CN111886716A - Battery, battery pack, power storage device, vehicle, and flying object - Google Patents

Abstract

The present invention relates to a battery comprising: an insulating film wound around an electrode group having a flat shape and a positive electrode collector sheet positioned at a first end surface; an electrode group-side positive electrode lead electrically connected to the positive electrode collector sheet; an exterior member accommodating the electrode group in a space formed by welding a flange portion of an opening of a first exterior member and a second exterior member; a positive electrode external terminal provided on the first exterior member; a positive electrode terminal lead electrically connected to the electrode group-side positive electrode lead; a first positive electrode insulation reinforcement member arranged on an inner surface side of the first exterior member and between the positive electrode terminal lead and the first exterior member; a second positive electrode insulation reinforcement member arranged on an inner surface side of the first exterior member and an inner surface side of the second exterior member; the insulating film arranged between the electrode group and the first exterior member, between the electrode group and the second exterior member, between the positive electrode collector sheet and the first positive electrode insulation reinforcement member, and between the positive electrode collector sheet and the second positive electrode insulation reinforcement member.

Description

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

technical field

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

Background technique

Batteries such as primary batteries and secondary batteries generally include an electrode group including a positive electrode and a negative electrode, and an exterior member that accommodates the electrode group.

Currently, metal cans and laminated film containers are actually used as exterior parts. Metal cans are obtained by deep drawing from sheet metal such as aluminum. In order to make a can by deep drawing, a certain thickness of the metal plate is required, which hinders thinning of the exterior parts and leads to loss of volumetric capacitance. For example, when an outer casing having a 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 casing to the thickness of the battery is about 7.7%. Since it is a thin battery, a method of compactly storing the lead wire in the battery by complicated bending or the like has been sought.

In the exterior member, the element of the battery and the electrode terminal are wire-bonded. Regarding the bending after joining, the operation space and the storage space are narrow, and it is difficult to realize the storage. Moreover, if it is set to the thickness which can be bent after joining, the lead wire becomes thin, and it is not suitable for a large current. In addition, if the welded portion is bent after the lead wire is welded, the joined portion is easily peeled off, and a battery that is not bent after joining is also desired from the viewpoint of quality.

prior art literature

Patent Literature

Patent Document 1: International Publication No. 2016/204147

SUMMARY OF THE INVENTION

(1) Technical problems to be solved

The technical problem to be solved by the present invention is to provide a battery, a battery pack, a power storage device, a vehicle, and an aircraft with excellent insulation between the outer casing material and the electrode group, lead wires, and electrode terminals in a thin battery.

(2) Technical solutions

The battery of the embodiment includes: a flat-shaped electrode group including a positive electrode, a positive electrode current collector sheet electrically connected to the positive electrode, a negative electrode, and a negative electrode current collector sheet electrically connected to the negative electrode, and the positive electrode current collector sheet rolled into a flat shape is located in the The first end face, and the negative electrode collector sheet wound into a flat shape is located on the second end face; the insulating film, which is wound around the electrode group; the positive electrode lead on the electrode group side, which is electrically connected to the positive electrode collector sheet; It is electrically connected to the negative electrode current collector; the outer casing includes a first outer casing part made of metal having a flange part at the opening part, and a second outer casing part made of metal, and the flange part of the first outer casing part is welded with the flange part. An electrode group is accommodated in the space formed by the second exterior part; the positive terminal part, the first exterior part has a through hole on the side of the positive electrode current collector, and the positive terminal part includes: a positive external terminal, which includes a head and extends from the head and a positive terminal lead, which has a through hole, the head protrudes to the outside of the first outer casing, the shaft is inserted into the through hole of the positive terminal lead, and the shaft is riveted and fixed to the first outer casing and the positive electrode A terminal lead; a negative terminal part, the first exterior part has a through hole on the side of the negative electrode current collector, and the negative terminal part includes: a negative electrode external terminal, which includes a head part and a shaft part extending from the head part; and a negative electrode terminal lead, which It has a through hole, the head protrudes to the outside of the first exterior part, the shaft part is inserted into the through hole of the negative terminal lead, and the shaft part is riveted and fixed to the first exterior part and the negative terminal lead; the first positive insulation reinforcement part; the second positive electrode an insulation reinforcement member; a first negative electrode insulation reinforcement member; and a second negative electrode insulation reinforcement member. The first positive electrode insulation reinforcement member is arranged on the inner surface side of the first exterior part between the positive electrode terminal lead and the first exterior part. The second positive insulation reinforcement member is arranged on the inner surface side of the first outer casing and the inner surface side of the second outer casing, the first negative insulation reinforcement member is arranged on the inner surface side of the first outer casing, and the negative electrode terminal lead is connected to the first outer casing. between the departments. The second negative electrode insulation reinforcing member is arranged on the inner surface side of the first exterior part and the inner surface side of the second exterior part. The insulating film is arranged between the electrode group and the first exterior part, between the electrode group and the second exterior part, between the positive electrode current collector sheet and the first positive electrode insulation reinforcement member, and between the positive electrode current collector sheet and the second positive electrode insulation reinforcement member. between the negative electrode current collector sheet and the first negative electrode insulation reinforcement member, and between the negative electrode current collector sheet and the second negative electrode insulation reinforcement member.

Description of drawings

FIG. 1 is a schematic perspective view of the battery of the first embodiment.

FIG. 2A is an exploded perspective view from the positive electrode side of the battery shown in FIG. 1 .

FIG. 2B is an exploded perspective view viewed from the negative electrode side of the battery shown in FIG. 1 .

FIG. 3 is a perspective view of an electrode group of the battery shown in FIG. 1 .

FIG. 4 is a perspective view showing a state where the electrode group is partially expanded.

FIG. 5 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 is cut along the longitudinal direction of the battery.

FIG. 6 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 is cut along the longitudinal direction of the battery.

FIG. 7 is a cross-sectional view obtained when the negative electrode portion of FIG. 1 is cut along the longitudinal direction of the battery.

FIG. 8 is a cross-sectional view obtained when the negative electrode portion of FIG. 1 is cut along the longitudinal direction of the battery.

9 is a perspective view showing a configuration in which a terminal portion is fixed to a first exterior portion of the battery shown in FIG. 1 .

FIG. 10( a ) is a plan view of the second exterior portion, and FIG. 10( b ) is a plan view of the first exterior portion.

(a), (b), (c), and (d) of FIG. 11 are three views showing the manufacturing process of the battery of the first embodiment.

12A is a process diagram showing an assembly process of a battery in which a plurality of electrode groups are accommodated.

12B is a process diagram showing an assembling process of a battery in which a plurality of electrode groups are accommodated.

12C is a process diagram showing an assembling process of a battery in which a plurality of electrode groups are accommodated.

12D is a process diagram showing an assembling process of a battery in which a plurality of electrode groups are accommodated.

13 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modification is cut along the longitudinal direction of the battery.

14 is a cross-sectional view obtained when the negative electrode portion of FIG. 1 in the modification is cut along the longitudinal direction of the battery.

15 is a schematic diagram showing a first example of the battery pack according to the second embodiment.

16 is a schematic diagram showing a second example of the battery pack according to the second embodiment.

17 is a schematic diagram of a power storage device according to a third embodiment.

FIG. 18 is a schematic diagram of a vehicle of the fourth embodiment.

FIG. 19 is a schematic diagram of a flying body according to the fifth embodiment.

Detailed ways

Embodiments are described below with reference to the drawings. In addition, in embodiment, the same code|symbol is attached|subjected to the common structure, and the overlapping description is abbreviate|omitted. In addition, each drawing is a schematic diagram for facilitating the description and understanding of the embodiment, and the shape, size, ratio, etc. are different from those of the actual device, but these can be appropriately changed in design with reference to the following description and known techniques. .

[First Embodiment]

The battery of the first embodiment will be described with reference to FIGS. 1 to 14 . Some of the drawings are perspective views and developed views, and some components and parts are not shown. However, since the positive electrode and the negative electrode are configured symmetrically, the part not shown in one electrode can be known from the structure of the other electrode. In addition, in the embodiment, the positive electrode and the negative electrode may be configured asymmetrically.

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 5 mm or more and 30 mm or less.

As shown in FIGS. 1 and 2 ( FIGS. 2A and 2B ), 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 cylindrical container, and has the flange part 5b in the opening part 5a. In the exterior member 1 , the electrode group 2 is accommodated in a space formed by welding the flange portion of the first exterior portion 5 and the second exterior portion 6 . In addition, FIG. 2A is an exploded perspective view seen from the positive electrode side of the battery shown in FIG. 1 . In addition, FIG. 2B is an exploded perspective view seen from the negative electrode side of the battery shown in FIG. 1 .

As shown in FIGS. 1 , 2 and 5 , a recessed portion protruding inward is provided near the center of the corner connecting the short side wall and the bottom of the second exterior portion 5 , and the bottom of the recessed portion is an inclined surface 5d. The second exterior part 5 has a depth equal to or less than the size of the opening part 5a (the maximum length of the part which is the opening area). More preferably, the second exterior portion 5 has a depth below the short side, which is a portion of the opening area (for example, as shown in FIG. 2 ). The first exterior part 5 is, for example, a stainless steel cup-shaped container having an opening and produced by shallow drawing from a stainless steel plate. On the other hand, the second exterior part 6 is a cover made of stainless steel. The second exterior part 6 covers the opening of the second exterior part 5 . Like the second exterior portion 5 , the second exterior portion 6 may be a stainless steel cup-shaped container produced by shallow drawing, or may be a plate shape. The electrode group 2 is accommodated in a space formed by welding the flange portion 5 b of the first exterior portion 5 to the four sides of the second exterior portion 6 . In welding, for example, resistance seam welding is used. Compared with laser welding, resistance seam welding can achieve higher air tightness and heat resistance at a lower cost.

In FIG. 5 , the peripheral portion of the through hole on the positive electrode current collector tab 7a side of the first exterior portion 5 has a burring portion (Japanese: バーリング portion) 16 toward the inside of the exterior member 1 . In FIG. 7 , the peripheral portion of the through hole on the side of the negative electrode current collector tab 8 a of the first exterior portion 5 has a burring portion 31 toward the inside of the exterior member 1 .

Since it is a thin battery, the space in which the electrode group 2 is accommodated is a low-height space. The height of the space in which one electrode group 2 is accommodated is obtained by dividing the distance from the bottom of the first exterior part 5 to the second exterior part 6 by the number of electrode groups 2 accommodated in the exterior member 1 and arranged in the height direction value. Since the battery is thin, the height of the space in which one electrode group 2 is accommodated is 5 mm or more and 30 mm or less. Since the space in which the electrode group 2 is accommodated is a low-height space, the shape of the lead wire is limited.

The exterior member 1 is not a laminated film but a metal. When the laminate film is used as the exterior member 1, it is not necessary to insulate the exterior member from the electrode group and the terminal portion. On the other hand, the metal exterior member 1 needs to be insulated so that the positive electrode and the negative electrode are not short-circuited with the exterior member 1 . Therefore, the insulating film 26 that insulates the exterior member 1 from the electrode terminals, the lead wires, and the electrode group 2 is used. The insulating film 26 is shown in FIG. 5 and subsequent figures.

As shown in FIG. 4 , the electrode group 2 has a flat shape, and includes a positive electrode 7 , a negative electrode 8 , and a separator 9 disposed between the positive electrode 7 and the negative electrode 8 . The flat electrode group 2 includes a positive electrode 7, a positive electrode current collector sheet 7a electrically connected to the positive electrode 7, a negative electrode 8, and a negative electrode current collector sheet 8a electrically connected to the negative electrode 8. The positive electrode current collector sheet 7a wound into a flat shape is located in the The first end surface, and the negative electrode collector sheet 8a wound into a flat shape is located on the second end surface. One of the two flat surfaces of the electrode group 2 faces the bottom surface of the first exterior part 5 , and the other of the two flat surfaces of the electrode group 2 faces the surface of the second exterior part 6 .

The positive electrode 7 includes, for example, a strip-shaped positive electrode current collector composed of foil, a positive electrode current collector tab 7a composed of one end portion parallel to the long side of the positive electrode current collector, and at least a portion other than the positive electrode current collector tab 7a formed in the positive electrode current collector. Positive electrode material layer (positive electrode active material-containing layer) 7b of the positive electrode current collector.

On the other hand, the negative electrode 8 includes, for example, a strip-shaped negative electrode current collector composed of foil, a negative electrode current collector tab 8a composed of one end portion parallel to the long side of the negative electrode current collector, and at least the negative electrode current collector other than the negative electrode current collector tab 8a. Part of the negative electrode material layer (negative electrode active material-containing layer) 8b formed in the negative electrode current collector. The electrode group 2 is a structure in which the positive electrode 7, the separator 9, and the negative electrode 8 are wound into a flat shape, so that the positive electrode material layer 7b of the positive electrode 7 and the negative electrode material layer 8b of the negative electrode 8 are opposite to each other with the separator 9 interposed therebetween, and the positive electrode current collector sheet. 7a protrudes from the negative electrode 8 and the separator 9 on one side of the winding shaft, and the negative electrode current collector tab 8a protrudes from the positive electrode 7 and the separator 9 on the other side. Therefore, in the electrode group 2, the positive electrode current collector tab 7a wound in a flat spiral shape is located on the first end face perpendicular to the winding axis.

In addition, the negative electrode current collector sheet 8a wound in a flat spiral shape is located on the second end face perpendicular to the winding axis. In addition, the electrode group 2 holds an electrolyte (not shown).

The backup positive electrode lead 11 has a structure in which a conductive plate is bent in a U-shape, and the layers of the positive electrode current collector tab 7a are brought into close contact with each other across the portion (near the center) of the positive electrode current collector tab 7a except for the bent portions at both ends. combine. The electrode group side positive electrode lead 12 is a conductive plate having a larger area than the backup positive electrode lead 11 . As shown in FIG. 5 , the positive electrode lead 12 on the electrode group side has a first extension 12 a on the side opposite to the side of the electrode group 2 . The positive electrode lead 12 on the electrode group side is connected to the surface of the backup positive electrode lead 11 . The backup positive electrode lead 11 is electrically connected to the positive electrode current collector tab 7a and the electrode group side positive electrode lead 12 . In addition, the positive electrode current collector tab 7a is electrically connected to the electrode group side positive electrode lead 12 .

The positive electrode current collector tab 7 a , 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 electrically connected to the electrode group side positive electrode lead 12 via the positive electrode current collector tab 7 a and the backup positive electrode lead 11 . 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. Welding of the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 is performed 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, the positive electrode current collector tab 7 a is preferably welded to the electrode-side positive electrode lead 12 .

The backup negative electrode lead 13 is a structure in which a conductive plate is bent into a U-shape, and the layers of the negative electrode current collector tab 8a are brought into close contact with each other by sandwiching the portion (near the center) of the negative electrode current collector tab 8a except for the bent portions at both ends. combine. The electrode group side negative electrode lead 14 is a conductive plate having a larger area than the backup negative electrode lead 13 . As shown in FIG. 7 , the negative electrode lead 14 on the electrode group side has a first extending portion 14 a on the side opposite to the side of the electrode group 2 . The first extension portion 14 a of the negative electrode lead 14 on the electrode group side is connected to the surface of the backup negative electrode lead 13 . The backup negative electrode lead 13 is electrically connected to the negative electrode current collector tab 8a and the negative electrode lead 14 on the electrode group side. In addition, the negative electrode current collector tab 8a is electrically connected to the negative electrode lead 14 on the electrode group side.

The negative electrode current collector 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 electrically connected to the electrode group side negative electrode lead 14 via the positive electrode current collector tab 8a and the backup negative electrode lead 13. Welding of the negative electrode current collector tab 8a and the backup negative electrode lead 13 is performed by, for example, laser welding or ultrasonic welding. Welding of the backup negative electrode lead 13 and the electrode group side negative electrode lead 14 is performed by, for example, laser welding or ultrasonic welding.

As shown in FIGS. 2 and 5 , the positive electrode terminal portion 3 includes a through hole 15 opened in the inclined surface 5d of the first exterior portion 5, a positive electrode external terminal 17, a positive electrode insulating member 18a, a positive electrode reinforcing member (ring member) 18b, Insulating spacer 19 and positive 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 current collector tab side. The positive external terminal 17 of the positive terminal portion 3 includes a head portion 21 and a shaft portion extending from the head portion 21 . The positive terminal portion 3 includes a positive terminal lead 23 having a through hole 23a. In the positive terminal portion 3 , the head portion 21 protrudes to the outside of the first housing portion 5 , the shaft portion is inserted into the through hole 23 a of the positive terminal lead 23 , and the shaft portion is crimped and fixed to the first housing portion 5 and the positive terminal lead 23 .

As shown in FIG. 5 , the burring portion (annular raised portion) 16 is a member formed by burring, extending from the peripheral edge portion of the through hole 15 toward the inside of the exterior member 1 .

As shown in FIG. 5 , the positive electrode external terminal 17 includes a head portion 21 in the shape of a truncated pyramid, and a cylindrical shaft portion which penetrates through the through hole 15 of the second outer casing portion 5 . The cylindrical shaft portion protrudes from a plane parallel to the top surface of the head portion 21 . The positive electrode external terminal 17 is formed of, for example, a conductive material such as aluminum or an aluminum alloy.

The positive electrode insulating member 18 a has a through hole and a convex portion, and insulates the first exterior portion 5 from the positive electrode external terminal 17 and the positive electrode terminal lead 23 . The positive electrode insulating member 18a is an annular member having a convex portion. The convex portion of the positive electrode insulating member 18a extends in a direction opposite to the direction in which the positive electrode terminal lead 23 exists. The positive electrode insulating member 18a is an insulating member.

The positive electrode insulating member 18a having the convex portion is preferably made of, for example, a fluororesin, fluororubber, polyphenylene sulfide resin (PPS resin), polyetheretherketone resin (PEEK resin), polypropylene resin (PP resin), and polypara It consists of one or more resin materials selected from the group consisting of butylene phthalate resin (PBT resin) and the like.

The positive electrode reinforcing member 18b is composed of, for example, a circular ring having a through hole formed of a material with higher rigidity than the gasket. The positive electrode reinforcing member 18b is arranged between the first exterior part 5 and the positive electrode insulating member 18a. Examples of materials with higher rigidity than gaskets include stainless steel, materials plated on iron (for example, Ni, NiCr, etc.), ceramics, and resins (for example, polyphenylene sulfide) that can have higher rigidity than gaskets. ether (PPS), polybutylene terephthalate (PBT), etc. As shown in FIG. 5, 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. Since the exterior member 1 is a thin member, it is preferable to reinforce the first exterior part 5 and the burring part 16 by the positive electrode reinforcing member 18b.

The positive electrode external terminal 17 is inserted into the through hole of the positive electrode insulating member 18a and the through hole of the positive electrode reinforcing member 18b. The positive electrode reinforcing member 18b is sandwiched between the convex portion of the positive electrode insulating member 18a and the burring portion 16 of the first exterior portion 5 . Even if the positive electrode terminal lead 23 is partially moved, the positive electrode insulating member 18a can more reliably prevent the positive electrode terminal lead 23 from short-circuiting with the first exterior part 5, which is preferable in this respect. Moreover, it is preferable to improve the reliability of the insulation of the positive electrode terminal lead 23 and the 1st exterior part 5 by the convex part of the positive electrode insulating member 18a.

As shown in FIGS. 2 and 5 , the insulating spacer 19 is a cylindrical body (tubular portion) having a flange portion 19a at one open end. As shown in FIGS. 2 and 5 , the cylindrical portion of the insulating spacer 19 is inserted into the through hole 15 and the inner flange portion 16 , and the flange portion 19 a is arranged in the through hole on the outer surface of the first exterior portion 5 . 15 perimeters. The insulating spacer 19 is made of, for example, fluororesin, fluororubber, polyphenylene sulfide resin (PPS resin), polyetheretherketone resin (PEEK resin), polypropylene resin (PP resin), and polybutylene terephthalate resin (PBT resin) and other resins.

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

The positive terminal portion 3 further includes a positive terminal lead 23 . The positive terminal lead 23 is a conductive plate and has a through hole 23a and a first extension portion 23b extending toward the opening of the first exterior portion 5 , that is, the second exterior portion 6 side. In FIG. 5 , the positive terminal lead 23 has a first extension portion 23 a extending on the electrode group 2 side. The first extension portion 23b of the positive electrode terminal lead 23 is integrated with the first extension portion 12a of the electrode group side positive electrode lead 12 by welding. The opposing surfaces of the first extension portion 23b and the first extension portion 12a are welded, and the end surface of the first extension portion 23b on the front end side and the end surface of the first extension portion 12a are also welded. At least the front ends of the first extension 23b of the positive terminal lead 23 and the first extension 12a of the electrode group side positive lead 12 are perpendicular or substantially perpendicular (80° to 100°) with respect to the surface of the second outer casing 6 . At least the front end portions of the first extension portion 23 b of the positive electrode terminal lead 23 and the first extension portion 12 a of the positive electrode lead 12 on the electrode group side are perpendicular or substantially perpendicular to the surface of the second exterior portion 6 . After an extension portion 23b is welded to the first extension portion 12a of the positive electrode lead 12 on the electrode group side, the lead is not bent for fabrication. By bending the lead after welding, there is an advantage that the wiring of the terminal portion of the electrode can be made compact. However, in order to perform the bending with high precision after welding, the thickness of the lead needs to be reduced. However, when the thickness of the lead wire is reduced, it is difficult to flow a large current, which is not preferable. The thickness of the lead wire can be increased by orienting the welded portion in the direction of the surface of the second exterior portion 6 . In addition, the bent shape of the lead wire is not limited to the shape shown in FIG. 5, and may be other shapes.

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 can be 0.5 mm or more and 3.0 mm or less. 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 preferably 1.0 mm or more and 1.2 mm or less in consideration of the lead bending process before the lead wires are welded together and the large current characteristics. Their thickness preferably satisfies the above-mentioned conditions at least in the welded portion.

The battery 100 further includes the first positive electrode insulation reinforcing member 24 . The first positive electrode insulation reinforcing member 24 is arranged on the inner surface side of the first exterior part 5 . More specifically, the first positive electrode insulation reinforcing member 24 is disposed on the inner surface side of the first exterior part 5 between the positive electrode terminal lead 23 and the first exterior part 5 . As shown in FIGS. 2 and 5 , the first positive electrode insulation reinforcing member 24 has a main body portion 24a having a structure in which a bottomed rectangular cylinder is divided into half in the longitudinal direction, a circular groove 24b formed in the main body portion 24a, and a circular groove 24b formed in the main body portion 24a. A through hole 24c opened in the center of the groove 24b. The positive electrode insulating member 18a, the positive electrode reinforcing member 18b, and the positive electrode external terminal 17 are arranged in the through hole 24c. The main body portion 24a of the first positive terminal insulation reinforcement member 24 covers the corner portion of the first exterior part 5 connected from the side wall on the short side to the bottom surface, and the side wall on the short side of the first exterior part 5 connected to the long side. side corners. Thereby, the 1st exterior part 5, especially the vicinity of the corner|angular which the short side side wall, the long side side wall, and the bottom intersect can be reinforced. The positive electrode insulating member 18a arranged on the outer peripheral surface of the burring portion 16 is arranged in the circular groove 24b. The through hole 24c communicates with the opening of the burring portion 16 and the through hole 15 of the first exterior portion 5 . The positive terminal lead 23 is arranged on the first positive terminal insulation reinforcement member 24 . The through hole 23 a of the positive terminal lead 23 communicates with the through hole 24 c of the first positive terminal insulation reinforcement member 24 , the opening of the inner flange portion 16 , and the through hole 15 of the first exterior portion 5 .

The first positive electrode insulation reinforcement member 24 and the pair of second positive electrode insulation reinforcement members 25 are arranged on the inner surface side of the first exterior part 5 and the inner surface side of the second exterior part 6 . As shown in FIG. 2 , the second positive electrode insulation reinforcement member 25 has a structure in which a bottomed rectangular cylinder is divided into half in the longitudinal direction. One first positive electrode insulation reinforcing member 24 covers approximately half of the positive electrode current collector tab 7a from the winding center to the first exterior portion 5 side. The other second positive electrode insulation reinforcing member 25 covers approximately half of the positive electrode current collector tab 7a from the winding center to the second exterior portion 6 side. Thereby, the 2nd exterior part 6, especially the vicinity of a short side can be reinforced.

The shaft portion of the positive electrode external terminal 17 is inserted into the insulating spacer 19 , the through hole 20 a of the positive electrode terminal insulating member 20 , the through hole 15 of the first exterior part 5 , the through hole 24 c of the positive electrode terminal insulation reinforcing member 24 , and the through hole 23 of the positive electrode terminal lead wire 23 . The hole 23a is then plastically deformed by caulking. As a result, these components are integrated, and the positive electrode external terminal 17 and the positive electrode terminal lead 23 are electrically connected. Therefore, the positive external terminal 17 also functions as a rivet. In addition, the end face of the shaft portion of the positive electrode external terminal 17 and the boundary portion of the through hole 23a of the positive electrode terminal lead 23 may be welded by laser or the like to achieve a stronger connection and improve electrical conductivity.

As shown in FIGS. 2 and 7 , the negative electrode terminal portion 4 includes a through hole 30 opened on the inclined surface 5d of the first exterior portion 5, a negative electrode external terminal 32, a negative electrode insulating member 33a, a negative electrode reinforcing member (ring member) 33b, The insulating spacer 34 and the 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 side of the negative electrode current collector tab 8a. The negative electrode external terminal 32 of the negative electrode terminal portion 4 includes a head portion 21 and a shaft portion extending from the head portion 21 . The negative electrode terminal portion 4 includes a negative electrode terminal lead 36 having a through hole 36a. In the negative terminal portion 4 , the head portion 21 protrudes outside the first housing portion 5 , the shaft portion is inserted into the through hole 36 a of the negative electrode terminal lead 36 , and the shaft portion is caulked and fixed to the first housing portion 5 and the negative electrode terminal lead 36 .

As shown in FIG. 6 , the burring portion (an annular raised portion) 31 is a member formed by burring, extending from the peripheral edge portion of the through hole 31 toward the inner side of the exterior member 1 .

As shown in FIG. 6 , the negative electrode external terminal 32 includes a head portion 21 in the shape of a truncated pyramid, and a cylindrical shaft portion penetrating through the through hole 30 of the second outer casing portion 5 . The cylindrical shaft portion protrudes from a plane parallel to the top surface of the head portion 21 . The negative electrode external terminal 32 is formed of, for example, a conductive material such as aluminum or an aluminum alloy.

The negative electrode insulating member 33 a has a through hole and a convex portion, and insulates the first exterior portion 5 from the negative electrode external terminal 32 and the negative electrode terminal lead 36 . The negative electrode insulating member 33a is an annular member having a convex portion on the outer periphery. The convex portion of the negative electrode insulating member 33a extends in a direction opposite to the direction in which the negative electrode terminal lead 36 exists. The negative electrode insulating member 33a is an insulating member.

The negative electrode insulating member 33a having convex portions is preferably made of, for example, a fluororesin, fluororubber, polyphenylene sulfide resin (PPS resin), polyetheretherketone resin (PEEK resin), polypropylene resin (PP resin), and polypara It consists of one or more resin materials selected from the group consisting of butylene phthalate resin (PBT resin) and the like.

The negative electrode reinforcing member 33b is composed of, for example, a circular ring having a through hole formed of a material having higher rigidity than the spacer. The negative electrode reinforcing member 33b is arranged between the first exterior part 5 and the negative electrode insulating member 33a. Examples of materials with higher rigidity than gaskets include stainless steel, materials plated on iron (for example, Ni, NiCr, etc.), ceramics, and resins (for example, polyphenylene sulfide) that can have higher rigidity than gaskets. ether (PPS), polybutylene terephthalate (PBT), etc. As shown in FIG. 7 , 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. Since the exterior member 1 is a thin member, it is preferable to reinforce the first exterior portion 5 and the burring portion 31 by the negative electrode reinforcing member 33b.

The negative electrode external terminal 32 is inserted into the through hole of the negative electrode insulating member 33a and the through hole of the negative electrode reinforcing member 33b. The negative electrode reinforcing member 33b is sandwiched between the convex portion of the negative electrode insulating member 33a and the burring portion 16 of the first exterior portion 5 . Even if the negative electrode terminal lead 36 is partially moved, the negative electrode insulating member 33a can more reliably prevent the negative electrode terminal lead 36 from being short-circuited with the first exterior part 5, which is preferable in this respect. Moreover, it is preferable to improve the reliability of the insulation of the negative electrode terminal lead 36 and the 1st exterior part 5 by having a convex part in the negative electrode insulating member 33a.

As shown in FIGS. 2 and 7 , the insulating spacer 34 is a cylindrical body (tubular portion) having a flange portion 34a at one open end. As shown in FIGS. 2 and 7 , the cylindrical portion of the insulating spacer 34 is inserted into the through hole 30 and the inner flange portion 31 , and the flange portion 34 a is arranged in the through hole on the outer surface of the first exterior portion 5 . 30 perimeter. The insulating spacer 34 is made of, for example, fluororesin, fluororubber, polyphenylene sulfide resin (PPS resin), polyetheretherketone resin (PEEK resin), polypropylene resin (PP resin), and polybutylene terephthalate resin (PBT resin) and other resins.

As shown in FIGS. 2 and 7 , the negative electrode terminal insulating member 35 is a plate-shaped member bent at an obtuse angle, and has a through hole 35 a at the bottom. The negative electrode terminal insulating member 35 is arranged on the outer surface of the first exterior part 5 . The flange portion 34a of the insulating gasket 34 is inserted into the through hole 35a of the negative electrode terminal insulating member 35 .

The negative electrode terminal portion 4 further includes a negative electrode terminal lead 36 . The negative terminal lead 36 is a conductive plate having a through hole 36a and a first extension portion 36b extending toward the opening of the first exterior portion 5 , that is, the second exterior portion 6 side. In FIG. 6 , the negative electrode terminal lead 36 has a first extension portion 36b extending on the electrode group 2 side. The first extending portion 36b of the negative electrode terminal lead 36 is integrated with the first extending portion 14a of the negative electrode lead 14 on the electrode group side by welding. The opposing surfaces of the first extension portion 36b and the first extension portion 14a are welded, and the end surface of the first extension portion 36b on the front end side and the end surface of the first extension portion 14a are also welded. At least the front end portions of the first extension portion 36b of the negative electrode terminal lead 36 and the first extension portion 14a of the electrode group side negative electrode lead 14 are perpendicular or substantially perpendicular (80° to 100°) with respect to the surface of the second exterior portion 6 . At least the front end portions of the first extension portion 36 b of the negative electrode terminal lead 36 and the first extension portion 14 a of the negative electrode lead 14 on the electrode group side are perpendicular or substantially perpendicular to the surface of the second exterior portion 6 . After an extension portion 36b is welded to the first extension portion 14a of the negative electrode lead 14 on the electrode group side, it is fabricated without bending the lead. By bending the lead after welding, there is an advantage that the wiring of the terminal portion of the electrode can be made compact. However, in order to perform the bending with high precision after welding, the thickness of the lead needs to be reduced. However, when the thickness of the lead wire is reduced, it is difficult to flow a large current, which is not preferable. The thickness of the lead wire can be increased by orienting the welded portion in the direction of the surface of the second exterior portion 6 . In addition, the bent shape of the lead wire is not limited to the shape shown in FIG. 7, and may be other shapes.

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 can be 0.5 mm or more and 3.0 mm or less. 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 preferably 1.0 mm or more and 1.2 mm or less in consideration of the bending process of the leads before the lead wires are welded and the large current characteristics.

The battery 100 further includes a first negative electrode terminal insulation reinforcing member 37 . The first negative electrode insulation reinforcing member 37 is arranged on the inner surface side of the first exterior part 5 . More specifically, the first negative electrode insulation reinforcing member 37 is arranged on the inner surface side of the first exterior part 5 between the negative electrode terminal lead 36 and the first exterior part 5 . As shown in FIGS. 2 and 7 , the first negative terminal insulation reinforcement member 37 has a main body portion 37a having a structure in which a bottomed rectangular cylinder is divided in half in the longitudinal direction, a circular groove 37b formed in the main body portion 37a, and a A through hole 37c opened in the center of the circular groove 37b. In the through hole 37c, the negative electrode insulating member 33a, the negative electrode reinforcing member 33b, and the negative electrode external terminal 32 are arranged. The main body portion 37 a of the first negative electrode terminal insulation reinforcement member 37 covers the corner portion of the first exterior part 5 connected from the short side side wall to the bottom surface, and the first exterior part 5 connected from the short side side wall to the long side side corners. Thereby, the 1st exterior part 5, especially the vicinity of the corner|angular which the short side side wall, the long side side wall, and the bottom intersect can be reinforced. A negative electrode insulating member 33b having a burring portion arranged on the outer peripheral surface of the burring portion 31 is arranged in the circular groove 37b. The through hole 37c communicates with the opening of the burring portion 31 and the through hole 30 of the first exterior portion 5 . A negative electrode terminal lead 36 is arranged on the first negative electrode terminal insulation reinforcement member 37 . The through hole 36 a of the negative terminal lead 36 communicates with the through hole 37 c of the first negative terminal insulation reinforcing member 37 , the opening of the inner flange portion 31 , and the through hole 30 of the first exterior part 5 .

The first negative electrode insulation reinforcement member 37 and the pair of second negative electrode insulation reinforcement members 38 are arranged on the inner surface side of the first exterior part 5 and the inner surface side of the second exterior part 6 . As shown in FIGS. 2 and 7 , each of the second negative electrode insulation reinforcing members 38 has a structure in which a bottomed rectangular cylinder is divided into half in the longitudinal direction. One first negative electrode insulation reinforcing member 37 covers approximately half of the negative electrode current collector sheet 8 a from the winding center to the first exterior portion 5 side. The other second insulation reinforcement member 38 covers approximately half of the negative electrode current collector sheet 8 a from the winding center to the second exterior portion 6 side. Thereby, the 2nd exterior part 6, especially the vicinity of a short side can be reinforced.

The shaft portion of the negative electrode external terminal 32 is inserted into the insulating spacer 34 , the through hole 35 a of the negative electrode terminal insulating member 35 , the through hole 30 of the first exterior part 5 , the through hole 37 c of the first negative electrode insulation reinforcing member 37 , and the holes of the negative electrode terminal lead 36 . The through hole 36a is then plastically deformed by caulking. As a result, as shown in FIGS. 2 and 7 , these components are integrated, and the negative electrode external terminal 32 and the negative electrode terminal lead 36 are electrically connected. Therefore, the negative external terminal 36 also functions as a rivet. In addition, the end face of the shaft portion of the negative electrode external terminal 32 and the boundary portion of the through hole 36a of the negative electrode terminal lead 36 may be welded by a laser or the like to achieve a stronger connection and improve electrical conductivity.

The backup positive electrode lead 11 , the electrode group side positive electrode lead 12 , the positive electrode terminal lead 23 , the backup negative electrode 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 that of the positive electrode current collector or the negative electrode current collector that can be electrically connected to the lead.

The first positive electrode insulation reinforcement member 24, the second positive electrode insulation reinforcement member 25, the first negative electrode insulation reinforcement member 37, and the second negative electrode insulation reinforcement member 38 are made of, for example, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), Polypropylene (PP), Polyethylene (PE), Nylon, Polybutylene Terephthalate (PBT), Polyethylene Terephthalate (PET), Polytetrafluoroethylene (PTFE), Polyphenylene Sulfide (PPS), and thermoplastic resins such as polyetheretherketone (PEEK).

The electrode group 2 is accommodated in the first exterior part 5 so that the first end surface 7 a faces the positive electrode terminal part 3 and the second end surface 8 a faces the negative electrode terminal part 4 . Therefore, the plane intersecting the first end face 7a and the second end face 8a of the electrode group 2 is opposed to the bottom face 5c in the first outer casing 5, and the curved face intersecting the first end face 7a and the second end face 8a is opposite to the first casing. The long-side side surfaces in the portion 5 are opposed to each other.

There are gaps between the corners of the first exterior part 5 connecting the short-side side walls and the bottom, and the first end surface 7a of the electrode group 2 and the second end surface 8a, respectively. By providing a concave portion protruding inward at the corner portion connecting the short side wall and the bottom of the first exterior portion 5, and forming the bottom of the concave portion as the inclined surface 5d, the dead space in the first exterior portion 5 can be reduced, so that it is possible to Improve the volumetric energy density of the battery. In addition, by arranging the positive electrode terminal portion 3 and the negative electrode terminal portion 4 on the inclined surface 5d, respectively, compared with the case where the positive electrode terminal portion 3 and the negative electrode terminal portion 4 are provided on the short side surface that does not have the inclined surface, the number of the positive electrode terminal portion 3 and the negative electrode terminal portion 4 can increase. The installation area of the terminal part. Therefore, since the diameter of the shaft portion of the positive electrode external terminal 17 and the shaft portion of the negative electrode external terminal 32 can be increased, a large current (high-speed current) can flow with low resistance.

The electrode group 2 is also wound by the insulating film 26 . The winding direction of the insulating film 26 is the same as or opposite to the winding direction of the electrode group 2 . The insulating film 26 is disposed between the electrode group 2 and the first exterior part 5 and between the electrode group 2 and the second exterior part 6 . The insulating film 26 is wound around the electrode group 2 so as to straddle the positive electrode current collector tab 7a and the negative electrode current collector tab 8a. The end portion on the positive electrode side of the insulating film 26 extends to the lead side of the positive electrode terminal portion 3 , and the end portion on the negative electrode side extends to the lead side portion of the negative electrode terminal portion 4 . The insulating film 26 is preferably fixed by a tape not shown.

As the insulating film 26, one selected from the group consisting of a nonwoven fabric, a film, and a paper can be used. The insulating film 26 includes a film comprising a nonwoven fabric containing cellulose fibers, polyolefin containing polyethylene and polypropylene, cellulose, polyester, polyvinyl alcohol, polyimide, polyolefin One of the group consisting of amide, polyamideimide, polytetrafluoroethylene, vinylon, paper containing polytetrafluoroethylene and cellulose fibers. The thickness of the insulating film 26 is not particularly limited, but if it is too thin, the insulating properties will be insufficient, and if it is too thick, the battery capacity will decrease. Therefore, the thickness of the insulating film 26 is typically 4 μm to 50 μm.

FIG. 5 shows a cross-sectional view obtained when the positive electrode terminal portion is cut in the longitudinal direction of the battery. FIG. 6 shows a cross-sectional view obtained when the battery is cut in the longitudinal direction of the positive electrode side excluding the positive electrode terminal portion. 5 and 6 , the first positive electrode insulation reinforcement member 24 is sandwiched by the insulating film 26 and the first exterior portion 5 , and the second positive electrode insulation reinforcement member 25 is sandwiched by the insulating film 26 and the second exterior portion 6 . . The insulating film 26 is provided to cover at least a part of the positive electrode current collector tab 7a of the electrode group 2 on the positive electrode side, and is disposed between the positive electrode current collector tab 7a and the first positive electrode insulation reinforcing member 24 and between the positive electrode current collector tab 7a and the second positive electrode between the insulation reinforcement members 25 . The film that is continuous from the center portion side of the electrode group 2 also insulates between the positive electrode current collector tab 7a and the first positive electrode insulation reinforcement member 24 and between the positive electrode current collector tab 7a and the second positive electrode insulation reinforcement member 25, thereby improving the positive electrode performance. Insulation property between the lead portion of the terminal on the side and the exterior member 1 is preferable in this respect.

The same applies to the negative electrode. FIG. 7 shows a cross-sectional view obtained when the negative electrode terminal portion is cut along the longitudinal direction of the battery. FIG. 8 shows a cross-sectional view obtained when the battery is cut in the longitudinal direction of the negative electrode side excluding the negative electrode terminal portion. 7 and 8 , the first negative electrode insulation reinforcement member 37 is sandwiched by the insulating film 26 and the first exterior portion 5 , and the second negative electrode insulation reinforcement member 38 is sandwiched by the insulating film 26 and the second exterior portion 6 . . The insulating film 26 is provided to cover at least a part of the negative electrode current collector sheet 8a of the electrode group 2 on the negative electrode side, and is arranged between the negative electrode current collector sheet 8a and the first negative electrode insulation reinforcing member 37 and between the negative electrode current collector sheet 8a and the second negative electrode between the insulation reinforcement members 38 . By the film continuous from the center portion side of the electrode group 2, the negative electrode current collector sheet 8a and the first negative electrode insulation reinforcement member 37 and between the negative electrode current collector sheet 8a and the second negative electrode insulation reinforcement member 38 are also insulated, thereby improving the negative electrode Insulation property between the lead portion of the terminal on the side and the exterior member 1 is preferable in this respect.

The electrode group 2 is accommodated in the first exterior part 5 , and as a result, the positive electrode current collector tab 7 a is formed by the bottom end of the second positive electrode insulation reinforcement member 25 being in contact with the upper end of the first positive electrode insulation reinforcement member 24 . covered by a hood. In addition, the negative electrode current collector tab 8a is covered with a bottomed rectangular cylindrical cover formed by contacting the lower end of the second negative electrode insulating reinforcing member 38 with the upper end of the first negative electrode insulating reinforcing member 37 .

The second exterior portion 6 functions as a cover of the first exterior portion 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 .

The battery shown in FIGS. 1 to 9 described above preferably includes an exterior member that is housed in a space formed by welding a first exterior portion made of stainless steel and a second exterior portion made of stainless steel having a flange portion at its opening There are electrode sets. The second exterior part 5 and the second exterior part 6 are made of stainless steel, so that even when the plate thicknesses of the first and second exterior parts are reduced, high strength can be maintained. As a result, since the flexibility of the exterior member can be improved, the electrode group 2 can be easily restrained by decompression sealing or applying a load from the outside of the exterior member 1 . Accordingly, it is easy to realize a battery pack in which the distance between the electrodes of the electrode group 2 is stable, the resistance can be reduced, and the vibration resistance and shock resistance are provided. Furthermore, when the flexibility of the first exterior part 5 and the second exterior part 6 is high, the distance from the inner surfaces of the first and second exterior parts to the electrode group can be easily shortened, so that the heat dissipation of the battery can be improved.

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

In addition, the shaft portion of the external terminal is caulked and fixed to the through hole, and as a result, plastic deformation occurs. As a result, although a force is applied in the radial direction of the insulating spacer, since the burring portion is reinforced by the annular member arranged on the outer side thereof, compressive stress is generated in the insulating spacer, and high strength can be obtained. The external terminal is connected to the first exterior part 5 . Even if the thickness of the first exterior part 5 is reduced, that is, the thickness of the burring part is reduced, the burring can be reinforced with the annular member. Therefore, regardless of the thickness of the first exterior part, the The external terminal can be connected to the first exterior part 5 with high strength. Furthermore, since the burring portion extends from the edge of the through hole toward the inside of the exterior member 1, liquid leakage when the internal pressure of the exterior member 1 rises due to gas generation or the like can be suppressed by the action of the external pressure. Therefore, even when the plate thicknesses of the first exterior part 5 and the second exterior part 6 are reduced, high reliability can be achieved.

Therefore, according to the battery of the first embodiment, since high strength and reliability can be obtained even when the plate thicknesses of the first exterior portion 5 and the second exterior portion 6 are reduced, flexibility and heat dissipation can be provided. Excellent battery with 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 increases. Although the second exterior part is welded to the four sides of the first exterior part, when the area of the opening part increases, the length of the welded side becomes longer, so it is easy to weld the three sides first and inject the electrolyte from the gap of the remaining one. liquid. In addition, since the exterior member 1 can be temporarily sealed by providing a site with a lower welding strength than other sites, a temporary sealing member (eg, a rubber stopper) can be unnecessary. Furthermore, since the exterior member 1 has a flat shape, the heat dissipation of the battery can be improved.

The 1st exterior part 5 has the recessed part which has the inclined surface 5d, and the dead space in the 1st exterior part 5 can be reduced by arranging the terminal part on the inclined surface 5d.

In addition, the inclined surface 5d is not limited to being provided in the vicinity of the center part of the short side of the exterior member 1, You may cover the whole short side of the exterior member.

It is desirable to further include a backup lead electrically connected to the positive electrode collector tab or the negative electrode collector tab, and to electrically connect the electrode terminal lead to the backup lead. Thereby, positioning at the time of welding becomes easy. In addition, even if the position of the backup lead with respect to the positive electrode current collector tab and the negative electrode current collector tab is slightly shifted, a sufficient connection area can be secured, so that a low-resistance battery can be realized.

Since the first end surface of the external terminal has a quadrangular top surface and first and second inclined surfaces connected to opposite sides of the top surface, it is possible to change the welding by selecting any one of the three surfaces as the welding surface. direction.

It is desirable that the plate thickness of the first exterior part and the second exterior part be in the range of 0.02 mm or more and 0.3 mm or less. By being within this range, it is possible to balance the opposite properties of mechanical strength and flexibility. A more preferable range of the plate thickness is 0.05 mm or more and 0.15 mm or less.

It is desirable that the difference (wall thickness) between the outer profile and the inner diameter of the positive electrode terminal portion 3 , the negative electrode terminal portion 4 , or both annular members be equal to or more than the thickness of the first exterior portion 5 . Thereby, the external terminal can be connected to the first exterior part with high strength regardless of the plate thickness of the first exterior part. Specifically, the shortest wall thickness can be 0.1 mm or more.

In addition, the outer shape of the annular member does not necessarily need to be the same shape as the cross-sectional shape of the inner edge flanging, and it may be a polyhedron such as a rectangle or a hexagon, or a compound of single or multiple curves and single or multiple straight lines. shape.

A flat plate as illustrated in FIGS. 5 to 8 can be used for the second exterior portion 6 , but a member having a flange portion at the opening portion may be used instead of the flat plate. In the example of such a structure, the same member as the 1st exterior part 5 can be mentioned.

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. In addition, it is also possible to adopt a configuration in which the backup positive electrode lead 11 or the backup negative electrode lead 13 or both of them is not used.

The exterior member may further include a safety valve or the like capable of releasing the pressure inside the battery when the pressure inside the battery rises to a predetermined value or more.

The battery of the first embodiment may be a primary battery or a secondary battery. As an example of the battery of the first embodiment, a lithium ion secondary battery can be mentioned.

The positive electrode, negative electrode, separator, and nonaqueous electrolyte of the battery of the first embodiment will be described below.

1) Positive pole

The positive electrode 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 sheet. 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, oxides or sulfides can be used. Examples of oxides and sulfides include manganese dioxide (MnO ₂ ) that occludes lithium, iron oxide, copper oxide, nickel oxide, and lithium-manganese composite oxides (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 CoyO ₂ ), lithium manganese cobalt composite Oxides (eg Li _x M _ny Co _1-y O ₂ ), lithium manganese nickel composite oxides with spinel structure (eg Li _x Mn _2-y Ni _y O ₄ ), lithium phosphorus oxides with olivine structure compounds (eg _LixFePO4 , _{LixFe1 - yMnyPO4} , _{LixCoPO4 )} , iron _sulfate (Fe2( _{SO4 ) 3 )} , vanadium oxides (eg _{V2O5 )} , and lithium nickel Cobalt manganese composite oxide. In the above chemical 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.

A binder is blended in order to bind the active material to the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and fluororubber.

A conductive agent is blended as necessary in order to improve the current collecting performance and 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 at a ratio of 80% by mass to 98% by mass and 2% by mass to 20% by mass, respectively.

Sufficient electrode strength can be obtained by setting the binder in an amount of 2 mass % or more. Moreover, by setting it to 20 mass % or less, the compounding quantity of the insulating material of an electrode can be reduced, and internal resistance can be reduced.

When a conductive agent is added, it is preferable that the positive electrode active material, the binder, and the conductive agent are respectively added in a ratio of 77% by mass to 95% by mass, 2% by mass to 20% by mass, and 3% by mass to 15% by mass, respectively. blend. The above-mentioned effects can be exhibited by setting the conductive agent in an amount of 3% by mass or more. In addition, by setting the content to 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 the group consisting of Mg, Ti, Zn, Ni, Cr, Mn, Fe, Cu, and Si.

The positive electrode current collector is preferably integral with the positive electrode current collector sheet. Alternatively, the positive electrode current collector may be separated from the positive electrode current collector sheet.

2) Negative pole

The negative electrode can include, for example, a negative electrode current collector, a negative electrode material layer held on the negative electrode current collector, and a negative electrode current collector sheet. The anode material layer can contain, for example, an anode active material, a conductive agent, and a binder.

As the negative electrode active material, for example, metal oxides, metal nitrides, alloys, carbon, etc., which can store and emit lithium ions, can be used. It is preferable to use a material that can store and emit lithium ions at a high potential of 0.4 V or more (vs. Li/Li ⁺ ) as the negative electrode active material.

Examples of the negative electrode active material include graphite materials or carbonaceous materials (for example, graphite, coke, carbon fiber, spherical carbon, thermally decomposed gas-phase carbonaceous materials, fired resin bodies, etc.), chalcogenides (for example, disulfide Titanium, molybdenum disulfide, niobium selenide, etc.), light metals (for example, aluminum, aluminum alloys, magnesium alloys, lithium, lithium alloys, etc.), with Li _4+x Ti ₅ O ₁₂ (x is at -1 according to the charge-discharge reaction Spinel-type lithium titanate, rhodochrosite-type Li _2+x Ti ₃ O ₇ represented by ≤x≤3) (x varies within the range of -1≤x≤3 according to the charge-discharge reaction) , a metal composite oxide containing Ti and at least one element selected from the group consisting of P, V, Sn, Cu, Ni, and Fe, a niobium-titanium composite oxide, and the like.

Examples of metal composite oxides containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni, and Fe include TiO ₂ -P ₂ O ₅ and TiO ₂ -V ₂ O _{5. TiO2} - _P2O5 - _SnO2 , _{TiO2 - P2O5 -} MO (M is at least one element selected from the group consisting of Cu, Ni, and Fe). These metal composite oxides are changed into lithium-titanium composite oxides by inserting lithium by charging. A substance containing at least one selected from the group consisting of lithium titanium oxide (for example, spinel-type lithium titanate), silicon, tin, and the like is preferable. The binder of the negative electrode active material layer and the binder of the positive electrode active material layer are common. The conductive agent of the negative electrode active material layer and the conductive agent of the positive electrode active material layer are common.

As the niobium-containing titanium composite oxide, for example, those having the general formula Li _a TiM _b Nb _2±β O _7±σ (here, the values of the subscripts are 0≤a≤5, 0≤b≤0.3, 0≤ Within the range of β≤0.3, 0≤σ≤0.3, M is a single element represented by at least one selected from the group consisting of Fe, V, Mo, and Ta (may be one or more)) A complex oxide with a slanted crystal structure, having the general formula Li _2+a1 M(I) _2-b1 Ti _6-c1 M(II) _d1 O _14+σ1 (here, the value of each subscript is 0≤ In the range of a1≤6, 0<b1<2, 0<c1<6, 0<d1<6, -0.5≤σ1≤0.5, M(I) is selected from Sr, Ba, Ca, Mg, Na, Cs And at least one in the group consisting of K (either one or more), M(II) is selected from Zr, Sn, V, Nb, Ta, Mo, W, Fe, Co, At least one of the group consisting of Mn and Al (may be one kind or plural kinds), and a complex oxide containing an orthorhombic crystal structure represented by Nb). In the above general formula Li _2+a1 M(I) _2-b1 Ti _6-c1 M(II) _d1 O _14+σ1 , the values of the subscripts are preferably 0≤a1≤6, 0<b1<2, 0< In the range of c1<6, 0<d1<6, -0.5≤σ1≤0.5, M(I) is at least one selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs and K (both may be one or more), M(II) is Nb, or Nb and Nb and selected from the group consisting of Zr, Sn, V, Ta, Mo, W, Fe, Co, Mn and Al A combination of at least one (or one or more). In particular, the monoclinic niobium-titanium-containing composite oxide is more preferable because the capacitance per unit weight is large and the battery capacitance can be improved.

A conductive agent is blended in order to improve the current collection performance and 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.

It is used to fill the gaps of the dispersed negative electrode active material, and a binder is blended to bind the negative electrode active material and the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, and styrene-butadiene rubber.

The active material, conductive agent, and binder in the negative electrode material layer are preferably blended at a ratio of 68% by mass to 96% by mass, 2% by mass to 30% by mass, and 2% by mass to 30% by mass, respectively. By setting the amount of the conductive agent to be 2 mass % or more, the current collection performance of the negative electrode layer can be improved. In addition, by setting the amount of the binder to be 2 mass % or more, the adhesion between the negative electrode material layer and the current collector can be sufficiently found, and excellent cycle characteristics can be expected. On the other hand, setting each of the conductive agent and the binder to 28% by mass or less is preferable because higher capacitance is obtained.

As the current collector, a material that is electrochemically stable in the storage potential and emission potential of lithium 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 the group consisting of Mg, Ti, Zn, Mn, Fe, Cu, and Si. The thickness of the current collector is preferably in the range of 5 to 20 μm. A current collector having such a thickness can achieve a balance between the strength and weight reduction of the negative electrode.

The negative electrode current collector and the negative electrode current collector sheet are preferably integrated. Alternatively, the negative electrode current collector may be separated from the negative electrode current collector sheet.

For example, a negative electrode active material, a binder, and a conductive agent are suspended in a general-purpose solvent to prepare a suspension, the suspension is applied to a current collector, dried, and a negative electrode material layer is formed, followed by pressing. , to make the negative electrode. Alternatively, the negative electrode can be produced by forming the negative electrode active material, the binder, and the conductive agent into a spherical shape as a negative electrode material layer, and disposing them on a current collector.

3) Spacer

It is a porous and thin insulating film. As the separator, nonwoven fabric, film, paper, inorganic particle layer and the like are included. Examples of the constituent material of the separator include polyolefins such as polyethylene and polypropylene, cellulose, polyester, polyvinyl alcohol, polyimide, polyamide, polyamideimide, polytetrafluoroethylene, and Pooh Lun. As an example of a separator preferable from the viewpoint of thinness and mechanical strength, a nonwoven fabric containing cellulose fibers can be mentioned. The inorganic particle layer contains oxide particles, a thickener, and a binder. Metal oxides such as aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, and barium sulfate can be used for the oxide particles. Carboxymethyl cellulose can be used in the thickener. As the binder, methyl acrylate, a propylene-based copolymer containing methyl acrylate, styrene-butadiene rubber (SBR), and the like can be used.

4) Electrolyte

As the electrolyte, it is preferable to use a solution containing an electrolyte salt and a non-aqueous solvent, a non-aqueous gel electrolyte in which a polymer material is compounded in a solution containing an electrolyte salt and a non-aqueous solvent, a solution containing an electrolyte salt and water, or a solution containing an electrolyte salt and a non-aqueous solvent. A water-based gel electrolyte in which a polymer material is compounded in a solution of salt and water.

As the electrolyte salt contained in the non-aqueous solution, for example, LiPF ₆ , LiBF ₄ , Li

(CF ₃ SO ₂ ) ₂ N (lithium bistrifluoromethanesulfonimide; commonly known as LiTFSI), LiCF ₃ SO ₃

(commonly known as LiTFS), Li(C ₂ F ₅ SO ₂ ) ₂ N (lithium bis-pentafluoroethanesulfonimide; commonly known as LiBETI), LiClO ₄ , LiAsF ₆ , LiSbF ₆ , LiB(C ₂ O ₄ ) ₂ ( Lithium bisoxalatoborate; commonly known as LiBOB), difluoro(trifluoro-2-oxide-2-trifluoro-propionic acid methyl ester (2-)-0,0), LiBF ₂ OCOOC(CF ₃ ) ₂ ( Lithium borate; commonly known as LiBF ₂ (HHIB)) as a lithium salt. These electrolyte salts may be used alone or in combination of two or more. LiPF ₆ and LiBF ₄ are particularly preferred. Among the lithium salts, support salts for ionic conductivity can be used. For example, lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate, imide-based supporting salts, and the like can be mentioned. Lithium salts may contain one type, or two or more types.

The nonaqueous electrolyte salt concentration is preferably within a range of 0.5 mol/L or more and 3.0 mol/L or less, and more preferably within a range of 0.7 mol/L or more and 2.0 mol/L or less. By specifying such an electrolyte concentration, the influence of an increase in viscosity due to an increase in the electrolyte salt concentration can be suppressed, and the performance when a high load current flows can be further improved.

The non-aqueous solvent is not particularly limited, and for example, cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), or ethyl methyl carbonate can be used (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, acetonitrile (AN). These solvents may be used alone or in combination of two or more. A non-aqueous solvent containing cyclic carbonate and/or chain carbonate is preferred. Examples of the polymer material contained in the non-aqueous gel electrolyte include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), polyacrylate, and the like.

Examples of the electrolyte salt contained in the aqueous solution include LiCl, LiBr, LiOH, Li ₂ SO ₄ , LiNO ₃ , LiN(SO ₂ CF ₃ ) ₂ (lithium trifluoromethanesulfonylamide; commonly referred to as LiTFSA), LiN (SO ₂ C ₂ F ₅ ) ₂ (lithium bis-pentafluoroethanesulfonylamide; commonly known as LiBETA), LiN(SO ₂ F) ₂

(Lithium bisfluorosulfonylamide; commonly known as LiFSA), LiB[(OCO) ₂ ] ₂ and the like. The type of the lithium salt used can be one type or two or more types. As a polymer material contained in an aqueous gel electrolyte, polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), polyacrylate, etc. are mentioned, for example.

The electrolyte salt concentration of the water system is preferably 1 mol/L or more and 12 mol/L, and more preferably 112 mol/L or more and 10 mol/L or less. In order to suppress the electrolysis of the electrolytic solution, LiOH and 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 normal temperature molten salt (ionic melt) containing lithium ions, a polymer solid electrolyte, an inorganic solid electrolyte, or the like can 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.) in an organic salt composed of a combination of an organic cation and an anion. The room temperature molten salt includes a room temperature molten salt that exists as a monomer as a liquid, a room temperature molten salt that becomes a liquid by mixing with an electrolyte, and a room temperature molten salt that becomes a liquid by dissolving in an organic solvent. In general, the melting point of a molten salt at room temperature used in a non-aqueous electrolyte battery is 25° C. or lower. In addition, organic cations generally have a quaternary ammonium skeleton.

The method for manufacturing the battery of the first embodiment will be described below. A process diagram of manufacturing a battery is shown in FIGS. 10A to 10B and FIGS. 11A to 11D .

An electrode group 2 as illustrated in FIG. 3 is produced, and then wound with an insulating film 26 . In addition, as illustrated in FIG. 9 , the first exterior part 5 to which the positive electrode terminal part 3 and the negative electrode terminal part 4 are fixed is produced. In addition, 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 is shown in FIG.10(a) and FIG.10(b). FIG. 10( a ) shows an example in which guide holes 39 for positioning are formed at the four corners of the second exterior portion 6 . FIG. 10( b ) shows an example in which guide holes 39 for positioning are formed at the four corners of the first exterior part 5 .

The electrode group 2 wound with the insulating film 26 is accommodated in the first exterior part 5 , the electrode group side positive electrode lead 12 and the positive electrode terminal lead 23 are joined by welding or the like, and the electrode group side negative electrode lead 14 and the negative electrode terminal lead are joined together. 36 is joined by welding or the like. For joining, for example, laser welding, TIG welding, and friction stir welding can be used. In an embodiment, any joint based on either is treated as welding.

Next, the second positive electrode insulation reinforcement member 25 and the second negative electrode insulation reinforcement member 38 are covered on the positive electrode current collector tab 7 a and the negative electrode current collector tab 8 a of the electrode group 2 . Next, the second exterior part 6 is arranged on the first exterior part 5 . Since the guide holes 39 are formed at the four corners of the first exterior part 5 and the second exterior part 6 , the position of the second exterior part 6 with respect to the first exterior part 5 can be easily determined.

Next, as shown in FIG. 11( a ), three sides (for example, both the long side and the short side) of the first exterior part 5 and the second exterior part 6 are welded. In welding, for example, resistance seam welding is used. The welding site is designated by reference numeral 40 . It is desirable that the welding site 40 is located more inward than the outer edges of the first exterior part 5 and the second exterior part 6 .

After injecting the electrolyte into the opening of the unwelded side, as shown in FIG. 11( b ), the side is welded by, for example, resistance seam welding. It is desirable that the welding portion 41 is at the outer edge portions of the first exterior portion 5 and the second exterior portion 6 .

Next, after performing aging and the first charge and discharge, as shown in FIG. 11( c ), a part of the welded portion 41 is cut out to form a cut portion 42 , and the gas in the exterior member is exhausted. After that, as shown in FIG. 11( d ), a welded portion (long side of the second exterior portion 6 ) 43 that is closer to the inner side than the welded portion 41 is welded by resistance seam welding or the like. It is desirable that this welding be performed under a reduced pressure atmosphere.

After that, if necessary, the guide holes 39 can be removed by cutting the vicinity of the outer edges of the first exterior part 5 and the second exterior part 6 . In addition, the guide hole 39 may also remain.

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

The battery of the first embodiment can include a plurality of electrode groups in one exterior member. In this case, it is desirable to use a member having a flange portion at the opening as the second exterior portion similarly to the first exterior portion.

In the case where a plurality of electrode groups are accommodated in one exterior member, the plurality of electrode groups can be connected in series or in parallel with each other. FIGS. 12A to 12D show process diagrams for manufacturing the positive electrode side of a battery in which a plurality of (two) electrode groups are connected in parallel. FIG. 12D shows the fabricated battery 101 . A plurality of electrode groups 2 wound with insulating films 26 are prepared, and the center front end of the positive electrode current collector tab 7 a is bound with the backup positive electrode lead 11 . Next, as shown in FIG. 12A , the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are welded. After welding, the positive electrode lead 12 on the electrode group side is bent to become the first extension portion 12 as shown in FIG. 12B . In addition, the electrode-side positive electrode lead and the backup positive electrode lead 11 which are bent in advance can be welded to obtain a member as shown in FIG. 12B .

Then, the member shown in FIG. 12B is inserted from the opening portion side of the first exterior material 5 in which the positive electrode terminal portion 3 is assembled in advance. After insertion, the first extension portion 12a of the electrode group side positive electrode lead 12 and the first extension portion of the positive electrode terminal lead 23 are laser welded and fixed, whereby one electrode group 2 is fixed in the first exterior portion 5 as shown in FIG. 12C . Similarly, by inserting the other electrode group 2 into the first exterior part 5, performing laser welding, and covering it with the second exterior part 6, the battery 101 in which the plurality of electrode groups 2 are accommodated as shown in FIG. 12D can be obtained. . The series connection can be performed by changing the orientation of the electrodes of the plurality of electrode groups.

FIG. 13 shows a modification of the positive electrode portion of the battery 100 according to the first embodiment. The negative electrode side is shown in FIG. 14 , and is configured symmetrically with the positive electrode portion in FIG. 13 . The battery 102 of FIG. 13 has the convex part 24d in the 1st positive electrode insulation reinforcement member 24, and has the recessed part 25b in the 2nd positive electrode insulation reinforcement member 25. By combining the convex portion 24d and the concave portion 25b, the first positive electrode insulation reinforcement member 24 and the second positive electrode insulation reinforcement member 25 are fitted on the opposite side to the positive electrode current collector tab 7a. The fitting by the concave portion and the convex portion is an example of the fitting method, and the first positive electrode insulation reinforcement member 24 and the second positive electrode insulation reinforcement member 25 are only required to be connected by fitting. The first positive electrode insulation reinforcement member 24 and the second positive electrode insulation reinforcement member 25 are connected not on the positive electrode collector tab 7a side but on the positive electrode terminal side. By connecting the first positive electrode insulation reinforcement member 24 and the second positive electrode insulation reinforcement member 25, on the positive electrode terminal side, when viewed from the positive electrode current collector tab 7a side, the exterior member 1 has the first positive electrode insulation reinforcement member 24 and the second positive electrode insulation reinforcement member 24 and the second positive electrode insulation reinforcement member. Reinforcing member 25 is not exposed. The exterior member 1 is not exposed, so that the positive electrode current collector tab 7a and the positive terminal portion 3 are not easily short-circuited with the exterior member 1. Therefore, the electrode group 2, the backup positive electrode lead 11, the electrode group side positive electrode lead 12, and the positive electrode terminal lead 23 are further improved. An insulating property of 1 is preferred in this regard.

The same applies to the negative electrode side. The battery 102 of FIG. 14 has a convex portion 37 d in the first negative electrode insulation reinforcement member 37 and a concave portion 38 b in the second negative electrode insulation reinforcement member 38 . The convex portion 37d and the concave portion 38b are combined so that the first negative electrode insulation reinforcement member 37 and the second negative electrode insulation reinforcement member 38 are fitted on the opposite side to the negative electrode current collector tab 8a. The fitting by the concave portion and the convex portion is an example of the fitting method, and the first negative electrode insulation reinforcement member 37 and the second negative electrode insulation reinforcement member 38 may be connected by fitting. The first negative electrode insulation reinforcement member 37 and the second negative electrode insulation reinforcement member 38 are connected not on the side of the negative electrode current collector tab 8a but on the side of the negative electrode terminal. By connecting the first negative electrode insulation reinforcement member 37 and the second negative electrode insulation reinforcement member 38, on the negative electrode terminal side, when viewed from the negative electrode current collector tab 8a side, the exterior member 1 has the first negative electrode insulation reinforcement member 37 and the second negative electrode insulation reinforcement member 37 and the second negative electrode insulation reinforcement. Reinforcing member 38 is not exposed. The exterior member 1 is not exposed, so that the negative electrode current collector 8a and the negative terminal portion 4 are not easily short-circuited with the exterior member 1, so that the electrode group 2, the backup negative electrode lead 12, the electrode group side negative electrode lead 13, and the negative electrode terminal lead 36 are further improved. An insulating property of 1 is preferred in this regard.

Even if the battery of the first embodiment described above is a thin battery, the reliability of the insulation of the positive electrode and the negative electrode and the exterior member 1 is high, and the safety of the battery is high.

In addition, the terminal portion may be applied to both the positive electrode terminal portion and the negative electrode terminal portion, but may be applied to either the positive electrode terminal portion or the negative electrode terminal portion.

(Second Embodiment)

The battery pack of the second embodiment includes one or more cells of the first embodiment. An example of the assembled battery of the battery according to the first embodiment is shown in FIGS. 15 and 16 .

As shown in FIG. 15 , the battery pack 200 uses the batteries 100 to 102 of the first embodiment as unit cells. The battery pack 200 may be covered with a not-shown laminated sheet. A triangular prism-shaped conductive connecting member 62 is arranged between the top surface 32 b of the negative electrode external terminal 32 of the first unit cell 60 and the top surface 32 b of the negative electrode external terminal 32 of the second unit cell 61 . In addition, a triangular prism-shaped conductive connecting member 62 is arranged between the top surface of the positive electrode external terminal 17 of the first unit cell 60 and the top surface of the positive electrode external terminal 17 of the second unit cell 61 . The two top surfaces and the conductive connecting member 62 are respectively electrically connected by soldering. Welding uses, for example, laser welding, arc welding, resistance welding. Thereby, the unit 63 of the assembled battery 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 cells 63 of the assembled battery to each other in series with the bus bar 64 .

The battery pack 201 shown in FIG. 16 uses the battery 100 of the first embodiment as a unit cell. The first unit cell 60 and the second unit cell 61 as the battery 100 are connected in series using the conductive connecting member 62 as the unit 65 of the assembled battery, and the unit 65 of the assembled battery is connected in series by the bus bar 64 connected to form a battery pack. 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 in FIG. 15 .

In the assembled battery shown in FIGS. 15 and 16 , the adjacent first unit cells 60 and second unit cells 61 are stacked in a state where the main surfaces of the exterior members 1 face each other. For example, in the unit 63 of the assembled battery shown in FIG. 15 , the main surface of the first exterior portion 5 of the first unit cell 60 is opposed to the principal surface of the first exterior portion 5 of the second unit cell 61 . In the adjacent assembled battery cells 63, the main surface of the second exterior portion 6 of the second unit cell 61 of the one assembled battery cell 63 and the second unit cell 61 of the other assembled battery cell 63 The main surfaces of the two exterior parts 6 face each other. In this way, the volume energy density of the assembled battery can be increased by stacking the batteries so that the main surfaces of the exterior members face each other.

In addition, as shown in FIGS. 15 and 16 , it is desirable to have an insulating space between the unit cell 60 and the unit cell 61 , or between the unit cells 60 , 60 , and the cells of the unit cells 61 , 61 , and a gap of 0.03 mm or more can be provided. , or an insulating member (eg, polypropylene, polyphenylene sulfide, epoxy resin as resin, alumina, zirconia, etc. as fine-grained ceramics) or the like is sandwiched therebetween.

The positive electrode external terminal 17 and the negative electrode external terminal 32 have a frusto-pyramid-shaped head, so that the unit cell can be connected to one (first inclined face) of two positions (eg, first and second inclined faces) of one head. , and connect the bus bar at the other place (the second inclined surface). That is, it is possible to perform connection in both directions with one head. As a result, since the path for electrical connection between the batteries can be shortened, a large current can flow 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 provide a battery pack that can achieve thinning and flexibility, and is excellent in reliability and can reduce manufacturing costs.

The battery pack is used, for example, as a power source for electronic equipment, vehicles (railway vehicles, automobiles, bicycles with prime movers, light vehicles, trolleybuses, etc.).

As described above, the assembled battery can include a structure in which a plurality of batteries are electrically connected in series, in parallel, or in a combination of series and parallel. In addition to the assembled battery, the battery pack may include circuits such as a battery control unit (BMU), but a circuit included in a device (for example, a vehicle or the like) equipped with the assembled battery can be used as the battery control unit. The battery control unit has functions such as monitoring the voltage or current of the single cell and the assembled battery, or both, and preventing 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 attached to the power storage device 300 . The power storage device 300 shown in the conceptual diagram of FIG. 17 includes battery packs 200 and 201 , an inverter 302 , and a converter 301 . The structure is such that the converter 301 converts the external AC power source 303 to DC, charges the battery packs 200 and 201, and converts the DC power source from the battery packs 200 and 201 to the AC inverter 302 and stores the power. The load 304 to which the device 300 is connected is powered. By providing the power storage device 300 having the present configuration of the battery packs 200 and 201 of the embodiment, a power storage device having excellent battery characteristics is provided. In addition, the batteries 100 to 102 can be used instead of the battery packs 200 and 201 .

(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 of the present embodiment will be briefly described using the schematic diagram of the vehicle 400 in FIG. 18 . The vehicle 400 includes battery packs 200 and 201 , a vehicle body 401 , an electric motor 402 , wheels 403 , and a control unit 404 . The battery packs 200 and 201 , the electric motor 402 , the wheels 403 , and the control unit 404 are arranged on the vehicle body 401 . The control unit 404 converts and adjusts the output of the electric power output from the battery packs 200 and 201 . The electric motor 402 uses the electric power output from the battery packs 200 and 201 to rotate the wheels 403 . In addition, the vehicle 400 also includes an electric vehicle such as an electric train, and a hybrid vehicle having another drive source such as an engine. The battery packs 200 , 201 can be charged with regenerative energy from the electric motor 402 . The device driven by the electric energy from the battery packs 200 and 201 is not limited to the electric motor, and may be used as a power source for operating the electric device included in the vehicle 400 . In addition, it is preferable to obtain regenerative energy while the vehicle 400 is decelerating, and to charge the battery packs 200, 201 using the obtained regenerative energy. By providing the vehicle 400 having the present configuration of the battery packs 200 and 201 of the embodiment, a vehicle having excellent battery characteristics is provided. In addition, the batteries 100 to 102 can be used instead of the battery packs 200 and 201 .

(Fifth Embodiment)

A fifth embodiment relates to a flying body (eg, a multi-plane). The flying object of the fifth embodiment uses the battery packs 200 and 201 of the second embodiment. The configuration of the flying object of the present embodiment will be briefly described using the schematic diagram of the flying object (quadcopter) 500 in FIG. 19 . The flying body 500 includes battery packs 200 and 201 , a body frame 501 , a motor 502 , a rotor 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 on the body frame 501 . The control unit 504 converts and adjusts the output of the electric power output from the battery packs 200 and 201 . The motor 502 uses the electric power output from the battery packs 200 and 201 to rotate the rotor 503 . By providing the flying body 500 having the present structure of the battery packs 200 and 201 of the embodiment, a flying body having excellent battery characteristics can be provided. In addition, the batteries 100 to 102 can be used instead of the battery packs 200 and 201 .

Although some embodiment of this invention was described, these embodiment is shown only as an example, Comprising: It does not intend to limit the scope of the invention. These new embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and their equivalents.

Description of reference numerals

1-exterior component; 2-electrode group; 3-positive terminal part; 4-negative terminal part; 5-first exterior part; 5a-opening part; 5b-flange part; 5c-bottom surface; 5d-inclined surface; 6 -Second exterior part; 7-Positive electrode; 7a-Positive electrode collector tab; 8-Negative electrode; 8a-Negative electrode collector tab; 12-Positive lead on electrode group side; Through holes in the exterior part; 16, 31-

17-positive external terminal; 18a-positive insulating part; 18b-positive reinforcing part; 19, 34-insulating gasket; 20-positive terminal insulating part; 21-head; 23-positive terminal lead; 24-first positive insulation reinforcement member; 25-second positive insulation reinforcement member; 26-insulation film; 32-negative external terminal; 33a-negative insulation member; 33b-negative reinforcement member; 35-negative terminal insulation member; 36- Negative terminal lead; 37-first negative insulation reinforcement member; 38-second negative insulation reinforcement member; 39-guide hole; 40, 41, 43-welding part; 42-cut out part; 60-first unit cell; 61 - second unit cell; 62 - conductive connection member; 63, 65 - unit of battery pack; 64 - bus bar; 100 to 104 - battery; 200, 201 - battery pack; ;302-inverter;303-external AC power supply;304-

Load; 400-vehicle; 401-body; 402-motor; 403-wheel; 404-control unit; 500-flying body; 501-framework; 502-motor; 503-rotary wing;

Claims (9)

1. A battery, comprising:

the flat electrode group comprises a positive electrode, a positive electrode collector sheet electrically connected with the positive electrode, a negative electrode and a negative electrode collector sheet electrically connected with the negative electrode, wherein the positive electrode collector sheet wound into a flat shape is positioned on a first end face, and the negative electrode collector sheet wound into a flat shape is positioned on a second end face;

an insulating film that winds the 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;

an exterior member including a first metal exterior part having a flange portion at an opening portion and a second metal exterior part, the electrode group being housed in a space formed by welding the flange portion of the first exterior part and the second exterior part;

a positive terminal portion having a through hole on the positive electrode collector tab side, the positive terminal portion including: a positive electrode external terminal including a head portion and a shaft portion extending from the head portion; and a positive electrode terminal lead having a through hole, the head portion protruding outward of the first exterior portion, the shaft portion being inserted into the through hole of the positive electrode terminal lead, and the shaft portion being fixed to the first exterior portion and the positive electrode terminal lead by caulking;

a negative electrode terminal portion having a through hole on the negative electrode collector tab side, the negative electrode terminal portion including: a negative external terminal including a head portion and a shaft portion extending from the head portion; and a negative electrode terminal lead having a through hole, the head portion protruding outward of the first exterior portion, the shaft portion being inserted into the through hole of the negative electrode terminal lead, and the shaft portion being fixed to the first exterior portion and the negative electrode terminal lead by caulking;

a first positive electrode insulation reinforcing member;

a second positive electrode insulation reinforcing member;

a first negative electrode insulation reinforcing member; and

a second negative electrode insulation reinforcing member for reinforcing the negative electrode,

the first positive electrode insulation reinforcing member is disposed on an inner surface side of the first exterior portion between the positive electrode terminal lead and the first exterior portion,

the second positive electrode insulation reinforcing member is disposed on an inner surface side of the first exterior portion and an inner surface side of the second exterior portion,

the first negative electrode insulation reinforcing member is disposed on the inner surface side of the first exterior portion between the negative electrode terminal lead and the first exterior portion,

the second negative electrode insulation reinforcing member is disposed on an inner surface side of the first exterior portion and an inner surface side of the second exterior portion,

the insulating films are disposed between the electrode group and the first exterior part, between the electrode group and the second exterior member, between the positive electrode collector tab and the first positive electrode insulation reinforcing member, between the positive electrode collector tab and the second positive electrode insulation reinforcing member, between the negative electrode collector tab and the first negative electrode insulation reinforcing member, and between the negative electrode collector tab and the second negative electrode insulation reinforcing member.

2. The battery according to claim 1,

the positive terminal portion further includes a through-hole positive insulating member and a positive reinforcing member having a through-hole,

the positive electrode external terminal is also inserted into the through hole of the positive electrode insulating member and the through hole of the positive electrode reinforcing member,

an inner edge burring part is provided on a peripheral part of the through hole on the positive electrode collector side of the first exterior member toward the inside of the exterior member,

the positive electrode reinforcing member is disposed between the first exterior part and the positive electrode insulating member,

the positive electrode reinforcing member is sandwiched by the inner edge flange portion of the first exterior part and the positive electrode insulating member,

the negative terminal portion further includes a through-hole negative insulation member, and a negative reinforcement member having a through-hole,

the negative electrode external terminal is also inserted into the through hole of the negative electrode insulating member and the through hole of the negative electrode reinforcing member,

an inner edge burring part is provided on a peripheral part of the through hole on the negative electrode collector side of the first exterior member toward the inside of the exterior member,

the negative electrode reinforcing member is disposed between the first exterior portion and the negative electrode insulating member,

the negative electrode reinforcing member is sandwiched by the inner edge flange portion of the first exterior portion and the negative electrode insulating member.

3. The battery according to claim 2,

the first positive electrode insulation reinforcing member has a through hole,

the positive electrode insulating member, the positive electrode reinforcing member, and the positive electrode external terminal are disposed in the through hole of the first positive electrode insulating and reinforcing member,

the first negative electrode insulation reinforcing member has a through hole,

the negative electrode insulating member, the negative electrode reinforcing member, and the negative electrode external terminal are disposed in the through hole of the first negative electrode insulating reinforcing member.

4. The battery according to any one of claims 1 to 3,

the first positive electrode insulation reinforcing member and the second positive electrode insulation reinforcing member are fitted and connected to each other on the opposite side of the positive electrode current collector side,

the first negative electrode insulation reinforcing member and the second negative electrode insulation reinforcing member are fitted and connected to each other on the side opposite to the negative electrode current collector.

5. The battery according to claim 4,

the fitting of the first positive electrode insulation reinforcing member and the second positive electrode insulation reinforcing member is performed by a combination of a concave portion and a convex portion,

the first negative electrode insulation reinforcing member and the second negative electrode insulation reinforcing member are fitted to each other by a combination of a concave portion and a convex portion.

6. A battery pack comprising one or more cells of claims 1 to 5.

7. An electricity storage device comprising the battery according to claims 1 to 5 or the battery pack according to claim 6.

8. A vehicle comprising the battery of claims 1 to 5 or the battery pack of claim 6.

9. A flying body comprising the battery of claims 1 to 5 or the battery pack of claim 6.

Images