JP3200340B2 - Non-aqueous battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 cooperate with the non-aqueous electrolyte. A nonaqueous battery comprising a wound laminated electrode assembly, wherein the positive electrode containing a positive electrode active material layer constituting the wound laminated electrode assembly (3);
The negative electrode active material layer-containing negative electrode and the separator are wound and laminated such 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 having a metal part having an equipotential with the positive electrode, the positive electrode equipotential metal part having a portion where the positive electrode active material layer is not formed on at least one side thereof, thereby extending in a longitudinal direction over a length of at least one circumference. A potential exposed metal portion (α) is formed, 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. Furthermore, the present invention also relates to a non-aqueous battery in which, instead of the above-mentioned wound laminated electrode assembly, a simple laminated electrode assembly or a meandered laminated electrode assembly having substantially the same configuration is housed in a casing. Due to the unique structure as described above, the casing may be crushed by external pressure, may be overcharged due to an abnormality in the charging circuit, may be stuck by a nail, or may be abnormally heated from the outside. Even in the case of an unexpected abnormal situation, a non-aqueous battery that can ensure safety by suppressing a sudden rise in temperature of the battery due to a short circuit between metals having sufficiently small electrical resistance can be provided. .

[0002]

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

[0003] This lithium ion secondary battery has a high capacity,
Since it has features such as high voltage and high output, it is possible to prevent the temperature of the battery from rising when the battery's temperature rises due to a short circuit between the positive electrode and the negative electrode of the battery due to an abnormal circuit, etc. 2. Description of the Related Art Various protection means such as a fuse and a PTC element are provided, and a safety valve is provided to prevent a rise in internal pressure of a battery.

[0004]

However, in addition to the short circuit between the positive electrode and the negative electrode of the battery due to an abnormality in the circuit, various abnormal situations are assumed. For example, in a case where the battery is crushed by an external pressure or is overcharged due to an abnormality in a charging circuit or the like, the separator between the positive electrode and the negative electrode is broken or melted, and the positive electrode and the negative electrode are damaged. Are short-circuited in the battery. Further, for example, in an unforeseen situation, such as when a conductor such as a nail is stuck in the casing, a nail that is integrally conducted with the negative electrode by penetrating the casing that is the negative electrode is short-circuited with the positive electrode in the battery, and In a situation such as abnormal heating from the outside, the separator disposed between the positive and negative electrodes melts earlier than the metal, and the positive and negative electrode active materials are similarly separated in the battery. Short circuit. At this time, there is no problem if the battery is not charged, but the characteristics of the lithium ion secondary battery such as high capacity and high voltage in the charged state are conversely from the viewpoint of maintaining safety. It becomes a negative factor compared with 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 a lithium and a transition metal and a non-transition metal.
The temperature of the cathode active material easily rises due to the passage of the short-circuit current, and the positive electrode active material during charging is in an unstable state in which lithium is ionized and escapes to some extent. There is a possibility that an excessive amount of oxygen is generated, and this oxygen reacts violently with the aluminum foil or the organic solvent coated with the positive electrode active material, causing a rapid temperature rise.

Accordingly, even when the battery is crushed or overcharged by external pressure, or when a conductor such as a nail is stuck in the casing or abnormally heated from the outside, the positive electrode is It has been desired to develop a non-aqueous battery that can prevent short-circuiting between the active material and the negative electrode, or suppress the rise in temperature of the positive electrode active material even when it occurs, thereby ensuring safety.

The present inventor has made intensive studies to solve the above problems and to 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 housed in the space so as to cooperate with the non-aqueous electrolyte. The positive electrode containing a positive electrode active material layer, the negative electrode containing a negative electrode active material layer, and the separator that constitute the wound laminated electrode assembly (3) are composed of the laminated electrode assembly, and the positive electrode active material layer and the negative electrode active material layer constitute the separator. In a non-aqueous battery that is wound and laminated so as to face each other via the intermediary, the battery has a metal part having the same potential as the positive electrode provided in association with the positive electrode, and the positive electrode equipotential metal part is at least By having a portion where the positive electrode active material layer is not formed on one side, a positive electrode equipotential exposed metal portion extending in the longitudinal direction over one or more turns is formed. If the component is configured to face the negative electrode equipotential exposed metal portion provided in connection with the negative electrode over a length of one or more turns, the casing is crushed at a time by external pressure, and at a plurality of locations. Even if the separator between the positive electrode and the negative electrode breaks at almost the same time, if the positive electrode equipotential exposed metal portion having no positive electrode active material layer and the negative electrode equipotential metal exposed portion are short-circuited, the short-circuited portion becomes a high-resistance positive electrode active portion. The short-circuit current is sufficiently small compared to the short-circuit point between the material and the negative electrode, and the short-circuit current is proportional to the resistance value at the short-circuit point. Since the current flows through the short-circuit point 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 internally short-circuited, resulting in rapid heat generation and a sudden temperature rise Surprisingly was also found that no risk.

In a non-aqueous battery in which a simple laminated electrode assembly or a zigzag laminated electrode assembly is housed in a casing, a positive electrode equipotentially exposed metal portion, a negative electrode, and the like are formed in the same configuration as in the above-described wound laminated electrode assembly. It has been 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.

[0008] That is, an object of the present invention is to provide an abnormal situation in which a battery is crushed by external pressure, is overcharged, or a conductor such as a nail is stabbed in a casing or is abnormally heated from the outside. Even if it becomes, the completely new idea of short-circuiting between the two metals, the positive electrode equipotential exposed metal part and the negative electrode equipotential exposed metal part,
It is an object of the present invention to provide a non-aqueous battery excellent in safety without a sudden heat generation and a rapid rise in temperature.

[0009]

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the appended claims, taken in conjunction with 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 non-aqueous electrolyte comprising a wound laminated electrode assembly accommodated in the space so as to cooperate with the non-aqueous electrolyte. An aqueous battery, wherein the wound laminated electrode assembly (3) comprises 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 the material layer, and a separator interposed between the positive electrode and the negative electrode, such that the positive electrode, the negative electrode, and the separator face each other with the positive electrode active material layer and the negative electrode active material layer interposed therebetween. The battery is wound and laminated, and the battery has a metal part having the same potential as 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. No part The positive electrode equipotential exposed metal portion (α) extending in the longitudinal direction over one or more turns, and the positive electrode equipotential exposed metal portion (α) is provided in association with the negative electrode. The non-aqueous battery is characterized in that the non-aqueous battery is positioned so as to face the negative electrode equipotential exposed metal portion (β) over one or more turns.

Next, the non-aqueous battery of the present invention will be described in detail. As described above, in one embodiment 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 It comprises a wound laminated electrode assembly housed in a space so as to cooperate with the non-aqueous electrolyte.
The wound laminated electrode assembly (3) includes a positive electrode and a negative electrode active material layer each having a positive electrode active material layer (a-2) formed on at least one surface of a positive electrode metal foil (a-1) functioning as a positive electrode current collector. 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 such 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 the nonaqueous battery having the wound laminated electrode assembly according to one aspect of the present invention is that the nonaqueous battery has a metal part having the same potential as the positive electrode provided in association with the positive electrode, and The portion has a portion where the positive electrode active material layer is not formed on at least one side thereof, thereby forming a positive electrode equipotential exposed metal portion (α) extending in the longitudinal direction over one or more turns. The exposed metal portion (α) is configured to be positioned so as to face the negative electrode equipotential exposed metal portion (β) provided in association with the negative electrode over 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; The negative electrode active material metal foil (b-3) functioning as both the negative electrode active material layer and the negative electrode current collector, and optionally the negative electrode active material metal foil (b-3) are connected to at least one surface thereof together with electrical connection. Negative electrode current collector metal foil (b-
Preferably, the method comprises 4).

In the present invention, the negative electrode equipotential exposed metal portion (β) is formed on at least one surface of the negative electrode metal foil (b-1) without the negative electrode active material layer (b-2). ), An exposed metal portion (d) on at least one surface of the negative electrode active material metal foil (b-3), and a 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 part (e) having no (b-3);
And negative electrode metal foil (b-1), negative electrode active material metal foil (b-
3) or at least one metal extension (f) electrically connected and extended from at least one of the inner peripheral end and the outer peripheral end of the negative electrode current collector metal foil (b-4).
Preferably two parts.

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

With such a configuration, for example, when a conductor such as a nail penetrates through the casing which has been turned into a negative electrode from the outside, the conductor which has been conducted integrally with the metal casing of the negative electrode, after passing through the separator, When the battery is short-circuited with the positive electrode equipotential exposed metal portion having no positive electrode active material layer in a low-resistance state, and when the battery is abnormally heated from the outside, the outermost separator closest to the casing is smaller than the innermost separator. Since the positive electrode equipotentially exposed metal portion formed on the outer peripheral side and the metal casing are short-circuited in a low-resistance state, the positive electrode active material is hardly energized, and the battery is safe without abnormal heat generation. Internal short circuit. When this positive electrode equipotential exposed metal portion is formed, for example, at the outer peripheral end of the positive electrode metal foil, the opposing positive electrode equipotential exposed metal portion via the separator is not limited to the negative electrode casing,
For example, it may be an exposed metal portion of the negative electrode metal foil. or,
The casing may serve as a positive electrode in addition to the case where the casing serves as a negative electrode.

The inner wall of the casing is formed of 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 a positive electrode nor a negative electrode, in which case the plastic casing may be provided with external electrodes. 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 has no positive electrode active material layer (a-2) at an inner peripheral end thereof. It is preferably at least one portion selected from an exposed metal portion (g) and a metal extension portion (h) extending electrically from the inner peripheral end of the positive metal foil (a-1). With this configuration, when the battery is slowly crushed by external pressure, the inner peripheral portion of the wound and laminated electrode assembly has a smaller radius of curvature than the outer peripheral portion, and With regard to 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 easily broken earlier than other parts. Therefore, the positive electrode equipotential exposed metal portion (α) having no positive electrode active material layer and the negative electrode equipotential exposed metal portion (β) are short-circuited more quickly and reliably with low resistance. Even when the battery is short-circuited, no short-circuit current flows there, suppressing the temperature rise of the positive electrode active material, and the battery is internally short-circuited safely.

In the battery of the present invention, the upper limit of the number of turns of the positive electrode equipotential exposed metal portion (α) facing the negative electrode equipotential exposed metal portion (β) is as large as possible in the casing. Although there is an effect of improving safety, if the amount is too large, the charge / discharge capacity of the battery is reduced. Therefore, the number is preferably 1 to 10 times, more preferably 2 to 4 times.

Further, the positive electrode equipotential metal part (α) is
It is preferable to have a portion where the positive electrode active material layer is not formed on both surfaces over one or more turns. In this case, when the battery is crushed at once by external pressure and the separator is broken at almost the same time at a plurality of points between the positive electrode and the negative electrode, or when a sharp conductor such as a nail penetrates the current collector foil. Furthermore, a more reliable low-resistance contact state between metals can be obtained.

Further, in the present invention, an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to the positive electrode at an equipotential is provided on the positive electrode equipotential exposed metal portion (α). Is also good. With such a 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 tab, the temperature near the electrode tab becomes higher than other parts, and the electrode tab is distributed. The separator for the provided positive electrode equipotential exposed metal part (α) melts before the other parts, and the positive electrode equipotential exposed metal part (α)
Is short-circuited to the negative electrode equipotential exposed metal part (β) with low resistance, and the battery is internally short-circuited safely without causing abnormal temperature rise of the battery due to thermal decomposition of the positive electrode active material.

However, an external electrode [a positive electrode equipotential exposed metal portion (α)] and a negative electrode equipotential exposed metal portion (a positive electrode equipotential exposed metal portion) such as a positive electrode casing which are connected to the positive electrode and equipotential through welding of an electrode tab having a slight resistance. When β) is short-circuited, a sufficiently low resistance short-circuit is obtained compared to 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 is hard to be.

Further, according to the present invention, the negative electrode equipotential exposed metal portion (α) is provided with an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to the negative electrode at an 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 tab, the temperature near the electrode tab becomes higher than other parts, and the electrode tab is distributed. The separator corresponding to the provided negative electrode equipotential exposed metal part (β) is melted before other parts, and the negative electrode equipotential exposed metal part (β) is lower in resistance than the positive electrode equipotential exposed metal part (α). The battery is safely internally short-circuited without causing a short circuit and abnormal temperature rise of the battery due to thermal decomposition of the positive electrode active material.

However, the external electrode [positive electrode equipotential exposed metal portion (β)] and the positive electrode equipotential exposed metal portion (β) are connected to the negative electrode and equipotential through welding of an electrode tab having a slight resistance. When α) is short-circuited, the negative electrode equipotential exposed metal portion (β) is sufficiently lower than when exposed metal portions (c) to (e) and / or metal extension portions (f). It becomes difficult to obtain a resistance short circuit.

The above-mentioned metal extension portion which is electrically connected and extends is, for example, a metal of the same material as the current collector metal foil of the positive electrode or the negative electrode, and has a width substantially equal to that of the current collector foil. The metal foil having a thickness of 5 to 20 times the thickness of the body metal foil is electrically and mechanically connected to the exposed metal portion at the inner and / or outer peripheral edge of the current collector metal foil with low resistance and electric / mechanical by a method such as welding. Connected. The metal material of the metal extension may be different from the material of the current collector metal foil, but in that case, a material that can be easily welded to the current collector metal foil is selected.

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

The electrode tab electrically connects a positive electrode and / or a negative electrode of the wound laminated electrode assembly to an external electrode provided on a casing. Usually, a small battery has a width of 3 to 5 mm. Is a sheet-like metal having a thickness of 100 to 200 μm and a positive electrode equipotential exposed metal part (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, stainless steel, or the like is used. Copper, nickel, stainless steel and the like can be used. The separator is not particularly limited, and a known battery separator can be used.

However, the separator preferably 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 formed of a positive electrode 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 formed 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 fabric, non-woven fabric, glass woven fabric, synthetic resin microporous membrane and the like can be used. When a thin film and a large-area electrode are used, for example, JP-A-58-59072 discloses a microporous synthetic resin membrane, particularly US Pat. No. 5,051,
No. 183, etc., are preferred in terms of thickness, strength and film resistance.

Further, in the present invention, it is preferable that the second separator portion is formed of an ion-insulating separator material. That is, the separator disposed between the positive electrode equipotentially exposed metal portion (α) and the negative electrode equipotentially exposed metal portion (β) does not have a battery action at the position, and thus has no ion permeability. Can be used.

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

The ion-insulating separator material is not only inexpensive than the ion-permeable separator material, but also has high strength, so that the required strength can be maintained even when 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. 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., generally 5 to 5 ° C., higher than the melting point of the first separator portion. It is preferable that the temperature is as low as 150 ° C.

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

The melting point of the separator in the second separator portion is within the operating temperature range (−20 to 1) of a normal nonaqueous electrolyte battery.
00 ° C.) and preferably with a significant difference from the melting point (120 ° C. to 250 ° C.) of the separator in the second separator portion. If the difference between the melting point of the second separator portion and the melting point of the first separator portion is less than 5 ° C., there is a problem that the first separator may be melted earlier due to the temperature distribution normally present in the casing, On the other hand, if the difference is larger than 150 ° C., there is a problem that the material may be melted within the operating temperature range.

Examples of the separator material used for the second separator portion include a polyethylene film and a polypropylene film. Further, in the present invention, a core formed of a rigid or elastic body is inserted at the center of the wound of the wound laminated electrode assembly, and when the casing receives a compressive force, the wound laminated electrode assembly is Preferably, it is compressed between the core.

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

Examples of the negative electrode metal foil include metal foils such as copper, nickel and stainless steel. It is preferably copper or stainless steel, and has a thickness of 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 of the negative electrode metal foil is preferably 30 to 300 per side.
μm, more preferably 70 to 130 μm.

The shape of the above-mentioned positive and negative electrode metal foils may be expanded metal, punched metal, foamed metal or the like, or carbon cloth or carbon paper as a metal equivalent body may be used. In the present invention, as the positive electrode active material, an alkali metal such as Li, Na, and Ca and a transition metal 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 composite metal oxide, a lithium ion having a layered structure and electrochemically intercalated (inte
rcalate) and a Li composite metal oxide that can be deintercalated. As a specific example of the above-mentioned Li composite metal oxide, Japanese Patent Application Laid-Open No. 55-13 / 1979
No. 6,131 (corresponding US Pat. No. 4,357,215)
Disclosed in Japanese Patent Application Laid-Open No.
No. 49,155 discloses LixNiyCo (1
-y) O 2 and LixMnO 2.

In order to obtain such a compound, an L compound such as lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate or the like is used.
i compound is a metal oxide, a metal hydroxide, a metal carbonate,
It can be easily obtained by subjecting it to a firing reaction with a metal nitrate or the like and, if desired, with another metal compound. 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 crushed, scale-like,
It may have any spherical shape. Although the carbonaceous material is not particularly limited, for example, Japanese Patent Application Laid-Open No. 58-35,881 (corresponding to U.S. Pat.
No. 17,243), a high surface area carbon material, graphite, and a calcined carbide such as a phenolic resin described in JP-A-58-209,864.
No. 111,907 (corresponding US Pat. No. 4,725,4
No. 22), and calcined carbides of the condensed polycyclic hydrocarbon-based compound. Alternatively, metal lithium, a composite oxide, or the like may be used as it is as a negative electrode.

The non-aqueous electrolyte is not particularly limited. 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 and KPF6 can be dissolved in an organic solvent and used as an organic electrolyte. The electrolyte concentration in the organic electrolyte 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, phosphoric acid Ester compounds, sulfolane compounds and the like can be used, and among them, ethers, ketones, nitriles, chlorinated hydrocarbons, carbonates, and sulfolane compounds are preferable. More preferred are cyclic carbonates. Representative examples of these include tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, anisole, monoglyme, acetonitrile, propionitrile, 4-methyl-2-pentanone, butyronitrile, valeronitrile, benzonitrile, 1,2- Dichloroethane, γ-butyrolactone, dimethoxyethane, methylformate, propylene carbonate, ethylene carbonate, vinylene carbonate, dimethylformamide, dimethylsulfoxide, dimethylthioformamide, sulfolane, 3-methyl-sulfolane, trimethyl phosphate, triethyl phosphate and these ethyl salts Examples thereof include a mixed solvent, but are not necessarily limited thereto.

Although 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, instead of the wound laminated electrode assembly,
Even in a non-aqueous battery using the simple laminated electrode assembly (FIGS. 9 to 10) or the meandering laminated electrode assembly (FIGS. 11 to 12), the positive electrode equipotential exposed metal portion, the negative electrode, and the like have substantially the same configuration as the above embodiment. The same effect as in the case of a non-aqueous battery having a wound laminated electrode assembly by forming a potential exposed metal portion can be exerted.

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

According to still another aspect of the present invention, (1 ″) a casing, (2 ″) a non-aqueous electrolyte contained in a space defined by an inner wall of the casing, and (3 ″) A non-aqueous battery comprising a spirally folded electrode assembly housed in said space so as to cooperate with said non-aqueous electrolyte, wherein said spirally folded electrode assembly (3 ") has a positive electrode metal foil functioning as a positive electrode current collector At least one side of (a ″ -1) has a positive electrode active material layer (a ″-).
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 folded and stacked so that the positive electrode active material layer and the negative electrode active material layer face each other with the separator interposed therebetween.The battery includes a positive electrode provided in association with the positive electrode. The positive electrode equipotential metal portion has at least one side on which the positive electrode active material layer is not formed, so that the positive electrode equipotential exposed metal portion (α) has a length of at least one layer. ))
The above-mentioned positive electrode equipotential exposed metal portion (α ″) is located opposite to the negative electrode equipotential exposed metal portion (β ″) provided in connection with the negative electrode over one or more layers. A non-aqueous battery is provided.

[0045]

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

[0046]

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

In the non-aqueous battery of this embodiment, the aluminum foil 1 having no positive electrode active material layer 2 on both sides for about two or more turns from the inner peripheral end of the positive metal foil (aluminum foil) 1.
Is wound in a state of being exposed. Similarly, the negative electrode metal foil (copper foil) 4 is wound over one or more rounds from the inner peripheral end in a state where the copper foil 4 is exposed without the negative electrode active material layers 5 on both surfaces. . That is, the inner peripheral end portion of the wound and laminated electrode assembly is such that the aluminum foil 1 and the copper foil 4 are opposed to each other via the separator 7 over at least one round, and the aluminum foil 1 is aligned with the aluminum foil 1 in the subsequent round. The negative electrode active material layer 5 faces each other via the separator 7, and thereafter, the positive electrode active material layer 2 faces the negative electrode active material layer 5 via the separator 7.

When pressure is applied to the nonaqueous battery of this embodiment as shown in FIG. 2, for example, in the vertical direction, in this battery, the stress applied to the innermost peripheral separator 7 adjacent to the pipe-shaped core 13 is the least. Since it is large, breakage occurs sequentially from here to the outer peripheral direction. That is, first, the exposed portion of the aluminum foil 1 and the copper foil 4 are shown in FIGS.
The exposed portions of the metal are short-circuited with low resistance. Further, even when the separator portion on the extension line in the direction in which the pressure is applied breaks almost at the same time, the short-circuit resistance value between metals having low resistance values such as A, B, F, G, H, and I is D. , E,
Since the short-circuit resistance between the positive-electrode active material layer 2 and the negative-electrode active material layer 5 having a high resistance, such as K and L, is remarkably small, the short-circuit current can be short-circuited with low resistance. F, G,
Most of the short-circuit currents flow through at least one of the six locations H and I, and only a small amount of current flows through the high-resistance short-circuits D, E, K, and L.
Therefore, the positive electrode metal foil (aluminum foil) 1 and the negative electrode metal foil (copper foil) substantially do not intervene the high-resistance positive electrode active material layer 2.
4 is short-circuited with low resistance, and internal short-circuit occurs only by mere generation of Joule heat without an abnormal rise in battery temperature due to thermal decomposition of the positive electrode active material.

Further, when it is assumed that there is not much time difference between the inner circumference and the outer circumference where the separator 7 is broken,
The position where the positive metal foil (aluminum foil) is exposed is not limited to the inner peripheral end, but may be the outer peripheral end or an intermediate part. The exposed portion of the aluminum foil 1 and the portion where the negative electrode active material layer 5 is short-circuited like C and J are:
Since the current flows without passing through the positive electrode active material layer 2 and causes an internal short circuit without an abnormal rise in the temperature of the battery due to thermal decomposition of the positive electrode active material or the like, the resistance value of the short circuit becomes high. Is not low compared to the short-circuit resistance value through
In particular, the effect is insufficient when short-circuits between active materials occur almost simultaneously.

Reference numeral 10 denotes an electrode tab disposed on the exposed portion of the aluminum foil 1 and connecting the positive electrode 3 to an external electrode. By disposing the electrode tab 10 at a position facing the exposed portion of the copper foil 4 of the negative electrode 6 without the interposition of the positive electrode active material layer 2, a large amount of battery is overcharged due to an abnormality in the charging circuit or the like. When a large current flows through the electrode tab 10, the temperature near the electrode tab 10 becomes higher than other parts. And
Separator 7 facing the place where electrode tab 10 is provided
Melts before the 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 abnormal temperature of the battery due to thermal decomposition of the positive electrode active material. The battery is safely internally short-circuited without rising. Also, a positive electrode equipotential exposed metal portion is formed at the inner peripheral end of the aluminum foil 1 which is a positive electrode metal foil, and an electrode tab is provided here. The generated heat is concentrated at the center of the wound laminated electrode assembly, and the aluminum foil 1 is more quickly and reliably formed as compared with the case where an exposed portion is formed other than the inner peripheral end portion and the electrode tab is provided. The separator 7 corresponding to the portion where 1 is exposed is melted.

Although not particularly shown, an electrode tab for connecting the external electrode to the exposed portion of the copper foil 4 of the negative electrode 6 opposed to the exposed portion of the aluminum foil 1 of the positive electrode 3 via the separator 7 is arranged. Even if it is installed, when the battery is overcharged due to an abnormality in the charging circuit or the like, a large amount of current flows to this electrode tab, the temperature near the electrode tab becomes higher than other parts, and this electrode tab becomes The facing 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 thermal decomposition of the positive electrode active material is performed. The battery can safely be internally short-circuited without causing an abnormal rise in the temperature of the battery due to the above.

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) are opposed to each other at least one round from the inner peripheral end via the separator. For example, when a pressure is applied from the outside, there is always one or more places where the metal of the positive electrode and the metal of the negative electrode are surely short-circuited without passing through the positive electrode active material on the extension line of the pressure, so that the resistance is low. Can be short-circuited.

Although not shown, by applying a conductive coating such as graphite to the exposed portion of the aluminum foil of the positive electrode, oxidation of the surface of the aluminum foil is prevented and a good conductive state is always obtained. In addition, as the conductive coating, when coating the positive electrode active material on the aluminum foil, a coating of graphite or the like previously applied as an anchor layer to the aluminum foil to improve adhesion is used as the conductive coating as it is. May be used.

FIG. 3 is a schematic sectional view showing another embodiment of the non-aqueous battery of the present invention. In this nonaqueous battery, a positive electrode metal foil (aluminum foil) 11 having a positive electrode active material layer 21 made of a lithium composite oxide on one side and an aluminum foil 12 having a positive electrode active material layer 22 formed on one side are also mutually bonded. A positive electrode 3 in which exposed surfaces having no active material layer are overlapped with each other; a negative electrode 6 in which a negative electrode active material layer 5 made of a carbonaceous material is formed on both surfaces of a negative electrode metal foil (copper foil) 4; A wound laminated assembly including a separator 7 made of a microporous polyethylene film or the like interposed between the positive electrode 3 and the negative electrode 6 is housed in a casing 8 connected to be an external electrode of the negative electrode. Things.

In this non-aqueous battery, only the inner aluminum foil 12 is wound around the outer periphery of the positive electrode 3 for about one round, and the outer aluminum foil 11 is absent.
That is, in one outer circumferential portion, the exposed portion of the positive electrode aluminum foil 12 and the negative electrode casing 8 face each other with the separator 7 interposed therebetween. In order to manufacture such a positive electrode 3, when two aluminum foils 11 and 12 are overlapped, one of them may be shifted by a length corresponding to one turn.

When a conductor such as an iron nail 19 in FIG. 4 penetrates through the casing 8 and penetrates the inside of the non-aqueous battery, the conductor is integrated with the casing 8 as the negative electrode when the casing 8 penetrates. The tip of the iron nail 19
First, the aluminum foil 12 of the positive electrode 3 is penetrated, then the positive electrode active material layer 22, the negative electrode active material layer 5, and the copper foil 4. . . , And penetrate while generating a short circuit between positive and negative electrodes in the order of A, B, C, D, and E (separator is omitted).

As described above, although the iron nail 19 eventually short-circuits the positive electrode active material layer and the negative electrode, the iron nail 19 that has broken through the casing 8 first short-circuits with the aluminum foil 12 of the positive electrode 3. The first short-circuit A has a sufficiently low resistance as compared with B, C, D and E in which the iron nail 19 penetrates the positive electrode active material later, and has a sufficiently low resistance. Most of the current flows between the casing 8 and the aluminum foil 12 through the nail 19 in the area A, whereby the non-aqueous battery of the present invention is safely internally short-circuited 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 is melted before the inner peripheral separator 7. First, the aluminum foil 12 of the positive electrode facing the casing 8 via the separator 7 on the outer peripheral side and the casing 8 are short-circuited in a low resistance state in a portion where the separator is melted. As a result, the battery is safely internally short-circuited without being supplied with electricity to the positive electrode active material and without causing an abnormal temperature rise.

FIGS. 5 to 8 show the structural characteristics at 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. 3 is a schematic cross-sectional view of four different embodiments of the non-aqueous battery of the present invention, designed to have structural features at the outer peripheral edge of the laminated electrode assembly. Less than,
The structure and effect of the inner peripheral end and outer peripheral end of each of the wound laminated electrode assemblies in these four aspects will be described.

FIG. 5 shows still another example of the nonaqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the nonaqueous battery of this embodiment, the positive electrode metal foil (aluminum foil) 1 of the positive electrode 3
There is a portion in which the aluminum foil 1 is exposed without the positive electrode active material layers 2 on both sides over about two rounds from the inner circumferential end of the metal foil, and then a part in which one round is exposed on one side is provided. . In the portion where the aluminum foil 1 is exposed, the portion where the negative electrode metal foil (copper foil) 4 does not have the negative electrode active material on both sides for about two turns via the separator 7 faces the portion where the copper foil 4 is exposed. Yes,
When the separator 7 is broken, the exposed metal portions of the positive electrode and the negative electrode are designed to be short-circuited.

Further, in the non-aqueous battery shown in FIG.
Even at the outer peripheral end of the wound laminated electrode assembly, about 2
There is a portion where the aluminum foil 1 is exposed without the positive electrode active material layer 2 on both sides over the circumference, and a portion where one side of the aluminum foil 1 is exposed is provided subsequently. The portion where the aluminum foil 1 is exposed is wound by the aluminum foil 1 alone without the interposition of the separator 7, but since there is a metal casing which is 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 with the separator 15 interposed therebetween.

When a conductor such as a sharp iron nail penetrates through the casing 8 to penetrate the nonaqueous battery and penetrates the inside of the casing 8, most of the short-circuit current is conducted between the casing and the casing, as in the embodiments of FIGS. The current flowing between the positive electrode active material layer 2 and the current flowing through the positive electrode active material layer 2 is suppressed sufficiently even if the iron nail flows through the positive electrode active material 2 later. Internal short circuit safely without abnormal temperature rise of battery due to decomposition.

In this embodiment, a separator made of an ion insulating material is interposed between the aluminum foil 1 and the casing 8 as described above. 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, so that the separator disposed at this position does not need to have ion permeability. Therefore, since a durable insulating film having no ion permeability can be used, the outermost peripheral separator is damaged due to 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 occurrence rate of defective products in which the casing and the electrode body are short-circuited from the initial state can be reduced.

FIG. 6 shows another example of the nonaqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the nonaqueous battery of this embodiment, the positive electrode metal foil (aluminum foil) 1 of the positive electrode 3
There is a portion where the aluminum foil 1 is exposed without the positive electrode active material layers 2 on both sides over about two rounds from the inner peripheral end portion. The portion where the aluminum foil 1 is exposed is a portion where the negative electrode metal foil (copper foil) 4 is exposed to the copper foil 4 without the negative electrode active material on both sides for about one round via the separator 7, The metal foil (copper foil) 4 is opposed to the portion where the copper foil 4 is exposed for about one round without the negative electrode active material on one side, and the separator 7
Is designed so that when the metal is broken, the exposed metal portions of the positive electrode and the negative electrode are short-circuited to each other.

Further, in this embodiment, instead of the pipe-shaped core 13, a slit-shaped core 14 which is partially cut out in the axial direction and has a substantially C-shaped cross section is used. The edge of this slit portion works to pierce the wound laminated electrode assembly from the inside, so that the insulating film at the inner peripheral end portion is more quickly and surely broken, and the exposed metal portion of the aluminum foil of the positive electrode and the copper foil of the negative electrode are removed. It is designed to short-circuit with the exposed metal part quickly and reliably 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 so as not to impair the rigidity, the effect of the edge piercing the wound laminated electrode assembly can be obtained. To increase
In addition, a stable effect can be exerted even when compression is applied from any direction of 360 degrees with respect to the winding axis of the electrode assembly.

Although not particularly shown, instead of the core having the slit, a protrusion or a ridge may be provided on the outer periphery, or a spiral body such as a screw or a spring may be inserted into the center of the wound laminated electrode assembly. Can obtain substantially the same effect. As described above, in the non-aqueous battery of the embodiment shown in FIG. 6, the outer peripheral side of the outer peripheral end of the aluminum foil 1 which is the positive metal foil 1 of the positive electrode 3 is exposed about one round on one side. When the copper foil 4 of the negative electrode is wound on the outer peripheral side of the portion where the aluminum foil 1 is exposed via a separator 7 so as to cover both sides of the negative electrode for approximately one round, and the separator 7 is broken at this portion. As in the non-aqueous battery of the embodiment shown in FIG. 3, a safe low-resistance short-circuit portion is realized.

That is, in the embodiment shown in FIG. 3 described above, the aluminum foil 12 of the positive electrode is exposed on the outermost periphery of the wound laminated electrode assembly for about one round, and this is interposed between the inner wall of the negative electrode casing 8 via the separator 7. However, the structure of the outer peripheral end 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 Even if the negative electrode 6 formed with the negative electrode active material layer 5 interposed therebetween, substantially the same effect can be obtained when a conductor such as an iron nail is inserted.

Further, for example, when the negative electrode 6 with the copper foil 4 exposed is interposed as in the non-aqueous battery of the embodiment of FIG. 6, the aluminum foil 1 of the positive electrode is short-circuited with the copper foil 4 instead of the casing 8. 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 non-metallic resin, for example. Moreover,
When the copper foil 4 is wound around the outermost periphery of the electrode assembly as in this embodiment, the same effect as that of the other negative electrode casing is realized by inserting the copper foil 4 into a casing having the same potential as the positive electrode. It goes without saying that.

FIG. 7 shows still another example of the nonaqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the non-aqueous battery of this embodiment, a sheet-shaped aluminum foil 9 having a thickness of about 100 μm and having no cathode active material layer and having substantially the same width as the aluminum foil is provided on the inner peripheral end of the aluminum foil 1 having a thickness of 15 μm. Electrically and mechanically connected together, about 2
It is the one wound around. The copper foil 4 is connected to the copper foil 4 so as to be electrically and mechanically integrated with the copper foil 4 at an inner circumference of the 18 μm copper foil 4 for about one round from the inner circumference.
A sheet-shaped copper foil 11 having substantially the same width as that of the above and having no negative electrode active material and having a thickness of 100 μm, and then a negative electrode metal foil (copper foil) 4 is wound around the circumference 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 embodiment,
Like the non-aqueous battery of FIG. 6, a stainless steel core having a slit is used, so that when the casing receives a compressive force, the stainless steel core pierces the 100 μm aluminum foil 9 and the 100 μm copper foil 11 from the inside. In this case, a 15 μm aluminum foil 1 and 18 μm
As compared with the case where the copper foil 4 of m.m. is pierced, there is an effect of realizing a more reliable and low-resistance electrical conduction state.

In this non-aqueous battery, a portion where the metal extension 9 from the positive electrode metal foil 1 faces the negative electrode metal foil 4 and the metal extension 11 therefrom is formed of an ion-insulating separator material. A separator thinner than the separator 7 is interposed. Generally, the separator requires ion permeability for expressing the battery function together with the electronic insulation, and also has a considerable number of pores inside to hold the electrolyte, and to maintain the mechanical strength. Can not make the film thickness too thin. However, in the facing portion between the exposed metal portions in the non-aqueous battery of the present invention, as long as the separator has electronic insulation, ion permeability for expressing the battery function is unnecessary,
A separator having a small thickness can be freely selected and used. This enables a design that effectively utilizes the volume in the casing and increases the battery capacity without compromising high safety.

As described above, on the outer periphery of the electrode assembly of the non-aqueous battery of the embodiment shown in FIG. 7, a 100 μm sheet having substantially the same width and having no positive electrode active material is formed on the outer peripheral end 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. In the negative electrode portion facing the aluminum foil 9, the copper foil 4 is exposed on one side on one side, and this portion has already realized the necessary exposed metal portions of the positive electrode and the negative electrode.
Therefore, if the casing is a negative electrode, it is more effective, but the present invention is not limited to this. As in the embodiment of FIG. 6, the casing may be a positive electrode, or a nonmetallic container such as a resin or a bag made of a film. It may be something like that.

As shown in FIG. 7, the outermost portion of the electrode assembly where the aluminum foil 1 is exposed,
When the non-aqueous battery inserted into the negative electrode casing 8 covered with the separator 16 having a lower melting point than the separator 7 is abnormally heated from the outside, the separator 16 having the lower melting point than the separator 7 closest to the casing 8 is connected to the positive electrode. Melting starts before the separator 7 separating 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 internally short-circuited without causing an abnormal temperature rise of the battery. Although such an effect has already been described as being exerted also in the non-aqueous battery of the embodiment of FIG. 3 in which the outermost periphery is covered with the separator 7, the separator 16 having a lower melting point than the separator 7 as in the embodiment of FIG.
The effect can be more remarkably realized by using.

FIG. 8 shows another example of the nonaqueous battery of the present invention.
It is a schematic sectional drawing which shows one aspect. In the nonaqueous battery of this embodiment, the positive electrode metal foil (aluminum foil) 1 of the positive electrode 3
There is a portion where the aluminum foil 1 is exposed on both sides over about two turns from the inner peripheral end, and a portion where one side is exposed on one side is provided. The exposed portion of the aluminum foil 1 is opposed to the metal lithium foil of the negative electrode via the separator 7. In this embodiment, even if the exposed portion of the current collector metal foil such as a copper foil is not provided, the negative electrode itself is not provided. Is a metal and has a sufficiently low electric resistance, so that when the separator 7 breaks, a low-resistance short circuit between the metals is realized between the aluminum foil 1 of the positive electrode and the battery is safely internally short-circuited. I 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 aluminum foil 1 is exposed on one side at the outer peripheral end of the positive metal foil 1 of the positive electrode 3. It faces a metal casing which is at the same potential as the negative electrode via a separator formed of an ion-insulating separator material. The mechanism for safely internally short-circuiting is almost the same as that 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 side, the structure of the negative electrode casing When a separator formed of an ion-permeable separator material is interposed between the electrodes, particularly when left over-discharged, ions dissolve out of the negative electrode casing material and move and precipitate on the positive electrode surface, or a hole is formed in the casing. There is also a concern that electrolyte leakage may occur. Also, when charging a non-aqueous secondary battery having a similar structure, a small amount of lithium ions migrate and precipitate from the positive electrode active material at the outer peripheral end A of the positive electrode to the casing serving as the negative electrode. It is not preferable. Therefore, the above-described disadvantage is solved by shutting off the space between the casing and the casing by the separator formed of the ion-insulating separator material as in the embodiment of FIG.

In each of the above-described embodiments, only the columnar non-aqueous battery in which the separator is interposed between the positive electrode and the negative electrode and the electrode assembly formed by winding and laminating the separator is accommodated is described. The configurations of the above-described embodiments of the present invention can be applied to a thin rectangular non-aqueous 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-shaped casing, a wound laminated electrode assembly having the same structure as that described in the above embodiment is press-formed so as to have a flat elliptical cross section. Alternatively, it may be wound into an oval shape from the beginning. Further, of course, the present invention is not limited to a wound laminated electrode assembly, but may be a simple laminated electrode assembly as shown in FIGS. 9 and 10 or a zigzag laminated as shown in FIGS. 11 and 12. Even if the electrode assembly is
A similar effect can be exerted.

In order to cope with external heating or a case where an iron nail is stabbed in the battery, in the case of a wound electrode assembly, at least one round of aluminum is provided around the outer peripheral end of the positive electrode metal foil of the positive electrode. Preferably, the foil is exposed to face the casing, but may be used in thin rectangular non-aqueous batteries, such as a simple stacked electrode assembly as shown in FIGS. 9 and 10 or as shown in FIGS. 11 and 12. In an electrode assembly folded in a zigzag stack, it is not necessary to arrange one or more rounds of the aluminum foil facing the casing on the outer periphery of the electrode assembly. This is because, considering the surface affected by the outside, in the case of the battery having the above-described structure, it is sufficient that the exposed metal portions of the positive electrode and the negative electrode are disposed on the surfaces of a pair of opposing layers. is there.

FIG. 9 is a schematic sectional view showing one embodiment of a non-aqueous battery of the present invention containing a simple laminated electrode assembly. In the non-aqueous battery of the embodiment shown in FIG. And a negative electrode layer in which the aluminum foil 1 is exposed on one side and a negative electrode layer in which the copper foil 4 is exposed on one side.
A separator 7 and a rigid or elastic body 18 as a conductor are interposed between them.

FIG. 10 is a schematic sectional view showing another embodiment of the non-aqueous battery of the present invention containing a simple laminated electrode assembly. In the non-aqueous battery of this embodiment, a positive electrode is provided on the outermost layer of the electrode assembly. Aluminum foil 1 of metal foil
Has a portion exposed on one side, and is opposed to the negative electrode casing 8 by metal. FIG. 11 is a schematic cross-sectional view showing one embodiment of the non-aqueous battery of the present invention containing a zigzag laminated electrode assembly. In the non-aqueous battery of this embodiment, the outer layer end of the zigzag laminated electrode assembly,
The metal extension portion 11 for extending the copper foil 4 as the negative electrode metal foil and the single-sided exposed portion of the aluminum foil 1 as the positive electrode metal foil are opposed to each other at the exposed metal portion, and the separator 7 or a separator material having a small thickness is formed therebetween. When a compressive force is applied from the outside in the vertical direction in the figure after the separator 17 is interposed, a low-resistance short circuit is positively realized therebetween.
A conductive rigid body or elastic body for applying 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 serving as the positive metal foil is exposed on one side at the outer layer end of the zigzag laminated electrode assembly, and the copper foil 4 serving as the negative metal foil are electrically connected. Metal extension 1 connected and extended
1, the exposed metal portions are opposed to each other, and a separator 7 and a rigid or elastic body 18 as a conductor are interposed therebetween.

FIG. 12 is a schematic cross-sectional view showing another embodiment of the non-aqueous battery of the present invention containing a zigzag laminated electrode assembly. In the non-aqueous battery of this embodiment, the portion where the positive electrode metal foil 1 is exposed on both sides in the outer layer of the electrode assembly is bent, and the 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, it is attempted to realize a more reliable low-resistance short-circuit portion by further inserting this into the negative electrode casing.

9 and 11, the conductor denoted by 18 is, for example, as shown in FIG.
Thickness 100-500 folded in zigzag at 000 μm
μm stainless steel plate, or a thickness 5 with 100-1000 μm deep striped irregularities on the surface
A stainless steel plate of 00 to 2000 μm or the like can be used. When the battery receives a compressive force from the outside in the vertical direction as in the embodiments of FIGS. 9 and 11, the convex portion of the conductor 18 applies a local pressing force to the separator 7 to positively The separator 7 is ruptured to short-circuit the exposed metal parts of the positive electrode and the negative electrode facing each other with low resistance, and internally short-circuit safely.

Needless to say, a separator formed of an ion-insulating separator material or a separator formed of a relatively low material is provided between the casing and the simple laminated electrode assembly or the zigzag laminated electrode assembly.
By using a separator having a smaller film thickness than the separator between the positive and negative active material layers, the same effect as described in the embodiment of the wound lamination can be obtained.

[0086]

The non-aqueous battery of the present invention has a unique electrode assembly structure, so that the casing is crushed by external pressure, overcharged due to an abnormality in the charging circuit or the like, and nails or the like are damaged. Safety that can prevent a sudden rise in battery temperature due to an internal short circuit between metals with sufficiently low electrical resistance, even in the event of an accident such as stabbing or abnormal heating from outside. It is a non-aqueous battery with excellent characteristics.

[Brief description of the 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 sectional view showing a state where the non-aqueous battery of FIG. 1 is crushed.

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

FIG. 4 is a schematic sectional view showing a state in which an iron nail is inserted into the non-aqueous battery of FIG. 3;

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

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

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

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

FIG. 9 is a schematic cross-sectional view showing one embodiment of the 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 a simple laminated 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 stacked electrode assembly.

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

[Explanation of symbols]

REFERENCE SIGNS LIST 1 positive electrode metal foil 2 positive electrode active material layer 3 positive electrode 4 negative electrode 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 metal foil 10 positive electrode tab 11 negative electrode metal Metal extension from foil 12 Negative electrode tab 13 Pipe-shaped core 14 Core with slit 15 Separator made of ion-insulating separator material 16 Separator made of material having relatively low melting point 17 Thinner than 7-separator Separator 18 Conductive rigid or elastic body 19 Iron nail

Claims (13)

(57) [Claims] 1. A casing, (2) 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 cooperate with the non-aqueous electrolyte. A non-aqueous battery comprising a wound laminated electrode assembly, wherein the wound laminated electrode assembly (3) has a positive electrode active material layer (a) on at least one surface of a positive electrode metal foil (a-1) functioning 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 include 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.The battery has a metal part having the same potential as the positive electrode provided in association with the positive electrode, and the metal part having the same potential as the positive electrode is provided. Positive on at least one side By having a portion where the active material layer is not formed, a positive electrode equipotential exposed metal portion (α) extending in the longitudinal direction over one or more turns is formed. 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 over one or more turns. 2. The non-aqueous battery according to claim 1, wherein the positive electrode equipotential metal portion has portions on both surfaces of which no positive electrode active material layer is 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) functioning as a negative electrode current collector.
-2) or a negative electrode active material metal foil (b−) that functions as both a negative electrode active material layer and a 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 surface thereof together with an electrical connection. (C) an exposed metal portion not having at least one surface of the negative electrode active material layer (b-2) of the negative electrode metal foil (b-1); (d) a negative electrode active material metal foil (b) (E) a negative electrode active material metal foil (b-) as a negative electrode active material layer on at least one surface of the negative electrode current collector metal foil (b-4).
3) Exposed metal portion not having, and (f) inner peripheral edge of negative electrode metal foil (b-1), negative electrode active material metal foil (b-3) or negative electrode current collector metal foil (b-4) The nonaqueous battery according to claim 1, wherein the nonaqueous battery is at least one portion selected from a metal extension portion electrically connected to and extended from at least one end of the outer peripheral end. 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) functioning 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 method according to claim 1, wherein the positive electrode equipotential exposed metal portion (α) is
(G) an exposed metal portion on at least one surface of the positive electrode metal foil (a-1) which does not have the positive electrode active material layer (a-2) at the outer peripheral end thereof; and (h) a positive electrode metal foil (a-1). The non-aqueous battery according to any one of claims 1 to 4, wherein the non-aqueous battery is at least one portion selected from a metal extension portion electrically connected to and extending from an outer peripheral end of the non-aqueous battery. 6. The positive electrode equipotential exposed metal part (α)
(G) an exposed metal portion on at least one side of the positive electrode metal foil (a-1) which does not have a positive electrode active material layer (a-2) at an inner peripheral end thereof; and (h) a positive electrode metal foil (a- The non-aqueous battery according to any one of claims 1 to 4, wherein the non-aqueous battery is at least one portion selected from a metal extension portion electrically extended from an inner peripheral end portion of 1). 7. The above-mentioned positive electrode equipotential exposed metal portion (α)
The non-aqueous battery according to any one of claims 1 to 6, further comprising an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to the positive electrode at an equal potential. 8. The negative electrode equipotential exposed metal portion (α) includes:
The non-aqueous battery according to any one of claims 1 to 6, further comprising an electrode tab for connecting an external electrode located outside the wound laminated electrode assembly to the negative electrode at an equal potential. 9. The separator comprises a first separator portion (S1) and a second separator portion (S2). The first separator portion (S1) comprises a positive electrode active material layer of a positive electrode and a negative electrode active material layer of a negative electrode. At least one opposing first
And the second separator portion (S2) is located in at least one second region where the positive electrode equipotential exposed metal portion (α) and the negative electrode equipotential exposed metal portion (β) face each other. And the first separator portion (S1) is formed of an ion-permeable separator material, and the second separator portion (S2) is formed of a separator material selected from an ion-insulating separator material and an ion-permeable separator material. 7. The method according to claim 1, wherein
Non-aqueous battery according to any of the above . 10. The melting point of the second separator portion is 1
The non-aqueous battery according to claim 9, wherein the temperature is at least 00 ° C. and at least 5 ° C. lower than the melting point of the first separator portion. 11. A core formed of a rigid body and an elastic body is inserted into the center of the wound of the wound laminated electrode assembly, and when the casing is subjected to a compressive force, the wound laminated electrode assembly is connected to the casing and the core. The non-aqueous battery according to claim 1, wherein the non-aqueous battery is compressed. 12. A non-aqueous electrolyte contained in a space defined by (1 ′) a casing, (2 ′) an inner wall of the casing, and (3 ′) in the space so as to cooperate with the non-aqueous electrolyte. A non-aqueous battery comprising a stored simple laminated electrode assembly, wherein the simple laminated electrode assembly (3 ') is a plurality of layers of positive electrodes electrically connected to each other, wherein each positive electrode serves as a positive electrode current collector. Functional positive electrode 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, wherein each negative electrode comprises a negative electrode active material layer; A separator having a plurality of layers, 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 stacked so as to face each other with the separator interposed therebetween.The battery has a metal part having the same potential as the positive electrode provided in association with the positive electrode, and the positive electrode equipotential metal part has at least its metal part. By having a portion where the positive electrode active material layer is not formed on one side, a positive electrode equipotential exposed metal portion (α ′) having a length of at least one layer is formed, and the above positive electrode equipotential exposed metal portion (α ′) is formed. Is the negative electrode provided in connection 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 non-aqueous electrolyte contained in a space defined by (1 ″) a casing, (2 ″) a space defined by an inner wall of the casing, and (3 ″) in the space so as to cooperate with the non-aqueous electrolyte. A non-aqueous battery comprising a housed spiral folded electrode assembly, wherein the spiral folded electrode assembly (3 ") has a positive electrode active material formed on at least one surface of a positive electrode metal foil (a" -1) functioning as a positive electrode current collector. A positive electrode having the layer (a ″ -2) formed thereon, a negative electrode including the negative electrode active material layer, and a separator interposed between the positive electrode and the negative electrode. The negative electrode active material layers are folded in a zigzag manner so as to face each other with the separator interposed therebetween. The battery has a metal part having the same potential as the positive electrode provided in association with the positive electrode, and The metal portion has at least one side on which a positive electrode active material layer is not formed, thereby forming a positive electrode equipotential exposed metal portion (α ″) having a length of at least one layer. The non-aqueous battery characterized in that the portion (α ″) is located facing the negative electrode equipotential exposed metal portion (β ″) provided in connection with the negative electrode over a length of at least one layer. .