JPH08203562A - Battery - Google Patents

Abstract

PURPOSE: To provide a battery without generated charge/discharge between a battery can to be a negative electrode and a positive electrode active material in the battery formed by layering respective positive and negative electrode plates with active materials stuck to a current collecting body foil via a separator. CONSTITUTION: An electrode plate layered body 1B is formed by stacking a positive electrode side current collecting body foil 11a, a positive electrode active material 11b, a separator 13, a negative electrode active material 12b, a negative electrode side current collecting body foil 12a, and an insulating film 16 in this order and winding around the insulating film 16, and in this case, the insulating film 16 only is extended by a round and a half to the outside face so as to be wound. This insulating film 16 is a separation film without having any ion and electron transmission function, and the aforementioned extension part 16a of this insulating film 16 is interposed between an end face part (A) of the positive electrode plate 11 constituting an electrode plate layered body 1B and a battery can 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a laminate of a positive electrode plate having a collector foil coated with a positive electrode active material, a negative electrode plate having a collector foil coated with a negative electrode active material, and a separator. The present invention relates to a battery including the electrode plate laminate in a battery can that serves as a negative electrode, and particularly to a battery in which charge / discharge between the positive electrode plate of the electrode plate laminate and the battery can is prevented.

[0002]

2. Description of the Related Art Lithium ion using a non-aqueous electrolyte
Rechargeable batteries have high voltage, high capacity and high output
Because it is light, it has been adopted as a power source for portable electronic devices.
is there. In such a lithium ion secondary battery,
Generally, aluminum foil is used as the current collector for the positive electrode.
In addition, the lithium composite oxide (LiCoO
₂Etc.) to form a positive electrode plate.
In addition, copper foil was used as the current collector of the negative electrode, and the negative electrode active material
Is applied to form a negative electrode plate by applying a material containing carbon.
A porous polyethylene with a fine pore size as a separator between
The electrode plate laminate wound in a spiral shape with a
It is stored in a polar cylindrical stainless steel battery can.

In currently available lithium ion secondary batteries, the structure of the electrode plate laminate is one positive electrode plate having an active material coating on both sides of an aluminum foil and an active material coating on both sides of a copper foil. There is one in which a certain negative electrode plate and two separators are layered in the order of a negative electrode plate, a separator, a positive electrode plate, and a separator, and are spirally wound so that the negative electrode plate is on the outside. Also, two positive electrode plates having an active material coating on one side of the aluminum foil, one negative electrode plate having an active material coating on both sides of the copper foil, and two separators, a negative electrode plate, a separator, two sheets Of the positive electrode plate (the aluminum foil sides are aligned with each other and the active material film side is directed to the outside), the separator is stacked in this order, and the negative electrode plate is wound in a spiral shape.

That is, there is a difference in whether a current collector foil has active material coatings on both sides or two current collector foils having an active material coating on one surface are stacked, but in any case, the electrode is The plate laminate has a positive electrode active material, a positive electrode side current collector foil, a positive electrode active material,
The separator, the negative electrode active material, the negative electrode side current collector foil, the negative electrode active material, the separator, and the positive electrode active material are laminated in this order.

[0005]

Such a lithium-ion secondary battery has a safety feature when the temperature inside the battery rises due to a short circuit between the positive electrode and the negative electrode of the battery due to circuit abnormality or incorrect usage. Safety valves, thermal fuses, PTC elements, etc. have been conventionally provided in order to ensure the safety, but further safety measures are required in preparation for various operating environments and accidents.

For example, when a nail such as a conductor is stabbed in a battery, the tip of the nail penetrates the battery can, which is the negative electrode, and comes into contact with the internal positive electrode plate in the negative electrode state.
A short circuit occurs through this nail. Further, when the battery is abnormally heated from the outside, the separator, which is an organic material, first melts, so that the positive electrode plate and the negative electrode plate, which are insulated by the separator, come into contact with each other to cause a short circuit.

At the time of such a short circuit, the lithium composite oxide (positive electrode active material) has a relatively high resistance value among the members constituting the electrode plate laminate, so that the temperature of the lithium composite oxide is reduced by the passage of the short circuit current. Easy to rise. Then, the heat generated by this temperature rise easily causes the decomposition reaction of the organic solvent inside the battery. Further, when such a short circuit occurs in the battery in the charged state, the lithium composite oxide in the charged state is in an unstable state in which lithium is released as ions to some extent. It is liable to be generated, and the oxygen easily causes a reaction in the aluminum foil or the organic solvent to which the lithium composite oxide is adhered.

From the above, a large amount of energy is likely to be generated inside the battery due to the temperature rise of the positive electrode active material due to the occurrence of a short circuit between the positive electrode active material and the negative electrode in the battery in the charged state, and the safety of the battery is improved. It becomes difficult to secure. Therefore, as a safety measure in response to various use environments and unexpected accidents, in particular, the short circuit between the positive electrode active material and the negative electrode does not occur in the charged state, and when the short circuit occurs, the positive electrode active material rises. It is important to keep the temperature low, but the conventional structure does not take any measures against it.

On the other hand, the applicant of the present invention, as described above, the positive electrode active material, the positive electrode side current collector foil, the positive electrode active material, the separator, the negative electrode active material, the negative electrode side current collector foil, the negative electrode active material, A separator, a conventional electrode plate laminate in which a positive electrode active material is laminated in this order, by providing a positive electrode side current collector foil exposed portion where the positive electrode active material is not deposited, when abnormally heated from the outside or Even when a sharp conductor such as a nail is stabbed in the battery can, it is difficult to cause a short circuit between the positive electrode active material and the negative electrode, or even if it occurs, suppressing the temperature rise of the positive electrode active material with it, A non-aqueous battery capable of ensuring safety has been proposed (see Japanese Patent Application Nos. 6-231399 to 231401).

Although the above-mentioned safety is ensured by this, if such a collector foil exposed portion is provided on the positive electrode plate,
An end surface of the positive electrode active material layer is formed at the boundary between the exposed portion and the other portion of the positive electrode plate. When the exposed portion of the current collector foil is on the outer surface of the electrode plate laminate, the end surface of the positive electrode active material layer faces the battery can via the separator, and thus the positive electrode active material and the negative electrode battery. Charge / discharge occurs between the can and the can, and in the case of a lithium secondary battery, metallic lithium may be deposited in the battery can during charging, and the battery can material may start to melt during overdischarging.

Further, even in the case of a battery provided with such an electrode plate laminate without a current collector foil exposed portion, the positive electrode plate (that is, the positive electrode active material) must be provided at the end of the electrode plate laminate on the battery can side. In order to prevent this from facing the battery can, it is necessary to make the negative electrode plate longer than the positive electrode plate and dispose only the end face of the negative electrode plate on the battery can side. However, if the negative electrode plate that does not form a pair with the positive electrode plate is long as described above, there is also a problem that it becomes a factor of lowering the cycle performance.

The present invention has been made by paying attention to the problems of the prior art as described above, and a positive electrode plate having a collector foil coated with a positive electrode active material, and a collector foil having a negative electrode active material. In a battery provided with an electrode plate laminate in which a negative electrode plate to which is adhered and a separator are laminated in a battery can that serves as a negative electrode, the electrode plate laminate is charged between the positive electrode active material and the battery can. It is an object to provide a battery that does not discharge.

[0013]

In order to achieve the above object, the invention according to claim 1 is a positive electrode plate in which a positive electrode active material is coated on a current collector foil, and a negative electrode active material on the current collector foil. A negative electrode plate having been adhered, and an electrode plate laminated body in which a separator is laminated,
A battery provided in a battery can that serves as a negative electrode, wherein a separator having neither an ionic conduction function nor an electron conduction function is interposed between the electrode plate laminate and the battery can.

According to a second aspect of the invention, in the battery according to the first aspect, the solvent of the electrolyte is an aprotic liquid,
The electrode plate laminate is a positive electrode active material, a positive electrode side current collector foil, a positive electrode active material, a separator, a negative electrode active material, a negative electrode side current collector foil,
Provided is one in which a negative electrode active material, a separator, and a positive electrode active material are laminated in this order, and the positive electrode side current collector foil exposed portion to which the positive electrode active material is not deposited is provided on the outer surface of the electrode plate laminate. .

According to a third aspect of the invention, in the battery according to the first aspect, the solvent of the electrolyte is an aprotic liquid,
The electrode plate laminate is a positive electrode plate having a positive electrode active material deposited on only one surface of a current collector foil, and a negative electrode plate having a negative electrode active material deposited on only one surface of a current collector foil. A unit battery layer is formed by arranging the active material-coated surfaces to face each other and interposing a separator therebetween, and the unit battery layers are laminated with an insulating film having no electron conduction function interposed therebetween. provide.

According to a fourth aspect of the present invention, in the battery according to the third aspect, the electrode plate laminate has a unit battery layer laminated such that the positive electrode plate side faces the battery can side. Examples of the positive electrode plate and the negative electrode plate according to claims 1 and 2 include those having an active material coating on both surfaces of one current collector foil, and those having an active material coating only on one surface. In the case of only one, it is necessary to combine two surfaces on the side without the active material coating and use them. Further, from the viewpoint of increasing the utilization efficiency of the current collector foil, it is preferable to have an active material film on both sides of one sheet.

The positive electrode plate according to claims 3 and 4 is not limited to one in which the active material is applied to the entire one surface of the current collector foil.
Some of them are partially coated, but the other surface is not coated with active material at all, and the surface of the current collector is entirely exposed. The same applies to the negative electrode plate. For the electrode plate laminate, a method of winding the unit laminate into a spiral shape by a winding machine (winding type), a method of overlapping in parallel (simple lamination type), or a method of arranging in parallel while being folded back with a predetermined width It is made by (a 99-fold type) or the like.

Particularly, the electrode plate laminate according to claim 3 is
A method of winding a unit battery layer in which the negative electrode plate, the separator, and the positive electrode plate are stacked as described above with the insulating film and winding it in a spiral shape with a winding machine (winding type), sandwiching the insulating film between the unit battery layers. In parallel with each other (simple stacking type), and by stacking a unit battery layer and an insulating film in parallel with each other with a predetermined width, and arranging them in parallel (multifold type 99).

In the wound type, the electrode plate laminate according to claim 4 is wound with the positive electrode plate side of the unit battery layer facing outward.
This is achieved by winding an insulating film around at least the outermost periphery thereof. In the simple laminated type, for example, a plurality of unit battery layers are laminated with the positive electrode plate side and the negative electrode plate side facing each other with an insulating film interposed therebetween, and this is laminated at the center of the stacking direction on the negative electrode plate side. And the insulating film is disposed at least between both end surfaces of each unit battery layer and the battery can. In the 99-fold type, of the inner surface of the battery can,
Achieved by folding the unit battery layer so that the positive electrode plate side is arranged on the inner side surface parallel to the folded unit surface and disposing an insulating film between at least the positive electrode plate arranged on the inner side surface and the inner side surface. To be done.

The exposed portion of the current collector foil on the positive electrode side is formed by not depositing the positive electrode active material on that portion of the current collector foil, and the electrode plate laminate has the active material on only one surface of the current collector foil. In the case of a wound type having two positive electrode plates with a coating, it is also formed by shifting the ends of both positive electrode plates and stacking them. Further, in the simple laminated type, it is also formed by using only one positive electrode plate having an active material coating on only one surface of the current collector foil in a portion corresponding to the exposed portion.

The current collector foil is aluminum,
Metal foil such as copper and titanium, expanded metal, punched metal, foamed metal, carbon cloth, carbon paper, etc. are used. Examples of the positive electrode active material include Li, N
a, a composite oxide of an alkali metal or alkaline earth metal such as Ca and a transition metal such as Co, Ni, Mn, and Fe, or a combination of the alkali metal or alkaline earth metal, a transition metal and a non-transition metal Complex oxides can be used.

As the negative electrode active material, carbon particles such as coke, graphite and amorphous carbon are used.
The shape thereof may be any of crushed shape, scale shape, spherical shape and the like. As the isolation film, for example, a polyolefin-based (polyethylene, polypropylene, ethylene-propylene copolymer, etc.) synthetic resin film having neither an ionic conduction function nor an electron conduction function is used.

As the separator interposed between the active materials of both electrodes, a fine porous film having a small pore size, which has no electronic conductivity, an ionic conductivity function, and a high resistance to an organic solvent, is used. , Polypropylene, etc.), a microporous membrane made of a resin, or a woven polyolefin porous fiber, or a nonwoven fabric thereof.

The separator disposed between the exposed portion of the positive electrode side current collector foil and the negative electrode plate and the battery can to be the negative electrode is
Since the battery action does not occur at this position, it is not necessary to have an ion conducting function. Therefore, for example, a synthetic resin film similar to the isolation film is used. Further, this separator may have an ion conducting function. As the insulating film, one having no electron conductivity and high resistance to an organic solvent, for example, a polyolefin-based (polyethylene, polypropylene, ethylene-propylene copolymer, etc.) synthetic resin film is used. Further, this insulating film may have an ionic conduction function.

[0025]

According to the battery of claims 1 to 4, since the end face of the positive electrode active material layer at the end of the electrode plate laminate on the battery can side faces the battery can through the isolation film, the positive electrode Charge and discharge do not occur between the active material and the battery can that is the negative electrode. Particularly, according to the battery of claim 2, since the end surface of the positive electrode active material layer at the boundary between the exposed portion of the current collector foil and the other portion of the positive electrode plate faces the battery can via the isolation film. Therefore, charge / discharge does not occur between the positive electrode active material and the negative electrode battery can.

According to the battery of claim 2, the structure of the electrode plate laminate in the exposed portion of the positive electrode side current collector is such that from the battery can side to the positive electrode side current collector foil, the positive electrode active material, the separator, The order of the negative electrode active material is as follows. Therefore, in the event of a nail stick accident, the tip of the nail penetrates the battery can, which is the negative electrode, and contacts the positive plate inside, causing a short circuit. In such a case, the tip first contacts the current collector foil before contacting the positive electrode active material, so that a short-circuit current hardly flows in the positive electrode active material.
Thereby, even when the resistance value of the positive electrode active material is higher than that of the current collector foil, the temperature rise of the positive electrode active material is suppressed during the short circuit as described above.

In particular, according to the batteries of claims 3 and 4, in the electrode plate laminate, the positive electrode active material surface and the negative electrode active material surface are opposed to each other with the separator interposed therebetween, and the positive and negative electrodes are respectively adhered. The collector foil surfaces face each other with the insulating film interposed therebetween. Therefore, when a short circuit occurs between the positive electrode active material and the negative electrode due to abnormal heating from the outside, crushing in the stacking direction of the battery, piercing with a nail, or the like, a short circuit between the positive and negative current collector foils is always generated. Therefore, when the resistance value of the positive electrode active material is higher than the resistance value of the current collector foil, the current mainly flows to the current collector foil having a low resistance value even in the short-circuited portion, and the current flowing to the positive electrode active material decreases. Thereby, even when the resistance value of the positive electrode active material is higher than the resistance value of the current collector foil, the temperature rise of the positive electrode active material is suppressed during a short circuit.

Further, according to the non-aqueous battery of claim 4, since the positive electrode plate side of the unit battery layer faces the battery can side, the structure of the electrode plate laminate is such that from the battery can side to the positive electrode side current collector. Body foil,
The order of the positive electrode active material, the separator, the negative electrode active material, the negative electrode side current collector foil, the insulating film, and the positive electrode side current collector foil. Therefore, in the case of a nail stick accident, the same effect as that of the second aspect can be obtained.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a cylindrical non-aqueous battery having a wound electrode plate laminate, which corresponds to the first embodiment of the present invention. This battery is a non-aqueous lithium ion secondary battery in which a spirally wound electrode plate laminate 1A is housed in a cylindrical battery can 2. Further, a thin cylindrical center pin 3 is inserted in the winding center of the electrode plate laminate 1. The center pin 3 functions as a flow path that guides the gas inside the battery can 2 toward the safety valve when the internal pressure inside the battery can 2 rises, and is made of stainless steel or the like.

The electrode plate laminated body 1A comprises _two positive electrode plates 11A and 11B in which a material containing LiCoO ₂ is applied as a positive electrode active material 11b on only one side of a current collector foil 11a made of aluminum, and copper is used. A negative electrode plate 12 coated with a material containing carbon particles as a negative electrode active material 12b on both sides of a current collector foil 12a, and a polyethylene fine particle disposed between the positive electrode active material 11b and the negative electrode active material 12b. Two separators 13A, 1 made of a porous film (film thickness 35 μm)
3B and 3B.

In this electrode plate laminate 1A, except for the outer peripheral portion, the positive electrode plates 11A and 11B are arranged so that the current collector foil 11a surface sides are aligned with each other, and the separator 13B, the negative electrode plate 12, the separator 13A, and the positive electrode The plate 11A and the positive electrode plate 11B are formed in this order as a unit laminate, and the center pin 3 has a separator 13 formed thereon.
It is produced by winding A and 13B several times and then winding the unit laminate body in a spiral shape with a separator 13B inside with a winding machine. Therefore, the layer structure of the electrode assembly 1A has a separator 13B, a negative electrode active material 12b, a negative electrode side current collector foil 12a, a negative electrode active material 12b, and a separator 13 in the inner peripheral portion on the peripheral side of the center pin 3.
A, positive electrode active material 11b, positive electrode side current collector foil 11a, positive electrode side current collector foil 11a, positive electrode active material 11b, separator 13B
The order is ...

Regarding the outer peripheral portion, by winding the unit laminated body without the positive electrode plate 11B and constituting the positive electrode only by the positive electrode plate 11A having the active material coating on only one surface, the current collector foil exposed portion 15 is formed. Has been formed. As a result, in the electrode plate laminated body 1A, in the outer peripheral portion where the current collector foil exposed portion 15 is present, from the battery can 2 side to the positive electrode side current collector foil 11.
a, the positive electrode active material 11b, the separator 13A, and the negative electrode active material 12b are laminated in this order.

The outside of the positive electrode (that is, the negative electrode plate 1)
2 inside), the separator 13B adjacent to the positive electrode plate 11
At the end face position of B, it is connected to the isolation film 4 made of a polyethylene resin film (film thickness 12 μm) having neither ion conductivity nor electron conductivity. Note that, here, the separator 13B and the isolation film 4 are connected by abutting and adhering the end faces of both, but by performing a certain length of overlapping and winding the end portions of both. Good.

The isolation film 4 is wound around the current collector foil exposed portion 15 of the electrode plate laminate 1A once or more, and is located at the boundary between the current collector foil exposed portion 15 and the other portion. The end face portion 11 of the battery 11 and the end face portion 11 of the positive electrode plate 11 at the winding end of the unit laminate face the battery can 2 with the separator film 4 in between. As a result, charging / discharging does not occur between the positive electrode active material 11b of each of the end face portions A and B and the battery can 2 that is the negative electrode, so that metallic lithium is deposited on the battery can 2 during charging or the battery can be overdischarged. There is no risk of the can material melting.

In the case of a nail stick accident, the tip of the nail penetrates the battery can 2 as the negative electrode and becomes a negative electrode and contacts the internal positive electrode plate 11A to cause a short circuit. When a small amount of is inserted into the collector foil 11a, its tip first contacts the current collector foil 11a before contacting the positive electrode active material 11b, so that most of the current is short-circuited in the current collector foil 11a. Flow into the positive electrode active material 11b,
The temperature rise of LiCoO ₂ is suppressed.

Therefore, even if the charging state is short-circuited, L
Generation of oxygen accompanying temperature rise of iCoO ₂ and reaction of aluminum (positive electrode side current collector foil) and organic solvent (electrolyte solvent) due to this oxygen are suppressed, so that large energy is prevented from being generated inside the battery, The safety of the battery is ensured. FIG. 2 is a cross-sectional view showing a cylindrical non-aqueous battery having a wound electrode plate laminate, which corresponds to the second embodiment of the present invention. In this example, instead of the electrode plate laminate 1A of the first embodiment, an electrode plate laminate 1B having a different structure is housed in the battery can 2.

In this electrode plate laminated body 1B, a positive electrode plate 11 in which a material containing LiCoO ₂ is applied as a positive electrode active material 11b on only one surface of a collector foil 11a made of aluminum.
And a negative electrode plate 12 in which a material containing carbon particles was applied as a negative electrode active material 12b on only one surface of a current collector foil 12a made of copper, and was arranged between the positive electrode active material 11b and the negative electrode active material 12b. Separator 1 similar to the separator 13A
3 and the insulating film 16 arranged between the positive and negative current collector foils 11a and 12a. The insulating film 16 is a polyethylene resin film (film thickness 12 μm) having neither ionic conductivity nor electronic conductivity.

In this electrode plate laminate 1B, the positive electrode side current collector foil 11a, the positive electrode active material 11b, the separator 13, the negative electrode active material 12b, the negative electrode side current collector foil 12a, and the insulating film 16 are laminated in this order. And the insulating film 16 is placed inside (that is, the positive electrode side current collector foil 11a is placed outside) and is wound into a spiral shape by a winding machine. At that time, only the insulating film 16 is formed into the electrode plate laminate 1B. It is wound around the outer peripheral surface by extending it by one and a half turns. The extended portion 16a of the insulating film 16 corresponds to the isolation film of the present invention, and the end surface portion A of the positive electrode plate 11 and the battery can 2 that constitute the electrode plate laminate 1B are the insulating film (isolation film) 16
Opposed via a.

As a result, the layer structure of the electrode laminate 1B is, from the battery can 2 side to the inside, the insulating film 16, the positive electrode side current collector foil 11a, the positive electrode active material 11b, the separator 13, and the like.
Negative electrode active material 12b, negative electrode side current collector foil 12a, insulating film 1
6 and the positive electrode side collector foil 11a ... In addition, in this electrode plate laminated body 1B, the positive electrode active material 11
Although a battery action occurs in the unit battery layer 5 formed by the positive electrode 11 and the negative electrode 12 in which b and the negative electrode active material 12b are arranged to face each other, and the separator 13 arranged therebetween, the insulating film 16 is interposed. No battery action occurs between the unit battery layers 5 (that is, between the positive and negative current collector foils 11a and 12a).

Therefore, when the battery is crushed in the stacking direction, generally, the stress applied to the innermost peripheral separator 13 and the insulating film 16 adjacent to the center pin 3 is the largest. The separator 13 and the insulating film 16 are broken, and the positive electrode active material 1
A short circuit occurs between 1b and the negative electrode active material 12b, but at the same time, a short circuit occurs between the positive and negative current collector foils 11a and 12a. As a result, most of the current flows in the current collector foils 11a and 12a even in the short-circuited portion, and the current that flows in the positive electrode active material 11b made of LiCoO ₂ decreases, so that the LiCo
The temperature rise of O ₂ is suppressed.

Therefore, even if the state of charge is short-circuited, L
Generation of oxygen accompanying temperature rise of iCoO ₂ and reaction of aluminum (positive electrode side current collector foil) and organic solvent (electrolyte solvent) due to this oxygen are suppressed, so that large energy is prevented from being generated inside the battery, The safety of the battery is ensured. In addition, at the time of a nail stab accident, the tip of the nail that became a negative electrode at the time of penetrating the battery can 2 has an insulating film 16, a collector foil 11a on the positive electrode side, a positive electrode active material 11b, a separator 13,
Negative electrode active material 12b, negative electrode side current collector foil 12a, insulating film 1
Since the positive electrode active material 11b and the negative electrode active material 12b are short-circuited via the nail because they come into contact with each other while penetrating in the order of 6 ..., As described above, substantially simultaneously with this, the positive and negative current collectors 11a. , 12a are also short-circuited. As a result, most of the current flows through the current collector foils 11a and 12a even at the short-circuited portion.
Generation of a large amount of energy inside the battery is suppressed, and the safety of the battery is ensured.

When the tip of the nail is slightly inserted, as in the case of the first embodiment, the nail is always brought into contact with the positive electrode side current collector 11a before coming into contact with the positive electrode active material 11b. Therefore, the short-circuit current hardly flows in the positive electrode active material 11b. As a result, the short-circuit current is safely internally discharged, so that the safety of the battery is ensured even in the case of a short-circuit in the charged state, as described above.

In addition, the end surface portion A of the positive electrode plate 11 and the battery can 2 which compose the electrode plate laminated body 1B are formed by the insulating film (isolation film) 1
Since they are opposed to each other through 6a, charging / discharging does not occur between the positive electrode active material 11b of the end face portion A and the battery can 2 which is the negative electrode. As a result, there is no risk that metallic lithium will be deposited on the battery can 2 during charging or that the battery can material will melt out during overdischarging.

FIG. 3 corresponds to a third embodiment of the present invention,
FIG. 3 is a vertical cross-sectional view showing a rectangular parallelepiped non-aqueous battery in which an electrode plate stack is a 99-fold type. Electrode plate laminate 1 in this example
C is on both surfaces of the collector foil 11a made of aluminum,
A positive electrode plate 11 coated with a material containing LiCoO ₂ as a positive electrode active material 11b, and two negative electrodes coated with a material containing carbon particles as a negative electrode active material 12b on only one surface of a current collector foil 12a made of copper. It is composed of plates 12A and 12B and separators 13A and 13B similar to those of the first embodiment, which are arranged between the positive electrode active material 11b and the negative electrode active material 12b.

This electrode plate laminated body 1C has a separator 13
A positive electrode plate 11 is sandwiched between the two negative electrode plates 12A and 12B via A and 13B to form a unit laminate (a layer structure includes a negative electrode side current collector foil 12a and a negative electrode active material 12).
b, the separator 13A, the positive electrode active material 11b, the positive electrode side current collector foil 11a, the separator 13B, the negative electrode active material 12b, the negative electrode side current collector foil 12a) in this order, and the unit laminate is formed into the width of the battery can 2. It is manufactured by arranging in parallel while folding back with a predetermined width according to.

At one end of the unit laminated body, the end faces of the positive electrode active material 11b and the negative electrode plates 12A and 12B are located inside the folded end position, and the positive electrode side collector foil 11 is provided from the end face.
a and the separators 13A and 13B are projected, and the tab 6a is fixed to the positive electrode side current collector foil 11a of this protruding portion.
Similarly, at the other end of the unit laminate, the end faces of the negative electrode active material 12b and the positive electrode plate 11 are set to the inside from the folded end position,
Two negative electrode side current collector foils 12a and separators 13A and 13B are projected from the end face, and tabs 6b are fixed to the negative electrode side current collector foils 12a at the protruding portions.

The electrode plate laminate 1C has a rectangular parallelepiped battery can in which the entire outer surface is covered with a separator film 4 made of a polyethylene resin film (thickness 12 μm) having neither ion conductivity nor electron conductivity. It is stored in 21. In this way, since the end surfaces A and B of the positive electrode plate 11 of the electrode plate laminate 1C and the battery can 21 face each other with the isolation film 4 interposed therebetween,
Charge and discharge do not occur between the positive electrode active material 11b of the end face portions A and B and the battery can 21 that is the negative electrode. As a result, there is no risk that metallic lithium will deposit on the battery can 21 during charging or that the battery can material will melt out during overdischarging.

FIG. 4 corresponds to a fourth embodiment of the present invention.
FIG. 3 is a vertical cross-sectional view showing a rectangular parallelepiped non-aqueous battery in which an electrode plate stack is a 99-fold type. Electrode plate laminate 1 in this example
D is a negative electrode side collector which is the outermost surface of the electrode plate laminated body 1C by extending and folding back the positive electrode side current collector foil 11a from both ends of the unit laminated body forming the electrode plate laminated body 1C of the third embodiment. The positive electrode side current collector foil exposed portion 17 is provided on the pair of outermost surfaces parallel to the folded surface of the unit laminate by being arranged on the entire outer surface of the current collector foil 12a. In addition, between the positive electrode side current collector foil 11a forming the positive electrode side current collector foil exposed portion 17 and the outermost negative electrode side current collector foil 12a, a separator which is folded back from both ends of the unit laminate body. 13A and 13B are respectively interposed.

This electrode plate laminated body 1D is housed in the battery can 21 through the same isolation film 4 as in the third embodiment. The tab 6a on the positive electrode side is fixed to the end of the positive electrode side current collector foil 11a forming the positive electrode side current collector foil exposed portion 17. Therefore, the end faces A and B of the positive electrode plate 11 of the electrode plate laminated body 1D and the battery can 21 are separated by the isolation film 4.
Since they are opposed to each other through, the charging / discharging does not occur between the positive electrode active material 11b of the end face portions A and B and the battery can 21 that is the negative electrode. As a result, there is no risk that metallic lithium will deposit on the battery can 21 during charging or that the battery can material will melt out during overdischarging.

Further, it intersects with the folded surface of the unit laminate.
Nail piercing with a small amount of nail tip inserted from the direction
In that case, the battery can 21 which is the negative electrode is penetrated to become the negative electrode.
The tip of the nail in contact with the positive electrode active material 11b.
First, the collector foil 11 forming the positive electrode side collector foil exposed portion 17
Since it contacts a, most of the current is a current collector even in the short-circuited part.
It flows to the foil 11a and almost to the positive electrode active material 11b.
Since there is no LiCoO ₂The temperature rise is suppressed. That
Therefore, even if the charging status is short-circuited,
The safety of the pond is secured.

FIG. 5 corresponds to a fifth embodiment of the present invention,
It is a longitudinal cross-sectional view showing a rectangular parallelepiped non-aqueous battery in which the electrode plate laminate is a simple laminate type. Electrode plate laminate 1E in this example
Is L on both sides of the current collector foil 11a made of aluminum.
a positive electrode plate 11 coated with a material containing iCoO ₂ as a positive electrode active material 11b, and a negative electrode plate 12 coated with a material containing carbon particles as a negative electrode active material 12b on both surfaces of a current collector foil 12a made of copper, Positive electrode active material 11b and negative electrode active material 1
2b and a separator 13 similar to that of the second embodiment.

In this electrode plate laminate 1E, the negative electrode plate 12, the positive electrode plate 11, and the separator 13 are arranged in the battery can 21 shown in FIG.
Are cut into rectangles of a predetermined size smaller than the upper and lower face plates in FIG. 1, and these are cut into a negative electrode plate 12, a separator 13, and a positive electrode plate 1.
1, the separator 13, the negative electrode plate 12, ... Are stacked in parallel in this order, and the negative electrode plate 12 is disposed on the outermost surfaces on both sides.

Further, a portion to which the positive electrode active material 11b is not applied is provided at the right end of each positive electrode plate 11 in FIG. 5, and the positive electrode side tab 6a is fixed to the positive electrode side current collector foil 11a at that portion. Similarly, a portion to which the negative electrode active material 12b is not applied is provided on the left end of each negative electrode plate 12 in FIG. 5, and the negative electrode side tab 6b is fixed to the negative electrode side current collector foil 12a at that portion.

The electrode plate laminate 1E has a rectangular parallelepiped battery can in which the entire outer surface is covered with a separator film 4 made of a polyethylene resin film (thickness 12 μm) having neither ion conductivity nor electron conductivity. It is stored in 21. Therefore, the end face portion A of each positive electrode plate 11 forming the electrode plate laminate 1E
~ L and the battery can 21 are opposed to each other via the isolation film 4, so that charging / discharging does not occur between the positive electrode active material 11b of the end face portions A to L and the battery can 21 as the negative electrode. As a result, metallic lithium is deposited on the battery can 21 during charging,
There is no fear that the battery can material will melt out when over-discharged.

FIG. 6 corresponds to a sixth embodiment of the present invention,
It is a longitudinal cross-sectional view showing a rectangular parallelepiped non-aqueous battery in which the electrode plate laminate is a simple laminate type. Electrode plate laminate 1F in this example
Is L on both sides of the current collector foil 11a made of aluminum.
The positive electrode plate 11C coated with a material containing iCoO ₂ as the positive electrode active material 11b, the positive electrode plate 11D coated with the positive electrode active material 11b on only one surface, and the carbon foil on both surfaces of the current collector foil 12a made of copper were coated with carbon particles. It is composed of a negative electrode plate 12 to which a material containing the same is applied as a negative electrode active material 12b, and a separator 13 similar to that of the second embodiment, which is arranged between the positive electrode active material 11b and the negative electrode active material 12b.

This electrode plate laminated body 1F has a positive electrode active material 11b on only one side, further outside each of the negative electrode plates 12 arranged on both outermost surfaces in the electrode plate laminated body 1E of the fifth embodiment.
The positive electrode plate 11D coated with is prepared by arranging the positive electrode active material 11b side toward the negative electrode plate 12 via the separator 13. The positive electrode plate 11D arranged on the outermost periphery forms the positive electrode side collector foil exposed portion 18.

Further, this electrode plate laminated body 1F is similar to that of the fifth embodiment in that the battery can 2 is provided with the same isolation film 4 interposed therebetween.
It is stored in 1. Also, the tabs 6a on the positive and negative electrodes,
6b is fixed to the ends of the positive and negative electrode side collector foils 11a and 12a in the same manner as in the fifth embodiment. Therefore, the end face portion A of each positive electrode plate 11 forming the electrode plate laminate 1F
To N and the battery can 21 face each other with the isolation film 4 interposed therebetween, charge and discharge do not occur between the positive electrode active material 11b of the end face portions A to N and the battery can 21 that is the negative electrode. As a result, metallic lithium is deposited on the battery can 21 during charging,
There is no fear that the battery can material will melt out when over-discharged.

Further, in the case of a nail puncture accident in which the tip of a nail or the like is slightly stabbed in from the vertical direction in FIG. 6, the tip of the nail penetrates the battery can 21, which is the negative electrode, and becomes the negative electrode. Before contacting the positive electrode active material 11b, first, the current collector foil 11a of the positive electrode plate 11D forming the positive electrode side current collector foil exposed portion 18 is contacted. Since it flows into 11a and hardly into the positive electrode active material 11b, the temperature rise of LiCoO ₂ can be suppressed. Therefore, even if it is a short circuit in the charging state, as described above,
The safety of the battery is ensured.

In the first embodiment, the isolation film 4 is connected to the end face of the separator 13B which constitutes the electrode plate laminate 1A. In the second embodiment, the isolation film 4 is attached to the electrode plate laminate. The extended portion 16a of the insulating film 16 that constitutes the body 1B is used. As described above, in each of the above embodiments, the electrode plate laminate is of the wound type, and in each case, the separator 4 is continuous with the electrode plate laminates 1A and 1B. Even in the case of the spiral type, the isolation film 4 may be separated from the electrode plate laminated bodies 1A and 1B like the multiplication table of the third and subsequent embodiments.

Even in the ninety-nine folding type or the like after the third embodiment, the isolation film 4 is connected to the end faces of the separators 13, 13A and 13B constituting the electrode plate laminates 1C to 1F. It may be a structure. Furthermore, in the 99-fold fold and the like after the third embodiment, it is not necessary to dispose the isolation film 4 so as to cover the entire electrode plate laminated bodies 1C to 1F.
It may be arranged at least on the side facing the end faces of the electrode plate laminates 1C to 1F (on the left and right inner face sides of the battery can 21 in each drawing).

Further, in each of the above-mentioned embodiments, the lithium ion secondary battery has been described, but the durability of the battery can can be secured in the same manner for other non-aqueous secondary batteries or non-aqueous primary batteries. You can

[0062]

As described above, according to the batteries of claims 1 to 4, since charging and discharging do not occur between the positive electrode active material forming the electrode plate laminate and the battery can as the negative electrode, the lithium battery Even in the case of the secondary battery, the durability of the battery can can be ensured without the risk of metal lithium being deposited on the battery can during charging or the material of the battery can starting to melt during overdischarging. Further, in the case of a battery provided with an electrode plate laminate having no exposed portion of the positive electrode side current collector foil, the negative electrode plate can be made to have the same length as the positive electrode plate, thus suppressing deterioration of cycleability. be able to.

Particularly, in the second to fourth aspects, since the structure of the electrode plate laminate is limited, the positive electrode active material and the negative electrode can be separated from each other by abnormal heating from the outside, crushing in the stacking direction of the battery, or piercing with a nail. Even if a short circuit occurs, the temperature rise of the positive electrode active material can be suppressed, so that even if a short circuit occurs in the charged state when the battery is a lithium ion secondary battery, a large amount of energy is generated inside the battery. It is suppressed and the safety of the battery is secured.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a cylindrical non-aqueous battery having a wound electrode plate laminate, which corresponds to the first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a cylindrical non-aqueous battery having a wound electrode plate laminate, which corresponds to the second embodiment of the present invention.

FIG. 3 is a schematic vertical cross-sectional view showing a rectangular parallelepiped non-aqueous battery in which an electrode plate laminated body is a 99-fold type, corresponding to a third embodiment of the present invention.

FIG. 4 is a schematic vertical cross-sectional view showing a rectangular parallelepiped non-aqueous battery corresponding to a fourth embodiment of the present invention, in which the electrode plate laminated body is a 99-fold type.

FIG. 5 is a schematic vertical cross-sectional view showing a rectangular parallelepiped nonaqueous battery in which an electrode plate laminate is a simple laminate type, which corresponds to a fifth embodiment of the present invention.

FIG. 6 is a schematic vertical cross-sectional view showing a rectangular parallelepiped nonaqueous battery in which an electrode plate laminate is a simple laminate type, which corresponds to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode plate laminated body 2 Battery can 3 Center pin 4 Isolation film 5 Unit battery layer 6a tab 6b tab 11, 11A to 11D Positive electrode plate 11a Positive electrode side current collector foil 11b Positive electrode active material 12, 12A, 12B Negative electrode plate 12a Negative electrode Side current collector foil 12b Negative electrode active material 13 Separator 13A Separator 13B Separator 15 Positive electrode side current collector exposed part 16 Insulating film 16a Insulating film extension part (isolation film) 17 Positive electrode side current collector exposed part 18 Positive electrode side current collector Body exposed part 21 Battery can

Claims (4)

[Claims] 1. An electrode plate laminate in which a positive electrode plate having a collector foil coated with a positive electrode active material, a negative electrode plate having a collector foil coated with a negative electrode active material, and a separator are stacked. A battery provided in a battery can that serves as a negative electrode, wherein a separator having neither an ionic conduction function nor an electron conduction function is interposed between the electrode plate laminate and the battery can. 2. The solvent of the electrolyte is an aprotic liquid, and the electrode plate laminate has a positive electrode active material, a positive electrode side current collector foil, a positive electrode active material, a separator, a negative electrode active material, and a negative electrode side current collector foil. A negative electrode active material, a separator, and a positive electrode active material are laminated in this order, and the positive electrode side current collector foil exposed portion to which the positive electrode active material is not deposited is provided on the outer surface of the electrode laminate. The battery according to item 1. 3. The electrolyte solvent is an aprotic liquid, and the electrode plate laminate has a positive electrode plate having a positive electrode active material deposited on only one surface of a current collector foil, and only one surface of the current collector foil. A negative electrode plate on which the negative electrode active material is adhered, the active material adhered surfaces of both of them are arranged to face each other, and a unit battery layer is formed by stacking them with a separator interposed therebetween, and the unit battery layers are The battery according to claim 1, wherein the battery is laminated with an insulating film having no electron conduction function interposed therebetween. 4. The battery according to claim 3, wherein the electrode plate laminate is formed by laminating unit battery layers so that the positive electrode plate side faces the battery can side.