor), and 5% by weight of PVdF (binder) were added to NMP as a solvent to prepare a negative electrode mixture slurry, which was then coated, dried and The negative electrode was prepared by pressing, and uniaxially stretched polypropylene using a dry method to prepare a separator having a microporous structure having a melting point of 165 ° C. and a width of 200 mm on one side, and separating the separator between the positive electrode and the negative electrode. A stacked electrode assembly was prepared through the intervening electrode.

1-2. Preparation of Means Including Lithium Metal

A thin metal thin film containing 0.128 g of lithium having 95% of the irreversible capacity was manufactured according to the irreversible capacity (about 10% of the battery capacity) of the negative electrode. The resistance of 60Ω was applied so that the initial self-charging rate of the battery was 0.01C. The metal thin film and the negative electrode terminal of the electrode assembly were connected to each other by using a resistor having the same.

1-3. Manufacture of batteries

After the electrode assembly including the lithium metal means connected to the pouch-type battery case was injected 1M LiPF6 carbonate-based electrolyte solution to complete the battery.

Comparative example

A battery was manufactured in the same manner as in the above example, except that no means including lithium metal was included.

Experimental Example  One

Initial capacity, initial output, and the like were evaluated using the batteries prepared according to Examples and Comparative Examples, and the results are shown in Table 1 below.

The initial capacity was measured by the method of measuring the discharge capacity after the charge / discharge at a rate of 1C for the prepared unit cell.

The initial output was measured by discharging for 10 seconds with a current of 120 A after charging half of the manufactured unit cell capacity.

Experimental Example  2

The charge / discharge characteristics and the high temperature storage characteristics of the batteries prepared according to the above Examples and Comparative Examples were evaluated, and the results are shown in Table 2 below.

The charge / discharge characteristics were performed by repeating the charging / discharging process 200 times at a rate of 1C of the secondary battery capacity at room temperature, and then checking the capacity and the output.

The high temperature storage characteristics were performed by checking the capacity and output after storage for 4 weeks in a chamber at 60 ℃.

Number of batteries manufactured (ea) Initial capacity (Ah) Initial output (W) Example 10 5.7 ± 0.1 740 ± 20 Comparative example 10 5.2 ± 0.1 700 ± 20

After 200 charge / discharge cycles
Capacity (Ah) After 200 charge / discharge cycles
Output (W) After high temperature storage
Capacity (Ah) After high temperature storage
Output (W) Example 5.1 ± 0.1 650 ± 20 5.1 ± 0.1 640 ± 20 Comparative example 4.7 ± 0.1 630 ± 20 4.5 ± 0.1 600 ± 20

 As can be seen in Table 1, in the case of the battery manufactured according to the present invention, it can be seen that the average initial capacity and initial output are both improved compared to the battery (comparative example) including the conventional electrode assembly.

In addition, as can be seen in Table 2, in the case of the secondary battery according to the present invention, it shows excellent results compared to the secondary battery containing a conventional electrode assembly in the capacity and output after repeated charge / discharge several times. In addition, it can be seen that the high temperature storage characteristics were also greatly improved.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the protection scope of the present invention should be interpreted by the following claims, and all the technologies within the equivalent scope of the present invention. The spirit will be construed as being included in the scope of the invention.

200, 300a, 300b electrode assembly
240, 340 conductive means
220, 320a, 320b negative electrode tab
210, 310a, 310b positive electrode tab
150, 350 resistor

Claims (18)

An electrode assembly including an anode, a cathode, and a separator,
An electrode assembly comprising means comprising lithium metal. The electrode assembly of claim 1, wherein the means comprising lithium metal is electrically connected to the cathode. 3. The electrode assembly of claim 2, wherein the means comprising the negative electrode and the lithium metal is connected by a resistor. The electrode assembly of claim 3, wherein the resistor is a conductive metal having a resistance size such that an initial self-charging rate of a battery including the electrode assembly can be charged at a rate of 0.01 to 1 C-rate. The electrode assembly of claim 3, wherein the resistor is a conductive metal having a resistance size such that an initial self-charging rate of a battery including the electrode assembly can be charged at a rate of 0.01 to 0.1 C-rate. The electrode assembly of claim 3, wherein the resistor is at least one conductive metal selected from a metal having a resistance of 10 mΩ to 100Ω. The electrode assembly of claim 1, wherein the means including lithium metal is a thin film including lithium metal. The electrode assembly of claim 1, wherein the means comprising lithium metal comprises lithium metal on a porous sheet. The electrode assembly of claim 1, wherein the means including the lithium metal laminates a thin film of lithium metal on the porous sheet. The electrode assembly of claim 1, wherein the amount of lithium metal included in the means comprising lithium metal is equal to the irreversible capacity of the negative electrode material used. The electrode assembly of claim 1, wherein the amount of lithium metal included in the means comprising lithium metal is less than 5% less than the irreversible capacity of the negative electrode material used. The electrode assembly of claim 1, wherein the means comprising lithium metal is connected to a plurality of electrode assemblies. The electrode assembly of claim 12, wherein the means including the lithium metal and the plurality of electrode assemblies are connected to the cathodes of the respective electrode assemblies. The electrode assembly of claim 1, wherein the electrode assembly is formed of any one structure selected from a stack type, a jelly roll type, a stack / fold type, and a stack-z-fold type. Electrochemical device comprising an electrode assembly according to claim 1. The electrochemical device of claim 15, wherein the electrochemical device is a lithium secondary battery. A medium to large battery pack comprising a plurality of electrochemical devices according to claim 15 electrically connected. The battery pack of claim 17, wherein the medium-large battery pack comprises: a power tool; An electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV); Electric two-wheeled vehicles including E-bikes and E-scooters; Electric golf carts; Electric trucks; Medium-large battery pack, characterized in that used as a power source for any one or more of the electric commercial vehicle or power storage system.

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