JP2007087652A - Nonaqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte battery suppressing voltage decrease and internal resistance increase when shock is applied from the outside by vibration, falling or the like. <P>SOLUTION: The nonaqueous electrolyte battery is equipped with an outer packaging member 1 made of film, an electrode group containing a positive electrode 7, a negative electrode 10 and a separator 13, a positive terminal electrically connected to the positive electrode, and a negative terminal electrically connected to the negative electrode, the positive terminal and the negative terminal are extended from the same end parts of the electrode group, or the facing end parts and drawn out to the outside of the the outer packaging member 1, and in the electrode group, the separator 13 is stretched out from at least one end part crossing at right angles to an end part to which the positive terminal and the negative terminal are extended, and a stretched out part 14b is fixed to the inner surface of the outer packaging member 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte battery.

  In recent years, with the development of electronic devices, there has been a demand for the development of secondary batteries that are small and light, have high energy density, and can be repeatedly charged and discharged. As such a secondary battery, a negative electrode using lithium or a lithium alloy as an active material and a suspension in which a suspension containing an active material of oxide, sulfide or selenide such as molybdenum, vanadium, titanium or niobium is applied. A non-aqueous electrolyte secondary battery including a positive electrode made of an electric body and a non-aqueous electrolyte is known.

  Also, non-aqueous using a current collector in which a suspension containing a carbonaceous material that occludes and releases lithium ions, such as coke, graphite, carbon fiber, a resin fired body, and pyrolytic vapor phase carbon, is applied to the negative electrode. An electrolyte secondary battery has been proposed. The secondary battery can improve the deterioration of the negative electrode characteristics due to the dendrite precipitation, so that the battery life and safety can be improved.

  On the other hand, instead of the conventional metal can, the exterior member has an external impact protection film typified by nylon film as the outermost layer for the purpose of further thinning, for the purpose of moisture and light shielding typified by aluminum foil It is advancing to use as a film material a composite film in which a metal layer is disposed in the middle and a heat-fusible resin film is disposed as an innermost layer for sealing an electrode group and an electrolytic solution.

  A non-aqueous electrolyte secondary battery equipped with an exterior member formed from such a film material can be developed in a wide variety of shapes at a relatively low cost compared to a conventional battery using a metal can. In particular, in the field where high capacity and high output of the battery are required, those using a film material as the exterior member have become mainstream.

  However, considering the safety of the battery, on the other hand, the strength of the film material is generally weaker than that of a metal can, so overheating due to overcharge and overdischarge, and explosion from internal pressure increase due to gas generation, etc. On the other hand, it is difficult and advantageous, but in the case of vibration or drop impact, the container itself is deformed by the movement of the electrode group inside the container, and the internal resistance is likely to increase due to the disconnection of the terminal, or a local short-circuit occurs.

  In this state, even when charging / discharging is repeated normally, there is a possibility that the battery itself may be ignited due to heat generation in the defective portion.

On the other hand, Patent Document 1 relates to a non-aqueous electrolyte secondary battery, and by fixing the surface of an electrode group to the inner surface of a film exterior material with an adhesive layer, the electrolytic solution is interposed between the electrode group and the exterior material. It is disclosed to suppress penetration.
JP 2000-235868 A

  The present invention provides a non-aqueous electrolyte battery in which a voltage drop and an increase in internal resistance are suppressed when an impact is applied from the outside due to vibration or dropping.

The non-aqueous electrolyte battery according to the present invention includes a film exterior member, an electrode group that is housed in the exterior member and includes a positive electrode, a negative electrode, and a separator, a positive electrode terminal that is electrically connected to the positive electrode, and the negative electrode A non-aqueous electrolyte battery comprising a negative electrode terminal electrically connected to
The positive electrode terminal and the negative electrode terminal are extended from the same end portion of the electrode group or opposite end portions, and are drawn out of the exterior member,
In the electrode group, the separator protrudes from at least one end perpendicular to the end from which the positive electrode terminal and the negative electrode terminal extend, and the protruding portion is fixed to the inner surface of the exterior member. It is a feature.

  According to the nonaqueous electrolyte battery according to the present invention, it is possible to suppress the movement of the electrode group in the exterior member when an impact is applied from the outside. The external impact here is not the case where the exterior member is broken or the battery itself is deformed by external force, but it assumes vibration during transportation and indirect force applied after packaging into an external device. is doing.

  In a nonaqueous electrolyte battery having an exterior member formed of a film material, the positive electrode terminal and the negative electrode terminal are pulled out from the exterior member to the outside, so that the positive electrode terminal and the negative electrode terminal are sandwiched and fixed between the film materials. However, the electrode group is in contact with the exterior member and is not fixed. For this reason, when an impact is applied in the direction of the gap existing inside the exterior member, the electrode group easily moves in the impact direction, and the exterior member may be deformed by the collision of the electrode group in a stronger impact. In order to suppress the movement of the electrode group, it seems necessary to reduce the gap in the exterior member as much as possible. However, it is difficult to consider the connection space between the positive and negative electrode terminals and the electrode group and the electrolyte solution space. Even if the surface of the electrode group is brought into close contact with the exterior member as in 1, the strength of the exterior member itself is insufficient, so that the electrode group may move in such a manner as to push away the exterior member.

  When the connection between the positive and negative electrode terminals and the electrode group is disconnected due to these impacts, or when the positive and negative electrode terminals or the electrode group are temporarily disconnected, and the disconnected portion is further contacted by the subsequent impact, the resistance is locally increased. Therefore, even if charging / discharging is repeated normally, there is a possibility that the battery itself may be ignited due to heat generation in the defective portion. In addition, deformation of the electrode group itself may cause a local short circuit, causing heat generation and ignition.

  As in the present invention, an exterior member is formed by projecting a separator from an electrode group at at least one end orthogonal to an end from which a positive electrode terminal and a negative electrode terminal are extended, and fixing the projecting portion to the inner surface of the exterior member. The movement of the electrode group can be suppressed against an external impact without changing the size of the inner space. The bonding of the electrode group and the exterior member can be performed, for example, by heat fusion, using an adhesive or a tape that does not affect the battery performance, but the method is simple and sufficient bonding strength is obtained. Moreover, heat fusion is desirable because there is little risk of side reactions.

  Assuming vibration during transportation and indirect force applied after packaging this non-aqueous electrolyte battery into an external device, the battery surface is protected from direct external force on the battery, concrete, etc. As a result of confirming the change of the battery voltage and the internal resistance when dropped several times from a certain height on the battery, the amount of change can be remarkably reduced as compared with the battery of the conventional structure as shown in the examples described later. As a result, it was possible to realize a nonaqueous electrolyte battery effective for external shock resistance.

  In the nonaqueous electrolyte battery according to the present invention, when the length of the end portion from which the positive electrode terminal and the negative electrode terminal are drawn is 1, the length of the end portion where the separator protrudes is 0.2. As mentioned above, it is desirable to set it to 10 or less, and according to the electrode group of such a structure, sufficient effect with respect to external impact can be acquired. If the length ratio of the separator overhanging portion is less than 0.2, it may not be possible to sufficiently suppress the movement of the electrode group when an external impact is applied. On the other hand, if the length ratio of the separator overhanging portion exceeds 10, the volume energy of the nonaqueous electrolyte battery may be reduced.

  According to the present invention, it is possible to suppress a voltage drop and an increase in internal resistance when an impact is applied from the outside to the nonaqueous electrolyte battery due to vibration or dropping.

  First, the exterior member and the electrode group will be described.

1) Exterior member As the exterior member, one having a recess (cup portion) in which an electrode group is accommodated can be used. As the exterior member, a member in which the container and the sealing plate are integrated may be used, or a member in which the sealing plate and the container have different structures may be used.

  The film material forming the exterior member preferably contains at least a resin film. Examples of such a film material include a resin film, a laminate film containing a resin and a metal, and the like.

  Although the kind of resin to be used is not particularly limited, examples thereof include polyamide resins such as nylon and thermoplastic resins such as polyolefin resins (polyethylene, polypropylene, etc.).

  As the laminate film, for example, a film including a metal layer, a thermoplastic resin layer formed on one surface of the metal layer, and a protective layer formed on the opposite surface of the metal layer can be used. . The metal layer can be formed from, for example, aluminum or an aluminum alloy. The protective layer can be formed from, for example, a polyamide resin such as nylon or polyethylene terephthalate.

  In the laminate film, an adhesive layer, a gas barrier layer, or the like may be provided between the external protective layer, the metal layer, and the thermoplastic resin layer.

2) Electrode group What has a flat shape can be used for an electrode group. The flat electrode group is produced, for example, by winding the positive electrode and the negative electrode in a spiral shape via a separator, or alternately laminating the positive electrode and the negative electrode with a separator interposed therebetween.

  The positive electrode includes a current collector and a mixture layer supported on the current collector.

As the positive electrode active material, various oxides such as manganese dioxide, lithium manganese composite oxide (for example, LiMn ₂ O ₄ , LiMnO ₂ ), lithium-containing nickel oxide, lithium-containing cobalt oxide (for example, LiCoO ₂ ), Examples thereof include lithium-containing nickel cobalt oxide (for example, LiNi _0.8 Co _0.2 O ₂ ), lithium-containing iron oxide, vanadium oxide containing lithium, and chalcogen compounds such as titanium disulfide and molybdenum disulfide. In addition, the kind of positive electrode active material to be used can be made into 1 type or 2 types or more.

  As the current collector, a conductive substrate having a porous structure or a nonporous conductive substrate can be used. These conductive substrates can be formed from, for example, aluminum, stainless steel, or nickel.

  The negative electrode includes a current collector and a mixture layer supported on the current collector.

  As the negative electrode active material, lithium ions or materials that occlude and release lithium can be used. For example, a graphite material or a carbonaceous material (for example, graphite, coke, carbon fiber, spherical carbon, pyrolytic gas phase carbonaceous material) , Resin fired bodies, etc.), chalcogen compounds (eg, titanium disulfide, molybdenum disulfide, niobium selenide, etc.), light metals (eg, aluminum, aluminum alloys, magnesium alloys, lithium, lithium alloys, etc.), lithium titanium oxides ( For example, spinel type lithium titanate) can be used.

  As the current collector, a conductive substrate having a porous structure or a nonporous conductive substrate can be used. These conductive substrates can be formed from, for example, copper, aluminum, stainless steel, or nickel.

  As the separator, a microporous film, a woven fabric, a non-woven fabric, a laminate of the same material or different materials among these can be used. Examples of the material for forming the separator include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-butene copolymer. As a material for forming the separator, one type or two or more types selected from the types described above can be used.

  A non-aqueous electrolyte is held in the electrode group. The non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte (for example, lithium salt) dissolved in the non-aqueous solvent. The form of this non-aqueous electrolyte can be liquid (non-aqueous electrolyte), gel or solid.

  Examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (γ -BL), sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. Nonaqueous solvents may be used alone or in combination of two or more.

Examples of the electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenide (LiAsF ₆ ), and trifluoromethanesulfone. Examples thereof include lithium salts such as lithium acid lithium (LiCF ₃ SO ₃ ). The electrolyte may be used alone or in combination of two or more. The amount of electrolyte dissolved in the non-aqueous solvent is desirably 0.2 mol / l to 3 mol / l.

  Next, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a plan view and a side view of an exterior member used in the nonaqueous electrolyte battery according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an exterior film constituting the exterior member of FIG. FIG. 3 is a plan view schematically showing the positive electrode. FIG. 4 is a plan view schematically showing the negative electrode. FIG. 5 is a plan view schematically showing the separator. FIG. 6 is a schematic diagram showing an example of a method for connecting positive and negative leads and tabs. FIG. 7 is a schematic diagram showing another example of a method for connecting positive and negative leads and tabs. FIG. 8 is a plan view schematically showing an electrode group. FIG. 9 is a schematic plan view showing a state where the electrode group of FIG. 8 is housed in a container. FIG. 10 is a perspective view schematically showing the nonaqueous electrolyte battery according to the first embodiment.

  As shown in FIG. 1, the exterior member 1 includes a rectangular cup portion 2 formed by press molding or drawing. On the four sides of the opening end of the cup part 2, a peripheral part 2a extending in the horizontal direction is formed. A flat plate portion is connected to one side in the longitudinal direction of the peripheral edge portion 2 a, and this flat plate portion functions as the sealing plate 3. FIG. 1A is a plan view and FIG. 1B is a side view.

  For example, as shown in FIG. 2, the exterior film includes a metal layer 4, a protective layer 5 formed on one surface of the metal layer 4, and a thermoplastic resin layer 6 formed on the opposite surface of the metal layer 4. Is formed from a laminate film. The thermoplastic resin layer 6 is disposed on the inner surface of the exterior member 1.

  As shown in FIG. 3, the positive electrode 7 includes a positive electrode current collector, a positive electrode lead portion 8 formed by projecting the central portion of the short side of the positive electrode current collector, and a positive electrode formed on both surfaces of the positive electrode current collector. And a mixture layer 9. On the other hand, as shown in FIG. 4, the negative electrode 10 is formed on both surfaces of the negative electrode current collector, the negative electrode lead portion 11 formed by projecting the central portion of the short side of the negative electrode current collector, and the negative electrode current collector. Negative electrode mixture layer 12.

  As shown in FIG. 5, the separator 13 has a bag shape and is bonded to both long sides. One bonding part 14a is located inside the long side end part, and an overhanging part 14b is formed outside the bonding part 14a.

  The positive electrode 7 is inserted into the bag portion of the separator 13, and the positive electrode lead 8 protrudes from the separator 13. The separators 13 in which the positive electrodes 7 are housed and the negative electrodes 10 are alternately stacked. In this laminate, as shown in FIG. 8, the negative electrode lead 11 protrudes from the short side end, and the positive electrode lead 8 protrudes from the opposite short side end. The separator may be housed in the negative electrode instead of the positive electrode.

  As shown in FIG. 6, for example, the positive electrode lead 8 included in each of the plurality of positive electrodes 7 is bundled into one, and a positive electrode tab 15 (for example, made of metal such as aluminum or nickel) in which the bundled tip is folded in half. ). The positive electrode lead 8 and the positive electrode tab 15 are fixed by welding, for example. The positive electrode lead 8 and the positive electrode tab 15 may be connected by the method shown in FIG. In FIG. 7, the positive electrode leads 8 are bundled together, and the bundled tip portion is fixed to the tip of the positive electrode tab 15 by, for example, welding. Connection between the negative electrode lead 11 and the negative electrode tab 16 (for example, made of metal such as copper or nickel) included in each of the plurality of negative electrodes 10 is also performed by the method shown in FIG. 6 or FIG. A thermoplastic insulating film (for example, acid-modified polyethylene film) 18 having metal adhesion is disposed in each heat-sealed portion of the positive electrode tab 15 and the negative electrode tab 16 to enhance the adhesion between the exterior film and the tab.

  In this embodiment, the positive and negative electrode tabs connected to the positive and negative electrode leads of the electrode group are used as the positive and negative electrode terminals. After connecting the leads, the above-described long leads can be directly pulled out of the container and used as positive and negative terminals.

  As shown in FIG. 8, the positive electrode 7, the negative electrode 10, and the separator 13 located at the corner of the electrode group are fixed with an insulating tape 17. The protruding portion 14b of the separator 13 protrudes from the positive electrode and the negative electrode at one end of the long side of the electrode group, and is joined together by, for example, heat fusion.

  Such an electrode group is accommodated in the rectangular cup portion 2 of the exterior member 1 as shown in FIG. The overhanging portion 14 b of the separator 13 is disposed on the long side peripheral portion (the long side peripheral portion on the side opposite to the sealing plate 3) of the rectangular cup portion 2. The positive electrode tab 15 is pulled out from the short side peripheral edge of the rectangular cup portion 2, and the negative electrode tab 16 is pulled out from the short side peripheral edge on the opposite side of the rectangular cup portion 2. Yes.

  After the sealing plate 3 is folded back to the rectangular cup portion 2 side and the rectangular cup portion 2 is covered with the sealing plate 3, the peripheral portion 2 a of the cup portion 2 and the peripheral portion of the sealing plate 3 are used with the thermoplastic resin layer 6. Heat seal. The overhanging portion 14 b of the separator 13 is heat-sealed between the long-side peripheral portion and the sealing plate 3 facing the long-side peripheral portion, and is fixed to the inner surface of the exterior member 1.

  In the nonaqueous electrolyte battery according to the first embodiment, the protruding portion of the separator 13 from the positive and negative electrodes of the electrode group at the long-side end that is orthogonal to the short-side end extending from the positive electrode terminal and the negative-electrode terminal. Since 14b protrudes and is fixed to the inner surface of the exterior member 1, it is possible to prevent the electrode group from sliding in the extending direction of the positive and negative terminals when an impact such as dropping or vibration is applied. As a result, disconnection of the positive and negative terminals and deformation of the electrode group can be avoided, so that an increase in internal resistance and a decrease in battery voltage when an impact is applied can be suppressed.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS. Note that the same configurations as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 11 is a plan view and a side view of a container used in a nonaqueous electrolyte battery according to a second embodiment of the present invention. 12 is a plan view and a side view schematically showing a sealing plate of the container of FIG. FIG. 13 is a plan view schematically showing the separator. FIG. 14 is a plan view schematically showing an electrode group. FIG. 15 is a schematic plan view showing a state where the electrode group of FIG. 14 is housed in a container. FIG. 16 is a perspective view schematically showing a nonaqueous electrolyte battery according to the second embodiment.

  In the second embodiment, an exterior member having a container and a sealing plate that are different from each other is used, and protrusions are formed at both end portions on the longitudinal direction side of the bag-shaped separator. Except this, it is the same as the first embodiment.

  That is, as shown in FIG. 11, the container 20 includes a rectangular cup portion 21 formed by press molding or drawing. On the four sides of the open end of the cup portion 21, peripheral edge portions 22 extending in the horizontal direction are formed. FIG. 11A is a plan view and FIG. 11B is a side view.

  As shown in FIG. 12, the sealing plate 23 is configured differently from the container 20 and has a rectangular shape. The container 20 and the sealing plate 23 are formed from the same exterior film as described in the first embodiment, and the inner surfaces of the container 20 and the sealing plate 23 are formed from a thermoplastic resin layer.

  The bag-shaped separator 24 has a bonded portion positioned on both long sides, both the bonded portions 25a are positioned on the inner side of the end portions, and a protruding portion 25b is formed on the outer side of each bonded portion 25a. ing. Except for using this separator 24, an electrode group is produced in the same manner as described in the first embodiment, and a schematic plan view of the produced electrode group is shown in FIG.

  As shown in FIG. 14, the protruding portion 25b of the separator 24 protrudes from the positive and negative electrodes at both ends of the long side of the electrode group. The overhanging portions 25b protruding from the same end portion are bundled together by being joined by thermal fusion.

  Such an electrode group is accommodated in the container 20 as shown in FIG. The overhang portion 25 b of the separator 24 is disposed on the long side direction side of the peripheral portion of the container 20. The positive electrode tab 15 is drawn out from the short side direction side of the peripheral edge of the container 20. On the other hand, the negative electrode tab 16 is drawn to the outside from a peripheral edge located on the opposite side of the positive electrode tab 15.

  The nonaqueous electrolyte battery shown in FIG. 16 is obtained by disposing the sealing plate 23 on the container 20 and thermally fusing the peripheral portion 22 of the container 20 and the peripheral portion of the sealing plate 23 using a thermoplastic resin layer. .

  In the obtained nonaqueous electrolyte battery, the overhanging portion 25 b of the separator 24 is fixed by being sandwiched between the heat fusion portion of the container 20 and the sealing plate 23. In the second embodiment, the separator is protruded from the positive and negative electrodes of the electrode group at both long side end portions orthogonal to the short side end portion from which the positive electrode terminal and the negative electrode terminal are extended, and the protruding portion is packaged. Since it is fixed to the inner surface of the member, the effect of restricting the movement of the electrode group when an impact such as dropping or vibration is applied can be further enhanced.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS. Note that the same configurations as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 17 is a plan view and a side view of an exterior member used in a nonaqueous electrolyte battery according to a third embodiment of the present invention. FIG. 18 is a plan view schematically showing the positive electrode. FIG. 19 is a plan view schematically showing the negative electrode. FIG. 20 is a plan view schematically showing an electrode group. FIG. 21 is a schematic plan view showing a state where the electrode group of FIG. 20 is housed in a container. FIG. 22 is a perspective view schematically showing a nonaqueous electrolyte battery according to the third embodiment.

  As shown in FIG. 17, the exterior member 30 includes a rectangular cup portion 31 formed by press molding or drawing. On the four sides of the open end of the cup portion 31, peripheral edge portions 31a extending in the horizontal direction are formed. A flat plate portion is connected to one side of the peripheral edge portion 31 a in the short side direction, and this flat plate portion functions as the sealing plate 32. FIG. 17A is a plan view and FIG. 17B is a side view. As the exterior film, the same film as described in the first embodiment can be used.

  As shown in FIG. 18, the positive electrode 33 includes a positive electrode current collector, a positive electrode lead portion 34 formed by protruding a short-side end portion (for example, the right end) of the positive electrode current collector, and both surfaces of the positive electrode current collector. And the positive electrode mixture layer 35 formed in the above. On the other hand, as shown in FIG. 19, the negative electrode 36 includes a negative electrode current collector, a negative electrode lead portion 37 formed by protruding a short side end portion (for example, the left end) of the negative electrode current collector, and a negative electrode current collector. And a negative electrode mixture layer 38 formed on both surfaces thereof.

  The positive electrode 33 is inserted into the same separator as described in the second embodiment, and the positive electrode lead 34 protrudes from the separator. The separator in which the positive electrode 33 is accommodated and the negative electrode 36 are alternately stacked. In this laminate, as shown in FIG. 20, the positive electrode lead 34 and the negative electrode lead 37 protrude from the same side so as not to overlap each other.

  The positive leads 34 included in each of the plurality of positive electrodes 33 are connected to a positive electrode tab 39 (for example, made of a metal such as aluminum or nickel) in a bundled state as shown in FIG. 6 or FIG. On the other hand, the negative electrode lead 37 included in each of the plurality of negative electrodes 36 is connected to the negative electrode tab 40 (for example, made of metal such as copper or nickel) in a bundled state as shown in FIG. 6 or FIG. Yes. The thermoplastic insulating film 18 having metal adhesiveness is disposed at the heat-sealed portion of each of the positive electrode tab 39 and the negative electrode tab 40 to enhance the adhesion between the exterior film and the tab.

  In this embodiment, the positive and negative electrode tabs connected to the positive and negative electrode leads of the electrode group are used as the positive and negative electrode terminals, but the positive and negative electrode leads of the electrode group are directly pulled out of the container and used as the positive and negative electrode terminals. It is also possible.

  As shown in FIG. 20, the positive electrode 33, the negative electrode 36, and the separator 24 located at the corner portion of the electrode group are fixed with an insulating tape 17. The protruding portion 25b of the separator 24 protrudes from the positive and negative electrodes at both ends of the long side of the electrode group, and is joined together by, for example, heat sealing at each end.

  Such an electrode group is housed in a rectangular cup portion 31 of the exterior member 30 as shown in FIG. The overhanging portion 25 b of the separator 24 is located at both long side peripheral portions of the rectangular cup portion 31. The positive electrode tab 39 and the negative electrode tab 40 are drawn out from the short side of the exterior member 30 to the outside.

  After the sealing plate 32 is folded back to the cup portion 31 side and the rectangular cup portion 31 is covered with the sealing plate 32, the peripheral edge portion 31 a of the cup portion 31 and the peripheral edge portion of the sealing plate 32 are heated using the thermoplastic resin layer 6. Fuse. The protruding portion 25 b of the separator 24 is heat-sealed between the long side peripheral portion of the cup portion 31 and the sealing plate 32 and is fixed to the inner surface of the exterior member 30.

  In the nonaqueous electrolyte battery according to the third embodiment, the positive electrode terminal and the negative electrode terminal are connected to the separator 24 from the positive and negative electrodes of the electrode group at both long side end portions orthogonal to the short side end portions. Since the projecting portion 25b is protruded and fixed to the inner surface of the exterior member 30, it is possible to suppress movement of the electrode group when an impact such as dropping or vibration is applied.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIGS. Note that the same configurations as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 23 is a schematic plan view of a positive electrode used in a nonaqueous electrolyte battery according to a fourth embodiment of the present invention. FIG. 24 is a plan view schematically showing the negative electrode. FIG. 25 is a plan view schematically showing the separator. FIG. 26 is a plan view schematically showing an electrode group. FIG. 27 is a schematic plan view showing a state where the electrode group of FIG. 26 is housed in an exterior member. FIG. 28 is a perspective view schematically showing a nonaqueous electrolyte battery according to the fourth embodiment.

  The fourth embodiment has the same configuration as that described in the first embodiment except that a wound electrode group is used. As shown in FIG. 23, the positive electrode 41 is formed by excluding a strip-shaped positive electrode current collector and one end portion 42 (hereinafter referred to as a positive electrode uncoated region) on the longitudinal direction side of the positive electrode current collector. 43.

  As shown in FIG. 24, the negative electrode 44 is formed by removing a strip-shaped negative electrode current collector and one end portion 45 (hereinafter referred to as a negative electrode uncoated region) on the longitudinal direction side of the negative electrode current collector. 46.

  The positive electrode 41 and the negative electrode 44 are wound into a flat spiral shape with a strip-shaped separator 47 shown in FIG. 25 interposed therebetween, and an electrode group is obtained. In this electrode group, as shown in FIG. 26, the plain portion 42 of the positive electrode 41 protrudes from the winding axis direction of the separator, and the plain portion 45 of the negative electrode 44 protrudes from the winding axis direction on the opposite side of the separator. . The outermost periphery of the electrode group is a separator 47, and a part 48 of the separator extends in a direction perpendicular to the winding axis. The winding end end portion 49 of the separator 47 is fixed with an insulating tape 50. The strip-shaped positive electrode tab 51 is welded to the plain portion 42 of the positive electrode 41 at the end. On the other hand, the strip-shaped negative electrode tab 52 is welded to the plain portion 45 of the negative electrode 44 at the end. The thermoplastic insulating film 18 having metal adhesiveness is disposed at each heat-sealed portion of the positive electrode terminal 51 and the negative electrode terminal 52, and plays a role of improving the adhesion between the exterior film and the terminal.

  Such an electrode group is accommodated in the rectangular cup portion 2 of the exterior member 1 as shown in FIG. The overhanging portion 48 of the separator 47 is disposed on the long side peripheral edge 2 a located on the opposite side of the sealing plate 3. Further, the positive electrode terminal 51 is drawn out from the peripheral portion on the short side of the exterior member 1 to the outside. On the other hand, the negative electrode terminal 52 is drawn to the outside from the peripheral portion on the short side opposite to the exterior member 1.

  After the sealing plate 3 is folded back to the cup portion 2 side and the rectangular cup portion 2 is covered with the sealing plate 3, the peripheral edge portion 2a of the cup portion 2 and the peripheral edge portion of the sealing plate 3 are heat-melted using a thermoplastic resin layer. Put on. The protruding portion 48 of the separator 47 is heat-sealed between the peripheral edge portion 2 a of the cup portion 2 and the sealing plate 3 and is fixed to the inner surface of the exterior member 1.

  In the nonaqueous electrolyte battery according to the fourth embodiment, the separator 47 protrudes from the electrode group at the long side end that is orthogonal to the short side end from which the positive electrode terminal 51 and the negative electrode terminal 52 are extended, Since the protruding portion 48 is fixed to the inner surface of the exterior member 1, it is possible to suppress the movement of the electrode group when an impact such as dropping or vibration is applied.

  In the above-described first to third embodiments, all of the protruding portions protruding from between the plurality of positive and negative electrodes are fixed to the inner surface of the exterior member in a state of being bundled together. Only a part of them can be bundled together and fixed to the inner surface of the exterior member. In this case, it is desirable to fix the overhanging portions located above and below and between the laminated electrodes to the inner surface of the exterior member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings described above.

Example 1
<Formation of container>
A deep drawing process was applied to an outer film having a total thickness of 0.095 mm composed of a nylon film 5 having a thickness of 0.025 mm, an aluminum foil 4 having a thickness of 0.04 mm, and a polyethylene film 6 having a thickness of 0.03 mm. A rectangular cup portion 2 having a depth of 4.0 mm, a length of 95 mm, and a width of 65 mm was formed to obtain the exterior member 1 shown in FIG. In the obtained exterior member 1, the width of two edges in the short side direction of the cup part 2 is set to 5 mm, the width of one edge in the long side direction is set to 10 mm, and another edge facing this edge part is provided. The width of the flat plate portion (sealing plate) 3 provided at the long side edge was 75 mm.

<Production of electrode group>
First, 89 parts by weight of LiCoO ₂ powder as an active material, 8 parts by weight of graphite powder as a conductive filler and 3 parts by weight of polyvinylidene fluoride resin as a binder are mixed with 25 parts by weight of N-methylpyrrolidone to prepare a positive electrode paste. Prepared.

  This positive electrode paste is continuously applied on both sides of a 0.03 mm thick aluminum foil hoop material as a current collector so that uncoated portions remain on both sides, dried, and then rolled to form a positive electrode mixture layer 9 After that, the coated part was cut out so that the outer dimension of the coated part was 80 × 60 mm and the dimension of the uncoated part 8 serving as the positive electrode lead was 5 × 20 mm.

  Next, after pulverizing the mesophase pitch-based carbon fiber, 100 parts by weight of the heat-treated carbon fiber powder was mixed with an aqueous solution containing 2 parts by weight of crosslinked rubber latex particles of carboxymethyl cellulose and styrene-butadiene to prepare a negative electrode paste.

  This negative electrode paste was continuously applied on both sides of a copper foil hoop material having a thickness of 0.015 mm as a current collector so that uncoated portions remained on both sides, dried, and then rolled to form a negative electrode mixture layer 12 After that, the coated part was cut out so that the outer dimension of the coated part was 81 × 61 mm and the dimension of the uncoated part 11 to be the negative electrode lead was 5 × 20 mm.

  Next, after a separator made of polyethylene microporous film was cut out to 168 × 69 mm, the long side was folded 180 ° in the center, one long side was heat-sealed with a width of 1 mm, and the other long side was 5 mm from the side. A bag portion was formed by heat-sealing the inner portion 14a with a width of 1 mm to produce a bag-shaped separator 13 having an outer dimension of 84 × 69 mm, a bag portion inner dimension of 84 × 62 mm, and a width of the overhanging portion 14b of 5 mm.

  Next, after the positive electrode 7 is inserted into the bag portion of the separator 13 and the positive electrode 7 and the separator 13 are combined, the negative electrode 10 and the negative electrode 10 are arranged in the order of the negative electrode 10, separator 13 + positive electrode 7, negative electrode 10, separator 13 + positive electrode 7. Then, the negative electrode 10 was stacked on the uppermost layer, and finally 21 negative electrodes and 20 positive electrodes + separators were laminated. The positions of the positive electrode lead 8 and the negative electrode lead 11 were opposed to each other by 180 °.

  An excess separator group (overhanging portion) 14b having a width of 5 mm located at one end of the long side of the bag portion of the separator 13 is integrated and fixed by heat fusion, and the four corner portions of the laminated electrode are stopped by the insulating tape 17. This fixed the positive electrode, the negative electrode, and the separator.

  Next, after 20 positive electrode leads 8 were joined together by ultrasonic welding, as shown in FIG. 6, with a positive electrode tab 15 made of an aluminum plate having a thickness of 0.1 mm and an outer dimension of 30 × 20 mm. The tip of the bundle of the positive electrode lead 8 was sandwiched and ultrasonic welding was performed, and the positive electrode tab 15 was joined to the positive electrode lead 8. An acid-modified polyethylene film 18 having an outer dimension of 7 × 30 mm was heat-sealed on both sides at a position 3 mm from the tip of the positive electrode tab 15.

  On the other hand, after 21 negative electrode leads 11 were joined together by ultrasonic welding, the negative electrode lead 16 was made of a negative electrode tab 16 made of a copper plate having a thickness of 0.1 mm and an outer dimension of 30 × 20 mm, as in the case of the positive electrode. 11, the tip of the bundle was sandwiched, ultrasonic welding was performed, and the negative electrode tab 16 was joined to the negative electrode lead 11. Next, an acid-modified polyethylene film 18 having an outer dimension of 7 × 30 mm was heat-sealed on both sides at a position 3 mm from the tip of the negative electrode tab 16.

As shown in FIG. 8, in the electrode group, the length L _{1 of the} end portion from which the positive and negative electrode tabs 15 and 16 are drawn out is 64 mm, and the length L _{2 of the} end portion where the protruding portion 14b is formed is 84 mm. there were. When the length L ₁ was 1, the length L ₂ was 1.31.

<Preparation of non-aqueous electrolyte>
LiPF ₆ as an electrolyte is dissolved to a concentration of 1 mol / L in a non-aqueous solvent in which ethylene carbonate (EC) and dimethyl carbonate (DMC) are mixed at a volume ratio of 1: 1 to obtain a non-aqueous electrolyte solution. Prepared.

<Production of nonaqueous electrolyte battery>
As shown in FIG. 9, the thermoplastic insulating film 18 of the positive electrode tab 15 is disposed on the short side edge portion, and the thermoplastic insulating film 18 of the negative electrode tab 16 is on the opposite short side, as shown in FIG. 9. The electrode group was housed so that it was arranged on the side edge and the overhanging portion 14b was placed on the long side edge.

Next, after the flat plate portion (sealing plate) 3 on the long side of the exterior member 1 is folded back in the 180 ° direction and overlapped on the opposite long side edge, the entire exterior member is placed so that the cup portion is on the upper surface. Inverted. Continuing, using a heat-sealing machine facing the surface of the upper and lower seal bars so that a recess having a width of 25 mm and a depth of 0.1 mm is processed, and the recess absorbs the thickness of the positive and negative electrode tabs at the time of heat-sealing. The two edges on the short side were thermally fused under the conditions of a temperature of 200 ° C., a pressure of 4.0 kgf / cm ² , and a heating time of 10 s.

Thereafter, a non-aqueous electrolyte was injected into the cup portion 2 from the unfused long side edge to impregnate the electrode group. Using a heat-sealing machine in which a seal bar with a width of 5 mm with no unevenness is formed on the inner surface from the portion inside 5 mm from the end face, the unbonded long side edge is set at a temperature of 180 ° C. and the applied pressure is 1. Heat-sealing was performed under the conditions of 0 kgf / cm ² and a heating time of 5 s, and the protruding portion 14 b of the separator 13 was heat-sealed to the thermoplastic resin film 6 on the inner surface of the exterior member 1.

Further, the remaining unfused portion of the long side edge portion is fused using the same heat-sealing machine under the conditions of a temperature of 180 ° C., a pressure of 4.0 kgf / cm ² , and a heating time of 5 seconds, and finally the thickness 100 nonaqueous electrolyte batteries shown in FIG. 10 having a size of 4 mm, a width of 75 mm, a length of 105 mm (excluding positive and negative electrode tab dimensions) and a capacity of 1500 mAh were produced.

(Example 2)
<Formation of exterior member>
As shown in FIG. 11, the same exterior film material as in Example 1 is deep-drawn to obtain a rectangular cup portion 21 having a depth of 4.0 mm, a length of 95 mm, and a width of 65 mm, and a short side direction 2 of the cup portion 21. A container 20 having an outer dimension of 105 × 75 mm, in which an edge portion having a width of 5 mm and an edge portion having a width of 10 mm were provided at two locations in the long side direction, was prepared. Further, the exterior film material was cut out to a size of 105 × 85 mm without performing drawing processing, and a sealing plate 23 shown in FIG. 12 was produced.

<Production of electrode group>
After a separator made of polyethylene microporous membrane is cut out to 168 × 74 mm, the long side is folded 180 ° in the center, and the long side is heat-sealed with 5 mm from both sides and the inner part is 1 mm wide to form a bag part. An electrode group was formed in the same manner as in Example 1 except that a bag-shaped separator 24 having an outer dimension of 84 × 74 mm, a bag portion inner dimension of 84 × 62 mm, and a width of each overhang portion 25b of 5 mm was prepared.

As shown in FIG. 14, in the electrode group, the length L _{1 of the} end portion from which the positive and negative electrode tabs 15 and 16 are drawn out is 65 mm, and the length L _{2 of the} end portion where the protruding portion 25b is formed is 84 mm. Met. When the length L ₁ was 1, the length L ₂ was 1.29.

<Preparation of non-aqueous electrolyte>
The same method as in Example 1 was used.

<Production of nonaqueous electrolyte battery>
As shown in FIG. 15, the thermoplastic insulating film 18 of the positive electrode tab 15 is disposed on the short side edge portion, and the thermoplastic insulating film 18 of the negative electrode tab 16 is on the opposite short side side, as shown in FIG. 15. The electrode group was housed so that both of the overhanging portions 25b were placed on the edge of the long side.

  Next, after overlapping the sealing plate 23 so that the thermoplastic resin film side was inside, these (exterior member) were inverted so that the cup part 21 became an upper surface.

Subsequently, a concave portion having a width of 25 mm and a depth of 0.1 mm is processed on the surface of the upper and lower seal bars, and the concave portion is opposed to the surface in such a manner that the thickness of the positive and negative electrode tabs is absorbed during thermal fusion. The two edges on the short side were thermally fused under the conditions of a temperature of 200 ° C., a pressure of 4.0 kgf / cm ² , and a heating time of 10 s. After this, using a heat-sealing machine in which a seal bar with a width of 5 mm without any irregularities on the inner surface from the part inside 5 mm from the end face is used, one side of the unfused long side edge is 180 ° C. Then, heating and pressurization were performed under the conditions of a pressure of 1.0 kgf / cm ² and a heating time of 5 s, and one overhanging portion 25 ^b was heat-sealed between the thermoplastic resin film of the container 20 and the thermoplastic resin film of the sealing plate 23. . Subsequently, after injecting the non-aqueous electrolyte into the cup part from the unfused long side edge part to impregnate the electrode group, the long side edge part where the unfused long side edge part was fused first Heating and pressing were performed under the same conditions as the edge, and the remaining overhang 25b was thermally fused between the thermoplastic resin film of the container 20 and the thermoplastic resin film of the sealing plate 23. Further, the remaining unfused portions of the two long side edges are fused at the temperature of 180 ° C., the applied pressure of 4.0 kgf / cm ² , and the heating time of 5 seconds. 100 nonaqueous electrolyte batteries shown in FIG. 16 having a thickness of 4 mm, a width of 85 mm, a length of 105 mm (excluding positive and negative electrode tab dimensions) and a capacity of 1500 mAh were produced.

(Example 3)
<Formation of exterior member>
The same exterior film as in Example 1 was deep-drawn, and as shown in FIG. 17, a rectangular cup part 31 having a depth of 4.0 mm, a length of 95 mm, and a width of 65 mm, and two places in the long side direction of the cup part 31 An exterior member provided with a 10 mm wide edge, a 5 mm wide edge at one location in the short side direction, and a 100 mm wide flat plate portion (sealing plate) 32 at the other long side edge facing this edge. 30 was obtained.

<Production of electrode group>
After forming the positive electrode mixture layer 35 by the same method as in Example 1, the outer dimension of the coated part is 80 × 60 mm, and the dimension of the non-coated part 34 as the positive electrode lead is 5 mm inside the long side part right end surface. The positive electrode 33 was obtained by cutting out to be 10 mm.

  Further, after forming the negative electrode mixture layer 38 by the same method as in Example 1, the outer dimension of the coated part is 81 × 61 mm, and the dimension of the uncoated part 37 as the negative electrode lead is 5 mm inside the long side part left end surface. It cut out so that it might become 5x10 mm, and the negative electrode 36 was obtained.

  The separator was prepared in the same manner as in Example 2. After the positive electrode was inserted into the bag portion of the separator and the positive electrode and the separator were combined, the positive electrode lead 34 was extended in the right direction and the negative electrode lead 37 was extended in the left direction. The negative electrode, separator + positive electrode, negative electrode, separator + positive electrode were stacked in this order from the bottom layer so that the negative electrode was in the uppermost layer, and finally 21 negative electrodes and 20 positive electrodes + separators were laminated. Next, by fixing and fixing the excess separator group (projection part) 25b having a width of 5 mm on both sides of the bag part of the separator by heat fusion, and fixing the laminated electrode with the insulating tape 17 at the four corners. A positive electrode, a negative electrode, and a separator were fixed.

  Next, 20 positive electrode leads 34 are joined together by ultrasonic welding, and then, as shown in FIG. 6, with a positive electrode tab 39 made of an aluminum plate having a thickness of 0.1 mm and an outer dimension of 30 × 10 mm. The tip of the bundle of positive electrode leads 34 was sandwiched and ultrasonic welding was performed, and a positive electrode tab 39 was joined to the positive electrode lead 34. An acid-modified polyethylene film 18 having an outer dimension of 7 × 20 mm was heat-sealed on both sides at a position 3 mm from the tip of the positive electrode tab 39.

  On the other hand, after 21 negative electrode leads 37 are joined together by ultrasonic welding, the negative electrode lead 40 is made of a negative electrode tab 40 made of a copper plate having a thickness of 0.1 mm and an outer dimension of 30 × 10 mm, as in the case of the positive electrode. The tip of the bundle of 37 was pinched, ultrasonic welding was performed, and the negative electrode tab 40 was joined to the negative electrode lead 37. Next, an acid-modified polyethylene film 18 having an outer dimension of 7 × 20 mm was heat-sealed on both sides at a position 3 mm from the tip of the negative electrode tab 40.

As shown in FIG. 20, in the electrode group, the length L _{1 of the} end portion from which the positive and negative electrode tabs 39 and 40 are drawn is 65 mm, and the length L _{2 of the} end portion where the protruding portion 25b is formed is 84 mm. Met. Further, when the length L ₁ was 1, the length L ₂ was 1.29.

<Preparation of non-aqueous electrolyte>
The same method as in Example 1 was used.

<Production of nonaqueous electrolyte battery>
As shown in FIG. 21, the thermoplastic insulating film 18 of the positive electrode tab 39 and the negative electrode tab 40 is disposed on the short side edge portion, and both the overhang portions 25 b are on the long side edge portion. The electrode group was housed so as to hang.

  Next, after the flat plate portion (sealing plate) on the short side of the exterior member is folded back in the 180 ° direction and overlapped with the opposing short side edge, the entire exterior member is inverted so that the cup portion is on the upper surface. It was.

Subsequently, two heat sinks having a width of 15 mm and a depth of 0.1 mm are processed on the surface of the upper and lower seal bars, and the recesses are opposed to each other so as to absorb the thickness of the positive and negative electrode tabs at the time of heat fusion. Was applied to the short side edge where the positive electrode tab 39 and the negative electrode tab 40 extended under the conditions of a temperature of 200 ° C., a pressure of 4.0 kgf / cm ² , and a heating time of 10 s.

After that, using a heat-sealing machine in which a seal bar with a width of 5 mm without any unevenness is formed on the inner surface from the portion 5 mm inside from the end face, the temperature is 180 ° C., the applied pressure is 1.0 kgf / cm ² , the heating time One overhanging part is applied between the thermoplastic resin film of the peripheral part 31a of the cup part 31 and the thermoplastic resin film of the sealing plate 32 by applying heat and pressure to one of the unfused long side edge parts under the condition of 5s. 25b was heat-sealed. Subsequently, after injecting the non-aqueous electrolyte into the cup part from the unfused long side edge part to impregnate the electrode group, the long side edge part where the unfused long side edge part was fused first Heating and pressing were performed under the same conditions as the edge portion, and the remaining overhang portion 25 b was thermally fused between the thermoplastic resin film on the peripheral edge portion 31 a of the cup portion 31 and the thermoplastic resin film on the sealing plate 32. Further, the remaining unfused portions of the two long side edges are fused at the temperature of 180 ° C., the applied pressure of 4.0 kgf / cm ² , and the heating time of 5 seconds. 100 nonaqueous electrolyte batteries shown in FIG. 22 having a thickness of 4 mm, a width of 85 mm, a length of 100 mm (excluding positive and negative electrode tab dimensions) and a capacity of 1500 mAh were produced.

Example 4
<Formation of exterior member>
The exterior member was produced by the same method as Example 1.

<Production of electrode group>
The same positive electrode paste as in Example 1 was continuously applied to both sides of a 0.03 mm thick aluminum foil hoop material, which is a current collector, so that an uncoated portion 42 remains on one side, dried, rolled, and then positive electrode A mixture layer 43 was formed. Then, the uncoated portion 42 was cut out with a width of 5 mm so that the outer dimensions were 85 × 1200 mm and the size of the mixture application portion 43 was 80 × 1200 mm.

  Next, the same negative electrode paste as in Example 1 was continuously applied to both sides of a 0.015 mm thick copper foil hoop material, which is a current collector, so that an uncoated part 45 remains on one side, dried, and then rolled. Thus, a negative electrode mixture layer 46 was formed. Then, the uncoated portion 45 was cut out with a width of 5 mm so that the outer dimensions were 86 × 1300 mm and the size of the mixture application portion 46 was 81 × 1300 mm.

Next, the mixture portion of the positive electrode 41 and the negative electrode 44 is made to face each other so that the uncoated portions 42 and 45 extend in opposite directions, and a polyethylene microporous film of 83 mm × 1500 mm is interposed between the positive electrode 41 and the negative electrode 44. Then, the separator 47 was wound by a winding machine until the negative electrode 44 was wound, and the separator 47 was wound once around the outer periphery to cover the negative electrode 44. Subsequently, this cylindrical object was heated and pressed at room temperature under a pressure of 10 to 30 kg / cm ² to form a flat shape, and then the unwound portion of the separator was connected to one long side of the flat electrode group. Winding was carried out in a form protruding 4 to 5 mm on the side, and the winding end portion 49 was fixed with an insulating tape 50.

  Next, after joining the aluminum foil of the positive electrode non-application part 42 extended from the separator 47 by ultrasonic welding, the same positive electrode tab 51 as Example 1 was ultrasonically welded. Similarly, the copper foil of the negative electrode uncoated portion 45 extending from the separator 47 was joined by ultrasonic welding, and then the same negative electrode tab 52 as in Example 1 was ultrasonically welded to obtain a final-shaped electrode group.

As shown in FIG. 26, in the electrode group, the length L _{1 of the} end portion from which the positive and negative electrode tabs 51 and 52 are drawn out is 64 mm, and the length L _{2 of the} end portion where the overhang portion 48 is formed is 86 mm. Met. When the length L ₁ was 1, the length L ₂ was 1.34.

<Preparation of non-aqueous electrolyte>
The same method as in Example 1 was used.

<Production of nonaqueous electrolyte battery>
100 non-aqueous electrolyte batteries shown in FIG. 28 having a thickness of 4 mm, a width of 75 mm, a length of 105 mm (excluding the dimensions of the positive and negative electrode tabs), and a capacity of 1500 mAh were manufactured in the same manner as in Example 1.

(Comparative Example 1)
<Formation of exterior member>
As shown in FIG. 1 described above, the same exterior film as in Example 1 is deep-drawn to form a rectangular cup part 2 having a depth of 4.0 mm, a length of 95 mm, and a width of 65 mm, and the short side direction of the cup part 2 An edge having a width of 5 mm was provided at two locations, an edge having a width of 5 mm at one location in the long side direction, and a flat plate portion (sealing plate) 3 having a width of 70 mm provided at another edge on the long side facing the edge. The exterior member 1 was formed.

<Production of electrode group>
As shown in FIG. 29, after a separator made of a polyethylene microporous film was cut out to 168 × 64 mm, the long side was folded back 180 ° in the center, and both end portions 61 of the long side were heat-sealed with a width of 1 mm, A bag-shaped separator 60 having a size of 84 × 64 mm and a bag portion inner size of 84 × 62 mm was produced. Other than this, the electrode group shown in FIG. 30 was produced in the same manner as in Example 1. In the obtained electrode group, the protruding portions of the separator are not formed at both end portions on the long side.

<Preparation of non-aqueous electrolyte>
The same method as in Example 1 was used.

<Production of nonaqueous electrolyte battery>
As shown in FIG. 31, the thermoplastic insulating film 18 of the positive electrode tab 15 spans the short side peripheral portion and the thermoplastic insulating film 18 of the negative electrode tab 16 is opposite to the electrode group in the cup portion 2 of the exterior member 1. It was stored so that it might span the short side peripheral part of the side. Next, after the flat plate portion 3 on the long side of the exterior member 1 was folded back in the 180 ° direction and overlapped on the opposing long side edge, the entire exterior member 1 was inverted so that the cup portion became the upper surface. .

Continuing, using a heat-sealing machine facing the surface of the upper and lower seal bars so that a recess having a width of 25 mm and a depth of 0.1 mm is processed, and the recess absorbs the thickness of the positive and negative electrode tabs at the time of heat-sealing. The two sides of the short side edge were heated and pressurized under the conditions of a temperature of 200 ° C., a pressure of 4.0 kgf / cm ² , and a heating time of 10 s. Thereafter, the nonaqueous electrolyte is injected into the cup portion 2 from the unfused long side edge and impregnated in the electrode group, and then the long side edge is heated at a temperature of 180 ° C. using a heat fusion machine. 32, having a pressure of 4.0 kgf / cm ² and a heating time of 5 s, and finally having a thickness of 4 mm, a width of 70 mm, a length of 105 mm (excluding positive and negative electrode tab dimensions), and a capacity of 1500 mAh. 100 water electrolyte batteries were produced.

(Comparative Example 2)
A flat spiral electrode group was produced in the same manner as described in Example 4 except that the protruding portion was not provided on the separator. The obtained electrode group was housed in the same container as described in Example 4, and then a solution of polyvinylidene fluoride (PVdF) dissolved in 0.3% by weight in dimethylformamide was injected. While penetrating the inside of the group, it was adhered to the entire surface of the electrode group.

  Next, after vacuum-drying the electrode group in the container, a non-aqueous electrolyte similar to that described in Example 1 was injected, sealing treatment was performed, and finally the thickness was 4 mm, the width was 75 mm, and the length was long. 100 nonaqueous electrolyte batteries having a thickness of 105 mm (excluding the dimensions of the positive and negative electrode tabs) and a capacity of 1500 mAh were produced.

  These fabricated batteries were charged, and the following impact tests were conducted assuming vibration during transportation and indirect force applied after being assembled into a pack by external equipment.

  First, after fixing the battery with a tape so that the side where the positive and negative electrode tabs extend parallel to the center of the vinyl chloride plate having a thickness of 3 mm and an outer dimension of 250 × 150 mm and the short side of the vinyl chloride plate are parallel, A vinyl chloride plate of the same size was placed on the battery, and the opposing vinyl chloride plate periphery was fixed with tape.

  Next, assuming that the positive electrode tab is on the + direction and the negative electrode tab is on the − direction, the battery fixed on the vinyl chloride plate is 10 times from the + direction from the height of 100 cm on the concrete plane, − It was dropped 10 times from the direction.

Table 1 below shows the average battery voltage before and after the test, the number of batteries whose battery voltage changed by 0.1 mV or more after the test, the average of the internal resistance before and after the test, and the number of batteries whose internal resistance changed by 5 mΩ or more after the test. Show.

  As is clear from Table 1, the separator was protruded from the positive and negative electrodes at the side perpendicular to the side where the positive and negative terminals of the electrode group were extended, and the protruding part of the separator was thermally fused to the inner surface of the container. In the nonaqueous electrolyte batteries of Examples 1 to 4, there was no decrease in battery voltage after the drop test, and there was no battery whose internal resistance changed by 5 mΩ or more by the drop test.

  In Examples 1-4, when the increase width of the internal resistance was compared, the increase width of the internal resistance of the secondary batteries of Examples 1-3 was as small as 0.5 mΩ. This is because in the secondary batteries of Examples 2 and 3, the separator protrusions were provided at both ends of the electrode group. Further, in the secondary battery of Example 1, the protruding portion of the separator was provided only on one side of the electrode group. However, since the stacked electrode group was used, the increase in internal resistance could be reduced. . In the laminated electrode group, the separator protrudes not only from the surface of the electrode group but also from the inside, and it is considered that these many protruding parts are fixed to the inner surface of the exterior member.

  On the other hand, according to the battery of Comparative Example 1 in which the positive and negative electrode tabs are merely heat-sealed between the film materials and the electrode group is not fixed to the exterior member, the electrode group is moved during the drop test, and the terminal is It broke, leading to a decrease in battery voltage and an increase in internal resistance. Further, in the battery of Comparative Example 2 in which the electrode group is fixed to the container with an adhesive layer as in Patent Document 1, the side slip near the surface of the electrode group can be suppressed during the drop test, but the vicinity of the center is deformed, Resistance increased. Furthermore, in the battery of Comparative Example 2, impregnation with the non-aqueous electrolyte was inhibited by PVdF as the adhesive, and the discharge capacity and the charge / discharge cycle life were also inferior.

  The present invention is not limited to the electrode active materials described in the examples. Further, it can be applied to a polymer battery using a solid electrolyte, a non-aqueous primary battery using lithium metal, and the like.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The top view and side view of an exterior member used with the nonaqueous electrolyte battery which concerns on the 1st Embodiment of this invention. FIG. 2 is a cross-sectional view schematically showing an exterior film constituting the exterior member of FIG. The top view which showed the positive electrode typically. The top view which showed the negative electrode typically. The top view which showed the separator typically. The schematic diagram which shows an example of the connection method of the lead | read | reed and tab of positive / negative electrode. The schematic diagram which shows another example of the connection method of the lead | read | reed and tab of positive / negative electrode. The top view which showed the electrode group typically. The typical top view which shows the state which accommodated the electrode group of FIG. 8 in the exterior member. 1 is a perspective view schematically showing a nonaqueous electrolyte battery according to a first embodiment. The top view and side view of a container which are used with the nonaqueous electrolyte battery which concerns on the 2nd Embodiment of this invention. The top view and side view which showed typically the sealing board of the container of FIG. The top view which showed the separator typically. The top view which showed the electrode group typically. The typical top view which shows the state which accommodated the electrode group of FIG. 14 in the container. The perspective view which showed typically the nonaqueous electrolyte battery which concerns on 2nd Embodiment. The top view and side view of an exterior member used with the nonaqueous electrolyte battery which concerns on the 3rd Embodiment of this invention. The top view which showed the positive electrode typically. The top view which showed the negative electrode typically. The top view which showed the electrode group typically. The typical top view which shows the state which accommodated the electrode group of FIG. 20 in the exterior member. The perspective view which showed typically the nonaqueous electrolyte battery which concerns on 3rd Embodiment. The typical top view of the positive electrode used with the nonaqueous electrolyte battery which concerns on the 4th Embodiment of this invention. The top view which showed the negative electrode typically. The top view which showed the separator typically. The top view which showed the electrode group typically. The typical top view which shows the state which accommodated the electrode group of FIG. 26 in the exterior member. The perspective view which showed typically the nonaqueous electrolyte battery which concerns on 4th Embodiment. The top view which showed typically the separator used with the nonaqueous electrolyte battery of the comparative example 2. FIG. The top view which showed typically the electrode group used with the nonaqueous electrolyte battery of the comparative example 2. FIG. The top view which showed typically the state which accommodated the electrode group of FIG. 30 in the exterior member. The perspective view which showed typically the nonaqueous electrolyte battery of the comparative example 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,30 ... Exterior member, 2, 21, 31 ... Cup part, 3, 23, 32 ... Sealing plate, 4 ... Metal layer, 5 ... Protective layer, 6 ... Thermoplastic resin layer, 7, 33, 41 ... Positive electrode, 8, 34 ... positive electrode lead, 9, 35, 43 ... positive electrode mixture layer, 10, 36, 44 ... negative electrode, 11, 37 ... negative electrode lead, 12, 38, 46 ... negative electrode mixture layer, 13, 24, 47 ... Separator, 14b, 25b, 48 ... overhang, 15, 39, 51 ... positive electrode tab, 16, 40, 52 ... negative electrode tab, 18 ... thermoplastic insulating film having metal adhesion, 20 ... container, 42, 45 ... combination Agent layer non-formation part.

Claims (4)

A film exterior member; an electrode group that is housed in the exterior member and includes a positive electrode, a negative electrode, and a separator; a positive electrode terminal that is electrically connected to the positive electrode; and a negative electrode terminal that is electrically connected to the negative electrode A non-aqueous electrolyte battery comprising:
The positive electrode terminal and the negative electrode terminal are extended from the same end portion of the electrode group or opposite end portions, and are drawn out of the exterior member,
In the electrode group, the separator protrudes from at least one end perpendicular to the end from which the positive electrode terminal and the negative electrode terminal extend, and the protruding portion is fixed to the inner surface of the exterior member. Non-aqueous electrolyte battery characterized.   The nonaqueous electrolyte battery according to claim 1, wherein the protruding portion of the separator is formed at an end portion on the longitudinal direction side of the electrode group.   The nonaqueous electrolyte battery according to claim 1, wherein the protruding portion of the separator is fixed to the inner surface of the exterior member by heat fusion.   When the length of the end portion from which the positive electrode terminal and the negative electrode terminal are extended is 1, the length of the end portion from which the separator projects is 0.2 or more and 10 or less. The nonaqueous electrolyte battery according to any one of claims 1 to 3.

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