WO2020129128A1

WO2020129128A1 - Battery, battery pack, electrical storage device, vehicle, and flying object

Info

Publication number: WO2020129128A1
Application number: PCT/JP2018/046374
Authority: WO
Inventors: 元気山岸; 直樹岩村; 博清間明田
Original assignee: 株式会社東芝
Priority date: 2018-12-17
Filing date: 2018-12-17
Publication date: 2020-06-25
Also published as: CN113169368A; JPWO2020129128A1; JP7155290B2; CN113169368B

Abstract

The present invention addresses the problem of providing, in a thin type battery, a lead-shaped battery which has excellent large current characteristics, a battery pack, an electrical storage device, a vehicle, and a flying object.　A battery 100 of an embodiment of the present invention includes: a flat-shaped electrode group 3 that has a positive electrode 7, a positive electrode collecting tab 7a which is electrically connected to the positive electrode 7, a negative electrode 8, and a negative electrode collecting tab 8a which is electrically connected to the negative electrode 8; an external member 1 that has a first external part 5 and a second external part 6; a positive electrode terminal part 3; a negative electrode terminal part 4; a first positive electrode insulation reinforcement member 24 that has a positive electrode insulation reinforcement maintaining part 24a; and a first negative electrode insulation reinforcement member 37 that has a negative electrode insulation reinforcement maintaining part 37a.

Description

Batteries, battery packs, power storage devices, vehicles and flying vehicles

Embodiments of the present invention relate to a battery, a battery pack, a power storage device, a vehicle, and a flying object.

A battery such as a primary battery and a secondary battery generally includes an electrode group including a positive electrode and a negative electrode, and an exterior member that houses the electrode group.

Currently, metal cans and laminated film containers are put to practical use as exterior materials. The metal can is obtained by deep drawing from a metal plate such as aluminum. In order to manufacture a can by deep drawing, the metal plate needs to have a certain thickness, which hinders the thinning of the exterior member and leads to a loss in volume capacity. For example, when the outer can having a plate thickness of 0.5 mm is applied to a battery having a thickness of 13 mm, the ratio of the total plate thickness of the outer can to the battery thickness is about 7.7%. Since it is a thin battery, the leads inside the battery are required to be compactly accommodated by being bent complicatedly.

　The thin battery has a thin exterior material, so the exterior material is easily deformed. The area around the terminal area is easily deformed by pressure reduction and pressure applied by a charge/discharge probe. In addition, the deformation may cause a sealing failure or a conduction failure during charging/discharging.

International Publication No. 2016/204147

The problem to be solved by the present invention is to provide a battery, a battery pack, a power storage device, a vehicle, and a flying body, which are hard to deform in a thin battery.

The battery of the embodiment includes a positive electrode, a positive electrode current collecting tab electrically connected to the positive electrode, a negative electrode, and a negative electrode current collecting tab electrically connected to the negative electrode. A flat electrode group in which the tab is located on the first end surface and the negative electrode current collecting tab wound in a flat shape is located on the second end surface, and an electrode group side positive electrode electrically connected to the positive electrode current collecting tab A flange of the first exterior part, which includes a lead, a negative electrode lead on the electrode group side electrically connected to the negative electrode current collecting tab, a first exterior part having a flange part in an opening, and a second exterior part. And a second exterior part, the exterior member having an electrode group housed in a space formed by welding, the first exterior part having a through hole on the side of the positive electrode current collecting tab, and the positive electrode head and the positive electrode. A positive electrode external terminal including a positive electrode shaft portion extending from the head portion, a positive electrode terminal lead having a through hole and electrically connected to the electrode group side positive electrode lead, and the positive electrode head portion is outside the first exterior portion. A positive electrode terminal portion protruding, the positive electrode shaft portion being inserted into the through hole of the positive electrode terminal lead, and the positive electrode shaft portion being caulked and fixed to the first outer casing portion and the positive electrode terminal lead; and the first outer casing portion being on the negative electrode collector tab side. Having a through hole, a negative electrode external terminal including a negative electrode head portion and a negative electrode shaft portion extending from the negative electrode head portion, including a negative electrode terminal lead having a through hole and electrically connected to the electrode group side negative electrode lead, A negative electrode terminal portion in which the negative electrode head portion protrudes outside the first exterior portion, the negative electrode shaft portion is inserted into the through hole of the negative electrode terminal lead, and the negative electrode shaft portion is caulked and fixed to the first exterior portion and the negative electrode terminal lead; A first positive electrode insulation reinforcing member that is disposed on the inner surface side of the first outer packaging portion and on the inner surface side of the second outer packaging portion and that is disposed between the positive electrode terminal and the second outer packaging portion, and the first outer packaging portion A first negative electrode insulating reinforcing member arranged between the negative electrode terminal and the second external portion, the first positive electrode insulating reinforcing member being disposed between the negative electrode terminal and the second external portion. A first negative electrode insulating reinforcing member having a slope facing the end of the positive electrode shaft portion opposite to the positive electrode head side, wherein the first negative electrode insulating reinforcing member is opposite to the negative electrode head side of the negative electrode shaft portion. And a negative electrode insulating reinforcement holding portion having a slope facing the end portion on the side.

FIG. 1 is a schematic perspective view of the battery according to the first embodiment. FIG. 2 is an exploded perspective view of the battery shown in FIG. 1 viewed from the positive electrode side. FIG. 3 is an exploded perspective view of the battery shown in FIG. 1 viewed from the negative electrode side. FIG. 4 is a perspective view of an electrode group of the battery shown in FIG. FIG. 5 is a perspective view showing a state where the electrode group is partially developed. FIG. 6 is a schematic view seen from the positive electrode terminal side (negative electrode terminal side) side. FIG. 7 is a cross-sectional view obtained when cut along the plane A-A′ on the positive electrode side of FIG. 6. FIG. 8 is a sectional view obtained when cut along the B-B′ surface on the positive electrode side of FIG. 6. is there. FIG. 9 is a cross-sectional view obtained when cut along the C-C′ surface on the positive electrode side of FIG. 6. is there. FIG. 10 is a cross-sectional view obtained when cut along the D-D′ surface on the positive electrode side of FIG. 7. FIG. 11 is a cross-sectional view obtained when cut along the A-A′ surface on the negative electrode side of FIG. 6. FIG. 12 is a schematic diagram for explaining the angles of the terminals, leads, and slopes. FIG. 13 is a cross-sectional view obtained when cut along the A-A′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 14 is a cross-sectional view obtained when cut along the A-A′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 15 is a cross-sectional view obtained when cut along the B-B′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 16 is a cross-sectional view obtained when cut along the C-C′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 17 is a cross-sectional view obtained when cut along the B-B′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 18 is a cross-sectional view obtained when cut along the A-A′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 19 is a cross-sectional view obtained when cut along the B-B′ surface on the positive electrode side of FIG. 6 in the modified example. FIG. 20 is a perspective view showing the battery shown in FIG. 1 with the terminal portion fixed to the first exterior portion. 21A is a plan view of the second exterior portion, and FIG. 21B is a plan view of the first exterior portion. 22A, 22</b>B, 22</b>C, and 22</b>D are three-sided views showing the manufacturing process of the battery according to the first embodiment. FIG. 23A is a process diagram showing an assembling process of a battery containing a plurality of electrode groups. FIG. 23B is a process diagram showing an assembling process of a battery containing a plurality of electrode groups. FIG. 23C is a process diagram showing an assembling process of a battery containing a plurality of electrode groups. FIG. 24 is a schematic diagram showing a first example of the battery pack according to the second embodiment. FIG. 25 is a schematic diagram showing a second example of the battery pack according to the second embodiment. FIG. 26 is a schematic diagram of the power storage device of the third embodiment. FIG. 27 is a schematic diagram of a vehicle of the fourth embodiment. FIG. 28 is a schematic diagram of the flying object of the fifth embodiment.

The embodiments will be described below with reference to the drawings. It should be noted that the same components throughout the embodiments are denoted by the same reference numerals, and overlapping description will be omitted. Further, each drawing is a schematic diagram for facilitating the description of the embodiment and its understanding, and the shape, dimensions, ratio, etc. may differ depending on the actual device, etc., but these are the following description and known techniques. The design can be changed as appropriate in consideration of the above.

[First Embodiment]
The battery according to the first embodiment will be described with reference to FIGS. 1 to 23. A part of the drawing is a perspective view or a developed view, and some members and parts are not shown, but the positive electrode and the negative electrode are symmetrically configured, and therefore the part of one electrode not shown is the other electrode. Will be revealed from the structure of. Note that the embodiments recognize that the positive electrode and the negative electrode are asymmetrically configured.

The battery 100 shown in FIG. 1 includes an exterior member 1, an electrode group 2, a positive electrode terminal portion 3, a negative electrode terminal portion 4, and an electrolyte (not shown). The battery 100 shown in FIG. 1 is, for example, a secondary battery. The battery 100 of the embodiment is thin. The thickness of the thin battery 100 is preferably 5 mm or more and 30 mm or less, and more preferably 5 mm or more and 25 mm or less.

FIG. 2 is an exploded perspective view of the battery shown in FIG. 1 viewed from the positive electrode side. FIG. 3 is an exploded perspective view of the battery shown in FIG. 1 viewed from the negative electrode side. As shown in FIGS. 1, 2, and 3, the exterior member 1 includes a first exterior portion 5 and a second exterior portion 6. The 1st exterior part 5 is a bottomed square tube container, and has the flange part 5b in the opening part 5a. In the exterior member 1, the electrode group 2 is housed in a space formed by welding the flange portion 5b of the first exterior portion 5 and the second exterior portion 6.

The first exterior part 5 and the second exterior part 6 are preferably made of any one selected from the group consisting of stainless steel, aluminum laminate, and aluminum. Further, in order to increase the battery capacity per volume of the battery 100, the thickness of the first exterior part 5 and the second exterior part 6, that is, the plates of the first exterior part 5 and the second exterior part 6. The thickness is preferably in the range of 0.02 mm or more and 0.3 mm or less. Within this range, the contradictory properties of mechanical strength and flexibility can be compatible. A more preferable range of the plate thickness is 0.05 mm or more and 0.15 mm or less.

As shown in FIG. 1, FIG. 2 and FIG. 3, an inwardly projecting recess is provided near the center of the corner connecting the short side wall and the bottom of the first exterior part 5, and the bottom of the recess is an inclined surface. It is 5d. The first exterior portion 5 has a depth equal to or smaller than the size of the opening 5a (the maximum length of the portion that becomes the opening area). The more preferable first exterior portion 5 has a depth equal to or less than the short side of the portion having the opening area (for example, the one shown in FIG. 2). The first outer casing 5 is, for example, a cup-shaped container having an opening formed from a steel plate by shallow drawing. On the other hand, the second exterior portion 6 is a lid. The second exterior portion 6 covers the opening of the first exterior portion 5. Similarly to the first exterior portion 5, the second exterior portion 6 may be a cup-shaped container formed by shallow drawing or a plate-like shape. When the second exterior portion 6 is a cup-shaped container, the side surface of the second exterior portion 6 can be regarded as a part of the side surface of the first exterior portion 5. Further, when the second exterior portion 6 is a cup-shaped container, the inner surface of the second exterior portion 6 on the side surface side can be regarded as a part of the inner surface of the first exterior portion 5. The electrode group 2 is housed in a space formed by welding the flange portion 5b of the first exterior portion 5 to the four sides of the second exterior portion 6. For the welding, for example, resistance seam welding is used. Resistance seam welding can achieve high airtightness and heat resistance at a lower cost than laser welding.

FIG. 4 is a perspective view of the electrode group 2 of the battery 100 shown in FIG. The positive electrode collector tab 7a of the electrode group 2 shown in FIG. 4 is electrically connected to the electrode group side positive electrode lead 12. When the backup positive electrode lead 11 is used, the positive electrode current collecting tab 7a may be sandwiched between the backup positive electrode lead 11 and the backup positive electrode lead 11 may be electrically connected to the electrode group side positive electrode lead 12. Similarly, the negative electrode collector tab 8a of the electrode group 2 shown in FIG. 4 is electrically connected to the electrode group side negative electrode lead 14. When the backup negative electrode lead 13 is used, the negative electrode current collecting tab 8a may be sandwiched between the backup negative electrode lead 13 and the backup negative electrode lead 13 may be electrically connected to the electrode group side negative electrode lead 14.

Since it is a thin battery, the space in which the electrode group 2 is housed is a space with a low height. The height of the exterior member 1 (the maximum distance between the first exterior portion 5 and the second exterior portion 6) is 5 mm or more and 30 mm or less. Although the battery 100 is thin, it is necessary to reduce the thickness of the member of the exterior member 1 in order to achieve high capacity. When the thickness of the member of the exterior member 1 is reduced, the battery is easily deformed, but there is a problem that it is difficult to reinforce because the battery is thin. In the embodiment, the positive electrode insulation reinforcement holding portion 24 a is provided on the first positive electrode insulation reinforcement member 24 immediately below the positive electrode terminal 17, and the negative electrode insulation reinforcement holding portion 37 a is provided on the first negative electrode insulation reinforcement member 37 immediately below the negative electrode terminal 32. The battery 100 is less likely to be deformed by external pressure or impact in the thickness direction of the battery 100.

As shown in FIG. 5, the electrode group 2 has a flat shape and includes a positive electrode 7, a negative electrode 8, and a separator 9 arranged between the positive electrode 7 and the negative electrode 8. The flat electrode group 2 includes a positive electrode 7, a positive electrode current collecting tab 7a electrically connected to the positive electrode 7, a negative electrode 8, and a negative electrode current collecting tab 8a electrically connected to the negative electrode 8, and has a flat shape. The positive electrode collector tab 7a wound on the first end face is located on the first end face, and the negative electrode collector tab 8a wound in a flat shape is located on the second end face. One of the two flat surfaces of the electrode group 2 faces the bottom surface of the first exterior portion 5, and the other of the two flat surfaces of the electrode group 2 faces the surface of the second exterior portion 6. To do.

The positive electrode 7 includes, for example, a strip-shaped positive electrode current collector made of foil, a positive electrode current collector tab 7a having one end parallel to the long side of the positive electrode current collector, and at least the positive electrode current collector tab 7a. And a positive electrode material layer (positive electrode active material-containing layer) 7b formed on the electric body. The positive electrode current collecting tab 7a is arranged at the center of the electrode group 2 in the width direction. The width of the positive electrode current collecting tab 7a is preferably narrower than the width of the electrode group 2. The width of the positive electrode current collector tab 7a and the width of the electrode group 2 are perpendicular to both the thickness direction of the battery 100 and the depth direction of the battery (direction from the positive electrode terminal 17 to the negative electrode terminal 32). That the positive electrode current collector tab 7a is narrower than the width of the electrode group 2 means that the widthwise end of the positive electrode current collector tab 7a is notched. From the viewpoint of efficiently accommodating the current collector 2 in the exterior member 1, it is more preferable that the positive electrode current collector tabs 7a are cut out from both ends by 5 mm or more and narrower than the width of the electrode group 2 by 10 mm or more. In FIG. 2 and the like, both ends of the positive electrode current collector tab 7a are notched.

On the other hand, the negative electrode 8 includes, for example, a strip-shaped negative electrode current collector made of foil, a negative electrode current collector tab 8a having one end portion parallel to the long side of the negative electrode current collector, and at least the negative electrode current collector tab 8a portion. And a negative electrode material layer (negative electrode active material-containing layer) 8b formed on the negative electrode current collector. The width of the negative electrode current collecting tab 8a is preferably narrower than the width of the electrode group 2. The width of the negative electrode current collector tab 8a and the width of the electrode group 2 are perpendicular to both the thickness direction of the battery 100 and the depth direction of the battery 100 (direction from the positive electrode terminal 17 to the negative electrode terminal 32). That the negative electrode current collecting tab 8a is narrower than the width of the electrode group 2 means that the widthwise end of the negative electrode current collecting tab 8a is notched. From the viewpoint of efficiently accommodating the electrode group 2 in the exterior member 1, it is more preferable that the negative electrode current collecting tabs 8a are cut out by 5 mm or more from both ends and are narrower than the width of the electrode group 2 by 10 mm or more. In FIG. 3 and the like, both ends of the negative electrode current collecting tab 8a are notched.

In the electrode group 2, the positive electrode material layer 7b of the positive electrode 7 and the negative electrode material layer 8b of the negative electrode 8 face each other via the separator 9, and the positive electrode current collecting tab 7a is provided on one side of the winding shaft more than the negative electrode 8 and the separator 9. The positive electrode 7, the separator 9, and the negative electrode 8 are wound in a flat shape so that the negative electrode current collecting tab 8a projects toward the other side than the positive electrode 7 and the separator 9. Therefore, in the electrode group 2, the positive current collecting tab 7a wound in a flat spiral shape is located on the first end surface perpendicular to the winding axis.

Also, the flat, spirally wound negative electrode current collector tab 8a is located on the second end face perpendicular to the winding axis. The insulating sheet 10 covers a part of the outermost circumference of the electrode group 2 between the positive electrode current collecting tab 7a and the negative electrode current collecting tab 8a. The insulating sheet 10 also covers a part of the positive electrode collector tab 7a and the negative electrode collector tab 8a in the outermost periphery of the electrode group 2. The electrode group 2 holds an electrolyte (not shown).

The backup positive electrode lead 11 is formed by bending a conductive plate into a U shape, and sandwiches the layers (around the center) excluding the curved portions at both ends of the positive electrode current collecting tab 7a to sandwich the layers of the positive electrode current collecting tab 7a. It is in close contact. The electrode group side positive electrode lead 12 is a conductive plate having a larger area than the backup positive electrode lead 11. The backup positive electrode lead 11 can be omitted. When the backup positive electrode lead 11 is not used, the positive electrode current collecting tab 7 a is directly electrically connected to the electrode group side positive electrode lead 12.

The backup negative electrode lead 13 is formed by bending a conductive plate into a U shape, and sandwiches the layers of the negative electrode current collecting tab 8a with the portions (near the center) excluding the curved portions at both ends of the negative electrode current collecting tab 8a sandwiched therebetween. It is in close contact. The electrode group side negative electrode lead 14 is a conductive plate having a larger area than the backup negative electrode lead 13. The backup negative electrode lead 13 can be omitted. When the backup negative electrode lead 13 is not used, the negative electrode current collecting tab 8a is directly electrically connected to the electrode group side negative electrode lead 14.

FIG. 6 shows a schematic view of the battery 100 viewed from the positive electrode terminal portion 3 side (negative electrode terminal portion 4 side) side. The view seen from the positive electrode terminal portion 3 side and the view seen from the negative electrode terminal side portion 4 are the same. FIG. 6 shows virtual lines (broken lines) of A-A', B-B' and C-C'. In the sectional views from FIG. 7 onward, these sectional views of the AA′ plane, the BB′ plane, and the CC′ plane, that is, from the virtual line to the depth direction of the battery 100 (from the positive electrode terminal portion 3 to the negative electrode terminal portion) 4 is a sectional view taken in the direction of (4).

FIG. 7 is a cross-sectional view obtained when cut along the A-A′ surface on the positive electrode terminal portion 3 side in FIG. 6. The A-A′ surface is a cross section that passes through the center of the positive electrode terminal 17 (the center of the inclined surface 5d) and includes the positive electrode insulating reinforcement holding portion 24a. FIG. 8 is a cross-sectional view obtained when cut along the B-B′ surface on the positive electrode terminal portion 3 side in FIG. 6. The B-B′ surface is a cross section that passes through the outside of the positive electrode terminal 17 near the positive electrode terminal 17, and does not include the positive electrode insulating reinforcement holding portion 24a. FIG. 9 is a cross-sectional view obtained when cut along the C-C′ surface on the positive electrode terminal portion 3 side in FIG. 6. The C-C′ surface is a cross section that passes near the end of the first outer casing 5, and does not include the positive electrode insulating reinforcement holding portion 24 a. As shown in FIG. 7, the inside of the battery 100 of the positive electrode terminal 17 is supported by the positive electrode insulating reinforcement holding portion 24a. The positive electrode insulation reinforcement holding portion 24a prevents deformation of the entire battery 100, particularly the positive electrode terminal portion 3 side when a force is applied from the outside of the battery 100.

Further, FIG. 10 shows a cross-sectional view obtained by cutting along the DD′ plane of FIG. 7. Then, FIG. 11 is a cross-sectional view obtained when cut along the AA′ surface on the negative electrode terminal portion 4 side in FIG. 6. The AA′ surface is a cross section that passes through the center of the negative electrode terminal 32 (the center of the inclined surface 5d) and includes the negative electrode insulation reinforcement holding portion 37a. As shown in FIG. 11, the inside of the battery 100 of the negative electrode terminal 32 is supported by the negative electrode insulating reinforcement holding portion 37a. The negative electrode insulation reinforcement holding portion 37a prevents deformation of the entire battery 100, particularly the negative electrode terminal portion 4 side when a force is applied from the outside of the battery 100. Since the positive electrode side and the negative electrode side are symmetric, the cross-sectional views of the BB′ surface, the CC′ surface, and the DD′ surface on the negative electrode side are not shown in FIG. The structure on the negative electrode terminal portion 4 side can be understood by referring to.
Hereinafter, the internal structure of the battery 100 will be described with reference to FIGS. 2, 3, and 7 to 11.

As shown in FIGS. 2, 3, and 7 to 10, the electrode group side positive electrode lead 12 includes a flat plate portion 12a electrically connected to the positive electrode current collecting tab 7a side on the positive electrode current collecting tab 7a side, and a second portion. Has a first extending portion 12b and a second extending portion 12c extending toward the exterior portion 6 side. As shown in FIG. 8, the first extending portion 12b and the second extending portion 12c are directly and electrically connected to the positive electrode terminal lead 23. A gap 12d where the electrode group side positive electrode lead 12 does not exist exists between the first extending part 12b and the second extending part 12c. As shown in FIGS. 7 and 10, the positive electrode shaft portion 17b is exposed from the gap 12d. The electrode group side positive electrode lead 12 is connected to the surface of the backup positive electrode lead 11 or the positive electrode current collecting tab 7a. The backup positive electrode lead 11 is electrically connected to the positive electrode current collecting tab 7a and the electrode group side positive electrode lead 12. The positive electrode collector tab 7a is electrically connected to the electrode group side positive electrode lead 12.

The positive electrode current collecting tab 7a, the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are integrated by welding, whereby the positive electrode 7 is connected to the electrode group side positive electrode lead 12 via the positive electrode current collecting tab 7a and the backup positive electrode lead 11. It is electrically connected. The welding of the positive electrode current collector tab 7a and the backup positive electrode lead 11 is performed by, for example, laser welding or ultrasonic welding. The backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are welded by, for example, laser welding or ultrasonic welding. The backup positive electrode lead 11 can be omitted. When the backup positive electrode lead 11 is omitted, it is preferable that the positive electrode current collecting tab 7a and the electrode side positive electrode lead 12 are welded.

As shown in FIGS. 2, 3 and 11, the electrode group side negative electrode lead 14 includes a flat plate portion 14a electrically connected to the negative electrode current collecting tab 8a side on the negative electrode current collecting tab 8a side, and a second exterior portion. It has a first extending portion 14b and a second extending portion 14c extending toward the 6 side. Referring to FIG. 8, the first extending portion 14b and the second extending portion 14c are directly and electrically connected to the negative electrode terminal lead 36. A gap 14d where the electrode group side negative electrode lead 14 does not exist exists between the first extending portion 14b and the second extending portion 14c. As shown in FIGS. 10 and 11 for reference, the positive electrode shaft portion 32b is exposed from the gap 14d. The electrode group side negative electrode lead 14 is connected to the surface of the backup negative electrode lead 13 or the negative electrode current collecting tab 8a. The backup negative electrode lead 13 is electrically connected to the negative electrode current collecting tab 8a and the electrode group side negative electrode lead 14. The negative electrode current collecting tab 8a is electrically connected to the electrode group side negative electrode lead 14.

The negative electrode current collecting tab 8a, the backup negative electrode lead 13 and the electrode group side negative electrode lead 14 are integrated by welding, whereby the negative electrode 8 is connected to the electrode group side negative electrode lead 14 via the negative electrode current collecting tab 8a and the backup negative electrode lead 13. It is electrically connected. The welding of the negative electrode current collecting tab 8a and the backup negative electrode lead 13 is performed by, for example, laser welding or ultrasonic welding. The backup negative electrode lead 13 and the electrode group side negative electrode lead 14 are welded by, for example, laser welding or ultrasonic welding.

As shown in FIG. 2, FIG. 3, FIG. 7, and FIG. 10, the positive electrode terminal portion 3 includes a through hole 15 formed in the inclined surface 5d of the first exterior portion 5, a positive electrode outer member 17, and a positive electrode insulating member. 18 a, a positive electrode reinforcing member (ring member) 18 b, an insulating gasket 19, and a positive electrode terminal insulating member 20.

In the positive electrode terminal portion 3, the first exterior portion 5 has a through hole 15 on the positive electrode collector tab 7a side. The positive electrode terminal 17 of the positive electrode terminal portion 3 includes a positive electrode head portion 17a and a positive electrode shaft portion 17b extending from the positive electrode head portion 17a. The positive electrode terminal portion 3 includes a positive electrode terminal lead 23 having a through hole 23e. In the positive electrode terminal portion 3, the positive electrode head portion 17a projects to the outside of the first exterior portion 5, the positive electrode shaft portion 17b is inserted into the through hole 23e of the positive electrode terminal lead 23, and the positive electrode shaft portion 17b becomes the first exterior portion. 5 and the positive electrode terminal lead 23 are fixed by crimping.

The burring portion (annular rising portion) 16 extends from the peripheral portion of the through hole 15 toward the inside of the exterior member 1 as shown in FIG. 7, and is formed by burring processing.

As shown in FIG. 7, the positive electrode terminal 17 includes a truncated pyramid-shaped positive electrode head portion 17 a and a cylindrical positive electrode shaft portion 17 b that penetrates the through hole 15 of the first exterior portion 5. The cylindrical positive electrode shaft portion 17b extends from a plane parallel to the top surface of the positive electrode head portion 17a. The positive electrode external terminal 17 is formed of a conductive material such as aluminum or aluminum alloy.

The positive electrode insulating member 18 a insulates the first exterior part 5 from the positive electrode terminal 17 and the positive electrode terminal lead 23. The positive electrode reinforcing member 18b is sandwiched between the first exterior part 5 and the positive electrode insulating member 18a.

The positive electrode reinforcing member 18b is, for example, a circular ring formed of a material having higher rigidity than a gasket. Examples of materials having higher rigidity than the gasket include stainless steel, iron plated (for example, Ni, NiCr, etc.), ceramics, resin that can have higher rigidity than the gasket (for example, polyphenylene sulfide (PPS), poly Butylene terephthalate (PBT)) and the like are included. As shown in FIG. 7, the positive electrode reinforcing member 18b is arranged on the outer peripheral surface of the burring portion 16 and is in contact with the burring portion 16 and the positive electrode insulating member 18a. When the positive electrode reinforcing member 18b is made of an insulating material such as resin or ceramics, it can be integrated with the second positive electrode insulating reinforcing member 25.

The insulating gasket 19 is a cylindrical body having a flange portion 19a at one open end. As shown in FIG. 7, the insulating gasket 19 has a cylindrical portion inserted into the through hole 15 and the burring portion 16, and the flange portion 19 a is arranged on the outer surface of the first exterior portion 5 on the outer periphery of the through hole 15. Has been done. The insulating gasket 19 is, for example, a resin such as fluororesin, fluororubber, polyphenylene sulfide resin (PPS resin), polyether ether ketone resin (PEEK resin), polypropylene resin (PP resin), and polybutylene terephthalate resin (PBT resin). Are formed from.

As shown in FIGS. 2 and 7, the positive electrode terminal insulating member 20 is a plate member bent at an obtuse angle, and has a through hole 20a at the bottom. The positive electrode terminal insulating member 20 is arranged on the outer surface of the first exterior portion 5. An insulating gasket 19 is inserted into the through hole 20 a of the positive electrode terminal insulating member 20.

The positive electrode terminal lead 23 is a conductive plate having a flat plate portion 23a, a first extending portion 23b, a second extending portion 23c and a third extending portion 23d. In FIG. 8, the positive electrode terminal lead 23 has a flat plate portion 23a on the electrode group 2 side. The first extending portion 23b and the second extending portion 23c extend to the opening side of the first exterior portion 5, that is, the second exterior portion 6 side. The first extending portion 23b and the second extending portion 23c are located on the second exterior material 6 side, and the first extending portion 12b and the second extending portion 12c of the electrode group side positive electrode lead 12 are located. It extends in the same direction as. The third extending portion 23d extends in the direction along the inclined surface 5d. A through hole 23e is provided in the center of the third extending portion 23d.

As shown in FIGS. 8 to 10, the first extending portion 23b of the positive electrode terminal lead 23 is integrated with the first extending portion 12b of the electrode group side positive electrode lead 12 by welding. Faces of the first extending portion 23b of the positive electrode terminal lead 23 and the first extending portion 12b of the electrode group side positive electrode lead 12 facing each other, and/or the first extending portion of the positive electrode terminal lead 23 on the tip side. The end surface of 23b and the end surface of the first extending portion 12b of the electrode group side positive electrode lead 12 are welded.

As shown in FIGS. 8 to 10, the second extending portion 23c of the positive electrode terminal lead 23 is integrated with the second extending portion 12c of the electrode group side positive electrode lead 12 by welding. Faces of the second extending portion 23c of the positive electrode terminal lead 23 and the second extending portion 12c of the electrode group side positive electrode lead 12 facing each other, and/or the second extending portion of the positive electrode terminal lead 23 on the tip side. The end surface of 23c and the end surface of the second extending portion 12c of the electrode group side positive electrode lead 12 are welded.

As shown in FIGS. 8 to 10, the extending direction of at least the tip portion of the first extending portion 23b of the positive electrode terminal lead 23 and the first extending portion 12b of the electrode group side positive electrode lead 12 is the second extending direction. It is preferably perpendicular or substantially perpendicular (80° or more and 100° or less) to the surface of the exterior portion 6. The extending direction of at least the tip end portion of the first extending portion 23b of the positive electrode terminal lead 23 and the first extending portion 12b of the electrode group-side positive electrode lead 12 is perpendicular or approximately to the surface of the second exterior portion 6. Being vertical means that the first extension portion 23b of the positive electrode terminal lead 23 and the first extension portion 12b of the electrode group-side positive electrode lead 12 are formed without welding after welding.

As shown in FIGS. 8 to 10, the extending direction of at least the tip portion of the second extending portion 23c of the positive electrode terminal lead 23 and the second extending portion 12c of the electrode group side positive electrode lead 12 is the second It is preferably perpendicular or substantially perpendicular (80° or more and 100° or less) to the surface of the exterior portion 6. The extending direction of at least the tip end portion of the second extending portion 23c of the positive electrode terminal lead 23 and the second extending portion 12c of the electrode group-side positive electrode lead 12 is perpendicular or approximately to the surface of the second exterior portion 6. Being vertical means that the second extension portion 23c of the positive electrode terminal lead 23 and the second extension portion 12c of the electrode group side positive electrode lead 12 are formed without welding after welding.

There is an advantage that the wiring of the terminal part of the electrode can be made compact by bending the lead after welding, but in order to perform bending accurately after welding, it is required to reduce the thickness of the lead. However, reducing the thickness of the leads is not preferable because it is difficult for a large current to flow. The thickness of the lead can be increased by making the welded portion face the direction of the surface of the second exterior portion 6.

Considering the large current characteristics, the thickness of the positive electrode terminal lead 23 can be 0.5 mm or more and 3.0 mm or less, and the thickness of the electrode group side positive electrode lead 12 is 0.5 mm or more and 3.0 mm. It can be: Further, considering the bending process of the leads before welding the leads to each other and the large current characteristic, the sum of the thickness of the positive electrode terminal lead 23 and the thickness of the electrode group side positive electrode lead 12 is 1.0 mm or more and 1.2 mm or less. It is preferable. These thicknesses are preferably filled at least in the welded parts.

The first positive electrode insulating reinforcing member 24 has a structure in which a rectangular cylinder with a bottom is divided in half in the long side direction, as shown in FIGS. 2, 3, and 7 to 10. The first positive electrode insulating reinforcing member 24 covers approximately half of the positive electrode current collecting tab 7a from the winding center to the second outer packaging portion 6 side, whereby the second outer packaging portion 6, particularly near the short side. Can be reinforced. The first positive electrode insulating reinforcing member 24 is arranged on the inner surface side of the first outer casing 5 and the inner surface side of the second outer casing 6, and is arranged between the positive electrode terminal 17 and the second outer casing 6. .. The first positive electrode insulating reinforcing member 24 has a positive electrode insulating reinforcing holding portion 24a. The positive electrode insulating reinforcement holding portion 24a has a sloped surface facing the end portion of the positive electrode shaft portion 17b on the side opposite to the positive electrode head portion 17a side. Since the positive electrode terminal portion 3 is supported by the sloped surface of the positive electrode insulating reinforcement holding portion 24a, the strength of the battery 100 is improved. The positive electrode insulation reinforcement holding portion 24a is a portion extending from the bottom portion 24b of the first positive electrode insulation reinforcement member 24 facing the second exterior portion 6 side. The first positive electrode insulating reinforcing member 24 includes a first side face 24c facing the positive electrode terminal side of the first outer casing 5 and a second side face 24d facing the widthwise face of the first outer casing 5. From the viewpoint of reinforcing the battery 100 on the positive electrode terminal portion 3 side, the surface of the positive electrode shaft portion 17b facing the positive electrode insulating reinforcement holding portion 24a, that is, the surface of the end portion of the positive electrode shaft portion 17b opposite to the positive electrode head portion 17a side. Is preferably smaller than the slope of the positive electrode insulating reinforcement holding portion 24a, that is, the surface facing the positive electrode shaft portion 17b of the positive electrode insulating reinforcement holding portion 24a and having the closest distance to the positive electrode shaft portion 17b. When this requirement is satisfied, the positive electrode shaft portion 17 crimped and fixed to the positive electrode terminal lead 23 comes into contact with the sloped surface of the positive electrode insulation reinforcement holding portion 24a having a large area and can be held, so that the battery 100 of the positive electrode terminal portion 3 side can be held. Strength is improved.

It is preferable that the positive electrode terminal portion 3 further includes a second positive electrode insulating reinforcing member 25. As shown in FIGS. 2, 3, and 7 to 10, the second positive electrode insulating reinforcing member 25 has a structure in which a rectangular cylinder with a bottom is divided in half in the long side direction. The second positive electrode insulating reinforcing member 25 is arranged on the inner surface side of the first outer casing 5 and between the positive electrode terminal lead 23 and the first outer casing 5, and is connected to the first positive electrode insulating reinforcing member 24. Facing each other.

The second positive electrode insulating reinforcing member 25 includes a bottom portion 25a facing the bottom side of the first exterior portion 5 and a first side surface portion facing the side surface (side wall on the short side side) side of the first exterior portion 5 in the positive electrode terminal direction. 25b, the bottom portion 25a and the first side surface portion 25b are connected to each other, the inclined portion 25c arranged in the center of the second positive electrode insulating and reinforcing member 25, the through hole 25d opened in the center of the inclined portion 25c, and the first A second side surface portion 25e that faces the side surface (long side sidewall) in the width direction of the exterior portion 5 is provided. The second positive electrode insulating reinforcing member 25 includes a corner portion connected from the short side wall of the first exterior portion 5 to the bottom surface and a corner portion connected from the short side wall of the first exterior portion 5 to the long side surface. To cover. As a result, it is possible to reinforce the first exterior portion 5, particularly, the vicinity of the corner where the short side wall, the long side wall, and the bottom portion intersect. The through hole 25d communicates with the through hole 15 of the first exterior portion 5. The positive electrode terminal lead 23 is arranged on the second positive electrode insulating reinforcing member 25. The through hole 23e of the positive electrode terminal lead 23 communicates with the through hole 25d of the second positive electrode insulating and reinforcing member 25 and the through hole 15 of the first exterior portion 5.

The second positive electrode insulating reinforcing member 25 is caulked and fixed to the positive electrode shaft portion 17b, the first outer casing portion 5 and the positive electrode terminal lead 23, and is fixed at the positive electrode terminal portion 3 from the viewpoint of imparting insulation and strength. Is preferred.

The first positive electrode insulating reinforcing member 24 and the second positive electrode insulating reinforcing member 25 are preferably insulative and molded resin.

For example, by partially winding the positive electrode current collector tab 7a with the insulating sheet 10 and covering at least the insulating sheet 10 on the positive electrode current collector tab 7a side with the first positive electrode insulating reinforcing member 24 and the second positive electrode insulating reinforcing member 25, It is preferable that the positive electrode current collecting tab 7a and the positive electrode terminal 17 inside the battery 100 are configured so as not to short-circuit with the first exterior part 5 and the second exterior part 6. The inner surface side of the first exterior part 5 and the second exterior part 6 between the positive electrode terminal 17 and the positive electrode current collecting tab 7a is provided with a first positive electrode insulation reinforcing member 24 and a second positive electrode insulation reinforcing member 25. It is preferable that the positive electrode current collecting tab 7a and the positive electrode terminal 17 inside the battery 100 are configured so as not to be short-circuited with the first exterior part 5 and the second exterior part 6 by being covered.

The positive electrode shaft portion 17b of the positive electrode external terminal 17 includes an insulating gasket 19, a through hole 20a of the positive electrode terminal insulating member 20, a through hole 15 of the first outer casing 5, a through hole 25c of the second positive electrode insulating reinforcing member 25, and a positive electrode. After being inserted into the through hole 23e of the terminal lead 23, caulking causes plastic deformation. As a result, these members are integrated and the positive electrode external terminal 17 is electrically connected to the positive electrode terminal lead 23. Therefore, the positive electrode external terminal 17 also serves as a rivet. It should be noted that the boundary between the end surface 17b of the positive electrode shaft portion of the positive electrode external terminal 17 and the through hole 23e of the positive electrode terminal lead 23 may be welded by a laser or the like to make a stronger connection and improve electrical conductivity.

As shown in FIGS. 3 and 11, the negative electrode terminal portion 4 has a through hole 30 formed in the inclined surface 5d of the first exterior portion 5, a negative electrode terminal 32, a negative electrode insulating member 33a, and a negative electrode reinforcing member (ring). Shaped member) 33b, an insulating gasket 34, and a negative electrode terminal insulating member 35.

In the negative electrode terminal portion 4, the first exterior portion 5 has a through hole 30 on the negative electrode current collector tab 8a side. The negative electrode terminal 32 of the negative electrode terminal portion 4 includes a negative electrode head portion 32a and a negative electrode shaft portion 32b extending from the negative electrode head portion 32a. The negative electrode terminal portion 4 includes a negative electrode terminal lead 36 having a through hole 36e. In the negative electrode terminal portion 4, the negative electrode head portion 32a projects to the outside of the first exterior portion 5, the negative electrode shaft portion 32b is inserted into the through hole 36e of the negative electrode terminal lead 36, and the negative electrode shaft portion 32b becomes the first exterior portion. 5 and the negative electrode terminal lead 36 are fixed by crimping.

As shown in FIG. 11, the burring portion (annular rising portion) 31 extends from the peripheral portion of the through hole 30 toward the inside of the exterior member 1, and is formed by burring processing.

As shown in FIG. 11, the negative electrode terminal 32 includes a truncated pyramid-shaped negative electrode head portion 32 a and a cylindrical negative electrode shaft portion 32 b that penetrates the through hole 30 of the first exterior portion 5. The columnar negative electrode shaft portion 32b extends from a plane parallel to the top surface of the negative electrode head portion 32a. The negative electrode terminal 32 is made of a conductive material such as aluminum or aluminum alloy.

The negative electrode insulating member 33 a insulates the first exterior part 5 from the negative electrode terminal 32 and the negative electrode terminal lead 36. The negative electrode reinforcing member 33b is sandwiched between the first exterior portion 5 and the negative electrode insulating member 33a.

The negative electrode reinforcing member 33b is, for example, a circular ring formed of a material having higher rigidity than the gasket. Examples of materials having higher rigidity than the gasket include stainless steel, iron plated (for example, Ni, NiCr, etc.), ceramics, resin that can have higher rigidity than the gasket (for example, polyphenylene sulfide (PPS), poly Butylene terephthalate (PBT)) and the like are included. As shown in FIG. 11, the negative electrode reinforcing member 33b is arranged on the outer peripheral surface of the burring portion 31 and is in contact with the burring portion 31 and the negative electrode insulating member 33a. When the negative electrode reinforcing member 33b is made of an insulating material such as resin or ceramics, it can be integrated with the first negative electrode insulating reinforcing member 37.

The insulating gasket 34 is a cylindrical body (cylindrical portion) having a flange portion 34a at one open end. In the insulating gasket 34, as shown in FIGS. 3 and 11, the cylindrical portion is inserted into the through hole 30 and the burring portion 31, and the flange portion 34 a is formed in the through hole 30 on the outer surface of the first exterior portion 5. It is arranged on the outer circumference. The insulating gasket 34 is, for example, a resin such as fluororesin, fluororubber, polyphenylene sulfide resin (PPS resin), polyether ether ketone resin (PEEK resin), polypropylene resin (PP resin), and polybutylene terephthalate resin (PBT resin). Are formed from.

As shown in FIGS. 3 and 11, the negative electrode terminal insulating member 35 is a plate member bent at an obtuse angle, and has a through hole 35a at the bottom. The negative electrode terminal insulating member 35 is arranged on the outer surface of the first exterior portion 5. An insulating gasket 34 is inserted into the through hole 35 a of the negative electrode terminal insulating member 35.

The negative electrode terminal lead 36 is a conductive plate having a flat plate portion 36a, a first extending portion 36b, a second extending portion 36c and a third extending portion 36d. In FIG. 11, the negative electrode terminal lead 36 has a flat plate portion 36a on the electrode group 2 side. The first extending portion 36b and the second extending portion 36c extend to the opening side of the first exterior portion 5, that is, the second exterior portion 6 side. The 1st extension part 36b and the 2nd extension part 36c are located in the 2nd exterior material 6 side, and the 1st extension part 14b and the 2nd extension part 14c of the electrode group side negative electrode lead 14 are located. It extends in the same direction as. The third extending portion 36d extends in the direction along the inclined surface 5d. A through hole 36e is provided at the center of the third extending portion 36d.

As shown in FIGS. 9 to 10 and FIG. 11 for reference, the first extending portion 36b of the negative electrode terminal lead 36 is integrated with the first extending portion 14b of the electrode group side negative electrode lead 14 by welding. There is. Faces of the first extension portion 36b of the negative electrode terminal lead 36 and the first extension portion 14b of the electrode group side negative electrode lead 14 facing each other and/or the first extension portion of the negative electrode terminal lead 36 on the tip side. The end face of 36b and the end face of the first extending portion 14b of the electrode group side negative electrode lead 14 are also welded.

As shown in FIGS. 9 to 10 and FIG. 11 for reference, the second extension portion 36c of the negative electrode terminal lead 36 is integrated with the second extension portion 14c of the electrode group side negative electrode lead 14 by welding. There is. The second extension part 36c of the negative electrode terminal lead 36 and the second extension part 14c of the electrode group side negative electrode lead 14 facing each other, and/or the second extension part of the negative electrode terminal lead 36 on the tip side. The end face of 36c and the end face of the second extending portion 14c of the electrode group side negative electrode lead 14 are welded.

As shown in FIGS. 9 to 10 and FIG. 11 for reference, the extending direction of at least the tip end portion of the first extension portion 36b of the negative electrode terminal lead 36 and the first extension portion 14b of the electrode group side negative electrode lead 14 Is preferably perpendicular or substantially perpendicular (80° or more and 100° or less) to the surface of the second exterior portion 6. The extending direction of at least the tip end portion of the first extending portion 36b of the negative electrode terminal lead 36 and the first extending portion 14b of the electrode group-side negative electrode lead 14 is perpendicular or approximately to the surface of the second exterior portion 6. Being vertical means that the first extension portion 36b of the negative electrode terminal lead 36 and the first extension portion 14b of the electrode group side negative electrode lead 14 are formed without welding after welding.

As shown in FIGS. 9 to 10 and FIG. 11 for reference, the extending direction of at least the tip portion of the second extending portion 36c of the negative electrode terminal lead 36 and the second extending portion 14c of the electrode group side negative electrode lead 14 Is preferably perpendicular or substantially perpendicular (80° or more and 100° or less) to the surface of the second exterior portion 6. The extending direction of at least the tip end portion of the second extending portion 36c of the negative electrode terminal lead 36 and the second extending portion 14c of the electrode group-side negative electrode lead 14 is perpendicular or approximately to the surface of the second exterior portion 6. Being vertical means that the second extension portion 36c of the negative electrode terminal lead 36 and the second extension portion 14c of the electrode group-side negative electrode lead 14 are formed without welding after welding.

Although there is an advantage that the wiring of the terminal portion of the electrode can be made compact by bending the lead after welding, it is required to reduce the thickness of the lead in order to perform bending accurately after welding. However, reducing the thickness of the leads is not preferable because it is difficult for a large current to flow. The thickness of the lead can be increased by making the welded portion face the direction of the surface of the second exterior portion 6.

Considering the large current characteristics, the thickness of the negative electrode terminal lead 36 can be 0.5 mm or more and 3.0 mm or less, and the thickness of the electrode group side negative electrode lead 14 is 0.5 mm or more and 3.0 mm. It can be: Furthermore, considering the lead bending process before welding the leads to each other and the large current characteristic, the sum of the thickness of the negative electrode terminal lead 36 and the thickness of the electrode group side negative electrode lead 14 is 1.0 mm or more and 1.2 mm or less. It is preferable.

The first negative electrode insulating reinforcing member 37 has a structure in which a rectangular cylinder with a bottom is divided in half in the long side direction, as shown in FIGS. 2, 3, 11 and 9 to 10 for reference. The first negative electrode insulating reinforcing member 37 covers about half of the negative electrode current collecting tab 8a from the winding center to the second outer packaging portion 6 side, whereby the second outer packaging portion 6, particularly near the short side. Can be reinforced. The first negative electrode insulating reinforcing member 37 is arranged on the inner surface side of the first outer casing 5 and the inner surface side of the second outer casing 6, and is arranged between the negative electrode terminal 32 and the second outer casing 6. .. The first negative electrode insulating reinforcing member 37 has a negative electrode insulating reinforcing holding portion 37a. The negative electrode insulation reinforcement holding portion 37a has a sloped surface facing the end portion of the negative electrode shaft portion 32b opposite to the negative electrode head portion 32a side. The negative electrode terminal portion 3 is supported by the sloped surface of the negative electrode insulating reinforcement holding portion 37a, thereby improving the strength of the battery 100. The negative electrode insulation reinforcement holding portion 37a is a portion extending from the bottom portion 37b of the first negative electrode insulation reinforcement member 37 facing the second exterior portion 6 side. The first negative electrode insulating reinforcing member 37 includes a first side surface 37c facing the negative electrode terminal side of the first outer casing 5 and a second side surface 37d facing the widthwise surface of the first outer casing 5. From the viewpoint of reinforcing the battery 100 on the negative electrode terminal portion 4 side, the surface of the negative electrode shaft portion 32b facing the negative electrode insulating reinforcement holding portion 37a, that is, the surface of the end portion of the negative electrode shaft portion 32b opposite to the positive electrode head portion 32a side. Is preferably smaller than the slope of the negative electrode insulating reinforcement holding portion 37a, that is, the surface facing the negative electrode shaft portion 32b of the negative electrode insulating reinforcement holding portion 37a and having the shortest distance from the negative electrode shaft portion 32b. When this requirement is satisfied, the negative electrode shaft portion 32 crimped and fixed to the negative electrode terminal lead 36 comes into contact with the slope of the negative electrode insulation reinforcement holding portion 37a having a large area and can be held, so that the battery 100 on the negative electrode terminal portion 4 side can be held. Strength is improved.

It is preferable that the negative electrode terminal portion 3 further includes a second negative electrode insulating reinforcing member 38. As shown in FIGS. 2, 3, and 11 and FIGS. 9 to 10 for reference, the second negative electrode insulating reinforcing member 38 has a structure in which a bottomed rectangular tube is halved in the long side direction. The second negative electrode insulating reinforcing member 38 is arranged on the inner surface side of the first outer casing 5 and between the negative electrode terminal lead 36 and the first outer casing 5, and is connected to the first negative electrode insulating reinforcing member 37. Facing each other.

The second negative electrode insulation reinforcing member 38 includes a bottom portion 38a that faces the bottom portion side of the first exterior portion 5, and a first side surface portion that faces the side surface (side wall on the short side side) side of the first exterior portion 5 in the negative electrode terminal direction. 38b, the bottom portion 38a and the first side surface portion 38b, and an inclined portion 38c arranged in the center of the second negative electrode insulating reinforcing member 38, a through hole 38d opened in the center of the inclined portion 38d, and the first A second side surface portion 38e that faces the side surface (long side wall) of the exterior portion 5 in the width direction. The second negative electrode insulating reinforcing member 38 includes a corner portion connecting the short side wall of the first exterior portion 5 to the bottom surface and a corner portion connecting the short side wall of the first exterior portion 5 to the long side surface. To cover. As a result, it is possible to reinforce the first exterior portion 5, particularly, the vicinity of the corner where the short side wall, the long side wall, and the bottom portion intersect. The through hole 38d communicates with the through hole 30 of the first exterior portion 5. The negative electrode terminal lead 36 is disposed on the second negative electrode insulating reinforcing member 38. The through hole 36 e of the negative electrode terminal lead 36 communicates with the through hole 38 d of the second negative electrode insulating reinforcing member 38 and the through hole 30 of the first exterior portion 5.

The second negative electrode insulation reinforcing member 38 is caulked and fixed to the negative electrode shaft portion 32b, the first exterior portion 5 and the negative electrode terminal lead 36, and is fixed at the negative electrode terminal portion 4 from the viewpoint of providing insulation and strength. Is preferred.

The first negative electrode insulating reinforcing member 37 and the second negative electrode insulating reinforcing member 38 are preferably insulative and molded resin.

For example, by partially winding the negative electrode current collecting tab 8a with the insulating sheet 10 and covering at least the insulating sheet 10 on the negative electrode current collecting tab 8a side with the first negative electrode insulating reinforcing member 37 and the second negative electrode insulating reinforcing member 38, It is preferable that the negative electrode current collecting tab 8a and the positive electrode terminal 17 inside the battery 100 are configured so as not to short-circuit with the first exterior part 5 and the second exterior part 6. The inner surfaces of the first outer casing 5 and the second outer casing 6 between the negative electrode terminal 32 and the negative electrode current collecting tab 8a are covered with a first negative electrode insulating reinforcing member 37 and a second negative electrode insulating reinforcing member 38. It is preferable that the negative electrode current collecting tab 8a and the negative electrode terminal 32 inside the battery 100 are configured so as not to be short-circuited with the first exterior part 5 and the second exterior part 6 by being covered.

The negative electrode shaft portion 32b of the negative electrode terminal 32 includes an insulating gasket 34, a through hole 35a of the negative electrode insulating member 35, a through hole 30 of the first exterior portion 5, a through hole 37c of the first negative electrode insulating reinforcing member 37, and a negative electrode terminal lead. After being inserted into the through hole 36e of 36, caulking causes plastic deformation. As a result, these members are integrated and the negative electrode terminal 32 is electrically connected to the negative electrode terminal lead 36. Therefore, the negative electrode terminal 32 also serves as a rivet. The boundary between the end surface 32b of the negative electrode shaft portion of the negative electrode terminal 32 and the through hole 36e of the negative electrode terminal lead 36 may be welded with a laser or the like for stronger connection and improved electrical conductivity.

The backup positive electrode terminal lead 11, the electrode group side positive electrode lead 12, the positive electrode terminal lead 23, the backup negative electrode terminal lead 13, the electrode group side negative electrode lead 14 and the negative electrode terminal lead 36 can be formed of, for example, aluminum or an aluminum alloy material. .. In order to reduce the contact resistance, the material of the lead is preferably the same as the material of the positive electrode current collector or the negative electrode current collector that can be electrically connected to the lead.

The positive electrode insulating member 18a, the first positive electrode insulating reinforcing member 24, the second positive electrode insulating reinforcing member 25, the negative electrode insulating member 33a, the first negative electrode terminal insulating reinforcing member 37, and the second negative electrode insulating reinforcing member 38 are, for example, Tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS) and polyether ether ketone It is formed of a thermoplastic resin containing at least one selected from the group consisting of (PEEK) and the like.

The electrode group 2 is housed in the first exterior part 5 such that the positive electrode current collecting tab 7 a faces the positive electrode terminal part 3 and the negative electrode current collecting tab 8 a faces the negative electrode terminal part 4. Therefore, a curved surface that intersects the positive electrode current collector tab 7a and the negative electrode current collector tab 8a with the flat surface that intersects the positive electrode current collector tab 7a and the negative electrode current collector tab 8a of the electrode group 2 facing the bottom surface 5c in the first exterior portion 5. Faces the side surface on the long side in the first exterior portion 5.

By providing the positive electrode insulating reinforcement holding portion 24a and the negative electrode insulating reinforcement holding portion 37a as in the embodiment, the strength of the battery 100 is improved. In the battery 100 having improved strength, the displacement of the battery 100 when a load of 10 N is applied to the positive electrode terminal or the negative electrode terminal in the direction from the first exterior part 5 to the second exterior part 6 is 1. It is less than 0 mm. Therefore, the reliability of the battery 100 is improved even in a harsh environment.

Next, with reference to FIG. 12, the angle and distance between the positive electrode terminal 17 (negative electrode terminal 32) and the positive electrode insulation reinforcement holding portion 24a (negative electrode insulation reinforcement holding portion 37a) will be described. FIG. 12 is a schematic diagram for explaining the angles of the terminals, leads, and slopes. Since the positive electrode side and the negative electrode side are the same, the positive electrode side will be mainly described.

The sloped surface facing the end of the positive electrode shaft portion 17b of the positive electrode insulation reinforcement holding portion 24a opposite to the positive electrode head portion 17a has an end portion opposite to the positive electrode head portion 17a of the positive electrode shaft portion 17b facing the sloped surface. If it is parallel or substantially parallel to, it is possible to further prevent deformation of the battery 100 due to external pressure. Therefore, the angle formed between the second exterior portion 6 and the surface of the positive electrode shaft portion 17a that faces the slope of the positive insulation reinforcement holding portion 24a is A1, and the slope of the positive insulation reinforcement holding portion 24a and the second exterior portion 6 are Is defined as A2, the angle between the surface of the negative electrode shaft portion 32b facing the sloped surface of the negative electrode insulation reinforcement holding portion 37a and the second exterior portion 6 is defined as B1, and the sloped surface of the negative electrode insulation reinforcement holding portion 37a is defined as the second surface. It is preferable that |A1−A2|≦8 degrees and |B1−B2|≦8 degrees are satisfied, where B2 is the angle formed by the exterior portion 6 of the above. When this relationship is satisfied, there is little difference in the angle of the end of the positive electrode shaft portion 17b opposite to the positive electrode head portion 17a facing the slope, so that the entire slope can receive external pressure. From the same viewpoint, it is more preferable to satisfy |A1-A2|≦5 degrees and |B1-B2|≦5 degrees.

The angle formed by the second exterior portion 6 and the surface of the positive electrode shaft portion 17a facing the inclined surface of the positive electrode insulation reinforcement holding portion 24a is A1, and the angle formed by the inclination surface of the positive electrode insulation reinforcement holding portion 24a and the second exterior portion 6 A2 is calculated using the virtual lines L1 to L5 in FIG. The angle is obtained by CT (Computed Tomography) inspection using X-rays on the center cross section of the battery 100 as shown in FIG. 7 that includes the positive electrode shaft portion 17a and the positive electrode insulating reinforcement holding portion 24a.

The virtual line L1 is a line along the bottom surface of the second exterior portion 6. The virtual line L2 is a line passing through two points (X1 and X2) where the third extending portion 23d of the positive electrode terminal lead 23 and the positive electrode shaft portion 17b are in contact with each other. The intersection point between the perpendicular line L3 from the imaginary line L2 passing through the contact point X1 and the positive electrode insulating reinforcement holding portion 24a is defined as Y1. Further, the intersection point of the perpendicular line L4 from the imaginary line L2 passing through the contact point X2 and the positive electrode insulating reinforcement holding portion 24a is defined as Y2. A line passing through Y1 and Y2 is defined as a virtual line L5. An angle A1 formed by the surface of the positive electrode shaft portion 17a facing the inclined surface of the positive electrode insulating reinforcement holding portion 24a and the second exterior portion 6 is an angle formed by the virtual line L1 and the virtual line L2. An angle A2 formed by the inclined surface of the positive electrode insulating reinforcement holding portion 24a and the second exterior portion 6 is an angle formed by the virtual line L1 and the virtual line L2.
The angle formed between the second exterior portion 6 and the surface of the negative electrode shaft portion 32b that faces the slope of the negative insulation reinforcement holding portion 37a is B1, and the slope between the negative insulation reinforcement holding portion 37a and the second exterior portion 6 is formed. The angle B2 is similarly obtained.

If the distance between the inclined surface of the positive electrode insulating reinforcement holding portion 24a and the positive electrode shaft portion 17b is large, the impact when the positive electrode insulating reinforcement holding portion 24a and the positive electrode shaft portion 17b come into contact with each other is likely to be large, and the strength of the battery 100 is improved. Less is. Therefore, it is preferable that the distance between the slope of the positive electrode insulating reinforcement holding portion 24a and the positive electrode shaft portion 17b is 0.0 mm or more and 1.0 mm or less. Similarly, the distance between the slope of the negative electrode insulating reinforcement holding portion 37a and the negative electrode shaft portion 32b is preferably 0.0 mm or more and 1.0 mm or less.

The distance between the slope of the positive electrode insulation reinforcement holding portion 24a and the positive electrode shaft portion 17b is obtained from the average value of the distance between X1 and Y1 and the distance between X2 and Y2. The distance between the slope of the negative electrode insulation reinforcement holding portion 37a and the negative electrode shaft portion 32b is also obtained from the average value of the distance between X1 and Y1 and the distance between X2 and Y2.

In order to make the strength improvement by the positive electrode insulation reinforcement holding part 24a more effective, the slope of the positive electrode insulation reinforcement holding part 24a is a wide slope and faces the positive electrode terminal lead 23 (third extension part 23d). Is preferred. Similarly, the slope of the negative electrode insulation reinforcement holding portion 37a is a wide slope and preferably faces the negative electrode terminal lead 36 (third extending portion 23d).

If the distance between the sloped surface of the positive electrode insulating reinforcing holding portion 24a and the positive electrode terminal lead 23 is large, the impact when the positive electrode insulating reinforcing holding portion 24a and the positive electrode terminal lead 23 come into contact with each other is likely to be large, so that the strength of the battery 100 is improved. The effect will decrease. Therefore, it is preferable that the distance between the inclined surface of the positive electrode insulating reinforcement holding portion 24a and the positive electrode terminal lead 23 is 0.0 mm or more and 1.0 mm or less. Similarly, the distance between the slope of the negative electrode insulation reinforcement holding portion 37a and the negative electrode terminal lead 36 is preferably 0.0 mm or more and 1.0 mm or less.

The distance between the slope of the positive electrode insulation reinforcement holding portion 24a and the positive electrode terminal lead 23 is the distance between the intersection of the virtual line L3 and the positive electrode terminal lead 23 on the positive electrode insulation reinforcement holding portion 24a side and Y1, the virtual line L4 and the positive electrode terminal lead 23. It is calculated from the average value of the distance between the intersection point on the positive electrode insulation reinforcement holding portion 24a side and Y2. Similarly, on the negative electrode side, the distance between the slope of the negative electrode insulation reinforcement holding portion 37a and the negative electrode terminal lead 36 is the distance between the virtual line L3 and the intersection of the negative electrode terminal lead 36 on the negative electrode insulation reinforcement holding portion 37a side and Y1. It is calculated from the average value of the distance between the intersection of the line L4 and the negative electrode terminal lead 36 on the side of the negative electrode insulating reinforcement holding portion 37a and Y2.

In the corner portion connecting the short side wall and the bottom portion of the first exterior portion 5, there are gaps between the electrode group 2 and the positive electrode current collecting tab 7a and between the negative electrode current collecting tab 8a. By providing a concave portion projecting inward at a corner portion connecting the short side wall and the bottom portion of the first exterior portion 5 and making the bottom portion of the concave portion an inclined surface 5d, the dead space in the first exterior portion 5 is reduced. Therefore, the volumetric energy density of the battery can be increased. Further, by disposing the positive electrode terminal portion 3 and the negative electrode terminal portion 4 on each of the inclined surfaces 5d, the terminal portion can be installed more than when the positive electrode terminal portion 3 and the negative electrode terminal portion 4 are provided on the short side surface having no inclined surface. The area can be increased. Therefore, the diameters of the positive electrode shaft portion 17b of the positive electrode terminal 17 and the negative electrode shaft portion 32b of the negative electrode terminal 32 can be increased, and a large current (high rate current) can be flowed with low resistance.

As a result of housing the electrode group 2 in the first exterior portion 5, a bottomed rectangular tubular shape formed by the lower end of the second positive electrode insulating reinforcing member 25 being in contact with the upper end of the first positive electrode insulating reinforcing member 24. The positive electrode current collecting tab 7a is covered with the cover. Further, the negative electrode current collecting tab 8a is covered with a bottomed rectangular tubular cover formed by the lower end of the second negative electrode insulating reinforcing member 38 being in contact with the upper end of the first negative electrode insulating reinforcing member 37.

The second exterior part 6 functions as a lid for the first exterior part 5. The electrode group 2 is sealed in the exterior member 1 by welding the flange portion 5 b of the first exterior portion 5 and the four sides of the second exterior portion 6 to each other.

The battery shown in FIGS. 1 to 11 described above is an exterior member in which the electrode group is housed in the space formed by welding the first exterior portion and the second exterior portion having the flange portion in the opening. It is preferable to include. By having the positive electrode insulation reinforcement holding part 24a and the negative electrode insulation reinforcement holding part 37a, high strength can be maintained even when the plate thickness of the first and second exterior parts is reduced. As a result, since the flexibility of the exterior member can be increased, it becomes easy to restrain the electrode group 2 by vacuum sealing or applying a load from the outside of the exterior member 1. As a result, the distance between the electrodes of the electrode group 2 can be stabilized and the resistance can be reduced, and a battery pack having vibration resistance and impact resistance can be easily realized. Furthermore, when the flexibility of the first exterior portion 5 and the second exterior portion 6 is high, it becomes easy to shorten the distance from the inner surface of the first and second exterior portions to the electrode group 2, and thus the battery The heat dissipation can be improved.

The stainless steel first exterior part 5 and the second exterior part 6 are easily welded and can be sealed by inexpensive resistance seam welding. Therefore, the exterior member 1 having a higher gas sealing property than the laminated film container can be realized at low cost. Moreover, the heat resistance of the exterior member 1 can be improved. For example, the melting point of SUS304 is 1400°C, whereas the melting point of Al is 650°C.

Also, the shaft portion of the external terminal is plastically deformed as a result of being caulked and fixed in the through hole. As a result, a force is applied in the radial direction of the insulating gasket, but since the burring portion is reinforced by the ring-shaped member arranged on the outer side of the insulating gasket, a compressive stress is generated in the insulating gasket, so that the external terminal is attached to the first exterior portion 5. Can be connected with high strength. Even if the plate thickness of the first exterior portion 5, that is, the thickness of the burring portion is reduced, the burring portion can be reinforced by the ring-shaped member, so that regardless of the thickness of the first exterior portion 5, the external The terminal can be connected to the first exterior portion 5 with high strength. Further, since the burring portion extends from the edge of the through hole toward the inside of the exterior member 1, it is possible to suppress liquid leakage when the internal pressure of the exterior member 1 rises due to gas generation or the like by the action of the external pressure. Becomes Therefore, high reliability can be realized even when the plate thickness of the first exterior portion 5 and the second exterior portion 6 is reduced.

Therefore, according to the battery of the first embodiment, high strength and reliability can be obtained even when the plate thicknesses of the first exterior part 5 and the second exterior part 6 are reduced, and thus the flexibility and It is possible to provide a battery having excellent heat dissipation and high strength and reliability.

When the first exterior part 5 has a depth equal to or less than the maximum length of the opening, the area of the opening of the first exterior part 5 becomes large. The second armor is welded to the four sides of the first armor, but when the opening area increases, the length of one side welded increases, so three sides are welded first and the remaining one side is welded. It becomes easy to inject the electrolytic solution through the gap. Moreover, since the exterior member 1 can be temporarily sealed by providing a portion having a welding strength lower than that of the other parts, a component for temporary sealing (for example, a rubber plug) can be eliminated. Furthermore, since the exterior member 1 has a flat shape, the heat dissipation of the battery can be improved.

The dead space in the first exterior part 5 can be reduced by including the concave portion having the inclined surface 5d in the first exterior part 5 and disposing the terminal portion on the inclined surface 5d.

The inclined surface 5d is not limited to being provided in the vicinity of the central portion of the short side of the exterior member 1, and may be the entire short side of the exterior member.

Since the end face of the head of the electrode terminal has a quadrilateral top face and first and second inclined faces connected to two opposite sides of the top face, any one of the three faces is welded. The welding direction can be changed by selecting the surface. Further, since the shaft portion of the electrode terminal has the step-like inclined surface, the electrode terminal is firmly fixed.

The difference (wall thickness) between the outer and inner diameters of the positive electrode terminal portion 3, the negative electrode terminal portion 4, or both ring-shaped members is preferably equal to or greater than the plate thickness of the first exterior portion 5. This makes it possible to connect the external terminals to the first outer casing 5 with high strength regardless of the plate thickness of the first outer casing 5. Specifically, the shortest wall thickness can be 0.1 mm or more.

Also, the outer shape of the ring-shaped member does not necessarily have to be the same as the burring cross-sectional shape, and may be a polyhedron such as a rectangle or a hexagon, or may be a composite shape of one or more curved lines and one or more straight lines.

The flat plate as illustrated in FIGS. 5 and 6 can be used for the second exterior portion 6, but a plate having a flange portion at the opening may be used instead of the flat plate. An example of such a structure may be the same as that of the first exterior portion 5.

The backup positive electrode lead 11 and the backup negative electrode lead 13 are not limited to U-shaped conductive plates, and conductive flat plates may be used. Further, it is also possible to adopt a configuration in which neither the backup positive electrode lead 11 or the backup negative electrode lead 13 or both are used.

The exterior member 1 can further include a safety valve or the like that can release the pressure inside the battery when the internal pressure of the battery rises above a specified value.

The battery 100 according to the first embodiment may be a primary battery or a secondary battery. A lithium ion secondary battery is an example of the battery 100 according to the first embodiment.

The positive electrode 7, the negative electrode 8, the separator 9, and the electrolyte of the battery 100 of the first embodiment will be described below.

1) Positive electrode 7
The positive electrode 7 can include, for example, a positive electrode current collector, a positive electrode material layer held by the positive electrode current collector, and a positive electrode current collector tab 7 a. The positive electrode material layer can include, for example, a positive electrode active material, a conductive agent, and a binder.

As the positive electrode active material, for example, an oxide or a sulfide can be used. Examples of oxides and sulfides are lithium-occluding manganese dioxide (MnO ₂ ), iron oxide, copper oxide, nickel oxide, lithium manganese composite oxide (for example, Li _x Mn ₂ O ₄ or Li _x MnO ₂ ), Lithium nickel composite oxide (eg Li _x NiO ₂ ), lithium cobalt composite oxide (eg Li _x CoO ₂ ), lithium nickel cobalt composite oxide (eg LiNi _1-y Co _y O ₂ ), lithium manganese cobalt composite oxide (e.g. _{_{_{Li x Mn y Co 1-y}}} O 2), lithium manganese nickel complex oxide having a spinel structure (e.g., _{_{_{Li x Mn 2-y Ni y}}} O 4), lithium phosphates having an olivine structure (e.g., Li _x _{_{_{FePO 4, Li x Fe 1-}}} y Mn y PO 4, Li x CoPO 4), iron sulfate _{_{_{(Fe 2 (SO 4) 3}}} ), vanadium oxide (e.g. V ₂ O ₅₎ and lithium nickel-cobalt-manganese composite oxide Things can be mentioned. In the above formula, 0<x≦1 and 0<y≦1. As the active material, these compounds may be used alone, or a plurality of compounds may be used in combination.

The binder is mixed to bind the active material and the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and fluororubber.

The conductive agent is blended as necessary to improve the current collecting performance and to suppress the contact resistance between the active material and the current collector. Examples of the conductive agent include carbonaceous materials such as acetylene black, carbon black and graphite.

In the positive electrode material layer, the positive electrode active material and the binder are preferably blended in the proportions of 80% by mass to 98% by mass and 2% by mass to 20% by mass, respectively.

ㆍSufficient electrode strength can be obtained by using the binder in an amount of 2% by mass or more. Further, when the content is 20% by mass or less, the compounding amount of the insulating material of the electrode can be reduced and the internal resistance can be reduced.

When a conductive agent is added, the positive electrode active material, the binder, and the conductive agent are 77% by mass or more and 95% by mass or less, 2% by mass or more and 20% by mass or less, and 3% by mass or more and 15% by mass or less, respectively. It is preferable to mix them in proportions. The conductive agent can exhibit the above-mentioned effects by adjusting the amount to 3% by mass or more. Further, when the content is 15% by mass or less, decomposition of the non-aqueous electrolyte on the surface of the positive electrode conductive agent under high temperature storage can be reduced.

The positive electrode current collector is preferably an aluminum foil or an aluminum alloy foil containing at least one element selected from Mg, Ti, Zn, Ni, Cr, Mn, Fe, Cu and Si.

The positive electrode current collector is preferably integrated with the positive electrode current collector tab. Alternatively, the positive electrode current collector may be separate from the positive electrode current collector tab.

2) Negative electrode 8
The negative electrode 8 can include, for example, a negative electrode current collector, a negative electrode material layer held by the negative electrode current collector, and a negative electrode current collector tab 8a. The negative electrode material layer can include, for example, a negative electrode active material, a conductive agent, and a binder.

As the negative electrode active material, for example, a metal oxide, a metal nitride, an alloy, carbon or the like that can store and release lithium ions can be used. It is preferable to use a substance capable of inserting and extracting lithium ions at a noble potential of 0.4 V or higher (vs. Li/Li ⁺ ) as the negative electrode active material.

As the negative electrode active material, for example, a graphite material or a carbonaceous material (for example, graphite, coke, carbon fiber, spherical carbon, pyrolytic gas phase carbonaceous material, resin fired body, etc.), chalcogen compound (for example, titanium disulfide, Molybdenum disulfide, niobium selenide, etc.), light metals (for example, aluminum, aluminum alloys, magnesium alloys, lithium, lithium alloys, etc.), Li _4+x Ti ₅ O ₁₂ (x is in the range of −1≦x≦3 due to charge/discharge reaction) Of the spinel type lithium titanate, ramsteride type Li _2+x Ti ₃ O ₇ (x changes within the range of −1≦x≦3 due to charge/discharge reaction), Ti and P, V, Sn , A metal composite oxide and a niobium titanium composite oxide containing at least one element selected from the group consisting of Cu, Ni and Fe.

Examples of the metal composite oxide containing Ti and at least one element selected from the group consisting of P, V, Sn, Cu, Ni and Fe include, for example, TiO ₂ —P ₂ O ₅ and TiO ₂ —V _2. O ₅ , TiO ₂ —P ₂ O ₅ —SnO ₂ and TiO ₂ —P ₂ O ₅ —MO (M is at least one element selected from the group consisting of Cu, Ni and Fe) can be mentioned. These metal composite oxides are changed into lithium titanium composite oxides by inserting lithium by charging. It is preferable to include one or more substances selected from the group consisting of lithium titanium oxide (eg, spinel type lithium titanate), silicon and tin. The binder for the negative electrode active material layer is the same as the binder for the positive electrode active material layer. The conductive agent of the negative electrode active material layer is common with the conductive agent of the positive electrode active material layer.

Examples of the niobium titanium-containing composite oxide include, for example, the general formula Li _a TiM _b Nb _{2 ±β} O _{7 ±σ} (where the value of each subscript is 0≦a≦5, 0≦b≦0.3, 0≦ It is within the range of β≦0.3, 0≦σ≦0.3, and M is at least one kind selected from the group consisting of Fe, V, Mo and Ta (may be one kind or plural kinds). A compound oxide having a monoclinic crystal structure represented by the general formula Li _2+a1 M(I) _2-b1 Ti _6-c1 M(II) _d1 O _14+σ1 (where: The value of each subscript is within the range of 0≦a1≦6, 0<b1<2, 0<c1<6, 0<d1<6, −0.5≦σ1≦0.5, and M(I) Is at least one kind selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs and K (may be one kind or plural kinds), and M(II) is Zr, Sn, V, A slant represented by at least one kind (which may be one kind or plural kinds) selected from the group consisting of Nb, Ta, Mo, W, Fe, Co, Mn, and Al and including Nb. A composite oxide having a tetragonal crystal structure can be used. In the above general formula Li _2+a1 M(I) _2-b1 Ti _6-c1 M(II) _d1 O _14+σ1 , the value of each subscript is 0≦a1≦6, 0<b1<2, 0<c1. <6, 0<d1<6, -0.5≦σ1≦0.5, and M(I) is at least selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs, and K. 1 type (may be 1 type or a plurality of types), M(II) is Nb, or Nb and Zr, Sn, V, Ta, Mo, W, Fe, Co, Mn and It is preferably a combination with at least one kind (may be one kind or plural kinds) selected from the group consisting of Al. In particular, the monoclinic niobium titanium-containing composite oxide is more preferable because it has a large capacity per weight and can increase the battery capacity.

　The conductive agent is added to improve the current collecting performance and to suppress the contact resistance between the negative electrode active material and the current collector. Examples of the conductive agent include carbonaceous materials such as acetylene black, carbon black and graphite.

The binder is mixed to fill the gap between the dispersed negative electrode active material and to bind the negative electrode active material and the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, and styrene butadiene rubber.

The active material, the conductive agent, and the binder in the negative electrode material layer are mixed in the proportions of 68% by mass to 96% by mass, 2% by mass to 30% by mass, and 2% by mass to 30% by mass, respectively. It is preferable. By setting the amount of the conductive agent to 2% by mass or more, the current collecting performance of the negative electrode layer can be improved. Further, when the amount of the binder is 2% by mass or more, the binding property between the negative electrode material layer and the current collector can be sufficiently exhibited, and excellent cycle characteristics can be expected. On the other hand, it is preferable that the content of each of the conductive agent and the binder is 28% by mass or less in order to increase the capacity.

As the current collector, a material that is electrochemically stable at the lithium storage and emission potentials of the negative electrode active material is used. The current collector is preferably made of copper, nickel, stainless steel, or aluminum, or an aluminum alloy containing at least one element selected from Mg, Ti, Zn, Mn, Fe, Cu, and Si. The thickness of the current collector is preferably in the range of 5 to 20 μm. The current collector having such a thickness can balance the strength and weight reduction of the negative electrode.

The negative electrode current collector is preferably integrated with the negative electrode current collector tab 8a. Alternatively, the negative electrode current collector may be separate from the negative electrode current collector tab 8a.

For the negative electrode 8, for example, a negative electrode active material, a binder, and a conductive agent are suspended in a commonly used solvent to prepare a slurry, and the slurry is applied to a current collector and dried to form a negative electrode material layer. Then, it is manufactured by pressing. The negative electrode may also be produced by forming a negative electrode active material, a binder and a conductive agent into a negative electrode material layer to form a negative electrode material layer, and disposing this on the current collector.

3) Separator 9
It is a thin porous insulating film. The separator 9 includes a non-woven fabric including a resin-made ultra-thin nanofiber film, a film, paper, an inorganic particle layer, and the like. Examples of the constituent material of the separator 9 include polyolefin such as polyethylene and polypropylene, cellulose, polyester, polyvinyl alcohol, polyimide, polyamide, polyamideimide, polytetrafluoroethylene, and vinylon. An example of the separator 9 that is preferable from the viewpoint of thinness and mechanical strength is a nonwoven fabric containing cellulose fibers. The inorganic particle layer contains oxide particles, a thickener, and a binder. For the oxide particles, metal oxides such as aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, and barium sulfate can be used. Carboxymethyl cellulose can be used as a thickener. As the binder, methyl acrylate, an acrylic copolymer containing the same, styrene-butadiene rubber (SBR) or the like can be used. As with the separator 9, the insulating sheet 10 may be made of non-woven fabric, film, or paper. The insulating sheet 10 is preferably further fixed with a tape (not shown).

4) Electrolyte Electrolytes include a solution containing an electrolyte salt and a non-aqueous solvent, a non-aqueous gel electrolyte in which a polymer material is combined with a solution containing an electrolyte salt and a non-aqueous solvent, a solution containing an electrolyte salt and water, or an electrolyte salt. It is preferable to use an aqueous gel electrolyte in which a polymer material is combined with a solution containing water.

The electrolyte salt contained in the non-aqueous solution is, for example, LiPF ₆ , LiBF ₄ , Li(CF ₃ SO ₂ ) ₂ N (lithium bistrifluoromethanesulfonylamide; commonly known as LiTFSI), LiCF ₃ SO ₃ (commonly LiTFS), Li(C). _{_{_{_{2 F 5 SO 2) 2 N}}}} ( bis pentafluoroethanesulfonyl amide lithium; called _{_{_{LiBETI), LiClO 4, LiAsF 6}}} , LiSbF 6, LiB (C 2 O 4) 2 ( bis oxa Lato lithium borate; called LiBOB), difluoro Lithium such as (trifluoro-2-oxide-2-trifluoro-methylpropionato(2-)-0,0), LiBF ₂ OCOOC(CF ₃ ) ₂ (lithium borate; commonly known as LiBF ₂ (HHIB)) Salts can be used. These electrolyte salts may be used alone or in combination of two or more. LiPF ₆ and LiBF ₄ are particularly preferable. A supporting salt that conducts ions can be used as the lithium salt. Examples thereof include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate, and imide-based supporting salts. The lithium salt may contain one kind or two or more kinds.

The non-aqueous electrolyte salt concentration is preferably in the range of 0.5 mol/L or more and 3 mol/L or less, and more preferably in the range of 0.7 mol/L or more and 2 mol/L or less. Such regulation of the electrolyte concentration makes it possible to further improve the performance when a high load current is passed while suppressing the influence of the viscosity increase due to the increase of the electrolyte salt concentration.

The non-aqueous solvent is not particularly limited, but examples thereof include cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC) or methyl ethyl carbonate (MEC). Or chain carbonate such as dipropyl carbonate (DPC), 1,2-dimethoxyethane (DME), γ-butyrolactone (GBL), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeHF), 1,3-dioxolane , Sulfolane, and acetonitrile (AN) can be used. These solvents may be used alone or in combination of two or more. A non-aqueous solvent containing a cyclic carbonate and/or a chain carbonate is preferable. Examples of the polymer material contained in the non-aqueous gel electrolyte include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), polymethacrylate, and the like.

The electrolyte salt contained in the aqueous solution is LiCl, LiBr, LiOH, Li ₂ SO ₄ , LiNO ₃ , LiN(SO ₂ CF ₃ ) ₂ (lithium trifluoromethanesulfonylamide; commonly known as LiTFSA), LiN(SO ₂ C ₂ F ₅ ) ₂ (lithium bispentafluoroethanesulfonylamide; commonly called LiBETA), LiN(SO ₂ F) ₂ (lithium bisfluorosulfonylamide; commonly called LiFSA), LiB[(OCO) ₂ ] _{2 and the} like. The type of lithium salt used may be one type or two or more types. Examples of the polymer material contained in the water-based gel electrolyte include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), polymethacrylate, and the like.

The concentration of the aqueous electrolyte salt is preferably 1 mol/L or more and 12 mol/L or more, and more preferably 112 mol/L or more and 10 mol/L or less. In order to suppress electrolysis of the electrolytic solution, LiOH or Li ₂ SO ₄ can be added to adjust the pH. The pH value is preferably 3 or more and 13 or less, and more preferably pH 4 or more and 12 or less.

Alternatively, as the non-aqueous electrolyte, a room temperature molten salt containing lithium ions (ionic melt), a polymer solid electrolyte, an inorganic solid electrolyte, or the like may be used.

The room temperature molten salt (ionic melt) refers to a compound that can exist as a liquid at room temperature (15 to 25° C.) among organic salts composed of a combination of organic cations and anions. The room-temperature molten salt includes a room-temperature molten salt that exists alone as a liquid, a room-temperature molten salt that becomes a liquid when mixed with an electrolyte, and a room-temperature molten salt that becomes a liquid when dissolved in an organic solvent. Generally, the melting point of the room temperature molten salt used in the non-aqueous electrolyte battery is 25° C. or lower. The organic cation generally has a quaternary ammonium skeleton.

FIG. 13 shows a positive electrode portion of a battery 101 which is a modified example of the battery 100 of the first embodiment. Since the positive electrode side and the negative electrode side are symmetrical, illustration and partial description of the negative electrode side are omitted. FIG. 13 shows a cross-sectional view of the A-A′ plane of FIG. 6 in the modified example. On the positive electrode terminal portion 3 side of the battery 101 shown in FIG. 13, the end portion side of the first positive electrode insulating reinforcing member 24 on the positive electrode current collecting tab 7a side projects to the second positive electrode insulating reinforcing member 25 side, and An end portion side of the positive electrode insulating reinforcing member 25 on the positive electrode current collecting tab 7a side projects to the first positive electrode insulating reinforcing member 24 side. The protruding portion of the first positive electrode insulating reinforcing member 24 is referred to as a protruding portion 24d. The protruding portion of the second positive electrode insulating reinforcing member 25 is referred to as a protruding portion 25f. It is preferable that the protruding portion 24d of the first positive electrode insulating reinforcing member 24 and the protruding portion 25f of the second positive electrode insulating reinforcing member 25 face each other. The protrusion 24d and the protrusion 25f prevent the positive electrode current collector tab 7a from approaching the positive electrode terminal portion 3 side, so that the deformation of the battery 101 due to the force in the depth direction of the battery 101 can be prevented. The same applies to the negative electrode terminal portion 4 side, and although not shown, the end portion side of the first negative electrode insulating reinforcing member 37 on the negative electrode current collecting tab 8a side projects to the second negative electrode insulating reinforcing member 38 side, Since the end portion side of the second negative electrode insulating reinforcing member 38 on the negative electrode current collecting tab 8a side projects toward the first negative electrode insulating reinforcing member 37 side, deformation of the battery 101 due to force in the depth direction of the battery 101 is prevented. be able to.

FIG. 14 shows a positive electrode terminal portion 3 side of a battery 102 which is a modified example of the battery 100 of the first embodiment. Since the positive electrode terminal portion 3 side and the negative electrode terminal portion 4 side are symmetrical, illustration and partial description of the negative electrode terminal portion 4 side are omitted. On the side of the positive electrode terminal portion 3 of the battery 102 shown in FIG. 14, the first positive electrode insulating reinforcing member 24 and the second positive electrode insulating reinforcing member 25 are fitted. FIG. 14 shows a cross-sectional view of the A-A′ plane of FIG. 6 in the modified example. The fitting will be specifically described. The convex portion 24e of the first side surface 24c along the side wall 5e between the flange portion 5b of the first exterior portion 5 and the inclined portion 5d of the first positive electrode insulating reinforcing member 24. And along the side wall 5e between the flange portion 5b and the inclined portion 5d of the first exterior portion 5 of the second positive electrode insulating reinforcing member 25 and faces the first side surface 24c of the first positive electrode insulating reinforcing member 24. It is preferable that the recess 25g of the first side surface portion 25b is fitted. By disposing the convex portion 24e on the first exterior portion 5 side with respect to the concave portion 25g, the first positive electrode insulating reinforcing member 25 that is not crimped is fixed by the second positive electrode insulating reinforcing member 25 that is crimped and fixed. , Can be fixed. By fixing the first positive electrode insulating reinforcing member 24 to prevent the first positive electrode insulating reinforcing member 24 from approaching the positive electrode current collecting tab 7a side, the deformation of the battery 102 due to the force in the depth direction of the battery 102 is prevented. Can be prevented. Although illustration is omitted, the first negative electrode insulating reinforcing member 37 and the second negative electrode insulating reinforcing member 38 are similarly fitted on the negative electrode terminal portion 4 side. By fitting the negative electrode terminal portion 4 side, the deformation of the battery 102 due to the force in the depth direction of the battery 102 can be prevented on the negative electrode terminal portion 4 side as well as on the positive electrode terminal portion 3 side. It is possible to arbitrarily select the shape of the fitting concavity and convexity and which is the convexity.

FIG. 15 shows a positive electrode terminal portion 3 side of a battery 103 which is a modified example of the battery 100 of the first embodiment. Since the positive electrode terminal portion 3 side and the negative electrode terminal portion 4 side are symmetrical, illustration and partial description of the negative electrode terminal portion 4 side are omitted. FIG. 15 shows a cross-sectional view of the B-B′ plane of FIG. 6 in the modified example. On the positive electrode terminal portion 3 side of the battery 103 shown in FIG. By preventing the deformation of the first positive electrode insulating reinforcing member 24 and the second positive electrode insulating reinforcing member 25, the strength of the battery 103 is improved. In FIG. 15, the projecting portion 24f of the first positive electrode insulating reinforcing member 24 and the projecting portion 25h of the second positive electrode insulating reinforcing member 25 form a column, but the projecting portion 24f or the projecting portion 25h alone forms a column. You can also do it. By providing the support pillars on the negative electrode terminal portion 4 side similarly to the positive electrode terminal portion 3 side, the deformation of the battery 103 due to the force in the thickness direction of the battery 103 can be prevented.

FIG. 16 shows the positive electrode terminal portion 3 side of a battery 104 which is a modified example of the battery 100 of the first embodiment. Since the positive electrode terminal portion 3 side and the negative electrode terminal portion 4 side are symmetrical, illustration and partial description of the negative electrode terminal portion 4 side are omitted. On the positive electrode terminal portion 3 side of the battery 104 shown in FIG. 16, the first positive electrode insulating reinforcing member 24 and the second positive electrode insulating reinforcing member 25 are fitted. FIG. 16 shows a cross-sectional view of the E-E′ plane of FIG. 6 in the modified example. The fitting will be specifically described. The recess 24g of the second side surface 24d facing the widthwise surface of the first exterior portion 5 of the first positive electrode insulating reinforcing member 24 and the first positive electrode insulating reinforcing member 25 of the second positive electrode insulating reinforcing member 25. It is preferable that the convex portion 25i of the second side surface portion 25e facing the side surface (long side side wall) in the width direction of the first exterior portion 5 is fitted. By fitting the convex portion 24e and the concave portion 25g, the first positive electrode insulating reinforcing member 24 which is not fixed by crimping can be fixed by the second positive electrode insulating reinforcing member 25 which is fixed by crimping. By fixing the first positive electrode insulating reinforcing member 24 to prevent the first positive electrode insulating reinforcing member 24 from approaching the positive electrode current collecting tab 7a side, deformation of the battery 104 due to force in the depth direction of the battery 102 is prevented. Can be prevented. Although illustration is omitted, the first negative electrode insulating reinforcing member 37 and the second negative electrode insulating reinforcing member 38 are similarly fitted on the negative electrode terminal portion 4 side. By fitting the negative electrode terminal portion 4 side, the deformation of the battery 102 due to the force in the depth direction of the battery 104 can be prevented on the negative electrode terminal portion 4 side as well as on the positive electrode terminal portion 3 side. It is possible to arbitrarily select the shape of the fitting concavity and convexity and which is the convexity.

FIG. 17 shows the positive electrode terminal portion 3 side of a battery 105 which is a modified example of the battery 100 of the first embodiment. Since the positive electrode side and the negative electrode side are symmetrical, illustration and partial description of the negative electrode side are omitted. A battery 105 shown in FIG. 17 is a modified example of the battery 102 shown in FIG. 14, in which the first positive electrode insulating reinforcing member 24 and the second positive electrode insulating reinforcing member 25 are fitted together. The concave portion 24h provided on the protruding portion 24f of the first positive electrode insulating reinforcing member 24 and the convex portion 25j provided on the protruding portion 25h of the second positive electrode insulating reinforcing member 25 are fitted to each other, and are fitted in the thickness direction of the supporting column. As a result, the strength of the battery 105 in the depth direction is improved. As with the positive electrode terminal portion 3 side, the negative electrode terminal portion 4 side can also prevent the battery 105 from being deformed by forces in the thickness direction and the depth direction. It is possible to arbitrarily select the shape of the fitting concavity and convexity and which is the convexity.

18 and 19 show the positive electrode terminal portion 3 side of a battery 106 which is a modified example of the battery 100 of the first embodiment. Since the positive electrode side and the negative electrode side are symmetrical, illustration and partial description of the negative electrode side are omitted. FIG. 18 shows a cross-sectional view of the A-A′ plane of FIG. 6 in the modified example. FIG. 19 shows a cross-sectional view of the B-B′ plane of FIG. 6 in the modified example. The center portion in the width direction of the positive electrode current collector tab 7a is cut away so that the ratio of the electrode group 2 in the battery 106 can be increased. The battery 106 shown in FIGS. 18 and 19 is a modified example of the battery 100, and a portion facing the positive electrode insulating reinforcement holding portion 24a in the widthwise center of the positive electrode current collector tab 7a is cut away. That is, the positive electrode current collecting tab 7a does not face the positive electrode insulating reinforcement holding portion 24a. The facing direction referred to here is a direction from the positive electrode external terminal 17 to the negative electrode external terminal 32. Similarly, the positive electrode backup lead 11 and the electrode group side positive electrode lead 12 do not face the positive electrode insulating reinforcement holding portion 24a, respectively. That is, the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are not provided in the portion where the positive electrode current collecting tab 7a does not exist, and the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are divided into two parts. There is. Similarly, on the negative electrode side, the negative electrode current collecting tab 8a does not face the negative electrode insulating reinforcement holding portion 37a. The backup negative electrode lead 13 and the electrode group side negative electrode lead 14 also do not face the negative electrode insulation reinforcement holding portion 37a. With such a configuration, it is possible to obtain a battery 106 having a larger capacity while increasing the battery strength.

Next, a method of manufacturing the battery according to the first embodiment will be described below. 21(a) to 21(b) and 22(a) to 22(d) are process diagrams for manufacturing a battery.

An electrode group 2 as shown in FIG. 4 is prepared. Further, as illustrated in FIG. 20, the first exterior portion 5 to which the positive electrode terminal portion 3 and the negative electrode terminal portion 4 are fixed is manufactured. At least one guide hole for positioning is opened in each of the first exterior part 5 and the second exterior part 6. An example thereof is shown in FIGS. 21(a) and 21(b). FIG. 21A shows an example in which guide holes 39 for positioning are opened at the four corners of the second exterior portion 6. FIG. 21B shows an example in which guide holes 39 for positioning are opened at the four corners of the first exterior part 5.

The electrode group 2 is housed in the first outer casing 5, the electrode group side positive electrode lead 12 is joined to the positive electrode terminal lead 23 by welding or the like, and the electrode group side negative electrode lead 14 is welded to the negative electrode terminal lead 36 or the like. And join. Laser welding, TIG welding, and friction stir welding can be used for joining, for example. In the embodiment, any joint is treated as welding.

Next, the second positive electrode insulating reinforcing member 25 and the second negative electrode insulating reinforcing member 38 are covered on the positive electrode current collecting tab 7a and the negative electrode current collecting tab 8a of the electrode group 2. Subsequently, the second exterior portion 6 is arranged on the first exterior portion 5. Since the guide holes 39 are opened at the four corners of each of the first exterior portion 5 and the second exterior portion 6, it is easy to determine the position of the second exterior portion 6 with respect to the first exterior portion 5.

Next, as shown in FIG. 22A, the three sides (for example, the long side and the two short sides) of the first exterior portion 5 and the second exterior portion 6 are welded. For the welding, for example, resistance seam welding is used. The welded portion is indicated by reference numeral 40. It is desirable that the welding location 40 be located inside the outer edges of the first exterior portion 5 and the second exterior portion 6.

After injecting the electrolytic solution from the opening on one side of the unwelded side, as shown in FIG. 22(b), this side is welded by, for example, resistance seam welding. It is desirable that the welded portion 41 be an outer edge portion of the first exterior portion 5 and the second exterior portion 6.

Next, after aging and initial charging/discharging, as shown in FIG. 22(c), a cut-out portion 42 is created by cutting off a part of the welded portion 41, and the gas in the exterior member 1 is released. After that, as shown in FIG. 22D, a welding portion 43 (long side of the second exterior portion 6) further inside than the welding portion 41 is welded by resistance seam welding or the like. It is desirable to perform this welding in a reduced pressure atmosphere.

After that, if necessary, the guide hole 39 can be removed by cutting the vicinity of the outer edges of the first exterior part 5 and the second exterior part 6. The guide hole 39 may be left as it is.

By the method described above, the battery of the first embodiment can be manufactured with high productivity.

The battery according to the first embodiment can include a plurality of electrode groups 2 in one exterior member 1. In this case, it is desirable to use, as the second exterior portion 6, one having a flange portion in the opening, as in the case of the first exterior portion 5. Considering the strength of the battery 100, it is preferable that only one electrode group 2 is provided in one exterior member 1.

FIG. 23 shows a process diagram on the positive electrode terminal portion 3 side for manufacturing the battery 100 in the case where one electrode group 2 is housed in one outer casing member 1. The electrode group 2 is prepared, and the backup positive electrode lead 11 bundles the central tips of the positive electrode current collecting tabs 7a. Next, as shown in the process diagram of FIG. 23A, the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are welded. After welding, the electrode group side positive electrode lead 12 is bent to form the first extending portion 12 as shown in FIG. 23B. The electrode-side positive electrode lead bent in advance may be welded to the backup positive electrode lead 11 to obtain a member as shown in FIG. 23B.

Then, the member shown in FIG. 23B is inserted from the opening side of the first exterior material 5 in which the positive electrode terminal portion 3 is incorporated in advance. After the insertion, the first extension portion 12b of the electrode group side positive electrode lead 12 and the first extension portion of the positive electrode terminal lead 23 are fixed by laser welding to fix one electrode group 2 to the first as shown in FIG. 23C. It is fixed in the exterior portion 5 of 1. Then, by covering the second exterior portion 6 with the lid, the battery 100 can be obtained.

The battery of the first embodiment described above is suitable for a large current because the lead in the exterior member 1 can have a large thickness even if it is a thin battery.

(Second embodiment)
The battery pack of the second embodiment includes one or more batteries of the first embodiment. An example of the assembled battery of the battery of the first embodiment is shown in FIGS. 24 and 25.

As shown in FIG. 24, the battery pack 200 uses the batteries 100 to 106 of the first embodiment as unit cells. The battery pack 200 may be covered with a laminate (not shown). A triangular columnar conductive connecting member 62 is disposed between the top surface of the negative electrode terminal 32 of the first unit cell 60 and the top surface of the negative electrode terminal 32 of the second unit cell 61. Further, a triangular columnar conductive connecting member 62 is arranged between the top surface of the positive electrode terminal 17 of the first unit cell 60 and the top surface of the positive electrode terminal 17 of the second unit cell 61. The two top surfaces and the conductive connecting member 62 are electrically connected by welding. Laser welding, arc welding, or resistance welding is used for welding. As a result, an assembled battery unit 63 in which the first unit cell 60 and the second unit cell 61 are connected in parallel is obtained. The battery pack 200 is obtained by connecting the units 63 of the assembled battery to each other in series by the bus bar 64.

The battery pack 201 shown in FIG. 25 uses the batteries 100 to 106 of the first embodiment as unit cells. A battery unit 65 is formed by connecting the first unit cell 60 and the second unit cell 61 in series using a conductive connecting member 62, and the battery unit units 65 are connected in series by a bus bar 64. The battery pack is composed of. The method of electrically connecting the first unit cell 60 and the second unit cell 61 using the conductive connecting member 62 is the same as that described with reference to FIG.

In the assembled battery shown in FIGS. 24 and 25, the first unit cell 60 and the second unit cell 61 which are adjacent to each other are stacked with the main surfaces of the exterior members 1 facing each other. For example, in the unit 63 of the assembled battery shown in FIG. 20, the main surface of the first exterior portion 5 of the first unit cell 60 and the main surface of the first exterior portion 5 of the second unit cell 61 face each other. ing. In addition, in the unit 63 of the adjacent battery pack, the main surface of the second exterior portion 6 of the second unit cell 61 of the unit battery 63 of one of the battery packs and the second unit cell of the unit 63 of the other battery pack The main surface of the second exterior portion 6 of 61 faces. By stacking the batteries so that the main surfaces of the exterior members face each other in this manner, the volume energy density of the battery pack can be increased.

Further, as shown in FIG. 24 and FIG. 25, it is desirable that there is an insulating space between the unit cell 60 and the unit cell 61, or between the

unit cells

60, 60 and the

unit cells

61, 61, 0.03 mm or more. Or an insulating member (for example, resin such as polypropylene, polyphenylene sulfide, epoxy, or fine ceramics such as alumina or zirconia) can be sandwiched therebetween.

Since the positive electrode external terminal 17 and the negative electrode terminal 32 have a truncated pyramid-shaped head portion, the unit cell is provided at one of two positions (for example, the first and second inclined surfaces) (first inclined surface) of one head. The external terminal can be connected to the other (the second inclined surface) of the bus bar. In other words, one head can be connected in two directions. As a result, the path for electrically connecting the batteries can be shortened, so that a large current can be easily passed through the battery pack with low resistance.

Since the battery pack of the second embodiment includes at least one battery of the first embodiment, it is possible to reduce the thickness and improve the flexibility, and since the battery itself has high strength, it has excellent reliability and low manufacturing cost. A battery pack that can be reduced can be provided.
The battery pack is used, for example, as a power source for electronic devices and vehicles (railroad vehicles, automobiles, motorbikes, light vehicles, trolleybuses, etc.).
As described above, the assembled battery may include a plurality of batteries connected in series, parallel, or a combination of series and parallel and electrically connected. In addition to the battery pack, the battery pack may include circuits such as a battery control unit (BMU), but the battery pack unit has a circuit included in a battery pack unit (for example, a vehicle). Can be used as The battery control unit has a function of monitoring the voltage or current or both of the unit cells and the assembled battery to prevent overcharge and overdischarge.

(Third Embodiment)
The third embodiment relates to a power storage device. The battery packs 200 and 201 of the second embodiment can be mounted on the power storage device 300. A power storage device 300 shown in the conceptual diagram of FIG. 26 includes battery packs 200 and 201, an inverter 302, and a converter 301. An external AC power source 303 is converted into a direct current by a converter 301, the battery packs 200 and 201 are charged, an alternating current is converted into an alternating current by an inverter 302 of a direct current power source from the battery packs 200 and 201, and electricity is supplied to a load 304 connected to a power storage device 300 It is configured to do. By using the power storage device 300 of this configuration including the battery packs 200 and 201 of the embodiment, a power storage device having excellent battery characteristics is provided. The batteries 100 to 106 may be used instead of the battery packs 200 and 201. By improving the reliability of the battery packs 200 and 201, the reliability of the storage battery 300 is also improved.

(Fourth Embodiment)
The fourth embodiment relates to a vehicle. The vehicle of the fourth embodiment uses the battery packs 200 and 201 of the second embodiment. The configuration of the vehicle according to this embodiment will be briefly described with reference to the schematic diagram of the vehicle 400 in FIG. 27. The vehicle 400 includes battery packs 200 and 201, a vehicle body 401, a motor 402, wheels 403, and a control unit 404. The battery packs 200 and 201, the motor 402, the wheels 403, and the control unit 404 are arranged on the vehicle body 401. The control unit 404 converts the power output from the battery packs 200 and 201 and adjusts the output. The motor 402 rotates the wheel 403 using the electric power output from the battery packs 200 and 201. Vehicle 400 also includes an electric vehicle such as a train and a hybrid vehicle having another drive source such as an engine. The battery packs 200, 201 may be charged by the regenerative energy from the motor 402. What is driven by the electric energy from the battery packs 200 and 201 is not limited to the motor, and may be used as a power source for operating the electric devices included in the vehicle 400. Further, it is preferable that regenerative energy is obtained when the vehicle 400 is decelerated and the battery packs 200 and 201 are charged using the obtained regenerative energy. By providing the vehicle 400 of this configuration including the battery packs 200 and 201 of the embodiment, a vehicle having excellent battery characteristics is provided. The batteries 100 to 106 may be used instead of the battery packs 200 and 201. As the reliability of the battery packs 200 and 201 is improved, the reliability of the vehicle 400 is also improved.

(Fifth Embodiment)
The fifth embodiment relates to a flying object (for example, a multicopter). The flying vehicle of the fifth embodiment uses the battery packs 200 and 201 of the second embodiment. The configuration of the flying object according to the present embodiment will be briefly described with reference to the schematic view of the flying object (quadcopter) 500 in FIG. The flying body 500 includes battery packs 200 and 201, a body skeleton 501, a motor 502, a rotary wing 503, and a control unit 504. The battery packs 200 and 201, the motor 502, the rotor 503, and the control unit 504 are arranged in the body skeleton 501. The control unit 504 converts the electric power output from the battery packs 200 and 201 and adjusts the output. The motor 502 rotates the rotor 503 using the electric power output from the battery packs 200 and 201. By using the flying body 500 of this configuration including the battery packs 200 and 201 of the embodiment, a flying body with improved reliability is provided. The batteries 100 to 106 may be used instead of the battery packs 200 and 201.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are also included in the invention described in the claims and an equivalent range thereof.

DESCRIPTION OF SYMBOLS 1... Exterior member, 2... Electrode group, 3... Positive electrode terminal part, 4... Negative electrode terminal part, 5... 1st exterior part, 5a... Opening part, 5b... Flange part, 5c... Bottom surface, 5d... Inclined surface, 5e ... Side wall, 6... Second exterior part, 7... Positive electrode, 7a... Positive electrode current collecting tab, 7b... Positive electrode material layer, 8... Negative electrode, 8a... Negative electrode collecting tab, 8b... Negative electrode material layer, 9... Separator, 10 Insulating sheet, 11... Backup positive electrode lead, 12... Electrode group side positive electrode lead, 13... Backup negative electrode lead, 14... Electrode group side negative electrode lead, 15, 30... Through hole of first exterior part, 16, 31... Burring Part, 17... Positive electrode external terminal, 17a... Positive electrode head part, 17b... Positive electrode shaft part, 18a... Positive electrode insulating member, 18b... Positive electrode reinforcing member, 19, 34... Insulating gasket, 20... Positive electrode terminal insulating member, 21... Head , 23... Positive electrode terminal lead, 24... First positive electrode insulating reinforcing member, 24a... Positive electrode insulating reinforcing member, 25... Second positive electrode insulating reinforcing member, 32... Negative electrode external terminal, 32a... Negative electrode head part, 32b... Negative electrode Shaft part, 33a... Negative electrode insulating member, 33b... Negative electrode reinforcing member, 35... Negative electrode terminal insulating member, 36... Negative electrode terminal lead, 37... First negative electrode insulating reinforcing member, 37a... Negative electrode insulating reinforcing holding part, 38... Second Insulation reinforcing member, 39... Guide hole, 40, 41, 43... Welding spot, 42... Cutout portion, 60... First unit cell, 61... Second unit cell, 62... Conductive connecting member, 63, 65 ... assembled battery unit, 64... busbars 100 to 106... batteries, 200, 201... battery pack, 300... power storage device, 301... converter, 302... inverter, 303... external AC power supply, 304... load, 400... vehicle, 401 ... vehicle body, 402... motor, 403... wheel, 404... control unit, 500... flying body, 501... airframe, 502... motor, 503... rotor, 504... control unit

Claims

A positive electrode current collecting tab electrically connected to the positive electrode, a negative electrode, and a negative electrode current collecting tab electrically connected to the negative electrode, wherein the positive electrode current collecting tab wound in a flat shape is Located on one end surface, and the negative electrode current collecting tab wound in a flat shape is located on the second end surface, a flat electrode group,
An electrode group side positive electrode lead electrically connected to the positive electrode current collecting tab,
An electrode group side negative electrode lead electrically connected to the negative electrode current collecting tab,
A first exterior portion having a flange portion in the opening and a second exterior portion, and in a space formed by welding the flange portion and the second exterior portion of the first exterior portion. An exterior member accommodating the electrode group,
The first exterior part has a through hole on the positive electrode current collector tab side, a positive electrode external terminal including a positive electrode head part and a positive electrode shaft part extending from the positive electrode head part, and a through hole, and the electrode group. A positive electrode terminal lead electrically connected to a side positive electrode lead, the positive electrode head portion protruding outside the first exterior portion, and the positive electrode shaft portion being inserted into a through hole of the positive electrode terminal lead. A positive electrode terminal portion having a portion fixed by crimping to the first outer packaging portion and the positive electrode terminal lead;
The first exterior portion has a through hole on the negative electrode current collecting tab side, a negative electrode external terminal including a negative electrode head portion and a negative electrode shaft portion extending from the negative electrode head portion, and a through hole, and the electrode group. A negative electrode terminal lead electrically connected to the side negative electrode lead, the negative electrode head portion protruding to the outside of the first exterior portion, the negative electrode shaft portion being inserted into a through hole of the negative electrode terminal lead, and the negative electrode shaft. A portion of the negative electrode terminal portion fixed by crimping to the first exterior portion and the negative electrode terminal lead;
A first positive electrode insulating and reinforcing member that is disposed on the inner surface side of the first outer packaging portion and the inner surface side of the second outer packaging portion and that is disposed between the positive electrode terminal and the second outer packaging portion;
A first negative electrode insulating reinforcing member that is disposed on the inner surface side of the first outer packaging portion and on the inner surface side of the second outer packaging portion and that is disposed between the negative electrode terminal and the second outer packaging portion;
Including,
The first positive electrode insulating reinforcing member includes a positive electrode insulating reinforcing holding portion having an inclined surface facing an end portion of the positive electrode shaft portion opposite to the positive electrode head side,
The said 1st negative electrode insulation reinforcement member is a battery containing the negative electrode insulation reinforcement holding|maintenance part which has a slope which opposes the edge part of the said negative electrode shaft part on the opposite side to the said negative electrode head side.
The angle formed between the surface of the positive electrode shaft portion facing the inclined surface of the positive electrode insulating reinforcement holding portion and the second exterior portion is A1,
The angle formed by the inclined surface of the positive electrode insulating reinforcement holding portion and the second exterior portion is A2,
The angle formed by the surface of the negative electrode shaft portion facing the inclined surface of the negative electrode insulating reinforcement holding portion and the second exterior portion is B1,
The angle formed by the slope of the negative electrode insulating reinforcement holding portion and the second exterior portion is B2,
The battery according to claim 1, wherein |A1-A2|≦8 degrees and |B1-B2|≦8 degrees are satisfied.
The distance between the inclined surface of the positive electrode insulation reinforcement holding portion and the positive electrode shaft portion is 0.0 mm or more and 1.0 mm or less,
The battery according to claim 1 or 2, wherein a distance between the inclined surface of the negative electrode insulating reinforcement holding portion and the negative electrode shaft portion is 0.0 mm or more and 1.0 mm or less.
The inclined surface of the positive electrode insulation reinforcement holding portion faces the positive electrode terminal lead,
The battery according to any one of claims 1 to 3, wherein the sloped surface of the negative electrode insulating reinforcement holding portion faces the negative electrode terminal lead.
The distance between the inclined surface of the positive electrode insulation reinforcement holding portion and the positive electrode terminal lead is 0.0 mm or more and 1.0 mm or less,
The battery according to any one of claims 1 to 4, wherein a distance between the sloped surface of the negative electrode insulation reinforcement holding portion and the negative electrode terminal lead is 0.0 mm or more and 1.0 mm or less.
A second positive electrode insulation reinforcing member that is disposed on the inner surface side of the first outer case part and between the positive electrode terminal lead and the first outer case part, and faces the first positive electrode insulation reinforcing member; ,
A second negative electrode insulation reinforcing member that is arranged on the inner surface side of the first outer case part and between the negative electrode terminal lead and the first outer case part, and faces the first negative electrode insulation reinforcing member; Further including,
The second positive electrode insulating reinforcing member is fixed to the positive electrode shaft portion, the first outer casing portion and the positive electrode terminal lead by crimping,
The battery according to claim 1, wherein the second negative electrode insulating reinforcing member is fixed to the negative electrode shaft portion, the first outer casing portion, and the negative electrode terminal lead by crimping.
An end portion side of the first positive electrode insulating reinforcing member on the positive electrode current collecting tab side projects toward the second positive electrode insulating reinforcing member side,
An end portion side of the second positive electrode insulating reinforcing member on the side of the positive electrode current collecting tab projects toward the first positive electrode insulating reinforcing member side,
An end portion side of the first negative electrode insulation reinforcing member on the side of the negative electrode current collecting tab projects toward the second negative electrode insulation reinforcing member side,
The battery according to claim 6, wherein an end portion side of the second negative electrode insulation reinforcing member on the side of the negative electrode current collecting tab projects toward the first negative electrode insulation reinforcing member side.
The first positive electrode insulating reinforcing member, the second positive electrode insulating reinforcing member, the first negative electrode insulating reinforcing member, and the second negative electrode insulating reinforcing member are resin,
Inner surface sides of the first exterior part and the second exterior part between the positive electrode terminal and the positive electrode current collecting tab are covered with the first positive electrode insulation reinforcing member and the second positive electrode insulation reinforcing member. ,
Inner surface sides of the first exterior portion and the second exterior portion between the negative electrode terminal and the negative electrode current collecting tab are covered with the first negative electrode insulation reinforcing member and the second negative electrode insulation reinforcing member. The battery according to claim 6 or 7, wherein.
The first positive electrode insulating reinforcing member and the second positive electrode insulating reinforcing member are fitted to each other,
The battery according to any one of claims 6 to 8, wherein the first negative electrode insulating reinforcing member and the second negative electrode insulating reinforcing member are fitted together.
The width of the positive electrode current collecting tab is narrower than the width of the electrode group,
The battery according to any one of claims 1 to 9, wherein a width of the negative electrode current collecting tab is narrower than a width of the electrode group.
The positive electrode current collecting tab is cut out from both ends by 5 mm or more,
The battery according to any one of claims 1 to 10, wherein the negative electrode current collecting tab is cut out from both ends by 5 mm or more.
The first exterior portion and the second exterior portion are made of any one selected from the group consisting of stainless steel, aluminum laminate and aluminum,
The battery according to any one of claims 1 to 11, wherein a plate thickness of the first exterior portion and the second exterior portion is 0.02 mm or more and 0.3 mm or less.
The positive electrode current collecting tab does not face the positive electrode insulating reinforcement holding portion,
The battery according to claim 1, wherein the negative electrode current collecting tab does not face the negative electrode insulating reinforcement holding portion.
The displacement of the battery is less than 1.0 mm when a load of 10 N is applied to the positive electrode terminal or the negative electrode terminal in the direction from the first exterior portion toward the second exterior portion. 13. The battery according to any one of 13 above.
The electrode group is one,
The battery according to claim 1, wherein the battery has a thickness of 5 mm or more and 30 mm or less.
A battery pack containing one or more batteries according to claims 1 to 15.
An electric storage device including the battery according to claim 1 or the battery pack according to claim 16.
A vehicle including the battery according to claim 1 to 15 or the battery pack according to claim 16.
A flying vehicle including the battery according to claim 1 or the battery pack according to claim 16.