JP2001143763A - Flat non-aqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide flat, non-aqueous electrolyte secondary battery, which has a small size and an excellent heavy load discharging characteristic. SOLUTION: A flat, non-aqueous electrolyte secondary battery includes a battery case serving as an electrode terminal. A hole is made in a portion of a cover plate closing up an entry to the cell case, and a second electrode terminal is disposed in the hole. The cover plate is electrically insulated from the second electrode terminal with an insulator. Also, the battery has power generating elements at least including a positive electrode, a separator and a negative electrode, as well as a non-aqueous electrolyte. As the total of opposed areas of the positive and negative electrodes is larger than the area of the cover plate, they are provided with advantages of a small cell size and high productivity. In addition, the heavy load discharging characteristics can be significantly improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat non-aqueous electrolyte secondary battery, and more particularly to a flat non-aqueous electrolyte secondary battery having improved heavy load discharge characteristics.

[0002]

_2. Description of the Related Art Metal oxides such as MnO ₂ and V ₂ O ₅ or inorganic compounds such as fluorinated graphite are used as positive electrode active substances.
Alternatively, an organic compound such as polyaniline or a polyacene structure is used, and a metal lithium or an organic compound such as a lithium alloy or a polyacene structure, or a carbonaceous material capable of absorbing and releasing lithium, or containing lithium titanate or lithium is used as a negative electrode. Using an oxide such as silicon oxide, the electrolyte is propylene carbonate, ethylene carbonate, butylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, dimethoxyethane, γ-butyl lactone in a non-aqueous solvent such as LiClO ₄ , LiPF ₆ , LiBF ₄ , L
iCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN
Flat non-aqueous electrolyte secondary batteries such as coin-shaped and button-type batteries using a non-aqueous electrolyte in which a supporting salt such as (C ₂ F ₅ SO ₂ ) ₂ is dissolved have already been commercialized, and the discharge current is several to several. It is applied to applications such as a backup power supply for SRAMs and RTCs that discharge at a light load of about several tens of μA, and a main power supply for wristwatches that do not require battery replacement.

On the other hand, the miniaturization of devices used has been accelerated, especially for small information terminals such as mobile phones and PDAs, and accordingly, it is essential to reduce the size of secondary batteries as main power supplies. I have. Conventionally, these power sources include lithium-containing oxides such as lithium cobalt oxide as the positive electrode active substance,
Lithium ion secondary battery using carbonaceous material for negative electrode,
Nickel-metal hydride storage batteries using nickel oxyhydroxide as the positive electrode active material and a hydrogen storage alloy as the negative electrode active material have been used, but these batteries apply an active material layer to a current collector consisting of metal foil or metal net. After filling and forming the electrode, the tab terminal is welded to the center of the electrode, then wound or laminated to form an electrode group, and the tab terminal taken out from the center of the electrode group is subjected to complicated bending processing to ensure safety. Batteries were manufactured by welding to elements, sealing pins, and battery cans.

[0004]

SUMMARY OF THE INVENTION In order to obtain a small and high-power battery, the present inventors first attempted to reduce the size of a cylindrical or prismatic lithium ion secondary battery. However, when trying to reduce the size, the tab connection taken out from the center of the electrode group as described above is complicatedly bent, and the safety element, the sealing pin, and the electrode connection work of welding to the battery can and the like are difficult work, It required skill.

Next, the application of a battery in which the positive electrode and the negative electrode were formed into a tablet shape slightly smaller than the opening diameter of the sealing plate, such as a button shape or a coin shape, was examined. It is far less satisfactory for the characteristics when discharged with a large current, and was not at a level that was satisfactory as a main power source for small portable devices.

It is an object of the present invention to raise the heavy load discharge characteristics of a small flat non-aqueous electrolyte secondary battery to an unprecedented level, and it is an object of the present invention to provide a flat non-aqueous electrolyte with remarkably excellent heavy load discharge characteristics. It is an object of the present invention to provide an electrolyte secondary battery.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on miniaturization of a cylindrical or prismatic lithium ion secondary battery. It has been found that the heavy load discharge characteristics are dramatically improved by making the size significantly larger than that of a conventional flat battery.

That is, a metal battery case also serving as an electrode terminal, a part of a sealing plate for sealing the battery case is opened, and another electrode terminal is arranged in the opening, and a sealing plate also serving as an electrode terminal and the other. A pole terminal is electrically insulated by an insulator, and a power generating element including at least a positive electrode, a separator, and a negative electrode therein, and a flat nonaqueous electrolyte secondary battery including a nonaqueous electrolyte, wherein It has been found that by providing a flat nonaqueous electrolyte secondary battery in which the sum of the positive and negative electrode facing areas is larger than the area of the sealing plate, the heavy load discharge characteristics are dramatically improved.

In the flat nonaqueous electrolyte secondary battery of the present invention,
For miniaturization of cylindrical or prismatic lithium ion secondary batteries, in order to improve workability, part of the sealing plate that seals the battery case is opened, and another electrode terminal is arranged in this opening, A current collecting plate electrically integrated with the other electrode terminal is arranged, and the positive electrode or the negative electrode is electrically connected to the current collecting plate and the positive electrode or the negative electrode via the separator housed in the battery, so that the electrode and the terminal are connected to each other. Contact was easily enabled.

It is supposed that increasing the electrode area is effective for improving the heavy load discharge characteristics. However, in the conventional flat nonaqueous electrolyte secondary battery, the positive and negative electrodes are opposed to each other via a separator. The facing area must inevitably be slightly smaller than the opening area of the sealing plate, and it was theoretically impossible to store an electrode having a facing area exceeding the opening area of the sealing plate in the battery. .

The inventors of the present invention have made a bold shift from the prior art and laid out the electrodes in a battery case of a flat battery, so that the sum of the positive and negative electrode facing areas in the electrode group can be sealed. It is possible to store an electrode group larger than the opening area of the plate. As described above, there is an example in which a secondary battery having a large volume such as a cylindrical shape or a rectangular shape contains an electrode having several tens of layers, but as described above, these batteries have a complicated structure, It has been difficult to apply the electrode structures of these batteries to non-aqueous electrolyte secondary batteries. In addition, even if it is applied, it is impossible to maintain the advantages of the flat non-aqueous electrolyte secondary battery such as being small and having excellent productivity. No effort has been made in the past to accommodate an electrode group having a positive and negative electrode facing area larger than the opening area.

Hereinafter, how the present inventors have realized the flat nonaqueous electrolyte secondary battery of the present invention will be described. First, various forms can be considered for storing an electrode in which the positive and negative electrode facing areas are larger than the opening area of the sealing plate in the flat nonaqueous electrolyte secondary battery. It was found that it is preferable to house the electrodes as an electrode group in which the electrodes are stacked so as to have the positive and negative electrode facing portions in the horizontal direction. Because, in order to obtain excellent heavy load discharge characteristics, the electrode area should be as large as possible, the number of parts should be reduced as much as possible, the space in the small battery should be used effectively, and the electrode group and the amount required for discharge should be reduced. It is necessary to store the water electrolyte in the battery, and this storage method can realize these. According to this storage method, the method of assembling the battery except for the electrodes is similar to the method of manufacturing a flat battery using a conventional tablet-like electrode,
Part of the conventional production equipment can be diverted, and it is excellent in practical aspects such as productivity and cost, and is preferable in mass production.

The method of actually preparing and storing an electrode group is as follows. When a positive electrode plate and a negative electrode plate having a current-carrying part provided in a part of the electrodes are prepared, and the positive electrode plate and the negative electrode plate are laminated via a separator, After laminating such that the energized part of the positive electrode plate is exposed from one direction of the separator and the energized part of the negative electrode plate is exposed from the opposite electrode direction, the positive electrode is welded to the positive electrode, and the negative electrode is welded to the negative electrode. It is preferable to form a group of electrodes by electrically connecting the electrodes to each other, and to house them in the battery. By arranging the current-carrying portions of the positive electrode and the negative electrode as counter electrodes, even in a flat nonaqueous electrolyte secondary battery, internal short-circuit due to contact between the current-carrying portions of the positive and negative electrodes can be prevented.

Next, a description will be given of a method of connecting the electrode group to a battery metal case which also serves as an external terminal.

As described above, in the case of a relatively large lithium ion secondary battery having a cylindrical shape or a rectangular shape, a tab terminal is welded to the center or the core of the electrode group, and the tab terminal is bent to form a safety element or a sealing pin. To collect electricity. However, since the bending process is complicated, the productivity is inferior. In addition, it is necessary to provide a space in the battery or to insert an insulating plate between the battery and the electrode group in order to prevent an internal short circuit. Also, when stress is applied to the portion where the tab terminal is welded to the electrode, the separator breaks through, or the electrode is deformed. Could not be used effectively. For this reason, these current collecting methods cannot be applied to a coin-shaped or button-shaped flat non-aqueous electrolyte secondary battery having a small internal volume of the battery, and a new current collecting method has to be devised.

In view of the above, the present inventors have exposed the conductive positive electrode constituent material at one end in the direction parallel to the flat surface of the flat battery in the electrode group, and provided the conductive negative electrode constituent material at the other end of the counter electrode. The present inventors have found that an electrode group having an exposed shape is produced, and that each of the electrode components is brought into contact with the positive and negative electrode battery cases to ensure current collection between the electrode group and the battery case. According to this method, it is not necessary to provide a useless space or an insulating plate between the electrode group and the battery case, and the discharge capacity can be increased. In addition, there is no short circuit between the battery case or the electrode and the tab terminal, and the safety and reliability are excellent.

In a flat battery having a sealed structure as in the present invention, since stress is applied in a direction perpendicular to the flat surfaces of the negative electrode case and the positive electrode case by caulking of the battery case, the flatness of the electrode group is reduced. Uniform pressing force is applied in the direction,
Charge and discharge can be performed smoothly. In addition, the contact between the electrode component exposed portion of the electrode group and the electrode case may be in direct contact, or may be indirectly electrically in contact via a metal foil, a metal net, a metal powder, a carbon filler, a conductive paint, or the like. May be.

As for the electrodes, for the positive and negative electrodes, a conventional method of molding a granular mixture or a method of filling a metallic substrate such as a metal net or foamed nickel with a mixture may be used, but it is easy to produce a thin electrode. In this respect, a slurry mixture is preferably applied to a metal foil and dried, and a rolled product thereof can also be used. When using an electrode in which a mixture layer containing an active substance is applied to such a metal foil, the electrode used inside the electrode group is one in which an active substance layer is formed on both sides of the metal foil. It is preferable from the top, and the electrode component exposed portion that contacts the battery case at both ends of the electrode group may be the active substance layer, but in order to reduce the contact resistance, the metal foil is particularly exposed among the electrode components. Is preferred. In this regard, an electrode having an active substance layer formed only on one side may be used only for this portion, or an active substance layer may be formed on both sides, and then the active substance layer may be removed only on one side.

Next, the electrode structure will be described below.
The electrode group is housed in a metal container and sealed with a sealing plate. In this case, an opening is provided in a part of the sealing plate, and a terminal electrically integrated with the current collector is arranged in the opening. The current collector and the sealing plate are insulated by an insulator. The current collection of the electrodes is performed by a metal container and a current collector, and the polarity of the positive electrode and the negative electrode may be either.

Regarding the battery sealing structure, a metal negative electrode case also serving as a negative electrode terminal and a metal positive electrode case also serving as a positive electrode terminal are fitted via an insulating gasket, and the positive electrode case or the negative electrode case is crimped. Although a crimped sealing structure may be used, it is preferable that the sealing portion of the container which does not transmit moisture in the outside air and has excellent long-term storage properties is sealed by laser welding.

The insulator may be any as long as the sealing plate and the negative electrode terminal are insulated and have excellent airtightness. Examples of the insulator include glass, olefin resins such as polypropylene and polyethylene, epoxy resins, fluorine resins, and the like. Poniphenylene sulfide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polymethylpentene resin, or a mixture of these resins with fillers such as glass fibers can be used.

The flat type non-aqueous electrolyte secondary battery of the present invention mainly focuses on the structure of the battery including the electrodes, and there is no limitation on the positive electrode active material, and MnO ₂ ,
V ₂ O ₅ , Nb ₂ O ₅ , LiTi ₂ O ₄ , Li ₄ Ti ₅
O ₁₂ , LiFe ₂ O ₄ , LiMn ₂ O ₄ , Li ₄ Mn ₅
Metal oxides such as O ₁₂ , Li _0.33 MnO ₂ , lithium cobaltate, lithium nickelate, and lithium manganate;
Alternatively, any of inorganic compounds such as fluorinated graphite and FeS ₂ and organic compounds such as polyaniline and polyacene structures can be applied. However, lithium-containing oxides in which lithium cobalt oxide, lithium nickelate, lithium manganate, mixtures thereof, and some of these elements are replaced with other metal elements, because of their high operating potential and excellent cycle characteristics. In a flat nonaqueous electrolyte secondary battery, which is more preferably used for a long period of time, lithium cobalt oxide is high in capacity, has low reactivity with an electrolyte or moisture, and is chemically stable. Is more preferred.

The negative electrode active material of the flat nonaqueous electrolyte secondary battery of the present invention is not limited, and may be metallic lithium, Li-Al, Li-In, Li-
Sn, Li-Si, Li-Ge, Li-Bi, Li-P
b, etc., an organic compound such as a polyacene structure, or a carbonaceous material capable of absorbing and releasing lithium, or Nb ₂ O ₅ , LiTi ₂ O ₄ , Li
₄ Ti ₅ O ₁₂ , oxides such as Li-containing silicon oxide and Li-containing tin oxide, and nitrides such as Li ₃ N are all applicable, but they have excellent cycle characteristics, low operating potential, A carbonaceous material capable of occluding and releasing Li is preferable because of its high capacity, and natural graphite, artificial graphite, expanded graphite, mesophase pitch fired body, mesophase, The surface spacing of d ₀₀₂ such as pitch fiber fired body is 0.338
A carbonaceous material having a graphite structure of nm or less is more preferable.

In the above-described battery of the present invention, a flat type battery such as a coin type or a button type has been mainly described. The present invention can be applied to a flat battery as well as the present invention.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention and comparative examples will be described in detail. (Embodiment 1) A method of manufacturing a battery according to Embodiment 1 of the present invention is shown in FIG.
This will be described with reference to the sectional view of FIG.

First, with respect to 100 parts by weight of LiCoO ₂ ,
5 parts by weight of acetylene black and graphite powder 5 as conductive agents
Then, 5 parts by weight of polyvinylidene fluoride was added as a binder, and the mixture was diluted and mixed with N-methylpyrrolidone to obtain a slurry-like positive electrode mixture. Next, this positive electrode mixture is applied to one side of a 0.02 mm thick aluminum foil as the positive electrode current collector 2a by a doctor blade method and dried to form a positive electrode active substance containing layer 2b on the aluminum foil surface. did. Thereafter, coating and drying were repeated until the coating thickness of the active substance-containing layer reached 0.39 mm, to produce a single-side coated positive electrode. next,
The coating thickness of the positive electrode active substance-containing layer was 0.39 m per side on both sides of the aluminum foil in the same manner as for the single-side coated positive electrode.
m to form a positive electrode.

Next, styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) were used as binders in 100 parts by weight of the graphitized mesophase pitch carbon fiber powder.
Are added by 2.5 parts by weight, and diluted with ion-exchanged water.
The mixture was mixed to obtain a slurry-like negative electrode mixture. This negative electrode mixture is repeatedly applied and dried on a 0.02 mm-thick copper foil as the negative electrode current collector 4 a in the same manner as in the case of the positive electrode so that the thickness of the negative electrode active substance containing layer 4 b becomes 0.39 mm. This was carried out to produce a single-sided coated negative electrode. Next, a double-sided coated negative electrode was prepared in the same manner as the single-sided coated negative electrode such that the coating thickness of the negative electrode active substance-containing layer was 0.39 mm per side on both surfaces of the copper foil.

These electrodes are 13 mm wide and 13 mm long.
Cut out into a shape with an overhang of 6 mm width and 2 mm length on one side of the square, and then peel off the active substance-containing layer formed on this overhang, expose the aluminum or copper layer, and use it as a current-carrying part. A double-sided and single-sided coated positive electrode plate and negative electrode plate on which an active substance-containing layer having a thickness of 13 mm and a length of 13 mm were formed were produced.

Next, a negative electrode plate coated on both sides is passed through a separator 3 made of a 25 μm-thick microporous polyethylene film on the positive electrode active material-containing layer forming portion of the single-side coated positive electrode plate. Install in the direction facing
, A double-sided coated positive electrode plate is placed so that the current-carrying part faces in the same direction as the previous positive electrode plate, and a single-sided coated negative electrode is further placed via a separator 3 such that the negative electrode active material-containing layer 4b is in contact with the separator surface. The plate was placed so that the current-carrying portion was oriented in the same direction as the previous negative electrode plate, and the positive-electrode current-carrying portion and the negative-electrode current-carrying portion were welded, respectively, to produce an electrode group.

The prepared electrode group was dried at 85 ° C. for 12 hours, and then subjected to insulation treatment by applying SBR to the inner surface side of the positive electrode metal case 1 having an opening diameter of 20 mm and an opening area of 3.14 cm ² . The uncoated side of the single-side coated positive electrode plate of the electrode group (that is, the positive electrode current collector 2a) is disposed so as to be in contact with the bottom surface, and is mixed with a solvent in which ethylene carbonate and methyl ethyl carbonate are mixed at a volume ratio of 1: 1. A non-aqueous electrolyte in which LiPF ₆ was dissolved at a rate of 1 mol / l as a supporting salt was injected. A current collector 8 electrically integrated with the negative electrode terminal 6 is provided at the center of the sealing plate 5.
The uncoated side of the one-side coated negative electrode plate of the electrode group (that is, the negative electrode current collector 4a) is in contact with the electrode group. The negative electrode terminal 6 and the positive electrode case 1 are electrically insulated by a glass seal 7. The positive electrode case 1 and the sealing plate 5 are sealed by laser welding so that the total height is 5 mm.
The flat nonaqueous electrolyte secondary battery of Example 1 having a diameter of 21.0 mm and a diameter of 21.0 mm was produced. The number of the positive and negative electrode facing surfaces via the separator of this battery was three in total, and the total area of the positive and negative electrode facing surfaces was 5.1 cm ² .

Example 2 The coating thickness of the active substance-containing layer per one side of the positive electrode and the negative electrode in the electrode group was 0.2
A battery was produced in the same manner as in Example 1, except that the number of layers of the double-sided coated positive electrode and the double-sided coated negative electrode in the middle of the electrode group was 2 mm, respectively. The total number of the positive and negative electrode facing surfaces via the separator of this battery was five, and the total area of the positive and negative electrode facing surfaces was 8.5 cm ² .

Example 3 The coating thickness of the active substance-containing layer per one side of the positive electrode and the negative electrode in the electrode group was 0.1, respectively.
A battery was produced in the same manner as in Example 1, except that the number of laminated layers of the double-sided coated positive electrode and the double-sided coated negative electrode in the middle of the electrode group was 3 mm, respectively. The total number of the positive and negative electrode facing surfaces via the separator of this battery was seven, and the total area of the positive and negative electrode facing surfaces was 11.8 cm ² .

Example 4 The coating thickness of the active substance-containing layer per one side of the positive electrode and the negative electrode in the electrode group was 0.1, respectively.
A battery was produced in the same manner as in Example 1, except that the number of layers of the double-sided coated positive electrode and the double-sided coated negative electrode in the middle of the electrode group was 4 mm, respectively. The number of the positive and negative electrode facing surfaces via the separator of this battery was nine in total, and the total area of the positive and negative electrode facing surfaces was 15.2 cm ² .

Comparative Example 1 5 parts by weight of acetylene black and 5 parts by weight of graphite powder were added as conductive agents to 100 parts by weight of LiCoO _2, and 5 parts by weight of polytetrafluoroethylene were added as a binder. The mixture was pulverized to obtain a granular positive electrode mixture. Next, this positive electrode granule mixture was subjected to pressure molding to a diameter of 19 mm and a thickness of 1.15 mm to obtain a positive electrode tablet.

Next, 2.5 parts by weight of styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) were added as binders to 100 parts by weight of the graphitized mesophase pitch carbon fiber powder, mixed, dried, and further pulverized. A granular negative electrode mixture was obtained. This negative electrode granule mixture was pressure-formed to a diameter of 19 mm and a thickness of 1.15 mm to obtain a negative electrode tablet. These positive and negative electrode tablets were placed at 85 ° C for 1 hour.
A battery was fabricated in the same manner as in Example 1, except that the battery dried for 2 hours was used.

FIG. 2 is a sectional view of the battery of Comparative Example 1, and FIG.
Is a positive electrode case, 2 is a positive electrode, 3 is a separator, 4 is a negative electrode,
Reference numeral 5 denotes a sealing plate, 6 denotes a negative electrode terminal, 7 denotes an insulator, and 8 denotes a negative electrode current collector plate. The number of positive and negative electrode facing surfaces via the separator of this battery is one, and the total area of the positive and negative electrode facing surfaces is 2.8.
cm ² .

(Comparative Example 2) A battery was prepared in the same manner as in Example 1 except that the positive electrode and the negative electrode in the electrode group were only single-side coated electrodes, and the coating thickness of the active substance-containing layer was 1.24 mm. Was prepared. The number of positive and negative electrode facing surfaces via the separator of this battery was one in total, and the total area of the positive and negative electrode facing surfaces was 1.7 cm ² .

Each of the batteries of this example and the comparative example produced as described above was subjected to a constant current and constant voltage of 4.2 V and 3 mA.
The first charge was performed for 8 hours. Thereafter, discharging was performed at a constant current of 30 mA to 3.0 V to determine a heavy load discharge capacity. Table 1 shows the results.

[0039]

[Table 1]

As is clear from Table 1, in each of the batteries of this example, the areas of the positive and negative electrodes using the tablet-shaped electrodes produced by the conventional granule mixture molding method of Comparative Example 1 were larger than the area of the sealing plate. Battery and the opposite surface of the positive and negative electrodes of Comparative Example 2 is 1
As compared with a battery having only one surface and a small facing area, the discharge capacity at the time of heavy load discharge is remarkably large.

In the embodiments of the present invention, a flat non-aqueous solvent secondary battery using a non-aqueous solvent as a non-aqueous electrolyte has been described. However, a polymer secondary battery using a polymer electrolyte as a non-aqueous electrolyte has been described. Of course, the present invention is also applicable to a solid electrolyte secondary battery using a solid electrolyte, and a polymer thin film or a solid electrolyte membrane can be used instead of a resin separator. Also, the positive and negative electrodes can be exchanged. Further, the shape of the battery does not need to be a perfect circle, and the present invention can be applied to a flat nonaqueous electrolyte secondary battery having a special shape such as an oval shape or a square shape.

[0042]

As described above, according to the present invention,
The flat battery has a small battery size, and while maintaining the advantages of excellent productivity, the discharge capacity during heavy load discharge can be significantly larger than that of conventional batteries. A flat nonaqueous electrolyte secondary battery can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a battery according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a battery of Comparative Example 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Positive electrode case, 2 ... Positive electrode, 2a ... Positive electrode collector, 2b ...
Positive electrode active substance containing layer, 3 ... separator, 4 ... negative electrode, 4a
... negative electrode current collector, 4b ... negative electrode active material containing layer, 5 ... sealing plate, 6 ... negative electrode terminal, 7 ... insulator, 8 ... negative electrode current collector plate (negative electrode case).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Udagawa 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Battery Corporation (72) Inventor Masaki Shikoda 3-4-1-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Corporation (72) Inventor Kiyoto Yoda 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Corporation F-term (reference) 5H011 AA03 AA09 AA13 BB04 CC06 DD13 DD15 FF02 GG02 JJ12 KK01 5H014 AA02 AA04 AA06 EE05 EE08 EE10 HH00 HH06 5H029 AJ03 AJ05 AJ12 AJ14 AK01 AK02 AK03 AK05 AK16 AL01 AL02 AL03 AL06 AL07 AL12 AL16 AM01 AM02 AM07 BJ01 BJ02 BJ03 BJ12 CJ02 CJ05 CJ08 H07 DJ02 DJ03

Claims (15)

[Claims] 1. A metal battery case also serving as an electrode terminal, and a part of a sealing plate for sealing said battery case is opened.
The other pole terminal is arranged in the opening, the sealing plate also serving as an electrode terminal and the other pole terminal are electrically insulated by an insulator, and a power generation element including at least a positive electrode, a separator, and a negative electrode therein. A flat nonaqueous electrolyte secondary battery including a nonaqueous electrolyte, wherein the sum of the positive and negative electrode facing areas in the electrode group is larger than the area of the sealing plate; . 2. The flat nonaqueous electrolyte secondary battery according to claim 1, wherein the positive and negative electrode facing surfaces of the positive electrode and the negative electrode facing each other via a separator are accommodated in a horizontal direction on a flat surface of the flat battery. 3. The flat non-aqueous electrolyte secondary battery according to claim 1, wherein the battery case and the sealing plate are hermetically sealed by laser sealing. 4. A current collector, which is electrically integrated with another electrode terminal, wherein the current collector and a positive electrode or a negative electrode are electrically connected via a separator housed in the battery. 2. The flat nonaqueous electrolyte secondary battery according to 1. 5. The flat nonaqueous electrolyte secondary battery according to claim 1, wherein an electrode group having at least three positive and negative electrode facing surfaces in which a positive electrode and a negative electrode face each other with a separator interposed therebetween is housed in the battery. 6. A positive electrode and a negative electrode are laminated in a multilayer with a separator interposed therebetween, and the positive electrode is connected to the positive electrode, and the negative electrode is connected to the negative electrode. 2. The flat nonaqueous electrolyte secondary battery according to 1. 7. When a positive electrode plate and a negative electrode plate provided with a current-carrying part in a part of an electrode and a positive electrode plate and a negative electrode plate are laminated via a separator, the current-carrying part of the positive electrode plate is exposed from one direction of the separator. The current-carrying portions of the negative electrode plate are laminated so that the current-carrying portions of the negative electrode plate are exposed from the counter electrode direction. The flat nonaqueous electrolyte secondary battery according to claim 1, wherein the flat portion is disposed so as to be located at a counter electrode. 8. A positive electrode component having conductivity is exposed on one outer surface in a direction horizontal to a flat surface of a flat battery from an electrode group including at least a positive electrode, a separator, and a negative electrode, and the positive electrode component is directly Or electrically connected to the positive electrode case, and expose the negative electrode component having conductivity on the other outer surface in the direction parallel to the flat surface of the flat battery of the electrode group,
The flat nonaqueous electrolyte secondary battery according to claim 1, wherein the negative electrode component is directly or electrically connected to the negative electrode case. 9. The flat non-aqueous electrolyte secondary battery according to claim 1, wherein the positive electrode is an electrode obtained by applying a slurry-type positive electrode mixture containing at least a positive electrode active substance to a metal foil and drying the mixture. 10. The flat nonaqueous electrolyte secondary battery according to claim 1, wherein the negative electrode is an electrode obtained by applying a slurry of a negative electrode mixture containing at least a negative electrode active material to a metal foil and drying the mixture. 11. The positive electrode and the negative electrode have active substance-containing layers formed on both sides of a metal foil, and the active substance layer is not previously coated on a surface directly or electrically contacted with a metal case, or 2. The flat nonaqueous electrolyte secondary battery according to claim 1, having a structure removed after coating. 12. The flat nonaqueous electrolyte secondary battery according to claim 1, wherein the positive electrode active substance is a lithium-containing oxide. 13. The flat non-aqueous electrolyte secondary battery according to claim 1, wherein the positive electrode active substance is lithium cobalt oxide. 14. The flat non-aqueous electrolyte secondary battery according to claim 1, wherein the negative electrode active substance is a carbonaceous material. 15. anode agents flat-shaped non-aqueous electrolyte secondary battery according to claim 1, wherein spacing of d ₀₀₂ plane is a carbon material of less 0.338 nm.