JPH11329408A - Nonaqueous secondary battery electrode sheet and nonaqueous secondary battery using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve stability in the manufacture of an electrode and improve the precision of the electrode dimension by specifying the length of a non- application part having no mix layer on each side of a current collector to the longer electrode part having a mix layer on one side. SOLUTION: The length of a non application part having no mixture layer on each side of the current collector of a nonaqueous secondary electrode sheet is set to 1% or more and 15% or less to the longer part having a mixture layer on one side. An electrode mixture layer 22a is formed on the upper surface of a current collector 21, and an electrode mixture layer 22b is formed on the lower surface. The upper surface of the current collector 21 has an application part B1 of electrode mixture and non-application parts A1, A2. The lower surface of the current collector 21 has an application part D1 of electrode mixture and non-application parts C1, C2. Each non-application part is extended from the current collector end part to the center. An electrode lead 23 is connected to the non-application part A1 on the upper surface of the current collector 21 by welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous secondary battery having excellent production stability and cycle characteristics.

[0002]

2. Description of the Related Art Compared with conventional nickel-cadmium batteries and nickel-metal hydride batteries, lithium-ion secondary batteries having a higher capacity have been widely used in portable equipment. However, although the cycle life of the lithium ion secondary battery has been greatly improved since the beginning of development, it is still insufficient, and further improvement is desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrode sheet which can improve the stability of the production of an electrode, and an electrode sheet which can improve the accuracy of the electrode dimensions and the like. Another object of the present invention is to provide a high capacity non-aqueous secondary battery having a long cycle life by using these electrode sheets.

[0004]

An object of the present invention is to provide a strip-shaped electrode sheet having a mixture layer on both sides of a current collector, wherein the uncoated layer has no mixture layer on both sides of the current collector. The electrode sheet for a non-aqueous secondary battery is characterized in that the length of the portion is 1% or more and 15% or less with respect to the longer electrode portion having the mixture layer on one surface. I have to do it.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be listed below, but the present invention is not limited thereto.

(1) In a strip-shaped electrode sheet having a mixture layer on both sides of a current collector, the length of an uncoated portion where there is no mixture layer on either side of the current collector is one side. 1% or more of the longer electrode portion having the mixture layer on its surface.
% Or less, the electrode sheet for non-aqueous secondary batteries.

(2) In a strip-shaped negative electrode sheet having a mixture layer on both sides of the current collector, the length of the uncoated portion where there is no mixture layer on either side of the current collector is one side. 1% or more and 5% with respect to the longer electrode part having a mixture layer on its surface
A negative electrode sheet for a non-aqueous secondary battery, comprising:

(3) In a strip-shaped negative electrode sheet having a mixture layer on both sides of the current collector, the length of the uncoated portion where there is no mixture layer on both sides of the current collector is one side. A negative electrode sheet for a non-aqueous secondary battery, wherein the amount is 1.5% or more and 4% or less with respect to a longer electrode portion having a mixture layer on a surface.

(4) The non-aqueous secondary battery according to item 2 or 3, wherein uncoated portions on both sides of the current collector are located at both ends in the longitudinal direction of the electrode sheet, and the length is 2 mm or more. Negative electrode sheet for secondary battery.

(5) The current collector of item 2 or 3 has a thickness of 5 μm.
A negative electrode sheet for a non-aqueous secondary battery, which is a sheet having a conductive layer having a thickness of not less than m and not more than 15 μm.

(6) In a strip-shaped positive electrode sheet having a mixture layer on both sides of the current collector, the length of the uncoated portion where there is no mixture layer on any of both sides of the current collector is one side. 5% or more with respect to the longer electrode portion having the mixture layer on its surface.
% Or less, the positive electrode sheet for a non-aqueous secondary battery.

(7) In the strip-shaped positive electrode sheet having a mixture layer on both sides of the current collector, the length of the uncoated portion where there is no mixture layer on any of both sides of the current collector is one side. 6% or more with respect to the longer electrode portion having the mixture layer on its surface.
% Or less, the positive electrode sheet for a non-aqueous secondary battery.

(8) The non-aqueous non-aqueous battery according to (6) or (7), wherein uncoated portions on both surfaces of the current collector are at both ends in the longitudinal direction of the electrode sheet, and the length is 2 mm or more. Positive electrode sheet for secondary batteries.

(9) The current collector of item 6 or 7 has a thickness of 5 μm.
A positive electrode sheet for a non-aqueous secondary battery, which is a sheet having a conductive layer having a thickness of not less than m and not more than 15 μm.

(10) In a non-aqueous secondary battery in which a non-aqueous electrolyte is incorporated in a battery can and an electrode group formed by winding a positive electrode sheet, a separator, and a negative electrode sheet, at least one of the positive and negative electrode sheets is defined by any of items 1 to 9 above. A nonaqueous secondary battery, which is the electrode sheet according to any one of the above.

(11) The outermost peripheral portion of the electrode sheet located at the outermost periphery of the electrode group does not have the mixture layer on the outer peripheral side of the current collector, but has the mixture layer only on the inner peripheral side. Characteristic item 1
The non-aqueous secondary battery according to 0.

(12) The innermost periphery of the electrode sheet located at the innermost periphery of the electrode group does not have a mixture layer at the center of the winding group of the current collector, and the mixture is formed only on the electrode group side. Item 11. The non-aqueous secondary battery according to Item 10, having a layer.

(13) A non-aqueous secondary battery, wherein the electrode sheets according to items 11 and 12 are negative electrode sheets.

(14) A non-aqueous secondary battery, wherein the electrode sheet according to item 11 is a negative electrode sheet and the electrode sheet according to item 12 is a positive electrode sheet.

(15) A non-aqueous secondary battery, wherein the electrode sheet of item 11 is a positive electrode sheet and the electrode sheet of item 12 is a negative electrode sheet.

(16) A non-aqueous secondary battery characterized in that the electrode sheets of items 11 and 12 are positive electrode sheets.

(17) An electrode lead for connecting an electrode sheet and an electrode terminal is attached to a mixture-unapplied portion where there is no mixture layer on both sides of the electrode sheet. The non-aqueous secondary battery according to any one of the above.

Hereinafter, embodiments of the present invention will be described in detail. A non-aqueous secondary battery has a positive electrode, a negative electrode, and a separator obtained by applying an electrode mixture to both surfaces of a current collector described in detail below, and an electrode in which the separator is laminated or wound so that the separator is separated from the positive and negative electrodes. The group is inserted into a battery can, sealed after adding and injecting an electrolyte, and aged appropriately to produce. It is desired to improve the cycle characteristics of the non-aqueous secondary batteries and to improve the manufacturing suitability and accuracy of the electrode sheets used in these batteries. The form of the battery may be any of a so-called square type, cylindrical type, flat type and the like as long as the wound electrode group is used.

The deterioration of the cycle characteristics of the non-aqueous secondary battery is as follows.
There are various factors. Although it is natural to stabilize the structure of the so-called lithium intercalation compound itself that absorbs and releases lithium ions, even if a stable compound is used, if the balance between the positive and negative electrodes is inappropriate, the deterioration is accelerated. From such a viewpoint, it is an issue to improve the dimensional accuracy and electrode arrangement accuracy of the electrodes. The cause of the micro short circuit between the electrodes when the charge and discharge are repeated is not only the generation of lithium dendrite but also the collapse of the electrode mixture layer and the mixing of electrode scraps when the electrodes are cut. Further, an increase in resistance or the like in any part of the circuit from the electrodes to the positive and negative terminals also causes deterioration. In particular, the resistance generated at the welded portion between the electrode lead and the current collector can cause heat deterioration and the like.

FIG. 1 is a sectional view of an electrode sheet. An electrode mixture layer 22a is formed on the upper surface of the current collector 21, and an electrode mixture layer 22b is formed on the lower surface. The upper surface of the current collector 21 has an applied portion B1 of the electrode mixture and uncoated portions A1 and A2. The lower surface of the current collector 21 has an applied portion D1 of the electrode mixture and uncoated portions C1 and C2. Each uncoated portion extends from the end of the current collector toward the center. The electrode lead 23 is joined to the uncoated portion A1 on the upper surface of the current collector 21 by welding. Due to the welding, burrs of the electrode lead 23 may protrude to the lower surface of the current collector 21. Since both surfaces of the current collector 21 to which the electrode leads 23 are bonded are the uncoated portions A1 and C1, the electrode mixture layer of the current collector 21 does not peel off due to burrs.

The portions at both ends of the electrode sheet having no mixture layer on any surface of the current collector are designated as X1 and X2. Less than,
A, B, C, D, and X also indicate the lengths of the areas (dimensions in the horizontal direction in the figure). In addition, mixture layer B
The longer one of D1 and D1 is defined as max (B1, D1). FIG.
X1 = A1 = C1, X2 = A2, m
ax (B1, D1) = B1.

The electrode sheet according to the embodiment of the present invention is intended to improve and reduce the above-mentioned deterioration factors. By cutting the portions 24 and 25 of the current collector only having no electrode mixture layer, The generation of cutting waste of the electrode mixture can be suppressed, and the accuracy of the electrode length can be improved. Also,
The electrode lead 23 is directly welded to the uncoated portion A1 of the current collector to peel off the electrode mixture to expose the current collector of the welded portion and to reduce the floating resistance generated by the method of welding the electrode lead there. Generation can be prevented. Further, according to the embodiment, it is possible to provide an electrode manufacturing method which does not include an extra step such as stripping of a mixture and has a low manufacturing cost and high accuracy.

The electrode sheet is a strip-shaped electrode sheet having the mixture layers 22a and 22b on both sides of the current collector 21 and has no mixture layer on both sides of the current collector 21. The length of the portion (X1 + X2) is one side of the mixture layer 22a.
Or the longer max (B
1, 1% or less of D1). "Longer electrode portion having mixture layer on one surface" means the longer one of the longitudinal lengths of electrode mixture layers 22a and 22b on the front and back surfaces of the long electrode sheet. Say This is because when the lengths of the mixture layers 22a and 22b on the front and back surfaces are intentionally changed, for example, by shifting the positions of the mixture application ends 26 and 27 on the front and back surfaces in the longitudinal direction, the electrode mixture is dried and dried. In order to avoid failures such as cutting during compression by a press roller, etc., or to improve efficiency and avoid deterioration by not providing a mixture layer on the part that does not face electrodes having different polarities. is there. Current collector 2
If the lengths X1 and X2 of the portions where the uncoated portions are present on both surfaces of the battery 1 are too long, the battery capacity decreases. If the length is too short, cutting of the electrodes and welding of the electrode leads 23 are hindered. It is preferable that it is 1% or more and 15% or less with respect to the longer one of the lengths B1 and D1 of the electrode portion having the mixture layer.

When the electrode is a negative electrode sheet, the length of the uncoated portion on both surfaces of the current collector is 1% or more of the longer electrode portion having the mixture layer on one surface. The case where it is 5% or less is more preferable, and the case where it is 1.5% or more and 4% or less is particularly preferable.

When the electrode is a positive electrode sheet, the length of the uncoated portion on both surfaces of the current collector is 5% or more of the longer electrode portion having the mixture layer on one surface. It is more preferably 15% or less, particularly preferably 6% or more and 12% or less.

When the length of the uncoated portion with respect to the mixture applied portion is long, the thin electrode portion of the uncoated portion and the thick portion of the mixture coated on both sides pass through the same transport path, so that wrinkles occur during transport. Or cause a disconnection failure.

If the length is short, the negative electrode tends to cause troubles in the welding process such as poor lead welding. In the case of a positive electrode, an internal short circuit which is considered to be caused by a positive electrode lead weld near the center of the winding group increases.

The uncoated portions on both surfaces of the current collector may be located at one end of the electrode, but may be located at both ends in the longitudinal direction of the electrode sheet and at least one end is at least 2 mm long. Is more preferred. That is, it is preferable that at least one of the uncoated portions X1 and X2 has a length of 2 mm or more. In the portion where the electrode lead 23 is to be welded, the uncoated portion is preferably at least 1 mm longer than the width of the lead (the length in the horizontal direction in FIG. 1).

As a method for forming the exposed portion of the current collector, a so-called intermittent coating method, a method in which the exposed portion is protected in advance by a tape or the like, and the tape including the mixture on the tape is peeled off is preferable. After the continuous application, there is a method in which the mixture layer is scraped off mechanically or by a chemical. The mixture layer contains components such as various salts, acids, and alkalis.In order to alter the surface of the metal current collector, the method of continuously applying the mixture onto the current collector involves applying an electrode lead. When welding, high resistance may be exhibited, which is not preferable.

In order to form the exposed part of the current collector, it is not preferable to apply the mixture layer once on the current collector and then remove it partially. It is preferable to create one. The uncoated portion of the mixture layer does not include a portion that has been removed after the mixture layer has been applied once on the current collector.

The current collector is preferably a sheet having a conductive layer having a thickness of 5 μm or more and 15 μm or less. When the thickness is less than 5 μm, cutting failures and the like during electrode production increase. On the other hand, when the thickness exceeds 15 μm, there is a problem that the battery capacity is reduced due to an increase in the volume occupied by the current collector.

As the material of the current collector, aluminum, stainless steel, nickel, titanium or an alloy thereof is used for the positive electrode, and copper, stainless steel, nickel,
Titanium or their alloys, in the form of
Foil, expanded metal, punched metal, wire mesh. In particular, an aluminum foil is preferable for the positive electrode, and a copper foil is preferable for the negative electrode.

Further, the current collector may be one in which metal layers are formed on both surfaces of a plastic sheet in order to reduce the thickness. The plastic is preferably excellent in stretchability and heat resistance, and is, for example, polyethylene terephthalate. Metals alone have little elasticity and are vulnerable to external forces. If a metal layer is formed on plastic, it will be resistant to impact.

The form of the current collector is perforated foil, expanded
For example, and JP-A-59-18578,
No. 61-74268, foamed metal, porous foamed gold
Genus, metal fiber sheath made of metal fiber of about 1 to 20 μm
Or wire mesh. The holes of the above-mentioned perforated current collector
The mouth ratio is preferably 0.1% or more and 20% or less, more preferably 1% or less.
Above, 10% or less is particularly preferable. Hole size of perforated current collector
The size is 1 × 10^-7cm^Two Above 1 × 10^-2cm^Two The following is good
Better 3 × 10^-6cm^TwoAbove 2 × 10^-3cm ^TwoLess than
Is particularly preferred. The holes allow lithium ions to pass through
It is necessary that the front and back surfaces of the current collector
You. Particularly preferred is when the hole penetrates the current collector
It is.

The electrode sheet used for the wound electrode group may have a portion having no mixture layer on both surfaces of the current collector and, if necessary, having a mixture layer on only one surface. Good. When the outermost electrode of the spirally wound electrode group is a negative electrode, there is no positive electrode facing the outermost outer surface of the negative electrode, so that there is no need to provide a negative electrode mixture. When the innermost electrode is a positive electrode, there is no negative electrode facing the innermost surface of the innermost periphery of the positive electrode, so there is no need for a positive electrode mixture.

FIG. 3 is a sectional view of a cylinder type battery.
The shape of the battery can be applied to both cylinders and corners. If the core is cylindrical, a cylindrical battery can be manufactured, and if the core is square, a square battery can be manufactured. The battery is formed by inserting the positive electrode sheet 3 and the negative electrode sheet 2 wound together with the separator 4 into the battery can 1, electrically connecting the battery can 1 and the negative electrode sheet 2, injecting an electrolyte, and sealing the battery. The terminal cap 13 also serves as a positive terminal,
It is fitted to the upper opening of the battery can 1 via the gasket 7.
The positive electrode sheet 3 is connected to the terminal cap 1 via a positive electrode lead 8, a welding plate 15, an explosion-proof valve body 9, a current cutoff switch 10, and a positive temperature coefficient resistance (hereinafter, PTC) ring 11.
3 is electrically connected.

The sealing member is a terminal cap 13 in order from the top,
PTC ring 11, current cutoff switch 10, explosion-proof valve body 9
Are superimposed and fitted and supported by the gasket 7. The terminal cap 13 is a surface exposed portion of the battery, and the explosion-proof valve body 9 is inside the battery. The insulating cover 16 covers the upper surface of the explosion-proof valve body 9. The current cutoff switch 10 is connected to the first conductor 1
0a, a second conductor 10b, and an insulating ring 10c.

The electrode group includes the positive electrode sheet 3 and the negative electrode sheet 2
Are wound with the separator 4 interposed therebetween. The upper insulating plate 6 is arranged between the electrode group and the explosion-proof valve body 9. The upper insulating plate 6 insulates the electrode group from the sealing body and also insulates the electrode group from the battery can 1. The lower insulating plate 5 is arranged between the electrode group and the battery can 1 to insulate the electrode group from the battery can 1.

The PTC ring 11 has a function of interrupting current by increasing the resistance when the temperature inside the battery rises. The current cutoff switch 10 includes a first conductor 10a and an insulating ring 10c.
And a second conductive body 10b.
0a is disposed on the explosion-proof valve body 9 side and has a through hole, and the second conductor 10b is on the PTC ring 11 side, that is, the terminal cap 1
This is a structure having through holes arranged on three sides. The first conductive body 10a and the second conductive body 10b are electrically connected at a central portion, and have a thin portion around the connection portion of the first conductive body 10a. The explosion-proof valve body 9 can be deformed to the side opposite to the electrode group side when the internal pressure rises, and may be any as long as it can push up the central connection portion of the first conductor 10a. When the internal pressure increases due to an abnormal reaction in the battery, the explosion-proof valve body 9 is deformed and the first conductor 10 of the current cutoff switch 10 is deformed.
The current is cut off by breaking the connection portion between a and the second conductor 10b, and when the pressure further increases, the thin portion of the explosion-proof valve body 9 breaks and releases the pressure. At this time, since the current cutoff switch 10 is arranged on the side opposite to the electrode group side of the explosion-proof valve body 9, even if a spark occurs in the cutoff portion, the explosion of the battery due to ignition of the electrolyte vapor is prevented. Is done.

The positive electrode (or negative electrode) sheet can be prepared by applying a positive electrode mixture (or negative electrode mixture) on a current collector and molding. The positive electrode mixture (or negative electrode mixture) includes, in addition to the positive electrode active material (or negative electrode material), a conductive agent, a binder,
It may contain a dispersant, a filler, an ionic conductive agent, a pressure enhancer, and various additives. These electrodes may be in the form of a disk or a plate, but are preferably formed of a flexible sheet that can be wound.

The materials used for the electrode mixture will be described below. The positive electrode active material is preferably a lithium-containing transition metal oxide. The lithium-containing transition metal oxide is Ti,
An oxide mainly containing lithium and at least one transition metal element selected from V, Cr, Mn, Fe, Co, Ni, Mo and W, wherein the molar ratio of lithium to the transition metal is from 0.3 to 0.3. 2.2.

More preferably, V, Cr, Mn, Fe,
An oxide mainly containing lithium and at least one transition metal element selected from Co and Ni, and a compound having a molar ratio of lithium to the transition metal of 0.3 to 2.2. It should be noted that Al, Ga, In, Ge, Sn,
It may contain Pb, Sb, Bi, Si, P, B and the like.

Further preferred lithium-containing transition metal oxides are Li _x CoO ₂ , Li _x NiO ₂ , and Li _x MnO.
₂ , Li _x Co _a Ni _1-a O ₂ , Li _x Co _b V _1-b O
_z , Li _x Co _b Fe _1-b O ₂ , Li _x Mn ₂ O ₄ , L
_{i x Mn c Co 2-c} O 4, Li x Mn c Ni 2-c O 4,
_{Li x Mn c V 2-c} O 4, Li x Mn c Fe 2-c O
₄ (where x = 0.02 to 1.2, a = 0.1 to 0.
9, b = 0.8 to 0.98, c = 1.6 to 1.96, z
= 2.01-2.3).

The most preferred lithium-containing transition metal oxides include Li _x CoO ₂ , Li _x NiO ₂ , and Li _x M
nO ₂ , Li _x Co _a Ni _1-a O ₂ , Li _x Mn ₂ O
₄ , Li _x Co _b V _1-b O _z (x = 0.02 to 1.2,
a = 0.1 to 0.9, b = 0.9 to 0.98, z = 2.
01 to 2.3). The value of x is a value before the start of charge / discharge, and increases / decreases due to charge / discharge.

The positive electrode active material can be synthesized by a method in which a lithium compound and a transition metal compound are mixed and fired, or by a solution reaction, but the firing method is particularly preferable.

For details of firing, see JP-A-6-60 / 86.
No. 7, paragraph 35, JP-A-7-14,579, etc., and these methods can be used. The positive electrode active material obtained by firing may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

Further, as a method of chemically inserting lithium ions into the transition metal oxide, a method of synthesizing lithium metal, a lithium alloy or butyl lithium by reacting with the transition metal oxide may be used.

The average particle size of the positive electrode active material is not particularly limited.
However, it is preferably 0.1 to 50 μm. 0.5-30
It is preferable that the volume of the particles of μm is 95% or more.
The volume occupied by particles having a particle size of 3 μm or less accounts for 18% of the total volume
Or less, and a particle group of not less than 15 μm and not more than 25 μm.
It is more preferable that the volume occupied be 18% or less of the total volume.
Good. The specific surface area is not particularly limited.
0.01 to 50m ^Two / G is preferred, especially 0.2 m
^Two / G-1m^Two / G is preferred. 5 g of the positive electrode active material
The pH of the supernatant when dissolved in 100 ml of distilled water
Is preferably 7 or more and 12 or less.

When the positive electrode active material is obtained by firing, the firing temperature is preferably from 500 to 1500 ° C., more preferably from 700 to 1200 ° C., and particularly preferably from 750 to 1000 ° C. The firing time is preferably 4 to 30 hours, more preferably 6 to 20 hours.
And particularly preferably from 6 to 15 hours.

As the negative electrode material, any compound capable of inserting and extracting lithium ions may be used. Examples of such a negative electrode material include lithium metal, a lithium alloy, a carbonaceous compound, an inorganic oxide, an inorganic chalcogen compound, a metal complex, and an organic polymer compound. These may be used alone or in combination. Preferred among these negative electrode materials are carbonaceous materials, oxides of metal or metalloid elements, and chalcogens.

One of the negative electrode materials is a carbonaceous material capable of inserting and extracting lithium. The carbonaceous material is a material substantially composed of carbon. Examples thereof include carbonaceous materials obtained by firing petroleum pitch, natural graphite, artificial graphite such as vapor-grown graphite, and various synthetic resins such as PAN-based resins and furfuryl alcohol resins. Further, PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber,
Various carbon fibers such as vapor-grown carbon fibers, dehydrated PVA-based carbon fibers, lignin carbon fibers, glassy carbon fibers, and activated carbon fibers, mesophase microspheres, graphite whiskers, and flat graphite can also be used.

These carbonaceous materials can be classified into non-graphitizable carbon materials and graphite-based carbon materials according to the degree of graphitization. Carbonaceous materials are disclosed in JP-A-62-22066, JP-A-2-66656, and 3-24547.
It is preferable to have a plane spacing, a density, and a crystallite size described in Japanese Patent Publication No.

The carbonaceous material need not be a single material, but may be a mixture of natural graphite and artificial graphite described in JP-A-5-290844, graphite having a coating layer described in JP-A-6-84516, and the like. Can also be used.

Another negative electrode material, an oxide of a metal or a metalloid, or a chalcogen compound is described in Periodic Table 1 below.
It is a compound comprising a group 3, 14, 15 atom and an oxygen or chalcogen group atom.

As the negative electrode material, the periodic tables 1, 2, 13, 1
An amorphous chalcogen compound or an amorphous oxide mainly containing three or more atoms selected from Group 4 and Group 15 atoms is particularly preferably used. Here, mainly amorphous is C
20 ° to 40 in 2θ value by X-ray diffraction using uKα ray
It has a broad scattering band with a peak at °,
It may have a crystalline diffraction line. Preferably, the strongest intensity of the crystalline diffraction lines observed at 40 ° to 70 ° in the 2θ value is 500 of the diffraction line intensity at the top of the broad scattering band observed at 20 ° to 40 ° in the 2θ value. It is preferably not more than 100 times, more preferably not more than 100 times, particularly preferably not more than 5 times, and most preferably not having a crystalline diffraction line.

The above chalcogen compounds and oxides are B,
Al, Ga, In, Tl, Si, Ge, Sn, Pb,
A complex chalcogen compound and a complex oxide mainly containing two or more elements among P, As, Sb, and Bi are more preferable.
Particularly preferred is a complex chalcogen compound or oxide mainly composed of two or more elements among B, Al, Si, Ge, Sn, and P. These complex chalcogen compounds and complex oxides contain at least one element selected from the elements of Groups 1 and 2 of the periodic table in order to mainly modify the amorphous structure.

Among the above-mentioned negative electrode materials, an amorphous composite oxide mainly composed of Sn is preferable, and is represented by the following general formula (1).

[0063] Formula (1) SnM ³ _c M ⁴ in _d O _t formula, M ³ is Al, B, P, Si, at least one of Ge
Species, M ⁴ is a Group 1 element periodic table, represents at least one second group element, c is 0.2 or more, two or less number, d is 0.01 or more, the number of 1 or less, 0.2 <c + d <2, t
Represents a number of 1 or more and 6 or less.

For the amorphous composite oxide, any of a firing method and a solution method can be adopted, but the firing method is more preferable. In the baking method, it is preferable to mix well the oxides or compounds of the elements described in the general formula (1) and then bake to obtain an amorphous composite oxide.

As the firing conditions, the heating rate is preferably 5 ° C. to 200 ° C. per minute, the firing temperature is preferably 500 ° C. to 1500 ° C., and the firing time is Is more than 1 hour 10
It is preferably 0 hours or less. And, it is preferable as the descending rate of temperature or less per minute 2 ℃ least 10 ⁷ ° C..

In the present specification, the heating rate is from “50% of the firing temperature (expressed in ° C.)” to “80% of the firing temperature (expressed in ° C.).
% ", The average rate of temperature rise from" 80% of firing temperature (° C display) "to" 50% of firing temperature (° C display) ". It is.

The temperature may be cooled in a firing furnace, or may be taken out of the firing furnace and put into, for example, water to cool. Also ceramic processing (Gihodo Publishing 19
87) Gun method described on page 217, Hammer-Anv
An ultra-quenching method such as an il method, a slap method, a gas atomizing method, a plasma spray method, a centrifugal quenching method, and a melt drag method can also be used. Alternatively, cooling may be performed using a single roller method or a twin roller method described in page 172 of the New Glass Handbook (Maruzen 1991). In the case of a material that melts during firing, a fired product may be continuously taken out while supplying raw materials during firing. In the case of a material that melts during firing, it is preferable to stir the melt.

The firing gas atmosphere is preferably an atmosphere having an oxygen content of 5% by volume or less, and more preferably an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, helium, krypton, xenon, and the like. The most preferred inert gas is pure argon.

The above compound has an average particle size of 0.1 to
60 μm is preferred. More specifically, the average particle size is 0.7
２５25 μm, and 60% or more of the total volume is 0.5〜
It is preferably 30 μm. Further, the volume occupied by the particle group having a particle size of 1 μm or less of the negative electrode active material of the present invention is 30% or less of the total volume, and the volume occupied by the particle group having a particle size of 20 μm or more is 25% or less of the total volume. Is preferred.
It goes without saying that the particle size of the material used does not exceed the thickness of the mixture on one side of the negative electrode.

To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, mortar, ball mill, sand mill, vibration ball mill, satellite ball mill,
A planetary ball mill, a swirling jet mill, a sieve, or the like is used. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed as necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be performed both in a dry type and a wet type.

The average particle diameter is a median diameter of primary particles, and is measured by a laser diffraction type particle size distribution measuring device.

The specific surface area of the negative electrode material is preferably from 0.1 to ⁵ m ² / g as measured by a BET specific surface area measurement method.

Examples of the negative electrode material are shown below.
It is not limited to these. SnAl_0.4B_0.5P
_0.5K_0.1O_3.65, SnAl_0.4B_0.5P_0.5Na_0.2
O _3.7, SnAl_0.4B_0.3P_0.5Rb_0.2O_3.4, S
nAl_0.4B_0.5P_0.5Cs_0.1O_3.65, SnAl_0.4
B_0.5P_0.5K_0.1Ge_0.05O_3.85, SnAl_0.4B
_0.5P_0.5K_0.1Mg_0.1Ge_0.02O_3.83,SnAl
_0.4B_0.4P_0.4O_3.2, SnAl_0.3B_0.5P_0.2O
_2.7, SnAl_0.3B_0.5P_0.2O_2.7, SnAl_0.4
B_0.5P_0.3Ba_0.08Mg_0.08O_3.26, SnAl_0.4B
_0.4P_0.4Ba_{0. 08}O_3.28, SnAl_0.4B_0.5P_0.5
O_3.6, SnAl_0.4B_0.5P_0.5Mg_{0. 1}O_3.7,

SnAl_0.5B_0.4P_0.5Mg_0.1F_0.2
O_3.65, SnB_0.5P_0.5Li_0.1Mg_0.1F_0.2O
_3.05, SnB_0.5P_0.5K_0.1Mg_0.1F_0.2O_3.05,
SnB_{0. Five}P_0.5K_0.05Mg_0.05F_0.1 O_3.03, SnB
_0.5P_0.5K_0.05Mg_0.1F_0.2O_3.03, SnAl_0.4
B_0.5P_0.5Cs_0.1Mg_0.1F_0.2O_3.65, SnB
_0.5P_0.5Cs_0.05Mg_0.05F_0.1O_3.03, SnB_0.5
P_0.5Mg_0.1F_0.1O_3.05, SnB_0.5P_0.5Mg
_0.1F_0.2O_Three , SnB_0.5P_0.5Mg_0.1F_0.06O_3.
07, SnB_0.5P_0.5Mg_0.1F_0.14O_3.03, SnPB
a_0.08O_3.58, SnPK _0.1O_3.55, SnPK_0.05Mg
_0.05O_3.58, SnPCs_0.1O_3.55, SnPBa _0.08F
_0.08O_3.54, SnPK_0.1Mg_0.1F_0.2O_3.55, Sn
PK_0.05Mg_0.05F_0.1O_3.53, SnPCs_0.1Mg
_0.1F_0.2O_3.55, SnPCs_0.05Mg_0.05F_0.1O
_3.53,

[0075] Sn_1.1Al_0.4B_0.2P_0.6Ba_0.08F
_0.08O_3.54, Sn_1.1Al_0.4B_0.2P_0.6Li_0.1K
_0.1Ba_0.1F_0.1O_3.65, Sn_1.1Al_0.4B_0.4P
_0.4Ba_0.08O_3.34, Sn_1.1Al_0.4PCs_0.05O
_4.23, Sn_1.1Al_0.4PK_0.05O_4.23, Sn_1.2Al
_0.5B_0.3P_0.4Cs_0.2O_3.5, Sn_1.2Al_0.4B
_{0. Two}P_0.6Ba_0.08O_3.68, Sn_1.2Al_0.4B_0.2P
_0.6Ba_0.08F_0.08O_3.64, Sn_1.2Al_0.4B_0.2P
_0.6Mg_0.04Ba_0.04O_3.68, Sn_1.2Al_0.4B _0.3
P_0.5Ba_0.08O_3.58, Sn_1.3Al_0.3B_0.3P_0.4
Na_0.2O_3.3 , Sn_1.3Al_0.2B_0.4P_0.4Ca
_0.2O_3.4, Sn_1.3Al_0.4B_0.4P_0.4Ba_0.2O
_3.6, Sn_1.4Al_0.4PK_0.2O_4.6, Sn_1.4Al
_0.2Ba_0.1PK_0.2O_4.45, Sn_1.4Al_0.2Ba
_0.2PK_0.2O_4.6, Sn_1.4Al_0.4Ba_0.2PK
_0.2Ba_0.1F_0.2O_4.9, Sn_1.4Al_0.4PK_0.3
O_4.65, Sn _1.5Al_0.2PK_0.2O_4.4, Sn_1.5A
l_0.4PK_0.1O_4.65, Sn_1.5Al _0.4PCs_0.05O
_4.63, Sn_1.5Al_0.4PCs_0.05Mg_0.1F_0.2O
_4.63,

[0076] SnSi_0.5Al_0.1B_0.2P_0.1Ca
_0.4O_3.1, SnSi_0.4Al_0.2B_{0. Four}O_2.7, Sn
Si_0.5Al_0.2B_0.1P_0.1Mg_0.1O_2.8, SnS
i_0.6Al_0.2B_0.2O_2.8, SnSi_0.5Al_0.3B
_0.4P_0.2O_3.55, SnSi_0.5Al_0.3B_0.4P_0.5
O_4.30, SnSi_0.6Al_0.1B_0.1P_0.3O_3.25, S
nSi_0.6Al_0.1B_0.1P_0.1Ba_0.2O_2.95, Sn
Si_0.6Al_0.1B_0.1P _0.1Ca_0.2O_2.95, SnS
i_0.6Al_0.4B_0.2Mg_0.1O_3.2, SnSi_{0. 6}A
l_0.1B_0.3P_0.1O_3.05, SnSi_0.6Al_0.2Mg
_0.2O_2.7, SnSi_0.6Al_0.2Ca_0.2O_2.7, S
nSi_0.6Al_0.2P_0.2O_Three , SnSi_{0. 6}B_0.2P
_0.2O_Three , SnSi_0.8Al_0.2O_2.9, SnSi_0.8
Al_0.3B_{0. Two}P_0.2O_3.85, SnSi_0.8B_0.2O
_2.9, SnSi_0.8Ba_0.2O_2.8, SnSi_0.8Mg
_0.2O_2.8, SnSi_0.8Ca_0.2O_2.8, SnSi
_0.8P_0.2O_3.1,

Sn _0.9 Mn _0.3 B _0.4 P _0.4 Ca _0.1 R
b _0.1 O _2.95 , Sn _0.9 Fe _0.3 B _{0 .4} P _0.4 Ca
_0.1 Rb _0.1 O _2.95 , Sn _0.8 Pb _0.2 Ca _0.1 P _0.9
O _3.35 , Sn _0.3 Ge _0.7 Ba _0.1 P _0.9 O _3.35 , Sn
_{0.9 Mn 0.1 Mg 0.1 P 0.9 O} 3. 35, Sn 0.2 Mn 0.8
Mg _0.1 P _0.9 O _3.35 , Sn _0.7 Pb _0.3 Ca _0.1 P
_0.9 O _3.35 , Sn _0.2 Ge _0.8 Ba _0.1 P _0.9 O _3.35 ,

[0078] SnSi_0.8B_0.2O_2.9, SnSi_0.7
B_0.3O_2.85, SnSi_0.7B_0.3Al_0.1O_3.0, S
nSi_0.5B_0.3Al_0.1Mg_0.1O_2.7, Sn_0.8S
i_0.6B_0.2Al_0.1Li_0.1O_2.5, Sn_0.8Si
_0.6B_0.2Al_0.1Cs_0.1O_{2. 65}, Sn_0.8Si_0.7
B_0.1P_0.1Al_0.1O_2.75, Sn_0.8Si_0.5B_0.3
P _0.2Al_0.1O_2.9, Sn_0.8Si_0.7B_0.1P_0.1
Al_0.1Li_0.05O_2.78, Sn_0.8Si_0.5B_0.3P
_0.1Al_0.1Li_0.1O_2.7, Sn_0.8Si_0.5B_{0. Three}
P_0.2Al_0.1Cs_0.1O_2.95, Sn_0.8Si_0.7P
_0.3O_2.95, Sn_0.8Si_0.7P_0.3Al_0.1O_3.1,
SnSi_0.5B_0.3Zr_0.1O_2.65, Sn_0.8Si_0.6
P_0.2Zr_0.1O_2.7, Sn_0.8Si_0.6B_0.2P_0.1
Zr_0.1O_2.75

The chemical formula of the compound obtained by calcining can be calculated by inductively coupled plasma (ICP) emission spectroscopy as a measuring method, and from the weight difference between powder before and after calcining as a simple method.

In the electrode having a perforated current collector, it is preferable that a lithium metal foil is pressure-bonded to at least one side of a mixture layer formed on both surfaces of the perforated current collector. The coverage of the lithium metal foil on the mixture layer is preferably 80% or more of the surface of the mixture layer on the side where the pressed lithium metal is present. It is preferable that the thickness of the coated lithium metal foil is 60 μm or less, and the thickness variation is 10% or less with respect to the average thickness. Particularly preferred is a thickness of 10 to 4
A lithium metal foil having a thickness of 0 μm and a thickness variation of 5% or less.

The electrode on which the lithium metal foil is pressed is:
The case of a negative electrode is preferred. When the electrode group is a wound electrode group, the surface on which the lithium metal foil is pressed is preferably the outer surface of the negative electrode. When the outermost layer electrode of the laminated electrode group or the wound electrode group is a negative electrode, since the outer peripheral side mixture layer of the negative electrode does not have an opposite positive electrode, the amount of the lithium metal foil to be pressed against the outer peripheral layer is adjusted. Is preferred. The amount of the mixture applied to the negative electrode, which has the opposite positive electrode only on one side,
When the applied amount of the mixture of the negative electrode having opposing positive electrodes on both sides is a times, the pressure-bonding amount of the lithium is also about a times, where a is 0.3 <a <0.7. To be satisfied. More preferably, a is 0.4 <a <0.6.

When the innermost and outermost electrodes of the wound electrode group are positive electrodes, it is preferable that the innermost and outermost positive electrodes have a mixture layer only on one side. .

The thickness of the lithium foil pressed to the negative electrode can be determined by the amount of lithium inserted into the negative electrode. The insertion of lithium is 0.01 V when lithium is used as a counter electrode.
In this embodiment, lithium is partially inserted in order to compensate for the irreversible capacity of the negative electrode material. When lithium is used as a counter electrode, the voltage is inserted up to 0.3 V. Adopt the method.

The lithium metal foil has a purity of 90% by weight.
The above is preferable, and the one with 98% by weight or more is particularly preferable. It is preferable that the lithium superimposed pattern on the negative electrode sheet is superimposed on the entire surface of the sheet. , Or a disc-shaped partial overlap. The term “overlap” as used herein means that a lithium metal foil is pressure-bonded directly on the negative electrode mixture layer or on a sheet having an auxiliary layer described below.

The handling atmosphere for cutting and affixing a metal foil mainly composed of lithium has a dew point of −30 ° C. or less and −80 ° C.
It is preferable to use a dry air or an argon gas atmosphere at a temperature of at least ℃. In the case of dry air, the temperature is more preferably -40 ° C or lower and -80 ° C or higher. In handling, carbon dioxide may be used in combination. Particularly, in the case of an argon gas atmosphere, it is preferable to use a carbon dioxide gas in combination.

The conductive agent used in the mixture may be any conductive material that does not cause a chemical change in the constructed battery. Specific examples include flake graphite, flake graphite, natural graphite such as earthy graphite, petroleum coke, coal coke, celluloses, sugars, high-temperature fired bodies such as mesophase pitch, and graphite such as artificial graphite such as vapor-grown graphite. , Acetylene black, furnace black, ketjen black, channel black, lamp black,
Carbon blacks such as thermal black, asphalt pitch, coal tar, activated carbon, carbon materials such as meso fuse pitch, polyacene, conductive fibers such as metal fibers, metal powders such as copper, nickel, aluminum, silver, and zinc oxide And conductive whiskers such as potassium titanate, and conductive metal oxides such as titanium oxide.
In the case of graphite, it is preferable to use a plate-like graphite having an aspect ratio of 5 or more. Among these, graphite and carbon black are preferable, and the particle size is 0.01 μm.
Not less than 20 μm, preferably not less than 0.02 μm and 1
Particles of 0 μm or less are more preferred. These may be used alone or in combination of two or more. When used together, carbon blacks such as acetylene black and 1
It is preferable to use graphite particles of up to 15 μm in combination.

The amount of the conductive agent to be added to the mixture layer is preferably 1 to 50% by weight, and more preferably 2 to 30% by weight, based on the negative electrode material or the positive electrode material. For carbon black and graphite, the content is particularly preferably 3 to 20% by weight.

A binder is used to hold the electrode mixture. Examples of the binder include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Preferred binders include starch, carboxymethyl cellulose,
Cellulose, diacetyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium alginate, polyacrylic acid, sodium polyacrylate, polyvinyl phenol, polyvinyl methyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyhydroxy (meth) acrylate, polystyrene Water-soluble polymers such as maleic acid copolymer, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer , Polyethylene, polypropylene, ethylene-
(Meth) acrylic ester copolymer containing (meth) acrylic ester such as propylene-diene terpolymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate, (meth) acryl Acid ester
Acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene butadiene copolymer, acrylonitrile butadiene copolymer, polybutadiene, neoprene rubber, fluorine rubber, polyethylene oxide, polyester polyurethane resin, poly Emulsions (latex) or suspensions of ether polyurethane resin, polycarbonate polyurethane resin, polyester resin, phenol resin, epoxy resin and the like can be given.

In particular, polyacrylate latex, carboxymethylcellulose, polytetrafluoroethylene and polyvinylidene fluoride can be mentioned. As these binders, it is preferable to use those in which fine powder is dispersed in water, and the average size of particles in the dispersion is 0.01 to 5%.
μm, more preferably 0.05 to 1 μm
It is particularly preferred to use m.

These binders can be used alone or as a mixture. If the amount of the binder is small, the holding power and cohesive strength of the electrode mixture are weak. If it is too large, the electrode volume increases and the capacity per unit volume or unit weight of the electrode decreases.
For these reasons, the amount of the binder added is preferably 1 to 30% by weight, particularly preferably 2 to 10% by weight.

As the filler, any fibrous material that does not cause a chemical change in the constructed battery can be used. Usually, fibers such as olefin-based polymers such as polypropylene and polyethylene, glass, and carbon are used. Although the amount of the filler is not particularly limited,
30% by weight is preferred.

As the ionic conductive agent, those known as inorganic and organic solid electrolytes can be used, and the details are described in the section of the electrolytic solution.

The pressure enhancer is a compound for increasing the internal pressure of the battery, and a representative example is a carbonate such as lithium carbonate.

Next, the configuration of the positive and negative electrodes will be described.
The positive and negative electrodes preferably have a form in which an electrode mixture is applied to both surfaces of a current collector. In this case, the number of layers per side may be one or two or more. When the number of layers per side is two or more, the number of layers containing the positive electrode active material (or the negative electrode material) may be two or more. A more preferable configuration is a case where the layer includes a layer containing a positive electrode active material (or a negative electrode material) and a layer containing no positive electrode active material (or a negative electrode material).

The layer not containing the positive electrode active material (or the negative electrode material) includes a protective layer for protecting the layer containing the positive electrode active material (or the negative electrode material) and the divided positive electrode active material (or the negative electrode material). There are an intermediate layer between the layers, an undercoat layer between the positive electrode active material (or negative electrode material) -containing layer and the current collector, and the like. In this specification, these are collectively referred to as an auxiliary layer.

The protective layer is preferably on both the positive and negative electrodes or on either the positive or negative electrode. In the negative electrode, when lithium is inserted into the negative electrode material in the battery, the negative electrode preferably has a form having a protective layer. The protective layer is composed of at least one layer, and may be composed of a plurality of layers of the same type or different types. Further, the current collector may have a form in which the protective layer is provided only on one side of the mixture layer on both sides. These protective layers are composed of water-insoluble particles, a binder and the like. As the binder, the binder used when forming the above-mentioned electrode mixture can be used. As the water-insoluble particles, various kinds of conductive particles, organic and inorganic particles having substantially no conductivity can be used. The solubility of the water-insoluble particles in water is preferably 100 ppm or less, and more preferably insoluble.

The proportion of the particles contained in the protective layer is preferably from 2.5% by weight to 96% by weight, more preferably from 5% by weight to 9% by weight.
The content is more preferably 5% by weight or less, particularly preferably 10% by weight or more and 93% by weight or less.

Examples of the water-insoluble conductive particles include metals, metal oxides, metal fibers, carbon fibers, and carbon particles such as carbon black and graphite. Among these water-insoluble conductive particles, those having low reactivity with alkali metals, particularly lithium, are preferable, and metal powder and carbon particles are more preferable. The electric resistivity at 20 ° C. of the elements constituting the particles is preferably 5 × 10 ⁹ Ω · m or less.

As the metal powder, a metal having low reactivity with lithium, that is, a metal which is unlikely to form a lithium alloy is preferable, and specifically, copper, nickel, iron, chromium, molybdenum, titanium, tungsten, and tantalum are preferable. The shape of these metal powders may be any of a needle shape, a column shape, a plate shape, and a lump shape, and the maximum diameter is preferably 0.02 μm or more and 20 μm or less, more preferably 0.1 μm or more and 10 μm or less. It is preferable that the surface of these metal powders is not excessively oxidized. When the surfaces are oxidized, it is preferable to perform heat treatment in a reducing atmosphere.

As the carbon particles, known carbon materials which are conventionally used as a conductive material to be used together when the electrode active material is not conductive can be used. Specifically, a conductive agent used when preparing an electrode mixture is used.

Examples of the water-insoluble particles having substantially no conductivity include fine powder of Teflon, SiC, aluminum nitride, alumina, zirconia, magnesia, mullite, forsterite, and steatite.
These particles may be used in combination with the conductive particles, and are preferably used in an amount of 0.01 to 10 times the conductive particles.

The positive (negative) electrode sheet can be prepared by applying a positive (negative) electrode mixture on a current collector, drying and compressing.

The mixture is prepared by mixing a positive electrode active material (or a negative electrode material) and a conductive agent, adding a binder (a suspension of resin powder or an emulsion) and a dispersion medium, kneading and mixing. Subsequently, the dispersion can be carried out by a mixer, a homogenizer, a dissolver, a planetary mixer, a paint shaker, a stirring mixer such as a sand mill, or a disperser. Water or an organic solvent is used as the dispersion medium, but water is preferred. In addition, additives such as a filler, an ion conductive agent, and a pressure enhancer may be appropriately added. The pH of the dispersion is 5 to 10 for the negative electrode and 7 to 10 for the positive electrode.
12 is preferred.

The coating can be performed by various methods.
Examples of the method include a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion method, a slide method, a curtain method, a gravure method, a bar method, a dip method, and a squeeze method. A method using an extrusion die and a method using a slide coater are particularly preferable. The coating is preferably performed at a speed of 0.1 to 100 m / min. At this time, by selecting the above-mentioned coating method in accordance with the liquid physical properties and drying properties of the mixture paste, a good surface state of the coating layer can be obtained.
When the electrode layer has a plurality of layers, it is preferable to apply the plurality of layers simultaneously from the viewpoint of uniform electrode production, production cost, and the like. The thickness, length and width of the coating layer are determined by the size of the battery. A typical thickness of the coating layer is 10 to 1000 μm in a compressed state after drying.

The electrode sheet after application is dried and dehydrated by the action of hot air, vacuum, infrared rays, far infrared rays, electron beams and low humidity air. These methods can be used alone or in combination. The drying temperature is preferably in the range of 80 to 350C, particularly preferably in the range of 100 to 260C. The water content after drying is preferably 2000 ppm or less, and 500 ppm or less.
ppm or less is more preferable.

For the compression of the electrode sheet, a commonly used press method can be used, but a die press method and a calendar press method are particularly preferable. The pressing pressure is not particularly limited, but is preferably from 10 kg / cm2 to 3 t / cm2. The press speed of the calendar press method is 0.1 ~
50 m / min is preferred. Press temperature is from room temperature to 200 ℃
Is preferred.

The separator may have a high ion permeability, a predetermined mechanical strength and an insulating thin film. The material may be an olefin polymer, a fluorine polymer,
Cellulose polymer, polyimide, nylon, glass fiber, alumina fiber is used, as the form, non-woven fabric,
Woven fabrics and microporous films are used. In particular, the material is preferably polypropylene, polyethylene, a mixture of polypropylene and polyethylene, a mixture of polypropylene and Teflon, a mixture of polyethylene and Teflon, and the form is preferably a microporous film. Especially,
A microporous film having a pore size of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferred. These microporous films may be a single film or a composite film composed of two or more layers having different properties such as the shape, density, and material of the micropores. For example, a composite film obtained by laminating a polyethylene film and a polypropylene film can be used.

The electrolyte is generally composed of a supporting salt and a solvent. As a supporting salt in a lithium secondary battery, a lithium salt is mainly used.

As the lithium salt, for example, LiClO
_Four , LiBF_Four , LiPF₆ , LiCF_Three CO_Two , Li
AsF₆ , LiSbF₆ , LiB_TenCl_Ten, LiOSO
_Two C _nF_{2n + 1}(Where n is 6 or less)
Lower positive integer), LiN (SO_Two C_nF_{2n + 1}) (SO_Two 
C_mF_{2m + 1}) (M and n are each 6)
The following positive integer), LiC (SO_Two C_pF_{2p + 1}) (SO
_Two C_qF_{2q + 1}) (SO _Two C_rF_{2r + 1}) Represented by)
Salt (p, q, and r are each a positive integer of 6 or less), lower fat
Lithium aliphatic carboxylate, LiAlCl_Four , LiCl,
LiBr, LiI, lithium chloroborane, tetraphenyl
Li salts such as lithium borate can be raised,
These can be used alone or in combination of two or more
You. Above all, LiBF_Four And / or LiPF₆ Dissolve
What is understood is preferred.

The concentration of the supporting salt is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolytic solution.

As the solvent, propylene carbonate,
Ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl formate, methyl acetate, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3- Dioxolane, formamide, dimethylformamide, dioxolane, dioxane, acetonitrile, nitromethane, ethyl monoglyme, phosphate triester, trimethoxymethane, dioxolane derivative,
Examples include aprotic organic solvents such as sulfolane, 3-methyl-2-oxazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ethyl ether, and 1,3-propane sultone. To use. Of these, carbonate-based solvents are preferable, and it is particularly preferable to use a mixture of a cyclic carbonate and a non-cyclic carbonate. As the cyclic carbonate, ethylene carbonate and propylene carbonate are preferable. As the acyclic carbonate, diethyl carbonate, dimethyl carbonate, and methyl ethyl carbonate are preferable.

As the electrolytic solution, ethylene carbonate,
Propylene carbonate, 1,2-dimethoxyethane,
LiCF ₃ SO ₃ and LiClO are added to an electrolyte solution appropriately mixed with dimethyl carbonate or diethyl carbonate.
₄ , an electrolyte containing LiBF ₄ and / or LiPF ₆ is preferred. Particularly, a mixed solvent of at least one of propylene carbonate or ethylene carbonate and at least one of dimethyl carbonate or diethyl carbonate is mixed with at least one salt selected from LiCF ₃ SO ₃ , LiClO ₄ , or LiBF ₄ and L
An electrolyte containing iPF ₆ is preferred. The amount of these electrolytes added to the battery is not particularly limited, and can be used according to the amounts of the positive electrode material and the negative electrode material and the size of the battery.

In addition to the electrolytic solution, the following solid electrolyte can be used in combination. Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes. Well-known inorganic solid electrolytes include nitrides, halides, and oxyacid salts of Li. Among them, Li ₃ N, LiI, Li ₅ N
_{I 2, Li 3 N-LiI} -LiOH, Li 4 SiO 4,
_{Li 4 SiO 4 -LiI-LiOH,} xLi 3 PO 4 -
(1-x) Li ₄ SiO ₄ , Li ₂ SiS ₃ , phosphorus sulfide compounds and the like are effective.

In the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative, a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ion dissociating group, a mixture of a polymer containing an ion dissociating group and the above aprotic electrolyte , A phosphate matrix polymer, and a polymer matrix material containing an aprotic polar solvent are effective. Furthermore, there is a method of adding polyacrylonitrile to the electrolytic solution. In addition, a method of using an inorganic and an organic solid electrolyte in combination is also known.

Also, the purpose of improving discharge and charge / discharge characteristics
Then, another compound may be added to the electrolyte. For example,
Lysine, pyrroline, pyrrole, triphenylamine,
Phenyl carbazole, triethyl phosphite, tri
Ethanolamine, cyclic ether, ethylenediamine,
n-glyme, hexaphosphoric triamide, nitrobenze
Derivatives, sulfur, quinone imine dyes, N-substituted oxazones
Lizinone and N, N'-substituted imidaridinone, ethylene glycol
Recall dialkyl ether, quaternary ammonium salt,
Polyethylene glycol, pyrrole, 2-methoxy eta
Knoll, AlCl _Three , Conductive polymer electrode active material
Mer, triethylene phosphoramide, trialkyl phos
Aryl compounds having fin, morpholine and carbonyl groups
, Crown ethers such as 12-crown-4,
Hexamethylphosphoric triamide and 4-alkylmo
Ruphorin, bicyclic tertiary amine, oil, quaternary phosphoni
And tertiary sulfonium salts.
You. Particularly preferred are triphenylamine, phenylca
When using rubazole alone or in combination
You.

Further, in order to make the electrolyte nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolyte. In addition, carbon dioxide gas can be included in the electrolytic solution in order to provide suitability for high-temperature storage.

It is desirable that the electrolyte contains as little water and free acid as possible. For this reason, it is preferable that the raw material of the electrolytic solution is sufficiently dehydrated and purified. The adjustment of the electrolytic solution is preferably performed in dry air or an inert gas having a dew point of −30 ° C. or less. The amount of water and free acid in the electrolytic solution is 0.1 to 500 ppm, more preferably 0.2 to 100 ppm.

The total amount of the electrolytic solution may be injected once, but it is preferable to inject it in two or more portions. In the case of injecting two or more times, even if each liquid has the same composition, different compositions (for example, after injecting a non-aqueous solvent or a solution in which a lithium salt is dissolved in a non-aqueous solvent, a non-aqueous solution having a higher viscosity than the solvent) A solution in which a lithium salt is dissolved in a solvent or a non-aqueous solvent is injected). Further, in order to shorten the injection time of the electrolyte solution, the pressure of the battery can may be reduced, or a centrifugal force or an ultrasonic wave may be applied to the battery can.

The battery can and the battery lid are made of nickel-plated iron steel plate or stainless steel plate (SUS30).
4, SUS304L, SUS304N, SUS316,
SUS316L, SUS430, SUS444, etc.), nickel-plated stainless steel plate (same as above), aluminum or its alloy, nickel, titanium, copper,
The shape is a true circular cylindrical shape, an elliptical cylindrical shape, a square cylindrical shape, or a rectangular cylindrical shape. In particular, when the outer can also serves as the negative electrode terminal, a stainless steel plate or a nickel-plated iron steel plate is preferable, and when the outer can also serves as the positive electrode terminal, a stainless steel plate, aluminum or an alloy thereof is preferable. The shape of the battery can may be any of buttons, coins, sheets, cylinders, corners, and the like.

A safety valve can be used for the sealing plate as a measure against the rise in the internal pressure of the battery can. In addition, a method of cutting a member such as a battery can or a gasket can also be used. In addition, various conventionally known safety elements (for example, a fuse, a bimetal, a PTC element, or the like as an overcurrent prevention element) may be provided.

The lead plate (lead electrode) is provided with a metal having electrical conductivity (for example, iron, nickel, titanium, chromium,
Molybdenum, copper, aluminum, and the like) and alloys thereof can be used. Known methods (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used for welding the battery lid, battery can, electrode sheet, and lead plate. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for sealing.

The gasket is made of an olefin polymer, a fluorine polymer, a cellulose polymer,
It is a polyimide or a polyamide, and is preferably an olefin-based polymer, particularly preferably a propylene-based polymer, in view of organic solvent resistance and low moisture permeability. Further, it is preferably a block copolymer of propylene and ethylene.

The battery is inserted into the battery can, injected with an electrolyte, caulked and sealed, and then aged before activation. It is preferable that the steps from the injection of the electrolyte to the caulking and closing of the battery can be performed at 20 ° C. or lower.

The battery assembled as described above is
It is preferable to perform an aging treatment. The aging treatment includes a pretreatment, an activation treatment, and a post-treatment, whereby a battery having high charge / discharge capacity and excellent cycleability can be manufactured. The pre-treatment is a treatment for making the distribution of lithium in the electrode uniform, such as a control of dissolution of lithium, a temperature control for making the distribution of lithium uniform, a swing and / or rotation treatment, and an optional charge and discharge. Are performed. Aging before activation is preferably performed at a temperature of 25 ° C. or more and 50 ° C. or less for 1 day or more and 10 days or less. The activation process is a process for inserting lithium into the negative electrode of the battery body, and it is preferable to insert 50 to 120% of the amount of lithium inserted when the battery is actually used and charged. The post-process is a process for sufficiently activating the activation process, and includes a preservation process for making the battery reaction uniform and a charge / discharge process for determination, and can be arbitrarily combined.

[0125] The battery is covered with an exterior material if necessary.
Examples of the exterior material include a heat-shrinkable tube, an adhesive tape, a metal film, paper, cloth, paint, a plastic case, and the like.
Further, at least a part of the exterior may be provided with a portion that changes color by heat so that the heat history during use can be recognized.

A plurality of batteries are assembled in series and / or in parallel as necessary and stored in a battery pack. In addition to safety elements such as positive temperature coefficient resistors, thermal fuses, fuses and / or current interrupting elements, battery packs have safety circuits (voltage, temperature, current, etc. of each battery and / or assembled battery as a whole, Then, a circuit having a function of interrupting the current may be provided. In addition to the positive and negative terminals of the whole battery pack, the positive and negative terminals of each battery, the temperature detection terminals of the whole battery pack and each battery, the current detection terminals of the whole battery pack, etc. shall be provided as external terminals on the battery pack. Can also. The battery pack may have a built-in voltage conversion circuit (such as a DC-DC converter). The connection of each battery may be fixed by welding a lead plate, or may be fixed by a socket or the like so that it can be easily detached. Further, the battery pack may be provided with a display function of the remaining battery capacity, the presence or absence of charging, the number of times of use, and the like.

The battery is used for various devices. In particular, video movies, portable VCRs with built-in monitors, movie cameras with built-in monitors, digital cameras, compact cameras, single-lens reflex cameras, film with lenses, notebook computers, notebook word processors, electronic organizers, mobile phones,
Cordless phones, shavings, electric tools, electric mixers,
It is preferably used for automobiles and the like.

[0128]

The present invention will be described in more detail with reference to specific examples, but the present invention is not limited to the examples.

(Example 1) [Preparation of positive electrode mixture paste] LiCo as a positive electrode active material
O ₂ to adjust. A mixture of lithium carbonate and tricobalt tetroxide at a molar ratio of 3: 2 was placed in an alumina crucible, heated to 750 ° C. at 2 ° C./min in air, calcined for 4 hours, and further heated at 2 ° C./min. The temperature is raised to 900 ° C. at the rate described above, and calcined and crushed at that temperature for 8 hours to obtain LiCoO ₂ . This LiCoO ₂ has a conductivity of 0.6 when 50 g of powder having a center particle size of 5 μm is dispersed in 100 ml of water.
mS / m, pH 10.1 and specific surface area by nitrogen adsorption method were 0.42 m ² / g. 200 g of LiCoO ₂
And 10 g of acetylene black (denoted as AB) having an average particle size of 0.1 μm, 90 g of a 2% by weight aqueous solution of carboxymethylcellulose and 70 g of water were added, kneaded and mixed, and further 2-ethylhexyl acrylate was added. Of acrylic acid and acrylonitrile (L
6 g of an aqueous dispersion (indicated as A) (solid content concentration: 50% by weight)
After the addition, the mixture was stirred and mixed with a homogenizer to prepare a positive electrode mixture paste.

[Preparation of negative electrode mixture paste] SnSi _0.5 B _0.3 P _0.2 Cs _0.05 Al _0.2 O as a negative electrode material
_3.28 (Pulverized by jet mill, average particle size 4.5μ
m of amorphous oxide) and an average particle size of 3.8 μm
30 g of artificial graphite (the median diameter of a particle size distribution analyzer LA-500 manufactured by Horiba Ltd.) was mixed with a homogenizer,
Further, 50 g of a 2% by weight aqueous solution of carboxymethylcellulose as a binder and 10 g of polyvinylidene fluoride powder having an average particle diameter of 0.35 μm were added and mixed, and 30 g of water was further added, followed by kneading and mixing to prepare a negative electrode mixture paste. did.

[Preparation of Negative Electrode Protective Layer Paste] Alumina 8
5 g and 9 g of artificial graphite having an average particle size of 3.8 μm were added to 300 g of a 2% by weight aqueous solution of carboxymethylcellulose and kneaded to prepare a negative electrode protective layer paste.

[Preparation of Positive and Negative Electrode Sheets] The positive electrode mixture paste prepared above was coated on both surfaces of a 15 μm-thick aluminum foil current collector with a blade coater at a coating weight of 240 g / m in terms of positive electrode active material per one side. Coated in ² and dried. The application length of the mixture was 495 mm, and intermittent application of providing a 33 mm uncoated portion was repeated. The mixture-coated ends on the front and back surfaces were aligned by positioning. Thereafter, the sheet was compressed by a roller press, and compression-molded so that the thickness of the sheet became 170 μm. After heat treatment at about 230 ° C. for 15 minutes, 56
The sheet was cut to a width of mm to prepare a long positive electrode sheet. Dry box (dew point; dry air below -50 ° C)
Heat with far infrared heater inside, electrode temperature about 180 ℃
, And a long strip-shaped positive electrode sheet was prepared.

Similarly, on both sides of a 13 μm copper foil current collector,
A negative electrode mixture paste and a negative electrode protective layer paste were applied. At this time, the negative electrode mixture paste was applied to the current collector side such that the negative electrode protective layer paste was the uppermost layer. A negative electrode sheet was prepared in which the coating amount in terms of the negative electrode material per one side was 80 g / m ² , the solid content of the protective layer was 15 g / m ² , and the thickness of the sheet after compression by a roller press was 110 μm.
This negative electrode sheet has a mixture applied portion 540 mm on both the front and back sides.
And the uncoated portion 18 mm is intermittently applied so as to be repeated. After heat treatment at about 240 ° C. for 15 minutes, the negative electrode sheet was cut into a width of 57.5 mm to prepare a long negative electrode sheet. Dry box (dew point;-
The resultant was heated with a far-infrared heater in a dry air at 50 ° C. or lower), and was sufficiently dehydrated and dried at an electrode temperature of about 210 ° C. to form a long strip-shaped negative electrode sheet.

A rectangular lithium metal (purity: 99.8%) foil having a width of 6 mm was adhered to both surfaces of the negative electrode sheet at a pitch of 10 mm.

[Preparation of Electrolyte Solution]
65.3 g of diethyl carbonate was placed in a cc narrow-neck polypropylene container, and 22.2 g of ethylene carbonate was dissolved little by little while taking care that the liquid temperature did not exceed 30 ° C. Next, 0.4 g of LiBF ₄ , 12.1 g of LiBF
While paying attention to PF _{6 so} that the liquid temperature does not exceed 30 ° C,
A small amount was dissolved in each of the polypropylene containers in order. The obtained electrolyte was a colorless and transparent liquid having a specific gravity of 1.135. Moisture is 18 ppm (measured by a Karl Fischer moisture meter, Model MKC-210, manufactured by Kyoto Electronics Co., Ltd.), and free acid content is 24 ppm (measured by neutralization titration with a 0.1 N NaOH aqueous solution using bromthymol blue as an indicator). )Met.

[Preparation of Cylinder Battery] A cylinder battery as shown in FIG. 2 was prepared. The wound electrode group is formed by laminating the long strip-shaped positive electrode sheet 3, a microporous polyethylene film separator (EF4500, manufactured by Ube Industries, Ltd.) 4, the negative electrode sheet 2 and the separator 4 in this order, and spirally winding the laminated sheet. Created. The welding of the electrode leads, the attachment of the protective tape, and the cutting of the electrode sheet were performed in a series of steps during winding.

The welding of the positive electrode lead was performed at a position 4 mm wide and 7 mm thick at a position 8 mm from the end of the uncoated portion of the long positive electrode sheet.
A 5 μm aluminum lead was resistance welded. The welded portion was protected by an insulating tape using polyethylene as a base material and an acrylic adhesive. Cutting is 3m from the edge of one mixture
m and 30 mm from the other end of the mixture, and this positive electrode sheet was designated as positive electrode sheet C-1. The length of the mixture applied portion is 495 mm, and the length of the uncoated portion is 33 mm. C-1 in the wound group was wound so that the welded part of the positive electrode lead was at the center of the wound electrode group, and the lead came to the inner peripheral side.

The welding of the negative electrode lead was performed at a position of 9 mm from the end of the long negative electrode sheet where the mixture was not applied, with a width of 4 mm and a thickness of 1 mm.
A nickel lead of 00 μm was ultrasonically welded. The welded portion was protected by an insulating tape using polyethylene as a base material and an acrylic adhesive. Cutting is 15 minutes from one end of the mixture.
mm and 3 mm from the other end of the mixture, and this negative electrode sheet was designated as negative electrode sheet A-1. The length of the mixture applied portion is 540 mm, and the length of the uncoated portion is 18 mm. A-1 in the wound group was wound so that the welded portion of the negative electrode lead was located at the outermost periphery of the wound electrode group, and the lead was on the inner peripheral side surface. The facing relationship between the positive and negative electrode mixture layers was such that the negative electrode mixture was wound about 2 mm ahead of the positive electrode mixture.

[0139] After storing this wound body in a nickel-plated iron bottomed cylindrical battery can 1 also serving as a negative electrode terminal,
The above electrolytic solution was poured into the battery can, and the battery cover 13 having the positive electrode terminal was caulked via the gasket 7 to form the cylindrical battery D-.
1 was created. The ratio of the length of the portion having uncoated portions on both surfaces of the current collector D-1 to the length of the portion having the mixture layer was 33 mm / 495 mm = 6.7% for the positive electrode and 1% for the negative electrode.
8 mm / 540 mm = 3.3%.

Instead of the positive electrode sheet C-1, the mixture application length was 473 mm, the uncoated portion length was 55 mm, the mixture application length was 463 mm, the uncoated portion length was 65 mm, and the mixture application length was 453 mm. C except that the length is 75 mm
-1 to C-4 to C-4
made. The ratio of the length of the portion having the uncoated portion on both surfaces of each current collector to the length of the portion having the mixture layer is 55 mm / 473 mm = 11.6%, 65 mm / 4
63 mm = 14.0%, 75 mm / 453 mm = 16.
5%. The electrode C-4 wrinkled during the transport of the electrode, and a cutting failure occurred in part. C-3 has a very low probability of occurrence of wrinkles and cutting failures, and C-2 has no failure.

The positive electrode sheet C-5 was operated in exactly the same manner as C-1 except that the mixture application length was 500 mm, the uncoated portion length was 28 mm, the mixture application length was 508 mm, and the uncoated portion length was 20 mm. , C-6. The ratio of the length of the portion having the uncoated portion on both surfaces of each current collector to the length of the portion having the mixture layer is 28 mm / 500 mm.
= 5.6%, 20mm / 508mm = 3.9%.
The positive electrode lead was welded to a position 5 mm from the front end of each positive electrode sheet, and cut so that the uncoated portion at the rear end was 3 mm. When the internal short circuit of the battery wound in the same manner as the battery D-1 using the negative electrode sheet A-1 was examined, many batteries using the positive electrode sheet C-6 were short-circuited,
In the battery using C-5, the number of short-circuit batteries was greatly reduced, and in the battery using C-1, there was almost no failure.

As described above, in the positive electrode, the ratio of the length of the uncoated portion on both surfaces of each current collector to the length of the portion having the mixture layer is 5% or more and 15% or less. It is particularly preferably 6% or more and 12% or less.

Instead of using the negative electrode sheet A-1, the length of the mixture was 535 mm, the length of the uncoated portion was 23 mm, the length of the mixture was 528 mm, and the length of the uncoated portion was 30 mm.
-1 and the negative sheets A-2 and A-3
made. The ratio of the length of the portion having the uncoated portion on both surfaces of each current collector to the length of the portion having the mixture layer is 23 mm / 535 mm = 4.3% and 30 mm / 52.
8 mm = 5.7%. The electrode A-3 was wrinkled during the transport of the electrode, but the electrode A-2 had a very low probability of wrinkling, and the electrode A-1 did not cause any failure.

Further, instead of the negative electrode sheet A-1, the mixture application length was 549 mm, the uncoated portion length was 9 mm, the mixture application length was 551 mm, the uncoated portion length was 7 mm, and the mixture application length was 553 mm. A- except that the coating length is 5 mm
By performing exactly the same operation as in No. 1, negative electrode sheets A-4 to A-6 were produced. The ratio of the length of the uncoated portion on both surfaces of each current collector to the length of the portion having the mixture layer is
9mm / 549mm = 1.64%, 7mm / 551mm
= 1.27%, 5mm / 553mm = 0.90%. Electrode A-6 was inspected after electrode lead welding, and as a result, the end of the mixture and the end of the lead overlapped, and many of the leads were raised. In A-5, there was no welding failure of the lead, but a portion near the lead was cut at the time of cutting after welding. Was recognized. In A-1 and A-4, these failures did not occur.

From the above, it is preferable that the ratio of the length of the uncoated portion on both surfaces of the current collector of the negative electrode to the length of the portion having the mixture layer is 1% or more and 5% or less,
It turns out that 1.5% or more and 4% or less are especially preferable.

(Example 2) Using the mixture of the positive electrode and the negative electrode used in the battery D-1 of Example 1, the mixture was continuously applied to the positive and negative electrodes. The positive electrode had a width of 56 mm, the length was 528 mm, and the negative electrode had a width of 57.
An electrode sheet having a mixture layer on both surfaces of a current collector having a length of 5 mm and a length of 558 mm was prepared. The positive electrode sheet is 3m from one end
m, the mixture layer on both sides of a portion 30 mm from the other end was swollen with N-methylpyrrolidone, and then the mixture layer was peeled off to form an exposed surface of the current collector. It was created. The negative electrode sheet is 3 mm from one end,
After swelling the mixture layer on both sides at a distance of 15 mm from the other end with N-methylpyrrolidone, the mixture layer was peeled off, an exposed surface of the current collector was created, and a negative electrode sheet similar to battery D-1 was created. did. An aluminum lead was resistance-welded 5 mm from the end of the 30 mm current collector exposed portion of the positive electrode sheet. In addition, 6 mm from the tip of the 15 mm current collector exposed portion of the negative electrode sheet.
The nickel lead was ultrasonically welded to the mm. Using this positive / negative electrode sheet, a battery D21 was made in the same manner as the battery D-1.

A battery D22 was made in the same manner as the battery D21, except that the mixture layer was peeled off by a mechanical method using a grinder and an adhesive tape together. Battery D-1 and batteries D21 and D22 are exactly the same except for the method of forming the current collector exposed portion of the electrode sheet. Battery D21, D
In the exposed portion of the current collector of the electrode sheet No. 22, the colors of the positive and negative electrodes were different from those of the current collector at the beginning. Further, the internal resistance of these batteries was higher than that of Battery D-1, and the decrease in discharge capacity over time of the cycle was greater than that of Battery D-1.

In the batteries D21 and D22, the mixture layer on both surfaces was peeled off, but a battery D23 was prepared in the same manner as the battery D21 except that the mixture layer was peeled off only on one side to be lead-welded. After the lead was welded to the electrode of the battery D23, it was observed that the mixture layer on the back surface of the lead was partially dropped. The battery D23 was found to be defective due to an internal short circuit during the cycle test.

It is preferable that the exposed portion of the current collector is formed by not applying the electrode mixture, rather than removing the portion after applying the electrode mixture once.

[0150]

According to the present invention, in the electrode sheet,
By setting the length of the uncoated portion to a predetermined length with respect to the length of the coated portion of the mixture layer, battery failure can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electrode sheet.

FIG. 2 is a cross-sectional view of a cylinder type battery used in the present example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery can (also serves as negative electrode terminal) 2 Negative electrode sheet 3 Positive electrode sheet 4 Separator 5 Lower insulating plate 6 Upper insulating plate 7 Gasket 8 Positive electrode lead 9 Explosion-proof valve body 10 Current cutoff switch 11 PTC ring 13 Battery cover (also serves as positive electrode terminal) Reference Signs List 15 welding plate 16 insulating cover 21 current collector 22 electrode mixture layer 23 electrode lead

Claims (4)

[Claims] In a strip-shaped electrode sheet having a mixture layer on both sides of a current collector, the length of an uncoated portion where there is no mixture layer on both sides of the current collector is one side. The electrode sheet for a non-aqueous secondary battery is 1% or more and 15% or less with respect to a longer portion having a mixture layer. 2. A strip-shaped negative electrode sheet having a mixture layer on both sides of a current collector, wherein the length of an uncoated portion where there is no mixture layer on any of both sides of the current collector is one side. A negative electrode sheet for a non-aqueous secondary battery, wherein the amount of the negative electrode sheet is 1% or more and 5% or less with respect to a longer portion having a mixture layer. 3. A strip-shaped positive electrode sheet having a mixture layer on both surfaces of a current collector, wherein the length of the uncoated portion where there is no mixture layer on any of both surfaces of the current collector is one side. A positive electrode sheet for a non-aqueous secondary battery, wherein the amount of the positive electrode sheet is not less than 5% and not more than 15% with respect to a longer portion having a mixture layer. 4. A non-aqueous secondary battery in which a positive electrode sheet, a separator, and an electrode group formed by winding a negative electrode sheet and a non-aqueous electrolyte are incorporated in a battery can, at least one of the positive and negative electrode sheets according to claim 1. A non-aqueous secondary battery, which is an electrode sheet.