JPH08153542A - Nonaqueous battery - Google Patents

Abstract

PURPOSE: To prevent the abrupt temperature rising of a battery and enhance safety by making a positive electrode equipotential exposed metal part and a negative electrode equipotential exposed metal part in which an active material layer is not formed in opposite to each other over the length of one round or more. CONSTITUTION: A positive electrode 3 constituting a wound and laminated positive electrode assembly has a part in which a positive electrode active material layer 2 is formed in the surface of positive electrode metal foil 1 and an equipotential exposed metal part in which the layer 2 is not formed. Similarly, a negative electrode 6 has a part in which a negative electrode active material layer 5 is formed in the surface of negative electrode metal foil 4 and an equipotential exposed metal part in which the layer 5 is not formed. The equipotential exposed metal parts of the positive electrode 3 and the negative electrode 6 are positioned in opposite to each other through a separator 7 over the length of one round or more. Thereby, even in the unusual situation, the abrupt temperature rising of a battery can be prevented by the internal short-circuiting between the metals having a small electric resistance.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel non-aqueous battery. More specifically, (1) a casing, (2) a non-aqueous electrolyte contained in a space defined by the inner wall of the casing, and (3) a non-aqueous electrolyte contained in the space so as to be capable of cooperating with the non-aqueous electrolyte. A non-aqueous battery comprising a wound laminated electrode assembly, the positive electrode active material layer-containing positive electrode constituting the wound laminated electrode assembly (3),
A negative electrode active material layer-containing negative electrode and a separator are wound and laminated so that the positive electrode active material layer and the negative electrode active material layer face each other with the separator interposed therebetween, and the battery is provided in association with the positive electrode. A positive electrode or the like that has a metal part that is equipotential to the positive electrode, and that the positive electrode equipotential metal part has a part in which the positive electrode active material layer is not formed on at least one side thereof, so that the positive electrode extends in the longitudinal direction over one or more rounds Forming a potential exposed metal portion (α), and the positive electrode equipotential exposed metal portion (α) and the negative electrode equipotential exposed metal portion (β) provided in association with the negative electrode extend over one or more turns The present invention relates to a non-aqueous battery configured to face each other. Further, the present invention also relates to a non-aqueous battery in which, in place of the above-mentioned wound laminated electrode assembly, a simple laminated electrode assembly or a serpentine laminated electrode assembly having substantially the same configuration as that is housed in a casing. Due to the unique structure as described above, the casing is crushed by pressure from the outside, overcharged due to an abnormality in the charging circuit, pierced by a nail, or abnormally heated from the outside. It is possible to provide a non-aqueous battery capable of ensuring safety by suppressing a rapid temperature rise of a battery by short-circuiting metals having sufficiently low electric resistance even in an unexpected abnormal situation. .

[0002]

2. Description of the Related Art Conventionally, in a lithium-ion secondary battery using a non-aqueous electrolyte, generally, an aluminum foil is coated with a lithium composite oxide as a positive electrode active material to form a positive electrode, and a copper foil is coated with a carbonaceous material. An electrode assembly formed by applying a negative electrode active material to form a negative electrode, interposing a separator made of a polyethylene microporous film or the like between the obtained sheet-shaped electrodes, and winding and laminating these separators is an external electrode. It is stored in a stainless steel can (for example, an external negative electrode).
Regarding the lithium ion secondary battery using the non-aqueous electrolyte solution as described above, for example, Japanese Patent Application Laid-Open No. 2-51875.
And Japanese Patent Laid-Open No. 5-234620.

This lithium ion secondary battery has a high capacity,
Due to its characteristics such as high voltage and high output, a temperature fuse and a current fuse are provided to prevent the temperature rise of the battery in the event of an abnormality such as a short circuit between the positive electrode and the negative electrode of the battery due to a circuit abnormality, etc. Various protection means such as fuses and PTC elements are provided, and a safety valve is provided to prevent an increase in internal pressure of the battery.

[0004]

However, in addition to the short circuit between the positive electrode and the negative electrode of the battery due to a circuit abnormality or the like, various abnormal situations are expected. For example, in an unexpected situation where the battery is crushed by pressure from the outside or overcharged due to an abnormality in the charging circuit, the separator between the positive electrode and the negative electrode breaks or melts, and the positive electrode and the negative electrode. And are short-circuited in the battery. Further, for example, in an unexpected situation where a conductor such as a nail sticks into the casing, the nail that is integrally conducted with the negative electrode is short-circuited between the positive electrode and the battery in the battery by penetrating the casing that is the negative electrode. In the case of abnormal heating from the outside, the separator disposed between the positive electrode and the negative electrode is melted earlier than the metal of the positive electrode and the negative electrode, and similarly, the positive electrode active material and the negative electrode active material inside the battery. Will result in a short circuit. At this time, although there is no problem if the battery is not charged, the characteristics of the lithium ion secondary battery such as high capacity and high voltage in the charged state, on the contrary, from the viewpoint of maintaining safety, It becomes a negative factor compared to the battery of. That is, in the lithium ion secondary battery, the positive electrode active material is LiCoO 2.
It is composed of a composite oxide of lithium and a transition metal such as 2 or lithium, a transition metal and a non-transition metal.Since such an active material is a metal oxide, the resistance value is relatively high,
The temperature of the battery itself tends to rise due to the passage of a short-circuit current, and the positive electrode active material during charging is in an unstable state in which lithium has ionized and escaped to some extent. There is a risk that a large amount of oxygen will be generated, and this oxygen will react violently with the aluminum foil coated with the positive electrode active material and the organic solvent to cause a rapid temperature rise.

Therefore, even when the battery is crushed or overcharged by the pressure from the outside, the conductor such as a nail is stuck in the casing, or the casing is abnormally heated from the outside, the positive electrode It has been desired to develop a non-aqueous battery that makes it difficult to cause a short circuit between the active material and the negative electrode, or suppresses the temperature rise of the positive electrode active material due to the short circuit even when the short circuit occurs to ensure safety.

The present inventor has conducted extensive studies to solve the above problems and develop a safe non-aqueous battery. As a result, (1) the casing, (2) the non-aqueous electrolyte contained in the space defined by the inner wall of the casing, and (3) the winding accommodated in the space so as to cooperate with the non-aqueous electrolyte. A positive electrode active material layer-containing positive electrode, a negative electrode active material layer-containing negative electrode and a separator which are composed of a laminated electrode assembly and constitute the wound laminated electrode assembly (3), and the positive electrode active material layer and the negative electrode active material layer are the separators. In a non-aqueous battery that is wound and laminated so as to be opposed to each other with a metal part having a potential equal to that of the positive electrode provided in association with the positive electrode, the positive potential equipotential metal part being at least The positive electrode equipotential exposed metal portion extending in the longitudinal direction over one or more rounds is formed by having a portion where the positive electrode active material layer is not formed on one side thereof. If the minute portion is configured to face the negative electrode equipotential exposed metal portion provided in association with the negative electrode for a length of one round or more, the casing is crushed at one time by the pressure from the outside, and the Even if the separator between the positive electrode and the negative electrode breaks almost at the same time, if the positive electrode equipotential exposed metal part having no positive electrode active material layer and the negative electrode equipotential metal exposed part are short-circuited, the short-circuited part will be Since the metal and the negative electrode are short-circuited to each other with a resistance value sufficiently smaller than that of the negative electrode, the short-circuit current does not have the positive electrode active material layer due to the proportional distribution of the current depending on the resistance value of the short-circuited portion. As the current flows through the short circuit between the equipotential exposed metal part and the negative electrode equipotential exposed metal part, the positive electrode active material is hardly energized and the battery is safely short-circuited internally, resulting in rapid heat generation and a rapid temperature rise accompanying it. Surprisingly was also found that no risk.

Also in a non-aqueous battery in which a simple laminated electrode assembly or a zigzag folded laminated electrode assembly is housed in a casing, a positive electrode equipotential-exposing metal portion, a negative electrode, etc. are formed by the same structure as in the above-mentioned wound laminated electrode assembly. It was found that the same effect can be obtained by forming the potential exposed metal portion. The present invention has been completed based on these findings.

That is, an object of the present invention is to provide an abnormal situation in which a battery is crushed by an external pressure, overcharged, or a casing is pierced by a conductor such as a nail or abnormally heated from the outside. Even if it becomes, by the completely new idea of short-circuiting between the two metals of the positive electrode equipotential exposed metal part and the negative electrode equipotential exposed metal part,
An object of the present invention is to provide a non-aqueous battery which is excellent in safety and does not cause a sudden heat generation and a rapid temperature rise accompanying it.

[0009]

The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description and claims taken with reference to the accompanying drawings. According to one aspect of the present invention, (1)
A casing, (2) a non-aqueous electrolyte contained in a space defined by the inner wall of the casing, and (3) a wound laminated electrode assembly housed in the space so as to cooperate with the non-aqueous electrolyte. A wound type electrode assembly (3) for use in a water-based battery, comprising a positive electrode active material layer (b) formed on at least one surface of a positive electrode metal foil (a) functioning as a positive electrode current collector. A negative electrode including a material layer, and a separator interposed between the positive electrode and the negative electrode, the positive electrode, the negative electrode and the separator, such that the positive electrode active material layer and the negative electrode active material layer face each other through the separator. The battery is wound and laminated, and the battery has a metal part that is equipotential to the positive electrode provided in association with the positive electrode, and the positive electrode equipotential metal part has a positive electrode active material layer formed on at least one side thereof. Not part By forming a minute portion, a positive electrode equipotentially exposed metal portion (α) extending in the longitudinal direction over one or more rounds is formed, and the positive electrode equipotentially exposed metal portion (α) is provided in association with the negative electrode. There is provided a non-aqueous battery characterized in that the non-aqueous battery is located so as to face the negative electrode equipotential exposed metal portion (β) for a length of at least one circumference.

Next, the non-aqueous battery of the present invention will be described in detail. As described above, in one aspect of the non-aqueous battery of the present invention, (1) the casing, (2) the non-aqueous electrolyte contained in the space defined by the inner wall of the casing, and (3) the above. The wound laminated electrode assembly is housed in the space so as to cooperate with the non-aqueous electrolyte.
The wound laminated electrode assembly (3) comprises a positive electrode active material layer (a-2) formed on at least one surface of a positive electrode metal foil (a-1) that functions as a positive electrode current collector, and a positive electrode and negative electrode active material layer. And a separator interposed between the positive electrode and the negative electrode. The positive electrode, the negative electrode, and the separator are wound and laminated so that the positive electrode active material layer and the negative electrode active material layer face each other with the separator interposed therebetween.

A feature of a non-aqueous battery having a wound laminated electrode assembly according to one aspect of the present invention is that it has a metal part equipotential to the positive electrode provided in association with the positive electrode. The part has a positive electrode active material layer on at least one side thereof to form a positive electrode equipotential exposed metal part (α) extending in the longitudinal direction over a length of at least one circumference, and the positive electrode equipotential The exposed metal portion (α) is arranged so as to face the negative electrode equipotential exposed metal portion (β) provided in association with the negative electrode for a length of one or more turns.

In the present invention, the negative electrode comprises a negative electrode metal foil (b-1) functioning as a negative electrode current collector and a negative electrode active material layer (b-2) formed on at least one surface thereof, or A negative electrode active material metal foil (b-3) that functions as both a negative electrode active material layer and a negative electrode current collector, and optionally the negative electrode active material metal foil (b-3) is bonded to at least one surface thereof with electrical connection. Negative electrode current collector metal foil (b-
4) is preferred.

In the present invention, the negative electrode equipotential exposed metal portion (β) does not have the negative electrode active material layer (b-2) on at least one surface of the negative electrode metal foil (b-1). ), The exposed metal part (d) on at least one surface of the negative electrode active material metal foil (b-3), and the negative electrode active material metal foil as a negative electrode active material layer on at least one surface of the negative electrode current collector metal foil (b-4). An exposed metal portion (e) having no (b-3),
And negative electrode metal foil (b-1), negative electrode active material metal foil (b-
3) or at least 1 selected from a metal extension portion (f) extending in electrical connection from at least one of the inner peripheral edge portion and the outer peripheral edge portion of the negative electrode current collector metal foil (b-4).
Preferably it is one part.

Further, in the present invention, the positive electrode equipotential exposed metal portion (α) is at least one surface of the positive electrode metal foil (a-1) and the positive electrode active material layer (a-
2) having no exposed metal part (g), and at least one part selected from a metal extension part (h) extending from the outer peripheral end of the positive electrode metal foil (a-1) by being electrically joined. Preferably there is.

With such a structure, for example, when a conductor such as a nail penetrates from the outside through the casing which is made into the negative electrode, the conductor which is integrally conducted with the metal casing of the negative electrode is penetrated through the separator. When a short circuit occurs in a low resistance state with a positive electrode equipotential exposed metal portion having no positive electrode active material layer, and when the battery is abnormally heated from the outside, the separator on the outer peripheral side closest to the casing is more than the separator on the inner peripheral side. The positive electrode active material is almost not energized due to short-circuiting between the metal casing that has been melted earlier and exposed to the positive electrode equipotential exposure and the metal casing in a low resistance state. Internal short circuit to. This positive electrode equipotential exposed metal portion, for example, when formed on the outer peripheral side end portion of the positive electrode metal foil, facing the positive electrode equipotential exposed metal portion via the separator is not limited to the negative electrode casing,
For example, it may be the exposed metal portion of the negative electrode metal foil. or,
The casing may be a positive electrode as well as a negative electrode.

The inner wall of the casing has a positive electrode equipotential exposed metal portion (α) or a negative electrode equipotential exposed metal portion (β).
Can be. Further, the casing may be made of plastic that is neither the positive electrode nor the negative electrode, in which case the plastic casing may be provided with external electrodes. In the present invention, the positive electrode equipotentially exposed metal portion (α) is on at least one surface of the positive electrode metal foil (a-1) and does not have the positive electrode active material layer (a-2) at the inner peripheral end thereof. It is preferably at least one portion selected from the exposed metal portion (g) and the metal extension portion (h) which is electrically joined and extends from the inner peripheral end portion of the positive electrode metal foil (a-1). With such a structure, when the battery is crushed slowly by the pressure from the outside, the inner peripheral part of the wound electrode assembly has a smaller radius of curvature than the outer peripheral part, and As for the applied pressure, the force applied per unit area is larger on the inner peripheral side than on the outer peripheral side, so that the separator located on the inner peripheral side is likely to break earlier than the other portions. Therefore, the positive electrode equipotentially exposed metal portion (α) having no positive electrode active material layer and the negative electrode equipotentially exposed metal portion (β) are short-circuited quickly and surely with low resistance, and then the positive electrode active material layer and negative electrode with high resistance are formed. If a short circuit occurs, the short-circuit current does not flow there, the temperature rise of the positive electrode active material is suppressed, and the battery is safely short-circuited internally.

In the battery of the present invention, the upper limit of the number of windings of the positive electrode equipotentially exposed metal portion (α) facing the negative electrode equipotentially exposed metal portion (β) is so large that it can be housed in the casing. Although it has an effect of improving safety, it is preferably 1 to 10 laps, and more preferably 2 to 4 laps, because if it is too large, the charge and discharge capacity of the battery is lowered.

Further, the positive electrode equipotential metal portion (α) is
It is preferable to have a portion where the positive electrode active material layer is not formed on both sides thereof over one or more turns. By doing so, when the battery is crushed by the pressure from the outside at a time and the separator is broken at multiple points between the positive electrode and the negative electrode almost at the same time, or when a sharp conductor such as a nail penetrates the current collector foil. In addition, a more reliable low resistance contact state between metals can be obtained.

Further, in the present invention, the positive electrode equipotentially exposed metal portion (α) is provided with an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to the positive electrode at equipotential. Is also good. With this configuration, when the battery is overcharged due to an abnormality in the charging circuit or the like, a large amount of current flows to the electrode tabs, causing the temperature near the electrode tabs to become higher than that of other parts, so that the electrode tabs are not arranged. The separator for the positive electrode equipotentially exposed metal portion (α) is melted before the other portion, and the positive electrode equipotentially exposed metal portion (α) is formed.
Is short-circuited to the negative electrode equipotentially exposed metal part (β) with low resistance, and the battery is safely short-circuited internally without causing abnormal temperature rise of the battery due to thermal decomposition of the positive electrode active material.

However, an external electrode [positive electrode equipotential exposed metal portion (α)] and negative electrode equipotential exposed metal portion (such as a positive electrode casing) which are connected to the positive electrode at equipotential through welding of an electrode tab having a slight resistance ( When β) is short-circuited, a sufficiently low resistance short circuit can be obtained as compared with the case where the positive electrode equipotential exposed metal part (α) is the exposed metal part (g) and / or the metal extension part (h). It's hard to get caught.

Further, in the present invention, the negative electrode equipotential exposed metal portion (α) is provided with an electrode tab for connecting an outer electrode located outside the wound laminated electrode assembly to the negative electrode at the same potential. Good. With this configuration, when the battery is overcharged due to an abnormality in the charging circuit or the like, a large amount of current flows into the electrode tab, the temperature in the vicinity of the electrode tab becomes higher than that in other parts, and the electrode tab is The separator corresponding to the negative electrode equipotentially exposed metal portion (β) melts before the other portion, and the negative electrode equipotentially exposed metal portion (β) has a low resistance with the positive electrode equipotentially exposed metal portion (α). The battery is safely short-circuited internally without causing an abnormal rise in battery temperature due to thermal decomposition of the positive electrode active material.

However, an external electrode [a positive electrode equipotential exposed metal portion (β)] and a positive electrode equipotential exposed metal portion (such as a negative electrode casing) which are connected to the negative electrode at an equipotential through welding of an electrode tab having a slight resistance ( When α) is short-circuited, it is sufficiently low as compared with the case where the negative electrode equipotential exposed metal portion (β) is the exposed metal portions (c) to (e) and / or the metal extension portion (f). It becomes difficult to obtain a resistance short circuit.

The electrically extending metal extension is, for example, a metal of the same material as the positive electrode or negative electrode current collector metal foil, and has substantially the same width as the current collector foil. A metal foil having a thickness of 5 to 20 times as thick as the body metal foil is exposed to the exposed metal portion of the inner and / or outer end portions of the current collector metal foil, by a method such as welding, with low resistance, electrically and mechanically. It is connected. The metal material of the metal extension may be different from the material of the current collector metal foil, in which case a material that can be easily welded to the current collector metal foil is selected.

With respect to the current collector metal foil, usually, the minimum necessary electric conductivity that can function as a current collector is used in order to effectively utilize the limited volume in the casing to increase the battery capacity. It is desirable to use a metal foil having a film thickness as thin as possible within the range where the mechanical strength can be maintained. For example, in a small battery, a foil having a thickness of 10 to 20 μm is generally used. As for the exposed metal portion, in order to achieve a sufficiently low short-circuit resistance, it is preferable that the exposed metal portion is a metal foil having a relatively large film thickness. Considering the ease of handling, a metal foil having a film thickness of 50 to 200 μm is used. It is desirable that the exposed metal portion of the outer and / or inner end of the current collector metal foil is electrically and mechanically connected with low resistance by welding or the like.

The electrode tab is for electrically connecting the positive electrode and / or the negative electrode of the wound layered electrode assembly and the external electrode provided on the casing, and usually, in a small battery, the width is 3 to 5 mm. And a sheet-like metal having a thickness of 100 to 200 μm, and a positive electrode equipotentially exposed metal portion (α)
And / or resistance welding or ultrasonic welding to the negative electrode equipotential exposed metal portion (β).

As the material of the electrode tab, the same metal as the current collector of the positive electrode and the negative electrode can be used. As the positive electrode tab, aluminum, titanium, nickel and stainless steel can be used, and as the negative electrode tab, Copper, nickel, stainless steel, etc. can be used. The separator is not particularly limited, and a known battery separator can be used.

However, it is preferable that the separator comprises a first separator portion (S1) and a second separator portion (S2) as described below. The first separator portion (S1) is located in at least one first region where the positive electrode active material layer of the positive electrode and the negative electrode active material layer of the negative electrode face each other, and the second separator portion (S2) is the positive electrode active material layer or the like. The potential exposed metal portion (α) and the negative electrode equipotential exposed metal portion (β) are located in at least one second region facing each other, and the first separator portion (S1) is an ion permeable separator. The second separator portion (S2) is made of a material, and is made of a separator material selected from an ion-insulating separator material and an ion-permeable separator material.

The ion-permeable separator material is not particularly limited, and woven cloth, non-woven cloth, glass woven cloth, synthetic resin microporous film, etc. can be used. When a thin film or large area electrode is used, for example, A synthetic resin microporous membrane disclosed in JP-A-58-59072, particularly US Pat. No. 5,051,
Polyolefin microporous membranes disclosed in Japanese Patent No. 183 and the like are preferable in terms of thickness, strength and membrane resistance.

Further, in the present invention, it is preferable that the second separator portion is formed of an ion insulating separator material. That is, since the separator disposed between the positive electrode equipotentially exposed metal portion (α) and the negative electrode equipotentially exposed metal portion (β) does not cause a battery action at that position, the separator does not have ion permeability. Can be used.

The ion-insulating separator material is not particularly limited as long as it has no electron conductivity and high resistance to an organic solvent, and the materials exemplified as the above-mentioned ion-permeable separator material can also be used. That is, a woven cloth, a non-woven cloth, a glass woven cloth, a synthetic resin microporous film or the like can be used. When a thin film or a large area electrode is used, for example, the synthetic resin disclosed in JP-A-58-59072 is used. A microporous membrane, particularly a polyolefin microporous membrane disclosed in US Pat. No. 5,051,183, etc. is preferably used in terms of thickness, strength and membrane resistance, but it is not necessary to be a microporous membrane.

This ion-insulating separator material is not only cheaper than the ion-permeable separator material, but also has high strength, so that the required strength can be maintained even if the film thickness is extremely thin. In this case, the total stacking length of the stacked electrode assemblies housed in the same size casing can be increased. Further, in the present invention, the melting point of the second separator portion is 100 ° C. or higher, generally 100 to 200 ° C., and at least 5 ° C. higher than the melting point of the first separator portion, and generally 5 to 5. It is preferably 150 ° C., low.

In this case, the positive electrode equipotential exposed metal portion (α)
And the negative electrode equipotential exposed metal portion (β) are located in at least one second region where the positive electrode active material layer and the negative electrode active material layer are opposed to each other. Since the melting point is lower than that of the first separator portion located in one of the first regions, when the temperature inside the battery becomes high, the second separator portion having a lower melting point than the first separator portion comes first. It becomes easier to melt, and the positive electrode equipotential exposed metal portion (α) and the negative electrode equipotential exposed metal portion (β) are more reliably short-circuited.

The melting point of the separator of the second separator portion is the operating temperature range (-20 to 1) of a normal non-aqueous electrolyte battery.
It is preferable that the temperature is higher than 00 ° C) and is significantly lower than the melting point (120 ° C to 250 ° C) of the separator of the second separator portion. When the difference between the melting point of the second separator portion and the melting point of the first separator portion is smaller than 5 ° C., there is a problem that the first separator may be melted first due to the temperature distribution normally existing in the casing, On the other hand, if the difference is larger than 150 ° C., there is a problem in that it may melt within the operating temperature range.

Examples of the separator material used for the second separator portion include polyethylene film and polypropylene film. Further, in the present invention, a core formed of a rigid body or an elastic body is inserted into a winding center of the wound laminated electrode assembly, and when the casing receives a compressive force, the wound laminated electrode assembly is formed into a casing. It is preferably designed to be compressed between itself and the core.

With such a structure, the insulating film separator is more easily broken from the center side of the electrode assembly when an external force is applied to the casing. Examples of the positive electrode metal foil that can be used in the battery of the present invention include a thickness of 5 to 1
Examples include metal foils of aluminum, titanium, stainless steel and the like having a thickness of 00 μm. Aluminum is preferable, and the thickness is 8 to 50 μm, and more preferably 10 to 30 μm.
m is used. Further, the thickness of the positive electrode active material layer formed on at least one side surface of the positive electrode metal foil, per one side,
Preferably 30-300 μm, more preferably 70-1
It is 30 μm.

Examples of the negative electrode metal foil include metal foils such as copper, nickel and stainless steel. Copper and stainless steel are preferable, and the thickness is 6 to 50 μm.
m, more preferably 8 to 25 μm.
The thickness of the negative electrode active material layer formed on at least one side surface of the negative electrode metal foil is preferably 30 to 300 per one side.
μm, more preferably 70 to 130 μm.

The above-mentioned positive and negative electrode metal foils may be in the shape of expanded metal, punched metal, foam metal or the like, or carbon cloth or carbon paper as a metal equivalent may be used. In the present invention, as the positive electrode active material, alkali metals such as Li, Na and Ca and transition metals such as Co, Ni, Mn and Fe,
Alternatively, a composite metal oxide of an alkali metal, a transition metal, and a non-transition metal can be used.

As an example of the complex metal oxide, Li ions are electrochemically intercalated (inte).
and r-composite metal oxides capable of deintercalation. Specific examples of the above-mentioned Li mixed metal oxide include Japanese Patent Laid-Open No. 55-13.
6,131 (corresponding US Pat. No. 4,357,215
No.) disclosed in Japanese Patent Application Laid-Open No. 3-
LixNiyCo (1 disclosed in Japanese Patent Publication No. 49,155)
-y) O 2, LixMnO 2, and the like.

To obtain such a compound, L such as lithium hydroxide, lithium oxide, lithium carbonate or lithium nitrate is used.
i-compound, metal oxide, metal hydroxide, metal carbonate,
It can be easily obtained by subjecting it to a calcination reaction with a metal nitrate or the like and, if desired, with another metal compound. Further, in the present invention, as the negative electrode active material, a carbonaceous material such as coke, graphite and amorphous carbon can be used, and the shape thereof is a crushed shape, a scale shape,
It may have any spherical shape. The carbonaceous material is not particularly limited, but for example, Japanese Patent Laid-Open No. 58-35,881 (corresponding US Pat.
No. 17,243), high surface area carbon materials, graphite, fired carbides such as phenolic resins described in JP-A-58-209,864, and JP-A-61-
111,907 (corresponding US Pat. No. 4,725,4
No. 22), the calcined carbides of condensed polycyclic hydrocarbon compounds, and the like. Alternatively, metallic lithium, composite oxide, or the like may be used as it is as the negative electrode.

The non-aqueous electrolyte is not particularly limited, but for example LiClO4, LiBF4, LiAsF6,
CF3SO3Li, (CF3SO2) 2N · Li, Li
PF6, LiI, LiAlCl4, NaClO4, Na
BF4, NaI, (n-Bu) 4N + ClO4, (n-
An electrolyte such as Bu) 4N + BF4 or KPF6 can be dissolved in an organic solvent and used as an organic electrolytic solution. The electrolyte concentration in the organic electrolytic solution is preferably about 0.1 to 2.5M. Also, a solid electrolyte can be used.

Examples of the organic solvent used include ethers, ketones, lactones, nitriles, amines, amides, sulfur compounds, chlorinated hydrocarbons, esters, carbonates, nitro compounds and phosphoric acid. Although ester compounds, sulfolane compounds, etc. can be used, among these, ethers, ketones, nitriles, chlorinated hydrocarbons, carbonates, sulfolane compounds are preferable. More preferred are cyclic carbonates. As typical examples of these, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, anisole, monoglyme, acetonitrile, propionitrile, 4-methyl-2-pentanone, butyronitrile, valeronitrile, benzonitrile, 1,2- Dichloroethane, γ-butyrolactone, dimethoxyethane, methyl formate, propylene carbonate, ethylene carbonate, vinylene carbonate, dimethylformamide, dimethylsulfoxide, dimethylthioformamide, sulfolane, 3-methyl-sulfolane, trimethyl phosphate, triethyl phosphate, and triethyl phosphate thereof. Examples of the mixed solvent include, but are not necessarily limited to, these.

The embodiment of the non-aqueous battery of the present invention having the wound laminated electrode assembly shown in FIGS. 1 to 8 has been described above. However, instead of the wound laminated electrode assembly,
Also in a non-aqueous battery using the simple laminated electrode assembly (FIGS. 9 to 10) or the zigzag folded laminated electrode assembly (FIGS. 11 to 12), a positive electrode equipotentially exposed metal portion, a negative electrode, etc. are formed by a configuration substantially similar to the above embodiment. By forming the potential-exposed metal portion, the same effect as in the case of the non-aqueous battery having the wound laminated electrode assembly can be exhibited.

That is, according to another aspect of the present invention,
(1 ') casing, (2') non-aqueous electrolyte contained in the space defined by the inner wall of the casing, and (3 ') simple laminate accommodated in the space so as to cooperate with the non-aqueous electrolyte. A non-aqueous battery including an electrode assembly, wherein the simple laminated electrode assembly (3 ') is a positive electrode having a plurality of layers electrically connected to each other, and each positive electrode functions as a positive electrode current collector. A positive electrode comprising a positive electrode active material layer (a'-2) formed on at least one surface of (a'-1), and a plurality of negative electrodes electrically connected to each other, each negative electrode being a negative electrode active material layer. A negative electrode comprising, and a separator of a plurality of layers, each separator consisting of a separator interposed between each positive electrode and each negative electrode, each positive electrode, each negative electrode and each separator, the positive electrode active material layer And the negative electrode active material layer is the separator. Are simply laminated so as to face each other with the positive electrode equipotential metal part provided in association with the positive electrode, the positive electrode equipotential metal part being provided on at least one side of the positive electrode. The positive electrode equipotentially exposed metal portion (α ′) is formed over one or more layers by having a portion where the active material layer is not formed, and the positive electrode equipotentially exposed metal portion (α ′) is the negative electrode. There is provided a non-aqueous battery, wherein the non-aqueous battery is located so as to face the negative electrode equipotentially exposed metal portion (β ′) provided in association with at least one layer over a length of at least one layer.

According to yet another aspect of the present invention, (1 ") the casing, (2") the non-aqueous electrolyte contained in the space defined by the inner wall of the casing, and (3 "). What is claimed is: 1. A non-aqueous battery comprising a serpentine laminated electrode assembly housed in the space so as to cooperate with the non-aqueous electrolyte, wherein the serpentine laminated electrode assembly (3 ") is a positive electrode metal foil that functions as a positive electrode current collector. The positive electrode active material layer (a ″ −) on at least one surface of (a ″ −1)
2) forming a positive electrode, a negative electrode including a negative electrode active material layer, and a separator interposed between the positive electrode and the negative electrode,
The positive electrode, the negative electrode, and the separator are folded and laminated so that the positive electrode active material layer and the negative electrode active material layer face each other with the separator interposed therebetween, and the battery has a positive electrode provided in association with the positive electrode. Since the positive electrode equipotential metal part has a metal part having an equipotential, and the positive electrode equipotential metal part has at least one side on which the positive electrode active material layer is not formed, the positive electrode equipotential exposed metal part (α )),
The positive electrode equipotentially exposed metal portion (α ″) is positioned to face the negative electrode equipotentially exposed metal portion (β ″) provided in association with the negative electrode for one or more layers, A non-aqueous battery is provided.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below with reference to embodiments, but these do not limit the scope of the present invention.

[0046]

EXAMPLE FIG. 1 is a schematic cross-sectional view (a casing is not shown) showing one embodiment of the non-aqueous battery of the present invention. This non-aqueous battery is a positive electrode metal foil (aluminum foil)
1, a positive electrode 3 having a positive electrode active material layer 2 formed on both surfaces thereof, a negative electrode 6 having a negative electrode active material layer 5 made of a carbonaceous material formed on both surfaces of a negative electrode metal foil (copper foil) 4, and the positive electrode 3 and a separator 7 made of a polyethylene microporous film or the like interposed between the negative electrode 6 and the negative electrode 6, and the wound laminated electrode assembly. Reference numeral 13 is a pipe-shaped core made of stainless steel or the like. This core has the function of a flow path that guides the gas toward the safety valve when the internal pressure of the casing rises, and at the same time, when a compressive force is applied from the outside of the casing, the wound laminated electrode assembly is separated from the core and the casing. It has a function of urging compression with the inner wall.

In the non-aqueous battery of this embodiment, the positive electrode metal foil (aluminum foil) 1 does not have the positive electrode active material layers 2 on both sides and extends for more than about two turns from the inner peripheral end portion of the aluminum foil 1.
It is wound in the state of exposing. Similarly, the negative electrode metal foil (copper foil) 4 is wound in a state in which the copper foil 4 is exposed without having the negative electrode active material layers 5 on both surfaces for about one or more turns from the inner peripheral end portion thereof. . That is, at the inner peripheral end portion of the wound and laminated electrode assembly, the aluminum foil 1 and the copper foil 4 face each other with the separator 7 in between for at least one round, and the aluminum foil 1 and the aluminum foil 1 at the next round. The negative electrode active material layer 5 faces each other via the separator 7, and then the positive electrode active material layer 2 and the negative electrode active material layer 5 face each other via the separator 7.

As shown in FIG. 2, when the non-aqueous battery of this embodiment is applied with pressure from above and below, for example, the innermost separator 7 adjacent to the pipe-shaped core 13 receives the most stress in this battery. Since it is large, fractures occur successively from here in the outer peripheral direction. That is, first, the exposed portion of the aluminum foil 1 and the copper foil 4 in FIGS.
The exposed parts of the metal are short-circuited with low resistance. Even when the separators on the extension line in the direction in which pressure is applied break at substantially the same time, the short-circuit resistance value between metals having small resistance values such as A, B, F, G, H, and I is D , E,
Since the short-circuit resistance value between the positive electrode active material layer 2 and the negative electrode active material layer 5 having high resistance such as K and L is remarkably small, the short-circuit current can be short-circuited with low resistance A, B, F, G,
Most of the short-circuit currents flow through at least one of H and I, and only a short circuit occurs, and the currents flowing through the high-resistance short circuits D, E, K, and L are very small.
Therefore, the positive electrode metal foil (aluminum foil) 1 and the negative electrode metal foil (copper foil) are substantially interposed without the high resistance positive electrode active material layer 2.
Since 4 and 4 are short-circuited with low resistance, Joule heat is simply generated without causing an abnormal rise in the temperature of the battery due to thermal decomposition of the positive electrode active material and an internal short-circuit is generated.

Further, assuming a situation where there is not much time difference between the break position of the separator 7 and the inner circumference,
The position at which the positive electrode metal foil (aluminum foil) is exposed is not limited to the end portion on the inner peripheral side, and may be the end portion on the outer peripheral side or a midway portion. In addition, the exposed portion of the aluminum foil 1 and the portion where the negative electrode active material layer 5 is short-circuited, such as C and J, are
A current flows without passing through the positive electrode active material layer 2, and an internal short circuit occurs without an abnormal rise in the temperature of the battery due to thermal decomposition of the positive electrode active material. Therefore, the resistance value of the short circuit is a high resistance positive electrode active material layer 2 It cannot be said that it is low compared to the short circuit resistance value via
In particular, when the active materials are short-circuited at almost the same time, the effect is insufficient.

Reference numeral 10 is an electrode tab which is arranged in the exposed portion of the aluminum foil 1 and which connects the positive electrode 3 and the external electrode. By disposing this electrode tab 10 at a position facing the exposed portion of the copper foil 4 of the negative electrode 6 without interposing the positive electrode active material layer 2, when the battery is overcharged due to an abnormality in the charging circuit or the like, a large amount of Since a large current flows through the electrode tab 10, the temperature in the vicinity of the electrode tab 10 becomes higher than that in other portions. And
Separator 7 facing the place where the electrode tab 10 is arranged
Melts before other parts, the exposed part of the aluminum foil 1 of the positive electrode 3 short-circuits with the exposed part of the copper foil 4 of the negative electrode 6 with low resistance, and the temperature of the battery is abnormal due to thermal decomposition of the positive electrode active material. The battery safely shorts internally without causing a rise. Further, by forming a positive electrode equipotential exposed metal portion on the inner peripheral end portion of the aluminum foil 1 which is the positive electrode metal foil and disposing the electrode tab here, when the battery is overcharged, the positive electrode equipotential exposed metal portion is provided in the vicinity of the electrode tab 10. The heat generated is concentrated at the center of the wound laminated electrode assembly, and compared with the case where the exposed portion is formed except the inner peripheral end portion of the aluminum foil 1 and the electrode tab is arranged, the aluminum foil is more quickly and surely. The separator 7 corresponding to the exposed portion of 1 melts.

Although not shown in particular, an electrode tab for connecting the exposed portion of the aluminum foil 1 of the positive electrode 3 to the exposed portion of the copper foil 4 of the negative electrode 6 facing the exposed portion of the aluminum foil 1 is connected to the exposed portion of the copper foil 4. Even when installed, when the battery is overcharged due to an abnormality in the charging circuit, etc., a large amount of current flows into this electrode tab, causing the temperature near the electrode tab to become higher than that in other parts, and this electrode tab The opposing separator 7 is melted before the other separator portions, the exposed portion of the aluminum foil 1 of the positive electrode 3 and the exposed portion of the copper foil 4 of the negative electrode 6 are short-circuited with low resistance, and the positive electrode active material is thermally decomposed. The battery can be safely short-circuited internally without causing an abnormal rise in battery temperature.

In the above embodiment, the exposed portion of the positive electrode metal foil (aluminum foil) and the exposed portion of the negative electrode metal foil (copper foil) may face each other from the inner peripheral end portion for one or more rounds with the separator interposed therebetween. For example, when pressure is applied from the outside, there is always one or more places on the extension line of this pressure where the metal of the positive electrode and the metal of the negative electrode are surely short-circuited without interposing the positive electrode active material. Is possible.

Although not particularly shown, by coating a conductive coating such as graphite on the exposed portion of the positive electrode aluminum foil, oxidation of the surface of the aluminum foil is prevented and a good conductive state is always obtained. Further, as the conductive coating, when the positive electrode active material is applied to the aluminum foil, a coating such as graphite which has been previously adhered to the aluminum foil as an anchor layer to improve the adhesiveness is used as the conductive coating as it is. You may use.

FIG. 3 is a schematic sectional view showing another embodiment of the non-aqueous battery of the present invention. This non-aqueous battery comprises a positive electrode metal foil (aluminum foil) 11 having a positive electrode active material layer 21 made of a lithium composite oxide on one surface and an aluminum foil 12 having a positive electrode active material layer 22 formed on the same surface. A positive electrode 3 formed by superposing exposed surfaces having no active material layer, and a negative electrode 6 formed by forming a negative electrode active material layer 5 made of a carbonaceous material on both surfaces of a negative electrode metal foil (copper foil) 4. A wound laminated assembly composed of a separator 7 made of a polyethylene microporous film or the like, which is interposed between the positive electrode 3 and the negative electrode 6, is housed in a casing 8 connected to serve as an external electrode of the negative electrode. It is something.

In this non-aqueous battery, only the inner aluminum foil 12 is wound about one round from the outer peripheral end of the positive electrode 3, and the outer aluminum foil 11 is absent.
That is, the exposed portion of the positive electrode aluminum foil 12 and the negative electrode casing 8 face each other with the separator 7 in between on the outer peripheral side. In order to manufacture such a positive electrode 3, it is sufficient to shift one of the two aluminum foils 11 and 12 by a length corresponding to one turn when they are overlapped.

When a conductor such as an iron nail 19 in FIG. 4 pierces the casing 8 and is inserted into the inside of the non-aqueous battery, when the casing 8 penetrates the casing, it is integrally conducted with the casing 8 which is the negative electrode. The tip of the iron nail 19
First, it penetrates the aluminum foil 12 of the positive electrode 3, and then the positive electrode active material layer 22, the negative electrode active material layer 5, and the copper foil 4. ． ． And positively and negatively in the order of A, B, C, D, and E while penetrating (a separator is omitted).

Thus, although the iron nail 19 finally short-circuits the positive electrode active material layer and the negative electrode, the iron nail 19 that pierces the casing 8 first short-circuits with the aluminum foil 12 of the positive electrode 3. Yes, this first short circuit A has a sufficiently low resistance because it is a metal-to-metal short circuit as compared with B, C, D, and E in which the iron nail 19 later penetrates the positive electrode active material, and the short circuit current is iron. Most of the current flows through the nail 19 between the casing 8 and the aluminum foil 12 at A, whereby the non-aqueous battery of the present invention can be safely short-circuited internally without an abnormal temperature rise.

When the non-aqueous battery of the present invention having the above-described structure is abnormally heated from the outside, the outer peripheral separator 7 closest to the casing 8 melts before the inner peripheral separator 7. First, the aluminum foil 12 of the positive electrode, which faces the casing 8 via the separator 7 on the outer peripheral side, and the casing 8 are short-circuited in a low resistance state at a portion where the separator is melted. As a result, the battery is safely short-circuited internally without energizing the positive electrode active material and without causing an abnormal temperature rise.

5 to 8 are structural features of the inner peripheral end of the wound laminated electrode assembly in the non-aqueous battery of the present invention shown in FIG. 1 and the winding of the non-aqueous battery of the present invention shown in FIG. FIG. 6 is a schematic cross-sectional view of four different embodiments of a non-aqueous battery of the present invention designed to combine structural features at the outer peripheral edge of a laminated electrode assembly. Less than,
The structure and effect of the inner peripheral end and the outer peripheral end of each wound laminated electrode assembly in these four modes will be described.

FIG. 5 shows still another example of the non-aqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the non-aqueous battery of this aspect, the positive electrode metal foil (aluminum foil) 1 of the positive electrode 3 is used.
There is a portion where the aluminum foil 1 is exposed without having the positive electrode active material layer 2 on both sides for about 2 rounds from the inner peripheral end portion, and subsequently, a portion where one side is exposed for one round is provided. . The exposed portion of the aluminum foil 1 is covered with the negative electrode metal foil (copper foil) 4 through the separator 7 for about two turns, and the exposed portion of the copper foil 4 without the negative electrode active material on both sides faces each other. Cage,
When the separator 7 is broken, the exposed metal parts of the positive electrode and the negative electrode are designed to be short-circuited.

Furthermore, in the non-aqueous battery shown in FIG.
Even at the outer peripheral edge of the wound laminated electrode assembly, about 2
There is a portion where the aluminum foil 1 is exposed without having the positive electrode active material layers 2 on both sides over the circumference, and subsequently, a portion where one surface is exposed for about one circumference is provided. The exposed portion of the aluminum foil 1 is wound only with the aluminum foil 1 without the separator 7 interposed therebetween. However, since there is a metal casing as a negative electrode on the outer peripheral side, it is formed of an ion-insulating separator material. The exposed metal portions of the positive electrode and the negative electrode face each other via the separator 15.

When a conductor such as a sharp iron nail pierces the casing 8 and is inserted into the non-aqueous battery, most of the short-circuit current is conducted to the casing as in the case of FIGS. 3 and 4. The current flowing in the positive electrode active material layer 2 is suppressed to a sufficiently low level even if the iron nail, which is the body, and the aluminum foil 1 penetrate the positive electrode active material 2 later. Safely short-circuits the battery internally without causing an abnormal rise in temperature.

Further, in this embodiment, as described above, the separator made of the ion insulating material is interposed between the aluminum foil 1 and the casing 8. this is,
This is because the battery action does not occur at the position where the aluminum foil 1 and the casing 8 face each other, and thus the separator arranged at this position does not need to have ion permeability. Therefore, since a strong insulating film having no ion permeability can be used, the outermost peripheral separator is scratched by friction or the like in the assembly process of inserting the wound laminated electrode assembly into the casing, and the insulating property is impaired. The incidence of defective products in which the casing and the electrode body are short-circuited from the initial state can be reduced.

FIG. 6 shows still another example of the non-aqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the non-aqueous battery of this aspect, the positive electrode metal foil (aluminum foil) 1 of the positive electrode 3 is used.
There is a portion in which the aluminum foil 1 is exposed without having the positive electrode active material layer 2 on both sides from about 2 rounds from the inner peripheral end portion of the above. The exposed portion of the aluminum foil 1 is a portion where the negative electrode metal foil (copper foil) 4 extends for about one round through the separator 7 and the copper foil 4 is exposed without the negative electrode active material on both sides, and then the negative electrode. The metal foil (copper foil) 4 is opposed to the exposed portion of the copper foil 4 without having the negative electrode active material on one side for about one round, and the separator 7
If the breakage occurs, the exposed metal parts of the positive electrode and the negative electrode are designed to be short-circuited.

Further, in this embodiment, instead of the pipe-shaped core 13, a slit-provided core 14 which is partially cut away in the axial direction and has a substantially C-shaped cross section is used, and when the casing is compressed and biased. , The edge of this slit portion works to pierce the wound laminated electrode assembly from the inside, and the insulating film at the inner peripheral edge is ruptured more quickly and surely, exposing the metal part of the aluminum foil of the positive electrode and the copper foil of the negative electrode. The exposed metal part is designed to short-circuit more quickly and surely with low resistance.

As the slit core having such a function, by providing several slits on the side surface of the substantially C-shaped elastic body to the extent that rigidity is not impaired, the effect of the edge piercing the wound laminated electrode assembly is obtained. Increase
In addition, it is possible to exert a stable effect regardless of the direction in which the electrode assembly is compressed and biased by 360 degrees with respect to the winding axis.

Although not shown in particular, instead of the core provided with slits, protrusions or ridges are provided on the outer circumference, or a spiral body such as a screw or a spring is inserted in the center of the wound laminated electrode assembly. Also, almost the same effect can be obtained. As described above, in the non-aqueous battery of the embodiment shown in FIG. 6, the outer peripheral side of the outer peripheral end portion of the aluminum foil 1 which is the positive electrode metal foil 1 of the positive electrode 3 is exposed about one side. When the copper foil 4 of the negative electrode is wound around the exposed portion of the aluminum foil 1 via the separator 7 so that both sides of the copper foil 4 are exposed and the separator 7 is broken at this portion. In the same manner as the non-aqueous battery of the aspect shown in FIG. 3, a safe low resistance short circuit portion is realized.

That is, in the embodiment of FIG. 3 described above, the aluminum foil 12 of the positive electrode is exposed at the outermost circumference of the wound laminated electrode assembly for about one turn, and the aluminum foil 12 is exposed through the separator 7 to the inner wall of the negative electrode casing 8. However, the structure of the outer peripheral end portion of the electrode assembly of the non-aqueous battery of the present invention is not necessarily limited to this, and the exposed portion of the aluminum foil 1 of the positive electrode and the casing 8 are not limited to this. Even if the negative electrode 6 formed with the negative electrode active material layer 5 is interposed therebetween, substantially the same effect is obtained when a conductor such as an iron nail is inserted.

Further, when the negative electrode 6 having the exposed copper foil 4 is interposed as in the non-aqueous battery of the embodiment shown in FIG. 6, the aluminum foil 1 of the positive electrode is short-circuited not with the casing 8 but with the copper foil 4. Therefore, the casing itself does not need to be at the same potential as the negative electrode, and the effect is exhibited even in the case of a casing made of a resin other than metal, for example. Furthermore,
When the copper foil 4 is wound around the outermost periphery of the electrode assembly as in this aspect, the effect similar to that of other negative electrode casings can be realized by inserting the copper foil 4 into the casing having the same electric potential as the positive electrode. Needless to say.

FIG. 7 shows another example of the non-aqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the non-aqueous battery according to this aspect, a sheet-like aluminum foil 9 having a thickness of 100 μm and having substantially the same width as the above-mentioned aluminum foil and having no positive electrode active material layer is provided at the inner peripheral end of the aluminum foil 1 having a thickness of 15 μm. Approximately 2 connected to be integrated electrically and mechanically
It is wound around. This aluminum foil 9 is connected to the inner peripheral end of the copper foil 4 having a length of about 18 μm from the inner peripheral end so as to be electrically and mechanically integrated with the copper foil 4.
100 μm sheet-like copper foil 11 having almost the same width as that of the negative electrode active material, followed by the negative electrode metal foil (copper foil) 4 for about one round without the negative electrode active material on one side. It faces the exposed part.

Further, in the non-aqueous battery of this aspect,
Since a stainless steel core having slits is used like the non-aqueous battery of FIG. 6, when the casing receives a compressive force, the stainless steel core pierces the aluminum foil 9 of 100 μm and the copper foil 11 of 100 μm from the inside. Short circuit, but in this case 15μm aluminum foil 1 and 18μ
As compared with the case of piercing the copper foil 4 of m, there is an effect of realizing a more reliable and low resistance electrical conduction state.

Further, in this non-aqueous battery, the metal extension 9 from the positive electrode metal foil 1, the negative electrode metal foil 4 and the metal extension 11 therefrom are formed of an ion-insulating separator material. A separator having a smaller film thickness than the separator 7 is interposed. In general, a separator needs ion permeability to develop a battery function as well as electronic insulation, and also has considerable pores inside to hold an electrolytic solution, in order to maintain mechanical strength. However, the film thickness cannot be made too thin. However, in the facing portion of the exposed metal portions in the non-aqueous battery of the present invention, as long as it is a separator having an electronic insulating property, ion permeability for expressing the battery function is unnecessary,
A thin separator can be freely selected and used. This makes it possible to effectively utilize the volume in the casing and design to increase the battery capacity without sacrificing high safety.

As described above, in the outer periphery of the electrode assembly of the non-aqueous battery of the embodiment shown in FIG. 7, a 100 μm sheet-shaped sheet having substantially the same width and having no positive electrode active material is provided at the outer peripheral edge of the 15 μm aluminum foil 1. Aluminum foil 9
Are connected so as to be integrated electrically and mechanically, and are wound about one round. The copper foil 4 is exposed on one side of the negative electrode portion facing the aluminum foil 9, and the exposed metal portion of the positive electrode and the negative electrode already required is realized in this portion.
Therefore, if the casing is a negative electrode, it is more effective, but the present invention is not limited thereto. As in the embodiment of FIG. 6, the casing may be a positive electrode, or a non-metal container such as resin or a bag made of a film. It doesn't matter if it is something like this.

Further, as in the embodiment of FIG. 7, the outermost portion of the aluminum foil 1 of the electrode assembly is exposed,
When the non-aqueous battery covered with the separator 16 having a lower melting point than the separator 7 and inserted in the negative electrode casing 8 is abnormally heated from the outside, the separator 16 having a lower melting point than the separator 7 closest to the casing 8 is the positive electrode. Melting starts before the separator 7 that separates the active material layer 2 and the negative electrode active material layer 5, and first, the aluminum foil 1 of the positive electrode and the casing 8 are short-circuited in a low resistance state. As a result, the positive electrode active material is not energized, and the battery is safely short-circuited internally without causing an abnormal temperature rise of the battery. It has already been described that such an effect is exhibited also in the non-aqueous battery of the aspect of FIG. 3 in which the outermost periphery is covered with the separator 7, but the separator 16 having a lower melting point than the separator 7 as in the aspect of FIG.
By using, the effect can be more remarkably realized.

FIG. 8 shows still another example of the non-aqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the non-aqueous battery of this aspect, the positive electrode metal foil (aluminum foil) 1 of the positive electrode 3 is used.
There is a portion where both sides of the aluminum foil 1 are exposed for about two turns from the inner peripheral end portion of the above, and subsequently a portion where one side is exposed for one turn is provided. The exposed portion of these aluminum foils 1 faces the metallic lithium foil of the negative electrode via the separator 7. In this embodiment, the negative electrode itself does not need to be provided with the exposed portion of the collector metal foil such as copper foil. Is a metal and has a sufficiently low electric resistance, so that when the separator 7 is broken, a low resistance short circuit between the metal and the aluminum foil 1 of the positive electrode is realized, and the battery is safely shorted internally. To do.

As described above, in the electrode assembly of the non-aqueous battery of the embodiment shown in FIG. 8, the outer peripheral side of the positive electrode metal foil 1 of the positive electrode 3 has one outer peripheral side of the aluminum foil 1 exposed. It faces a metal casing that is at the same potential as the negative electrode, with a separator made of an ion-insulating separator material interposed therebetween. The mechanism for safely performing an internal short circuit is almost the same as the embodiment shown in FIG. 3, but since the outermost periphery of the wound laminated electrode assembly is the positive electrode 3 having the positive electrode active material layer 2 on one surface, When a separator made of an ion-permeable separator material is placed in between, ions are dissolved from the negative electrode casing material and migrate and deposit on the positive electrode surface, or a hole is formed in the casing, especially when left to stand overdischarge. There is also a concern that electrolyte leakage may occur. When charging a non-aqueous secondary battery having a similar structure, lithium ions move from the positive electrode active material at the outer peripheral end A of the positive electrode to the casing, which is the negative electrode, but deposit a small amount. It is not preferable. Therefore, by blocking the space between the casing and the casing by the separator made of the ion-insulating separator material as in the embodiment of FIG. 8, the disadvantages described above are eliminated.

In each of the above-mentioned embodiments, only the cylindrical non-aqueous battery having the separator interposed between the positive electrode and the negative electrode and accommodating the electrode assembly in which the separator is wound and laminated has been described, but it is not particularly described in detail. The configuration of each of the above aspects of the present invention can be applied to a thin rectangular nonaqueous battery that is often used in portable mobile terminal devices and the like at present.

As the electrode assembly to be inserted into the thin rectangular casing, a wound laminated electrode assembly having the same structure as that described in the above-mentioned embodiment is press-molded to have a flat elliptical cross section. Alternatively, it may be wound in an oval shape from the beginning. Further, of course, the present invention is not limited to the wound laminated electrode assembly, and may be a simple laminated electrode assembly as shown in FIGS. 9 and 10 or a serpentine laminated as shown in FIGS. 11 and 12. Even the assembled electrode assembly,
The same effect can be exhibited.

In the case of a wound electrode assembly, in order to cope with external heating or a case where an iron nail sticks into the battery, the aluminum foil is wound around the positive electrode metal foil of the positive electrode for one or more turns. It is preferable to expose the foil and face the casing, but a simple laminated electrode assembly as shown in Figures 9 and 10 or as shown in Figures 11 and 12 that may be used in thin rectangular shaped non-aqueous batteries. In the electrode assembly folded in a zigzag stack, it is not necessary to dispose the aluminum foil facing the casing once or more around the outer periphery of the electrode assembly. This is because in the case of a battery having the above structure, the exposed metal portions of the positive electrode and the negative electrode may be disposed on the surfaces of a pair of layers facing each other, considering the surface affected by the outside. is there.

FIG. 9 is a schematic cross-sectional view showing one embodiment of the non-aqueous battery of the present invention containing the simple laminated electrode assembly. In the non-aqueous battery of the embodiment shown in FIG. 9, the inner layer of the simple laminated electrode assembly is In the positive electrode layer where the aluminum foil 1 is exposed on one side and the negative electrode layer where the copper foil 4 is exposed on one side, the exposed metal surfaces are opposed to each other.
In between, a separator 7 and a rigid or elastic body 18, which is a conductor, are interposed.

FIG. 10 is a schematic cross-sectional view showing another embodiment of the non-aqueous battery of the present invention containing the simple laminated electrode assembly. In the non-aqueous battery of this embodiment, the positive electrode is the outermost layer of the electrode assembly. Aluminum foil of metal foil 1
Has a portion exposed on one side, and is opposed to the negative electrode casing 8 with metals. FIG. 11 is a schematic cross-sectional view showing one embodiment of the non-aqueous battery of the present invention containing the zigzag laminated electrode assembly. In the non-aqueous battery of this aspect, the outer layer end of the zigzag laminated electrode assembly,
The metal extension 11 extending the copper foil 4 which is the negative electrode metal foil and the one-sided exposed portion of the aluminum foil 1 which is the positive electrode metal foil are opposed to each other with the exposed metal portion, and are formed between the separator 7 or a separator material having a small film thickness. When a compressive force is applied from the outside in the vertical direction of the figure after the separator 17 is placed, the low resistance short circuit between them is positively realized.
A conductive rigid body or elastic body that applies a local pressing force to the separator or the insulating film is interposed.

In this embodiment, the positive electrode layer in which the aluminum foil 1 which is the positive electrode metal foil is exposed on one side at the outer layer end of the zigzag laminated electrode assembly and the copper foil 4 which is the negative electrode metal foil are electrically connected. Metal extension 1 connecting and extending
1 is configured so that exposed metal portions face each other, and a separator 7 and a rigid body or elastic body 18 that is a conductor are interposed between the exposed metal portions.

FIG. 12 is a schematic cross-sectional view showing another embodiment of the non-aqueous battery of the present invention containing the zigzag laminated electrode assembly. In the non-aqueous battery of this aspect, a portion where both surfaces of the positive electrode metal foil 1 are exposed in the outer layer of the electrode assembly is bent, and a portion where the copper foil 4 of the negative electrode current collector is exposed on one side and the separator 7 are interposed. Although they are opposed to each other, by inserting this into the negative electrode casing, it is attempted to realize a more reliable low resistance short circuit portion.

The conductor represented by 18 in FIGS. 9 and 11 has a width of, for example, 500 to 2 as shown in FIG.
Thickness of 100 to 500 bent zigzag at 000 μm
μm stainless steel plate, or thickness 5 with 100-1000 μm deep stripe-shaped irregularities on the surface
A stainless steel plate having a thickness of 00 to 2000 μm can be used. When the battery receives a compressive force from the outside in the vertical direction as in the embodiment of FIGS. 9 and 11, the convex portion of the conductor 18 applies a local pressure contact force to the separator 7 to positively The separator 7 is ruptured, and the exposed metal portions of the positive electrode and the negative electrode that face each other are short-circuited to each other with low resistance, and the internal short-circuiting is safely performed.

Needless to say, a separator made of an ion insulating separator material or a separator made of a relatively low material is provided between the simple laminated electrode assembly or the zigzag folded laminated electrode assembly and the casing.
By using a separator or the like having a thickness smaller than that of the separator between the positive and negative active material layers, the same effect as that described in the embodiment of the winding lamination is exhibited.

[0086]

EFFECTS OF THE INVENTION Since the non-aqueous battery of the present invention has a unique electrode assembly structure, the casing is crushed by pressure from the outside, overcharged due to abnormality in the charging circuit, nails, etc. Safety that can prevent a rapid temperature rise of the battery by an internal short circuit between metals with sufficiently low electric resistance, even in the unlikely event of an accident such as sticking or abnormal heating from the outside It is an excellent non-aqueous battery.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of a non-aqueous battery of the present invention containing a wound laminated electrode assembly.

FIG. 2 is a schematic cross-sectional view showing a crushed state of the non-aqueous battery of FIG.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the non-aqueous battery of the present invention containing the wound laminated electrode assembly.

FIG. 4 is a schematic cross-sectional view showing a state where an iron nail is inserted into the non-aqueous battery of FIG.

FIG. 5 is a schematic cross-sectional view showing still another embodiment of the non-aqueous battery of the present invention containing the wound laminated electrode assembly.

FIG. 6 is a schematic cross-sectional view showing still another embodiment of the non-aqueous battery of the present invention containing the wound laminated electrode assembly.

FIG. 7 is a schematic cross-sectional view showing still another embodiment of the non-aqueous battery of the present invention containing the wound laminated electrode assembly.

FIG. 8 is a schematic cross-sectional view showing still another embodiment of the non-aqueous battery of the present invention containing the wound laminated electrode assembly.

FIG. 9 is a schematic cross-sectional view showing one embodiment of a non-aqueous battery of the present invention containing a simple laminated electrode assembly.

FIG. 10 is a schematic cross-sectional view showing another embodiment of the non-aqueous battery of the present invention containing the simple stacked electrode assembly.

FIG. 11 is a schematic cross-sectional view showing one embodiment of a non-aqueous battery of the present invention containing a zigzag laminated electrode assembly.

FIG. 12 is a schematic cross-sectional view showing another embodiment of the non-aqueous battery of the present invention containing the zigzag laminated electrode assembly.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Positive electrode metal foil 2 Positive electrode active material layer 3 Positive electrode 4 Negative metal foil 5 Negative electrode active material layer 6 Negative electrode 7 Separator formed of ion-permeable separator material 8 Casing 9 Metal extension from positive electrode metal foil 10 Positive electrode tab 11 Negative electrode metal Metal extension from foil 12 Negative electrode tab 13 Pipe-shaped core 14 Slitted core 15 Separator made of an ion-insulating separator material 16 Separator made of a material having a relatively low melting point 17 Thinner film than the separator described in 7 above Separator 18 Conductive rigid or elastic body 19 Iron nail

Claims (13)

[Claims] 1. A casing, (1) a non-aqueous electrolyte contained in a space defined by an inner wall of the casing, and (3) a non-aqueous electrolyte contained in the space so as to be able to cooperate with the non-aqueous electrolyte. A non-aqueous battery comprising a wound laminated electrode assembly, wherein the wound laminated electrode assembly (3) comprises a positive electrode active material layer (a) on at least one surface of a positive electrode metal foil (a-1) which functions as a positive electrode current collector. -2), a positive electrode, a negative electrode including a negative electrode active material layer, and a separator interposed between the positive electrode and the negative electrode. The positive electrode, the negative electrode, and the separator are the positive electrode active material layer and the negative electrode active material. The layers are wound and laminated so as to face each other with the separator interposed therebetween, and the battery has a metal part that is equipotential to the positive electrode and that is provided in association with the positive electrode. Positive on at least one side By having a portion in which the active material layer is not formed, a positive electrode equipotentially exposed metal portion (α) extending in the longitudinal direction over one or more rounds is formed, and the positive electrode equipotentially exposed metal portion (α) is A non-aqueous battery, wherein the non-aqueous battery is located so as to face the negative electrode equipotential exposed metal portion (β) provided in association with the negative electrode for a length of at least one circumference. 2. The non-aqueous battery according to claim 1, wherein the positive electrode equipotential metal portion has portions on both surfaces thereof where the positive electrode active material layer is not formed. 3. The negative electrode has a negative electrode active material layer (b) on at least one surface of a negative electrode metal foil (b-1) which functions as a negative electrode current collector.
-2), or a negative electrode active material metal foil (b- that functions as both the negative electrode active material layer and the negative electrode current collector).
3) and optionally a negative electrode current collector metal foil (b-4) having the negative electrode active material metal foil (b-3) bonded to at least one side thereof together with an electrical connection. The exposed metal portion (β) is (c) an exposed metal portion having no negative electrode active material layer (b-2) on at least one surface of the negative electrode metal foil (b-1), (d) negative electrode active material metal foil (b) -3) at least one exposed metal portion of the negative electrode current collector metal foil (b-4) on at least one surface of the negative electrode active material metal foil (b-) as a negative electrode active material layer.
3) Exposed metal portion not having, and (f) negative electrode metal foil (b-1), negative electrode active material metal foil (b-3) or negative electrode current collector metal foil (b-4) inner peripheral end portion. The non-aqueous battery according to claim 1 or 2, wherein the non-aqueous battery is at least one portion selected from a metal extension portion that electrically extends from at least one of the outer peripheral end portion. 4. The negative electrode has a negative electrode active material layer (b) on at least one surface of a negative electrode metal foil (b-1) which functions as a negative electrode current collector.
-2), wherein the negative electrode equipotential exposed metal portion (β) does not have the negative electrode active material layer (b-2) on at least one surface of the negative electrode metal foil (b-1). The non-aqueous battery according to claim 1, wherein 5. The positive electrode equipotentially exposed metal portion (α),
(G) Exposed metal portion having at least one surface of the positive electrode metal foil (a-1) and not having the positive electrode active material layer (a-2) at the outer peripheral end thereof, and (h) the positive electrode metal foil (a-1). 5. The non-aqueous battery according to any one of claims 1 to 4, wherein the non-aqueous battery is at least one part selected from a metal extension part which is electrically joined and extends from the outer peripheral end part. 6. The positive electrode equipotentially exposed metal portion (α),
(G) Exposed metal portion having at least one surface of the positive electrode metal foil (a-1) and not having the positive electrode active material layer (a-2) at its inner peripheral end, and (h) positive electrode metal foil (a- The non-aqueous battery according to any one of claims 1 to 4, which is at least one part selected from a metal extension part which is electrically joined and extends from the inner peripheral end part of 1). 7. The positive electrode equipotentially exposed metal portion (α),
7. The non-aqueous battery according to claim 1, further comprising an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to a positive electrode at an equal potential. 8. The negative electrode equipotentially exposed metal part (α),
7. The non-aqueous battery according to claim 1, further comprising an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to the negative electrode at an equipotential. 9. The separator comprises a first separator part (S1) and a second separator part (S2).
The separator portion (S1) is located in at least one first region where the positive electrode active material layer of the positive electrode and the negative electrode active material layer of the negative electrode face each other, and the second separator portion (S2) is the positive electrode equipotential exposed metal portion. (Α) and negative electrode equipotential exposed metal part (β)
Are located in at least one second region facing each other, and the first separator portion (S1) is formed of an ion-permeable separator material, and the second separator portion (S2) is an ion-insulating separator. A non-aqueous battery formed of a separator material selected from a material and an ion-permeable separator material. 10. The melting point of the second separator portion is 1
The non-aqueous battery according to claim 9, wherein the temperature is not lower than 00 ° C and is lower than the melting point of the first separator portion by at least 5 ° C. 11. The wound laminated electrode assembly is formed by inserting a core formed of a rigid body and an elastic body into a winding center of the wound laminated electrode assembly, and when the casing receives a compressive force, the wound laminated electrode assembly forms a casing and a core. The non-aqueous battery according to claim 1, wherein the non-aqueous battery is compressed between the two. 12. A casing (1 '), (2') a non-aqueous electrolyte contained in a space defined by an inner wall of the casing, and (3 ') capable of cooperating with the non-aqueous electrolyte in the space. A non-aqueous battery comprising a housed simple laminated electrode assembly, wherein the simple laminated electrode assembly (3 ') is a plurality of positive electrodes electrically connected to each other, each positive electrode serving as a positive electrode current collector. Functional positive metal foil (a'-1)
A positive electrode having a positive electrode active material layer (a′-2) formed on at least one surface thereof, a plurality of negative electrodes electrically connected to each other, each negative electrode including a negative electrode active material layer, and A plurality of layers of separators, each separator being interposed between each positive electrode and each negative electrode, each positive electrode, each negative electrode, and each separator being the positive electrode active material layer and the negative electrode active material layer. Are simply laminated so as to face each other with the separator interposed therebetween, the battery has a metal part that is equipotential to the positive electrode that is provided in association with the positive electrode, and the positive electrode equipotential metal part is at least that part. A positive electrode equipotentially exposed metal portion (α ′) having a length of one or more layers is formed by having a portion on one side where the positive electrode active material layer is not formed, and the positive electrode equipotentially exposed metal portion (α ′) is formed. Is the negative electrode provided in association with the negative electrode Are located opposite across the potential exposed metal part (beta ') and one or more layers of long, non-aqueous battery, characterized in that. 13. A casing (1 "), (2") a non-aqueous electrolyte contained in a space defined by an inner wall of the casing, and (3 ") capable of cooperating with the non-aqueous electrolyte in the space. A non-aqueous battery comprising a zigzag folded laminated electrode assembly housed therein, wherein the zigzag laminated electrode assembly (3 ") comprises: a positive electrode metal foil (a" -1) that functions as a positive electrode current collector. A positive electrode formed by forming the layer (a ″ -2), a negative electrode including a negative electrode active material layer, and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode, the negative electrode, and the separator are the positive electrode active material layer and the The negative electrode active material layers are folded and laminated so as to face each other with the separator interposed therebetween, and the battery has a metal part that is equipotential to the positive electrode provided in association with the positive electrode. The metal part has a positive electrode equipotentially exposed metal part (α ″) having a length of one or more layers by having a part where the positive electrode active material layer is not formed on at least one side thereof. The non-aqueous battery characterized in that the part (α ″) is located opposite to the negative electrode equipotential exposed metal part (β ″) provided in association with the negative electrode over the length of one or more layers. .