JPWO2019186849A1 - Batteries, battery packs, power storage devices, vehicles and flying objects - Google Patents

Abstract

The problem to be solved by the present invention is to provide a battery, a battery pack, a power storage device, a vehicle, and a flying object having a lead shape excellent in high current characteristics in a thin battery. The battery of the embodiment includes a positive electrode, a positive electrode current collecting tab electrically connected to the positive electrode, a negative electrode, and a negative electrode current collecting tab electrically connected to the negative electrode, and the positive electrode is wound in a flat shape. A flat electrode group in which the tab is located on the first end surface and the negative electrode current collecting tab wound in a flat shape is located on the second end surface, and a positive electrode group side positive electrode electrically connected to the positive electrode current collecting tab. A flange of the first exterior portion including a lead, a negative electrode group-side negative electrode lead electrically connected to the negative electrode current collecting tab, a first exterior portion having a flange portion at the opening, and a second exterior portion. It includes an exterior member in which an electrode group is housed in a space formed by welding a portion and a second exterior portion, a positive electrode terminal portion, and a negative electrode terminal portion.

Description

Embodiments of the present invention relate to batteries, battery packs, power storage devices, vehicles and flying objects.

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 for accommodating the electrode group.

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

Inside the exterior member, the battery element and the electrode terminal are joined by a lead. It is difficult to bend the joint after joining because the work space and the accommodation space are narrow. Further, if the thickness is set so that it can be bent after joining, the lead becomes thin and is not suitable for a large current. Further, if the welded portion is bent after the reed is welded, the joint portion is easily peeled off, and from the viewpoint of quality, a battery that is not bent after joining is desired.

International Publication No. 2016/20147

The problem to be solved by the present invention is to provide a battery, a battery pack, a power storage device, a vehicle, and a flying object having a lead shape excellent in high current characteristics in a thin battery.

The battery of the embodiment includes a positive electrode, a positive electrode current collecting tab electrically connected to the positive electrode, a negative electrode, and a negative electrode current collecting tab electrically connected to the negative electrode, and is wound into a flat positive electrode. A flat electrode group in which the tab is located on the first end surface and a negative electrode current collecting tab wound in a flat shape is located on the second end surface, and a positive electrode group side positive electrode electrically connected to the positive electrode current collecting tab. A flange of the first exterior portion including a lead, a negative electrode group-side negative electrode lead electrically connected to the negative electrode current collecting tab, a first exterior portion having a flange portion at the opening, and a second exterior portion. The exterior member in which the electrode group is housed in the space formed by welding the portion and the second exterior portion, and the first exterior portion has a through hole on the positive electrode current collecting tab side, and the head and the head The shaft includes a positive electrode external terminal including a shaft portion extending from the shaft portion and a positive electrode terminal lead having a through hole, the head projecting to the outside of the first exterior portion, and the shaft portion being inserted into the through hole of the positive electrode terminal lead. The positive electrode terminal portion whose portion is caulked and fixed to the first exterior portion and the positive electrode terminal lead, and the first exterior portion have a through hole on the negative electrode current collecting tab side, and the head portion and the shaft portion extending from the head portion. The negative electrode external terminal including the negative electrode and the negative electrode terminal lead having a through hole are included, the head portion protrudes to the outside of the first exterior portion, the shaft portion is inserted into the through hole of the negative electrode terminal lead, and the shaft portion is the first exterior portion. The negative electrode terminal portion and the negative electrode terminal portion crimped to the negative electrode terminal lead are included. The positive electrode terminal lead has a first extending portion extending toward the second exterior portion side. The electrode group side positive electrode lead has a first extending portion of the electrode group side positive electrode lead on the side opposite to the electrode group side. The first extension portion of the positive electrode terminal lead and the first extension portion of the positive electrode group side positive electrode lead are welded. The tips of the first extension of the welded positive electrode terminal lead and the first extension of the electrode group side positive electrode lead are relative to the surface of the second exterior that is parallel to the opening of the first exterior. Vertical or nearly vertical. The negative electrode terminal lead has a first extending portion extending toward the second exterior portion side. The electrode group side negative electrode lead has a first extending portion of the electrode group side negative electrode lead on the side opposite to the electrode group side. The first extension portion of the negative electrode terminal lead and the first extension portion of the negative electrode group side negative electrode lead are welded. The tips of the first extension of the welded negative electrode terminal lead and the first extension of the electrode group side negative electrode lead are relative to the surface of the second exterior that is parallel to the opening of the first exterior. Vertical or nearly vertical.

FIG. 1 is a schematic perspective view of the battery of the first embodiment. FIG. 2A is an exploded perspective view of the battery shown in FIG. 1 as viewed from the positive electrode side. FIG. 2B is an exploded perspective view of the battery shown in FIG. 1 as viewed from the negative electrode side. FIG. 3 is a perspective view of the electrode group of the battery shown in FIG. FIG. 4 is a perspective view showing a state in which 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 long side direction of the battery. FIG. 6 is a cross-sectional view obtained when the negative electrode portion of FIG. 1 is cut along the long side direction of the battery. FIG. 7 is a perspective view showing a battery in which the terminal portion is fixed to the first exterior portion of the battery shown in FIG. 8 (a) is a plan view of the second exterior portion, and FIG. 8 (b) is a plan view of the first exterior portion. 9 (a), (b), (c), and (d) are three views showing the manufacturing process of the battery of the first embodiment. FIG. 10A is a process diagram showing an assembly process of a battery containing a plurality of electrode groups. FIG. 10B is a process diagram showing a process of assembling a battery containing a plurality of electrode groups. FIG. 10C is a process diagram showing a process of assembling a battery containing a plurality of electrode groups. FIG. 10D is a process diagram showing a process of assembling a battery containing a plurality of electrode groups. FIG. 11A is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the long side direction of the battery. FIG. 11B is a cross-sectional view obtained when the negative electrode portion of FIG. 1 in the modified example is cut along the long side direction of the battery. FIG. 12 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the longitudinal direction of the battery. FIG. 13A is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the long side direction of the battery. FIG. 13B is a cross-sectional view obtained when the negative electrode portion of FIG. 1 in the modified example is cut along the long side direction of the battery. FIG. 14 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the longitudinal direction of the battery. FIG. 15A is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the long side direction of the battery. FIG. 15B is a cross-sectional view obtained when the negative electrode portion of FIG. 1 in the modified example is cut along the long side direction of the battery. FIG. 16 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the longitudinal direction of the battery. FIG. 17 is a cross-sectional view obtained when the positive electrode portion of FIG. 1 in the modified example is cut along the longitudinal direction of the battery. FIG. 18 is a schematic view showing a first example of the battery pack according to the second embodiment. FIG. 19 is a schematic view showing a second example of the battery pack according to the second embodiment. FIG. 20 is a schematic view of the power storage device of the third embodiment. FIG. 21 is a schematic view of the vehicle of the fourth embodiment. FIG. 22 is a schematic view of the flying object of the fifth embodiment.

Hereinafter, embodiments will be described with reference to the drawings. In addition, the same reference numerals are given to common configurations throughout the embodiment, and duplicate description will be omitted. In addition, each figure is a schematic view for explaining the embodiment and promoting its understanding, and the shape, dimensions, ratio, etc. of the figure are different from those of the actual device, but these are described below and known techniques. The design can be changed as appropriate by taking into consideration.

[First Embodiment]
The battery of the first embodiment will be described with reference to FIGS. 1 to 15. A part of the drawing is a perspective view or a developed view, and some members and parts are not shown. However, since the positive electrode and the negative electrode are symmetrically configured, the part of one electrode not shown is the other electrode. It is clarified from the structure of. In the embodiment, it is allowed that the positive electrode and the negative electrode are asymmetrically configured.

The battery 100 shown in FIG. 1 includes an exterior member 1, an electrode group 2, a positive electrode terminal portion 3, a negative electrode terminal portion 4, and an electrolyte (not shown). The battery 100 shown in FIG. 1 is, for example, a secondary battery. The battery 100 of the embodiment is thin. The thickness of the thin battery 100 is 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 first exterior portion 5 is a square cylinder container with a bottom, and has a flange portion 5b in the opening 5a. In the exterior member 1, the electrode group 2 is housed in a space formed by welding the flange portion of the first exterior portion 5 and the second exterior portion 6. Note that FIG. 2A is an exploded perspective view of the battery shown in FIG. 1 as viewed from the positive electrode side. 2B is an exploded perspective view of the battery shown in FIG. 1 as viewed from the negative electrode side.

As shown in FIGS. 1, 2 and 5, a recess 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 recess is an inclined surface. It is 5d. The second exterior portion 5 has a depth equal to or less than the size of the opening 5a (the maximum length of the portion that becomes the opening area). The more preferable second exterior portion 5 has a depth equal to or less than the short side of the portion to be the opening area (for example, the one shown in FIG. 2). The first exterior portion 5 is, for example, a stainless steel cup-shaped container having an opening made from a stainless steel plate by shallow drawing. On the other hand, the second exterior portion 6 is a stainless steel lid. The second exterior portion 6 covers the opening of the second exterior portion 5. Similar to the second exterior portion 5, the second exterior portion 6 may be a stainless steel cup-shaped container or a plate-shaped container made by shallow drawing. The electrode group 2 is housed in a space formed by welding the flange portion 5b of the first exterior portion 5 to the four sides of the second exterior portion 6. For welding, for example, resistance seam welding is used. Resistive seam welding can achieve high airtightness and heat resistance at a lower cost than laser welding.

Since it is a thin battery, the space in which the electrode group 2 is housed is a space having a low height. The height of the space in which one electrode group 2 is accommodated is the number of electrode groups 2 accommodated in the exterior member 1 and arranged in the height direction, from the bottom of the first exterior portion 5 to the second exterior portion. It is the value obtained by dividing the distance to 6. Since the battery is thin, the height of the space in which each 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 space having a low height, the shape of the reed is limited.

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

The positive electrode 7 includes, for example, a strip-shaped positive electrode current collector made of foil, a positive electrode current collector tab 7a having one end parallel to the long side of the positive electrode current collector, and a positive electrode collector except at least a portion of the positive electrode current collector tab 7a. The positive electrode material layer (positive electrode active material-containing layer) 7b formed on the electric body is included.

On the other hand, the negative electrode 8 excludes, for example, a strip-shaped negative electrode current collector made of foil, a negative electrode current collector tab 8a having one end parallel to the long side of the negative electrode current collector, and at least a portion of the negative electrode current collector tab 8a. The negative electrode material layer (negative electrode active material-containing layer) 8b formed on the negative electrode current collector is included. In the electrode group 2, the positive electrode material layer 7b of the positive electrode 7 and the negative electrode material layer 8b of the negative electrode 8 face each other via the separator 9, and the positive electrode current collecting tab 7a is placed on one side of the winding shaft more than the negative electrode 8 and the separator 9. The positive electrode 7, the separator 9 and the negative electrode 8 are wound in a flat shape so as to protrude and the negative electrode current collecting 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 collecting tab 7a wound in a flat spiral shape is located on the first end surface perpendicular to the winding axis.

Further, the negative electrode current collecting tab 8a wound in a flat spiral shape is located on the second end surface perpendicular to the winding axis. The insulating sheet 10 covers the outermost periphery of the electrode group 2 between the positive electrode current collecting tab 7a and the negative electrode current collecting tab 8a. The insulating sheet 10 covers the outermost periphery of the electrode group 2 except for the positive electrode current collecting tab 7a and the negative electrode current collecting tab 8a. The electrode group 2 holds an electrolyte (not shown).

The backup positive electrode lead 11 is obtained by bending a conductive plate into a U shape, and sandwiches the layers of the positive electrode current collecting tabs 7a from each other with a portion (near the center) excluding the curved portions at both ends of the positive electrode current collecting tab 7a. It is in close contact. The electrode group side positive electrode lead 12 is a conductive plate having a larger area than the backup positive electrode lead 11. As shown in FIG. 5, the electrode group side positive electrode lead 12 has a first extending portion 12a on the side opposite to the electrode group 2 side. The electrode group side positive electrode lead 12 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 collecting tab 7a and the electrode group side positive electrode lead 12. Further, the positive electrode current collecting tab 7a is electrically connected to the positive electrode group side positive electrode lead 12. The first extension portion 12a of the electrode group side positive electrode lead 12 is arranged closer to the electrode group 2 side than the first extension portion 23b of the positive electrode terminal lead 23.

The positive electrode current collecting tab 7a, the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are integrated by welding, whereby the positive electrode 7 is integrated with the electrode group side positive electrode lead 12 via the positive electrode current collecting tab 7a and the backup positive electrode lead 11. It is electrically connected. Welding of the positive electrode current collecting 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, it is preferable that the positive electrode current collecting tab 7a and the electrode side positive electrode lead 12 are welded.

The backup negative electrode lead 13 is obtained by bending a conductive plate into a U shape, and sandwiches the layers of the negative electrode current collecting tabs 8a from each other with the portions (near the center) excluding the curved portions at both ends of the negative electrode current collecting tab 8a. It is in close contact. The electrode group side negative electrode lead 14 is a conductive plate having a larger area than the backup negative electrode lead 13. As shown in FIG. 6, the electrode group side negative electrode lead 14 has a first extending portion 14a on the side opposite to the electrode group 2 side. The first extending portion 14a of the electrode group side negative electrode lead 14 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 collecting tab 8a and the electrode group side negative electrode lead 14. Further, the negative electrode current collecting tab 8a is electrically connected to the negative electrode group side negative electrode lead 14. The first extension portion 14a of the electrode group side negative electrode lead 14 is arranged closer to the electrode group 2 side than the first extension portion 36b of the negative electrode terminal lead 36.

The negative electrode current collecting tab 8a, the backup negative electrode lead 13, and the electrode group side negative electrode lead 14 are integrated by welding, whereby the negative electrode 8 becomes the electrode group side negative electrode lead 14 via the positive electrode current collecting tab 8a and the backup negative electrode lead 13. It is electrically connected. Welding of the negative electrode current collecting tab 8a and the backup negative electrode lead 13 is performed by, for example, laser welding or ultrasonic welding. 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, and a positive electrode reinforcing member ( A ring-shaped member) 18b, an insulating gasket 19, and a positive electrode terminal insulating member 20 are included.

In the positive electrode terminal portion 3, the first exterior portion 5 has a through hole 15 on the positive electrode current collecting tab side. The positive electrode external terminal 17 of the positive electrode terminal portion 3 includes a head portion 21 and a shaft portion extending from the head portion 21. The positive electrode terminal portion 3 includes a positive electrode terminal lead 23 having a through hole 23a. In the positive electrode terminal portion 3, the head portion 21 protrudes to the outside of the first exterior portion 5, the shaft portion is inserted into the through hole 23a of the positive electrode terminal lead 23, and the shaft portion is the first exterior portion 5 and the positive electrode terminal lead. It is fixed to 23 by caulking.

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

As shown in FIG. 5, the positive electrode external terminal 17 includes a pyramidal trapezoidal head 21 and a columnar shaft portion penetrating through a through hole 15 of the second exterior portion 5. The columnar shaft portion extends from a plane parallel to the top surface of the head 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 18a insulates the second exterior portion 5 from the positive electrode external terminal 17 and the positive electrode terminal lead 23. The positive electrode reinforcing member 18b is sandwiched between the second exterior portion 5 and the positive electrode insulating member 18a.

The positive electrode reinforcing member 18b is made of, for example, a circular ring made of a material having a higher rigidity than a gasket. Examples of materials that are more rigid than gaskets are stainless steel, iron plated (eg Ni, NiCr, etc.), ceramics, resins that can have higher rigidity than gaskets (eg polyphenylene sulfide (PPS), poly). Butylene terephthalate (PBT)) and the like are included. 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. Further, when the positive electrode reinforcing member 18b is formed of an insulating material such as resin or ceramics, it can be integrated with the positive electrode terminal insulating reinforcing member 24.

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

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 electrode terminal insulating member 20 is arranged on the outer surface of the first exterior portion 5. The flange portion 19a of the insulating gasket 19 is inserted into the through hole 20a of the positive electrode terminal insulating member 20.

The positive electrode terminal portion 3 further includes a positive electrode terminal lead 23. The positive electrode terminal lead 23 is a conductive plate having a through hole 23a and a first extending portion 23b extending toward the opening side of the second exterior portion 5, that is, the second exterior portion 6 side. In FIG. 5, the positive electrode terminal lead 23 has a first extending portion 23b extending to the electrode group 2 side. The first extending portion 23b of the positive electrode terminal lead 23 is integrated with the first extending portion 12a of the positive electrode group side positive electrode lead 12 by welding. The opposing surfaces of the first extension 23b and the first extension 12a are welded together, and the end face of the first extension 23b and the end surface of the first extension 12a on the distal end side are also welded. It is welded. At least the tip portion of the first extending portion 23b of the positive electrode terminal lead 23 and the first extending portion 12a of the electrode group side positive electrode lead 12 is perpendicular to or substantially perpendicular to the surface of the second exterior portion 6 (80). ° or more and 100 ° or less). At least the tip portion of the first extension portion 23b of the positive electrode terminal lead 23 and the first extension portion 12a of the electrode group side positive electrode lead 12 is perpendicular to or substantially perpendicular to the surface of the second exterior portion 6. Indicates that the lead was created without bending after welding the first extending portion 23b of the positive electrode terminal lead 23 and the first extending portion 12a of the positive electrode group side positive electrode lead 12. There is an advantage that the wiring of the terminal portion of the electrode can be made compact by bending the lead after welding, but in order to perform bending after welding with high accuracy, it is required to reduce the thickness of the lead. However, it is not preferable to reduce the thickness of the reed because it is difficult for a large current to flow. The thickness of the reed can be increased by making the welded portion face the surface of the second exterior portion 6.

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

The positive electrode terminal portion 3 further includes a first positive electrode insulating reinforcing member 24. As shown in FIGS. 2 and 5, the first positive electrode insulating reinforcing member 24 includes a main body portion 24a having a structure in which a bottomed rectangular cylinder is divided in half in the long side direction, and a circular groove 24b formed in the main body portion 24a. , Has a through hole 24c opened in the center of the circular groove 24b. The first positive electrode terminal insulating reinforcing member 24 has a corner portion in which the main body portion 24a is connected from the short side side wall of the first exterior portion 5 to the bottom surface, and the short side side wall to the long side side surface of the first exterior portion 5. Cover the corners that connect to. As a result, it is possible to reinforce the first exterior portion 5, particularly the vicinity of the corner where the short side side wall, the long side side wall, and the bottom portion intersect. A 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 electrode terminal lead 23 is arranged on the first positive electrode terminal insulating reinforcing member 24. The through hole 23a of the positive electrode terminal lead 23 communicates with the through hole 24c of the first positive electrode terminal insulating reinforcing member 24, the opening of the burring portion 16, and the through hole 15 of the first exterior portion 5.

As shown in FIG. 2, the second positive electrode insulating reinforcing member 25 has a structure in which a bottomed rectangular cylinder is divided in half in the long side direction. The second positive electrode insulating reinforcing member 25 covers about half of the positive electrode current collecting tab 7a from the winding center to the second exterior portion 6 side, thereby covering the second exterior portion 6, particularly near the short side. Can be reinforced.

The shaft portion of the positive electrode external terminal 17 includes an insulating gasket 19, a through hole 20a of the positive electrode terminal insulating member 20, a through hole 15 of the first exterior portion 5, a through hole 24c of the positive electrode terminal insulating reinforcing member 24, and a positive electrode terminal lead 23. After being inserted into the through hole 23a, plastic deformation is caused by caulking. As a result, these members are integrated, and the positive electrode external terminal 17 is electrically connected to the positive electrode terminal lead 23. Therefore, the positive electrode external terminal 17 also plays the role of a rivet. The boundary between the end surface of the shaft portion of the positive electrode external terminal 17 and the through hole 23a of the positive electrode terminal lead 23 may be welded by a laser or the like to provide a stronger connection and improve electrical conductivity.

As shown in FIGS. 2 and 6, the negative electrode terminal portion 4 includes a through hole 30 opened in the inclined surface 5d of the first exterior portion 5, a negative electrode external terminal 32, a negative electrode insulating member 33a, and a negative electrode reinforcing member ( A ring-shaped member) 33b, an insulating gasket 34, and a negative electrode terminal insulating member 35 are included.

In the negative electrode terminal portion 4, the first exterior portion 5 has a through hole 30 on the negative electrode current collecting tab 8a side. 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 electrode terminal portion 4, the head portion 21 protrudes to the outside of the first exterior portion 5, the shaft portion is inserted into the through hole 36a of the negative electrode terminal lead 36, and the shaft portion is the first exterior portion 5 and the negative electrode terminal lead. It is fixed to 36 by caulking.

As shown in FIG. 6, the burring portion (annular rising portion) 31 extends from the peripheral edge portion of the through hole 31 toward the inside of the exterior member 1, and is formed by burring.

As shown in FIG. 6, the negative electrode external terminal 32 includes a pyramidal trapezoidal head 21 and a columnar shaft portion penetrating the through hole 30 of the second exterior portion 5. The columnar shaft portion extends from a plane parallel to the top surface of the head 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 33a insulates the second exterior portion 5 from the negative electrode external terminal 32 and the negative electrode terminal lead 36.
The negative electrode reinforcing member 33b is sandwiched between the second exterior portion 5 and the negative electrode insulating member 33a.

The negative electrode reinforcing member 33b is made of, for example, a circular ring made of a material having a higher rigidity than a gasket. Examples of materials that are more rigid than gaskets are stainless steel, iron plated (eg Ni, NiCr, etc.), ceramics, resins that can have higher rigidity than gaskets (eg polyphenylene sulfide (PPS), poly). Butylene terephthalate (PBT)) and the like are included. As shown in FIG. 6, 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. Further, when the negative electrode reinforcing member 33b is formed of an insulating material such as resin or ceramics, it can be integrated with the terminal insulating reinforcing member 37.

The insulating gasket 34 is a cylindrical body (cylinder portion) having a flange portion at one open end. As shown in FIGS. 2 and 6, the insulating gasket 34 has a cylindrical portion inserted into the through hole 30 and the burring portion 31, and the flange portion is the outer circumference of the through hole 30 on the outer surface of the first exterior portion 5. It is located in. The insulating gasket 34 is a resin such as a fluororesin, a fluororubber, a polyphenylene sulfide resin (PPS resin), a polyetheretherketone resin (PEEK resin), a polypropylene resin (PP resin), and a polybutylene terephthalate resin (PBT resin). Is formed from.

As shown in FIGS. 2 and 6, the negative electrode terminal insulating member (third negative electrode insulating member) 35 is a plate-shaped member bent at an obtuse angle and has a through hole at the bottom. The negative electrode terminal insulating member 35 is arranged on the outer surface of the first exterior portion 5. The flange portion of the insulating gasket 34 is inserted into the through hole of the negative electrode terminal insulating member 35.

The negative electrode terminal portion 4 further includes a negative electrode terminal lead 36 (first negative electrode lead). The negative electrode terminal lead 36 is a conductive plate having a through hole 36a and a first extending portion 36b extending toward the opening side 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 extending portion 36b extending to the electrode group 2 side. The first extension portion 36b of the negative electrode terminal lead 36 is integrated with the first extension portion 14a of the electrode group side negative electrode lead 14 by welding. The facing surfaces of the first extension portion 36b and the first extension portion 14a are welded to each other, and the end face of the first extension portion 36b on the distal end side and the end surface of the first extension portion 14a are also welded. It is welded. At least the tip portion of the first extending portion 36b of the negative electrode terminal lead 36 and the first extending portion 14a of the electrode group side negative electrode lead 14 is perpendicular to or substantially perpendicular to the surface of the second exterior portion 6 (80). ° or more and 100 ° or less). At least the tip portion 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 is perpendicular to or substantially perpendicular to the surface of the second exterior portion 6. Indicates that the lead was created without bending after welding 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. There is an advantage that the wiring of the terminal portion of the electrode can be made compact by bending the lead after welding, but in order to perform bending after welding with high accuracy, it is required to reduce the thickness of the lead. However, it is not preferable to reduce the thickness of the reed because it is difficult for a large current to flow. The thickness of the reed can be increased by making the welded portion face the surface of the second exterior portion 6.

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

The negative electrode terminal portion 4 further includes a first negative electrode terminal insulating reinforcing member 37. As shown in FIG. 2, the first negative electrode terminal insulating reinforcing member 37 has a main body portion 37a having a structure in which a bottomed rectangular cylinder is divided in half in the long side direction, a circular groove 37b formed in the main body portion 37a, and a circle. It has a through hole 37c opened in the center of the groove 37b. The first negative electrode terminal insulating reinforcing member 37 has a corner portion in which the main body portion 37a is connected from the short side side wall of the first exterior portion 5 to the bottom surface, and the short side side wall to the long side side surface of the first exterior portion 5. Cover the corners that connect to. As a result, it is possible to reinforce the first exterior portion 5, particularly the vicinity of the corner where the short side side wall, the long side side wall, and the bottom portion intersect. In the circular groove 37b, a negative electrode insulating member 33a arranged on the outer peripheral surface of the burring portion 31 is arranged. The through hole 37c communicates with the opening of the burring portion 31 and the through hole 30 of the first exterior portion 5. The negative electrode terminal lead 36 is arranged on the first negative electrode terminal insulation reinforcing member 37. The through hole 36a of the negative electrode terminal lead 36 communicates with the through hole 37c of the first negative electrode terminal insulating reinforcing member 37, the opening of the burring portion 31, and the through hole 30 of the first exterior portion 5.

As shown in FIG. 2, the second negative electrode insulating reinforcing member 38 has a structure in which a bottomed rectangular cylinder is divided in half in the long side direction. The second negative electrode insulating reinforcing member 38 covers about half of the negative electrode current collecting tab 8a from the winding center to the second exterior portion 6 side. As a result, the second exterior portion 6, particularly the vicinity of the short side, can be reinforced.

The shaft portion of the negative electrode external terminal 32 includes an insulating gasket 34, a through hole 35a of the negative electrode terminal insulating member 35, a through hole 30 of the first exterior portion 5, a through hole 37c of the first negative electrode terminal insulating reinforcing member 37, and a negative electrode terminal. After being inserted into the through hole 36a of the lead 36, plastic deformation is caused by caulking. As a result, as shown in FIGS. 2, 6 and 7, these members are integrated and the negative electrode external terminal 32 is electrically connected to the negative electrode terminal lead 36. Therefore, the negative electrode external terminal 36 also plays the role of a rivet. The boundary between the end surface of the shaft portion of the negative electrode external terminal 32 and the through hole 36a of the negative electrode terminal lead 36 may be welded by a laser or the like to provide a stronger connection and improve electrical conductivity.

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

The positive electrode insulating member 18a, the first positive electrode insulating reinforcing member 24, the second positive electrode insulating reinforcing member 25, the negative electrode insulating member 33a, the first negative electrode terminal insulating reinforcing member 37, and the second negative negative insulating reinforcing member 38 are, for example, Tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polypropylene (PP), polyethylene (PE), nylon, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), It is formed from a thermoplastic resin such as polyphenylene terephide (PPS) and polyetheretherketone (PEEK).

The electrode group 2 is housed in the first exterior portion 5 so that the first end surface 7a faces the positive electrode terminal portion 3 and the second end surface 8a faces the negative electrode terminal portion 4. Therefore, the plane intersecting the first end surface 7a and the second end surface 8a of the electrode group 2 faces the bottom surface 5c in the first exterior portion 5, and the curved surface intersecting the first end surface 7a and the second end surface 8a is the first. It faces the long side side surface in the exterior portion 5.

In the corner portion connecting the short side wall surface and the bottom portion of the first exterior portion 5, there are gaps between the first end surface 7a and the second end surface 8a of the electrode group 2. By providing an inwardly projecting recess in the corner portion connecting the short side wall surface and the bottom of the first exterior portion 5 and making the bottom of the recess a inclined surface 5d, the dead space in the first exterior portion 5 is reduced. Therefore, it is possible to increase the volumetric energy density of the battery. Further, by arranging the positive electrode terminal portion 3 and the negative electrode terminal portion 4 on each of the inclined surfaces 5d, the terminal portions are installed as compared with the case where the positive electrode terminal portion 3 and the negative electrode terminal portion 4 are provided on the short side side surfaces having no inclined surface. The area can be increased. Therefore, the diameters 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, so that a large current (high rate current) can flow with low resistance.

As a result of the electrode group 2 being housed in the first exterior portion 5, a bottomed rectangular tubular shape formed by contacting the lower end of the second positive electrode insulating reinforcing member 25 with the upper end of the first positive electrode insulating reinforcing member 24. The positive electrode current collecting tab 7a is covered with the cover of. Further, the negative electrode current collecting tab 8a is covered with a bottomed rectangular tubular 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 lid of the first exterior portion 5. The electrode group 2 is sealed in the exterior member 1 by welding the flange portion 5b of the first exterior portion 5 and the four sides of the second exterior portion 6.

The batteries shown in FIGS. 1 to 7 described above have electrodes in a space formed by welding a first stainless steel exterior portion having a flange portion at the opening and a second stainless steel exterior portion. It is preferable to include an exterior member in which the group is housed. Since the second exterior portion 5 and the second exterior portion 6 are made of stainless steel, high strength can be maintained even when the plate thickness of the first and second exterior portions is reduced. As a result, since the flexibility of the exterior member can be increased, the electrode group 2 can be easily restrained by vacuum sealing or applying a load from the outside of the exterior member 1. As a result, the distance between the electrodes of the electrode group 2 can be stabilized and the resistance can be lowered, and it becomes easy to realize a battery pack having vibration resistance and impact resistance. Further, if the second exterior portion 5 and the second exterior portion 6 have high flexibility, it becomes easy to shorten the distance from the inner surface of the first and second exterior portions to the electrode group, so that the heat dissipation of the battery is increased. Can improve sex.

The second exterior portion 5 and the second exterior portion 6 made of stainless steel are easy to weld and can be sealed by inexpensive resistance seam welding. Therefore, it is possible to realize an exterior member having a higher gas sealing property than a container made of a laminated film at a low cost. In addition, the heat resistance of the exterior member can be improved. For example, SUS304 has a melting point of 1400 ° C, whereas Al has a melting point of 650 ° C.

Further, as a result of caulking and fixing the shaft portion of the external terminal to the through hole, plastic deformation occurs. As a result, a force is applied in the radial direction of the insulating gasket, but since the burring portion is reinforced by the ring-shaped member arranged on the outside thereof, compressive stress is generated in the insulating gasket and the external terminal is connected to the first exterior portion 5. Can be connected with high strength. Even if the plate thickness of the first exterior portion 5, that is, the plate thickness of the burring portion is reduced, the burring portion can be reinforced by the ring-shaped member. Therefore, regardless of the plate thickness of the first exterior portion, the external terminal Can be connected to the first exterior portion 5 with high strength. Further, since the burring portion extends from the edge of the through hole toward the inside of the exterior member 1, it is possible to suppress liquid leakage when the internal pressure of the exterior member 1 rises due to gas generation or the like by the action of the external pressure. It becomes. Therefore, high reliability can be realized even when the plate thickness of the first exterior portion 5 and the second exterior portion 6 is reduced.

Therefore, according to the battery of the first embodiment, high strength and reliability can be obtained even when the plate thickness of the first exterior portion 5 and the second exterior portion 6 is reduced, so that the flexibility is increased. It is possible to provide a battery having excellent heat dissipation and high strength and reliability.

When the first exterior portion 5 has a depth equal to or less than the maximum length of the opening, the opening area of the first exterior portion 5 becomes large. The second exterior part is welded to the four sides of the first exterior part, but as the opening area increases, the length of one side to be welded becomes longer, so the three sides are welded first and the remaining one side It becomes easy to inject the electrolytic solution through the gap. Further, since the exterior member 1 can be temporarily sealed by providing a portion having a welding strength lower than the others, it is possible to eliminate the need for a part for temporary sealing (for example, a rubber stopper). Further, since the exterior member 1 has a flat shape, the heat dissipation of the battery can be improved.

The dead space in the first exterior portion 5 can be reduced by arranging the terminal portion on the inclined surface 5d so that the first exterior portion 5 includes the recess having the inclined surface 5d.

The inclined surface 5d is not limited to the one provided near the center of the short side of the exterior member 1, and may extend over the entire short side of the exterior member 1.

It is desirable to further include a second lead electrically connected to the positive electrode current collecting tab or the negative electrode current collecting tab, and to electrically connect the second lead to the first lead. This facilitates positioning during welding. Further, even if the positions of the first leads with respect to the positive electrode current collecting tab and the negative electrode current collecting tab are slightly deviated, a sufficient connection area can be secured, so that a low resistance battery can be realized.

One of the three surfaces is welded by having the first end surface of the external terminal having a quadrilateral top surface and first and second inclined surfaces connected to two opposite sides of the top surface. Welding direction can be changed by selecting the surface.

It is desirable that the plate thickness of the first exterior portion and the second exterior portion be in the range of 0.02 mm or more and 0.3 mm or less. Within this range, the contradictory properties of mechanical strength and flexibility can be compatible with each other. 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 (thickness) between the outer shell and the inner diameter of the positive electrode terminal portion 3, the negative electrode terminal portion 4 or both ring-shaped members is the same as or greater than the plate thickness of the first exterior portion 5. As a result, the external terminal can be connected to the first exterior portion with high strength regardless of the plate thickness of the first exterior portion. Specifically, the shortest wall thickness can be 0.1 mm or more.

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

As the second exterior portion 6, a flat plate as illustrated in FIGS. 5 and 6 can be used, but instead of the flat plate, a flat plate having a flange portion at the opening may be used. Examples of such a structure include those similar to the first exterior portion 5.

The backup positive electrode lead 11 and the backup negative electrode lead 13 are not limited to the U-shaped conductive plate, and a conductive flat plate may be used. It is also possible to configure the configuration so that the backup positive electrode lead 11 and / or the backup negative electrode lead 13 are not used.

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

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

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

1) Positive electrode 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 tab. The positive electrode material layer can contain, for example, a positive electrode active material, a conductive agent, and a binder.

As the positive electrode active material, for example, an oxide or a sulfide can be used. Examples of oxides and sulfides include manganese dioxide (MnO ₂ ) that stores lithium, iron oxide, copper oxide, nickel oxide, lithium manganese composite oxides (eg Li _x Mn ₂ O ₄ or Li _x MnO ₂ ), lithium nickel composite oxides (e.g., Li _x NiO _2), lithium cobalt composite oxide (e.g., Li _x CoO _2), lithium nickel cobalt composite oxide (e.g., _{LiNi 1-y Co y O 2} ), lithium manganese cobalt composite oxide (For example, Li _x Mn _y Co _1-y O ₂ ), lithium manganese nickel composite oxide having a spinel structure (for example, Li _x Mn _2-y Ni _y O ₄ ), lithium phosphorus oxide having an olivine structure (for example, Li _{x) FePO 4, Li x Fe 1-} y Mn y PO 4, Li x CoPO 4), iron sulfate _{(Fe 2 (SO 4) 3} ), vanadium oxide (e.g. V ₂ O ₅₎ and lithium nickel-cobalt-manganese composite oxide Things can be mentioned. In the above equation, 0 <x ≦ 1 and 0 <y ≦ 1. As the active material, these compounds may be used alone, or a plurality of compounds may be used in combination.

The binder is compounded to bind the active material to the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and fluorine-based rubber.

The 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 conductive agents include carbonaceous materials such as acetylene black, carbon black and graphite.

In the positive electrode material layer, the positive electrode active material and the binder are preferably blended in a proportion of 80% by mass or more and 98% by mass or less and 2% by mass or more and 20% by mass or less, respectively.

Sufficient electrode strength can be obtained by adjusting the amount of the binder to 2% by mass or more. Further, by setting the content to 20% by mass or less, the blending amount of the insulating material for the electrode can be reduced and the internal resistance can be reduced.

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

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

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

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

As the negative electrode active material, for example, a metal oxide, a metal nitride, an alloy, carbon or the like capable of occluding and releasing lithium ions can be used. It is preferable to use a substance capable of occluding and releasing lithium ions at a noble potential of 0.4 V or more (against 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 fibers, spherical carbon, thermally decomposed vapor phase carbonaceous materials, fired resin bodies, etc.), chalcogen compounds (for example, titanium disulfide, etc.). Molybdenum disulfide, niobium selenium, etc.), light metals (eg, aluminum, aluminum alloys, magnesium alloys, lithium, lithium alloys, etc.), Li _{4 + x} Ti ₅ O ₁₂ (x is in the range of -1≤x≤3 due to charge / discharge reaction. Spinel type lithium titanate represented by), ramsteride type Li _{2 + x} Ti ₃ O ₇ (x changes in the range of -1≤x≤3 due to charge / discharge reaction), Ti and P, V, Sn , A metal composite oxide containing at least one element selected from the group consisting of Cu, Ni and Fe, and a niobium titanium composite oxide.

Examples of the metal composite oxide 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, TiO 2 -P 2 O} 5 -SnO 2, TiO 2 -P 2 O 5 -MO (M is at least one element selected from the group consisting of Cu, Ni and Fe) can be exemplified. These metal composite oxides are changed to lithium titanium composite oxides by inserting lithium by charging. It preferably contains one or more substances in the group consisting of lithium titanium oxide (eg, spinel-type lithium titanate), silicon and tin. The binder of the negative electrode active material layer is common to the binder of the positive electrode active material layer. The conductive agent of the negative electrode active material layer is common to the conductive agent of the positive electrode active material layer.

Examples of the niobium titanium-containing composite oxide include the general formula Li _a TiM _b Nb _{2 ± β} O _{7 ± σ} (where, the values of each subscript are 0 ≦ a ≦ 5, 0 ≦ b ≦ 0.3, 0 ≦. Within the range of β ≦ 0.3, 0 ≦ σ ≦ 0.3, and M is at least one selected from the group consisting of Fe, V, Mo, and Ta (one type or a plurality of types may be used). A composite oxide having a monoclinic crystal structure represented by), 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 in the range of 0≤a1≤6, 0 <b1 <2, 0 <c1 <6, 0 <d1 <6, -0.5≤σ1≤0.5, and is M (I). Is at least one type (may be one type or may be a plurality of types) selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs and K, and M (II) is Zr, Sn, V, At least one selected from the group consisting of Nb, Ta, Mo, W, Fe, Co, Mn and Al (which may be one or more) and is represented by Nb). A composite oxide having a square crystal structure can be used. In the above general formula Li _{2 + a1} M (I) _2-b1 Ti _6-c1 M (II) _d1 O _{14 + σ1} , the values of each subscript are 0 ≦ a1 ≦ 6, 0 <b1 <2, 0 <c1. Within the range of <6,0 <d1 <6, −0.5 ≦ σ1 ≦ 0.5, M (I) is at least selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs and K. One type (one type or a plurality of types), M (II) is Nb, or Nb and Zr, Sn, V, Ta, Mo, W, Fe, Co, Mn and It is preferably a combination with at least one type (may be one type or a plurality of types) selected from the group consisting of Al. In particular, a monoclinic niobium-titanium-containing composite oxide is more desirable because it has a large capacity per weight and can increase the battery capacity.

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

The binder is blended to fill the gaps between the dispersed negative electrode active materials and to bind the negative electrode active material and the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorinated rubber, and styrene butagen rubber.

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

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

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

For the negative electrode, for example, a negative electrode active material, a binder and a conductive agent are suspended in a general-purpose solvent to prepare a slurry, and this slurry is applied to a current collector and dried to form a negative electrode material layer. , Made by pressing. The negative electrode may also be manufactured by forming a negative electrode active material, a binder, and a conductive agent in the form of pellets to form a negative electrode material layer, which is arranged on a current collector.

3) Separator A porous, thin, insulating thin film. The separator includes a non-woven fabric, a film, paper, an inorganic particle layer, and the like. Examples of the constituent materials of the separator include polyolefins such as polyethylene and polypropylene, cellulose, polyester, polyvinyl alcohol, polyimide, polyamide, polyamideimide, polytetrafluoroethylene and vinylon. An example of a separator preferable from the viewpoint of thinness and mechanical strength is a non-woven fabric containing cellulose fibers. 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 as the oxide particles. Carboxymethyl cellulose can be used as the thickener. As the binder, methyl acrylate, an acrylic copolymer containing the same, styrene-butadiene rubber (SBR), or the like can be used. As for the insulating sheet 10, a non-woven fabric, a film, or paper may be used as in the separator 9. It is preferable that the insulating sheet 10 is further fixed with a tape (not shown).

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

The electrolyte salts contained in the non-aqueous solution include, for example, LiPF ₆ , LiBF ₄ , Li (CF ₃ SO ₂ ) ₂ N (bistrifluoromethanesulfonylamide lithium; commonly known as LiTFSI), LiCF ₃ SO ₃ (commonly known as LiTFS), Li (C). _{2 F 5 SO 2) 2 N} ( bis pentafluoroethanesulfonyl amide lithium; called _{LiBETI), LiClO 4, LiAsF 6} , LiSbF 6, LiB (C 2 O 4) 2 ( bis oxa Lato lithium borate; called LiBOB), difluoro Lithium such as (trifluoro-2-oxide-2-trifluoro-methylpropionato (2-) -0.0), LiBF ₂ OCOC (CF ₃ ) ₂ (lithium borate; commonly known as LiBF ₂ (HHIB)) Salt can be used. These electrolyte salts may be used alone or in combination of two or more. In particular, LiPF ₆ and LiBF ₄ are preferable. As the lithium salt, a supporting salt that conducts ions can be used. Examples thereof include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate, and an imide-based supporting salt. The lithium salt may contain one kind or two or more kinds.

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

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

The electrolyte salts contained in the aqueous solution are LiCl, LiBr, LiOH, Li ₂ SO ₄ , LiNO ₃ , LiN (SO ₂ CF ₃ ) ₂ (lithium trifluoromethanesulfonylamide; commonly known as LiTFSA), LiN (SO ₂ C ₂ F _5). ) ₂ (Lithium bispentafluoroethanesulfonylamide; commonly known as LiBETA), LiN (SO ₂ F) ₂ (Lithium bisfluorosulfonylamide; commonly known as LiFSA), LiB [(OCO) ₂ ] _{2 and the} like. The type of lithium salt used can be one or more. Examples of the polymer material contained in the aqueous gel electrolyte include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), polymethacrylate and the like.

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

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

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

The method for manufacturing the battery of the first embodiment will be described below. 8 (a) to 8 (b) and 9 (a) to 9 (d) show a process diagram for manufacturing the battery.

An electrode group 2 with an insulating sheet 10 as illustrated in FIG. 3 is produced. Further, as illustrated in FIG. 7, a first exterior portion 5 to which the positive electrode terminal portion 3 and the negative electrode terminal portion 4 are fixed is manufactured. At least one positioning guide hole is opened in each of the first exterior portion 5 and the second exterior portion 6. An example thereof is shown in FIGS. 8 (a) and 8 (b). FIG. 8A shows an example in which guiding holes 39 for positioning are opened at the four corners of the second exterior portion 6. FIG. 8B shows an example in which guiding holes 39 for positioning are opened at the four corners of the first exterior portion 5.

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

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

Next, as shown in FIG. 9A, the three sides (for example, the long side and the short side) of the first exterior portion 5 and the second exterior portion 6 are welded. For welding, for example, resistance seam welding is used. The welded portion is indicated by reference numeral 40. It is desirable that the welded portion 40 is located inside the outer edges of the first exterior portion 5 and the second exterior portion 6.

After injecting the electrolytic solution through the opening on one side that has not been welded, this side is welded by, for example, resistance seam welding, as shown in FIG. 9B. It is desirable that the welded portion 41 be an outer edge portion of the first exterior portion 5 and the second exterior portion 6.

Next, after aging and initial charge / discharge, as shown in FIG. 9C, a part of the welded portion 41 is cut off to form a cut-out portion 42, and the gas in the exterior member is released. After that, as shown in FIG. 9D, the welded portion (long side of the second exterior portion 6) 43 further inside the welded portion 41 is welded by resistance seam welding or the like. It is desirable that this welding be performed in a reduced pressure atmosphere.

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

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

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

When a plurality of electrode groups are housed in one exterior member, the plurality of electrode groups can be connected in series or in parallel. 10A to 10D show a process diagram on the positive electrode side for manufacturing a battery form in which a plurality of (two) electrode groups are connected in parallel. FIG. 10D represents the created battery 101. A plurality of electrode groups 2 are prepared, and the central tip of the positive electrode current collecting tab 7a is bundled with the backup positive electrode lead 11. Next, the backup positive electrode lead 11 and the electrode group side positive electrode lead 12 are welded. After welding, the electrode group side positive electrode lead 12 is bent to form a first extending portion 12 as shown in FIG. 10B. The electrode-side positive electrode lead that has been bent in advance may be welded to the backup positive electrode lead 11 to obtain a member as shown in FIG. 10B.

Then, the member of FIG. 10B is inserted from the opening side of the first exterior material 5 in which the positive electrode terminal portion 3 is incorporated in advance. After insertion, the first extending portion 12a of the positive electrode group side positive electrode lead 12 and the first extending portion of the positive electrode terminal lead 23 are fixed by laser welding, and one electrode group 2 is formed as shown in FIG. 10C. It is fixed in the exterior portion 5 of 1. Similarly, another electrode group 2 is inserted into the first exterior portion 5, laser welded, and the second exterior portion 6 is covered to accommodate the plurality of electrode groups 2 shown in FIG. 10D. The battery 101 can be obtained. By changing the orientation of the electrodes of a plurality of electrode groups, a series connection can be made.

FIG. 11 shows a positive electrode portion (FIG. 11A) and a negative electrode portion (FIG. 11B) of the battery 102, which is a modification of the battery 100 of the first embodiment. The negative electrode portion shown in FIG. 11B is configured symmetrically with the positive electrode portion of FIG. 11A. In the batteries 102 of FIGS. 11A and 11B, the positive electrode terminal lead 23 has a second extending portion 23c, and the negative electrode terminal lead 36 has a second extending portion 36c. The second extending portions 23c and 36c physically contact and support the positive electrode current collecting tab 7a, the negative electrode current collecting tab 8a, the backup positive electrode lead 11, and the backup negative electrode lead 13. The backup positive electrode lead 11 sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a is sandwiched between the second extending portion 23c of the positive electrode terminal lead 23 and the electrode group side positive electrode lead 12. The second extending portion 23c of the positive electrode terminal lead 23 supports the side of the positive electrode current collecting tab 7a opposite to the side where the electrode group side positive electrode lead 12 exists. A backup negative electrode lead 13 sandwiching the negative electrode current collecting tab 8a or the negative electrode current collecting tab 8a is sandwiched between the second extending portion 36c of the negative electrode terminal lead 36 and the electrode group side negative electrode lead 14. The second extending portion 36c of the negative electrode terminal lead 36 supports the side of the negative electrode current collecting tab 8a opposite to the side where the electrode group side negative electrode lead 14 exists. The second extension portions 23c and 36c are not welded to the positive electrode current collecting tab 7a, the negative electrode current collecting tab 8a, the backup positive electrode lead 11, and the backup negative electrode lead 13. When the current collecting tab portion is supported by the second extending portions 23c and 36c, the structure is stabilized. It is also preferable in that the accuracy of positioning between leads is improved. It is preferable that the second extending portions 23c and 36c are provided at any of the central portion, both ends, and the whole of the positive electrode terminal lead 23 and the negative electrode terminal lead 36 from the viewpoint of positioning and stability. Therefore, such a modified example can provide a battery that is easy to manufacture, has excellent stability of the lead portion, and is suitable for a large current.

FIG. 12 shows a positive electrode portion of the battery 103, which is a modification of the battery 102 of the first embodiment. The negative electrode side is configured symmetrically with the positive electrode side and is not shown. The difference between the battery 103 and the battery 102 is that the back-up positive electrode lead 11 sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a and the second extending portion 23c of the positive electrode terminal lead 23 are the electrode group side positive electrode lead 12 The electrode group side positive electrode lead 12 is sandwiched between the backup negative electrode lead 13 sandwiching the negative electrode current collecting tab 8a or the negative electrode current collecting tab 8a and the second extending portion 36c of the negative electrode terminal lead 36. Is.
The second extension portions 23c and 36c are not welded to the positive electrode current collecting tab 7a, the negative electrode current collecting tab 8a, the backup positive electrode lead 11, and the backup negative electrode lead 13. When the current collecting tab portion is supported by the second extending portions 23c and 36c, the structure is stabilized. It is also preferable in that the accuracy of positioning between leads is improved. It is preferable that the second extending portions 23c and 36c are provided at any of the central portion, both ends, and the whole of the positive electrode terminal lead 23 and the negative electrode terminal lead 36 from the viewpoint of positioning and stability. Therefore, such a modified example can provide a battery that is easy to manufacture, has excellent stability of the lead portion, and is suitable for a large current.

FIG. 13A shows a positive electrode portion of the battery 104, which is a modification of the battery 100 of the first embodiment. FIG. 13B shows the negative electrode portion of the battery 103. The negative electrode portion of FIG. 13B is configured symmetrically with the positive electrode portion of FIG. 13A. In the batteries 103 of FIGS. 13A and 12B, the first extension portion 23b of the positive electrode terminal lead 23 and the first extension portion 12a of the positive electrode group side positive electrode lead 12 are fitted, and the first extension portion of the negative electrode terminal lead 36 is fitted. The portion 36b and the first extending portion 14a of the electrode group side negative electrode lead 14 are fitted. On the positive electrode side, the concave portion 12b of the positive electrode lead 12 on the electrode group side and the convex portion 23d of the positive electrode terminal lead 23 are fitted to facilitate positioning, strengthen the connection by welding, and improve the stability of the connection. doing. On the negative electrode side, the concave portion 14b of the negative electrode lead 14 on the electrode group side and the convex portion 36d of the negative electrode terminal lead 36 are fitted to facilitate positioning, strengthen the connection by welding, and improve the stability of the connection. doing. Therefore, such a modification can provide a battery having a more stable connection and suitable for a large current.

FIG. 14 shows a positive electrode portion of the battery 105, which is a modification of the battery 104 of the first embodiment. The negative electrode side is configured symmetrically with the positive electrode side and is not shown. In the battery 104, the electrode group side positive electrode lead 12 is arranged between the backup positive electrode lead 11 sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a and the second positive electrode insulating reinforcing member 25, but the battery 105. The difference is that the electrode group side positive electrode lead 12 is arranged between the backup positive electrode lead 11 sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a and the first positive electrode insulating reinforcing member 24. is there. The same applies to the negative electrode of the battery 105, and the electrode group side negative electrode lead 14 is arranged between the backup negative electrode lead 13 sandwiching the negative electrode current collecting tab 8a or the negative electrode current collecting tab 8a and the first negative electrode insulating reinforcing member 37. ing. Like the battery 104, the battery 105 is easier to position by fitting, and the connection by welding is stronger, and the stability of the connection is improved. Therefore, the battery 105 of such a modified example can provide a battery having a more stable connection and suitable for a large current.

FIG. 15A shows a positive electrode portion of the battery 106, which is a modification of the battery 100 of the first embodiment. FIG. 15B shows the negative electrode portion of the battery 106. The negative electrode portion of FIG. 15B is configured symmetrically with the positive electrode portion of FIG. 15A. In the batteries 104 of FIGS. 15A and 15B, the first extending portion 23b of the positive electrode terminal lead 23 extends to the side opposite to the electrode group 2 side, and the first extending portion 36b of the negative electrode terminal lead 36 is an electrode. It extends to the side opposite to the group 2 side. The backup positive electrode lead 11, the electrode group side positive electrode lead 12 and the positive electrode terminal lead 23 sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a are the backup positive electrodes sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a. The leads 11, the electrode group side positive electrode leads 12, and the positive electrode terminal leads 23 are arranged in this order. Further, the backup negative electrode lead 13 sandwiching the negative electrode current collecting tab 8a or the negative electrode current collecting tab 8a, the electrode group side negative electrode lead 14 and the negative electrode terminal lead 36 are backed up by sandwiching the negative electrode current collecting tab 8a or the negative electrode current collecting tab 8a. The negative electrode lead 13, the electrode group side negative electrode lead 14, and the negative electrode terminal lead 36 are arranged in this order. In the structures of FIGS. 15A and 15B, the wiring of the reed is more compact than that of FIGS. 5 and 6, but the thickness of the reed can be increased, so that a battery suitable for a large current can be provided.

FIG. 16 shows a positive electrode portion of the battery 107, which is a modification of the battery 106 of the first embodiment. The negative electrode side is configured symmetrically with the positive electrode side and is not shown. In the battery 107, the backup positive electrode lead 11, the electrode group side positive electrode lead 12, and the positive electrode terminal lead 23 sandwiching the positive electrode current collecting tab 7a or the positive electrode current collecting tab 7a are the electrode group side positive electrode lead 12, the positive electrode current collecting tab 7a, or The backup positive electrode lead 11 and the positive electrode terminal lead 23 sandwiching the positive electrode current collecting tab 7a are arranged in this order. Further, similarly to the positive electrode side, in the battery 107, the backup negative electrode lead 13 sandwiching the negative electrode current collecting tab 8a or the negative electrode current collecting tab 8a, the electrode group side negative electrode lead 14 and the negative electrode terminal lead 36 are the electrode group side negative electrode lead. 14. The negative electrode current collecting tab 8a or the backup negative electrode lead 13 sandwiching the negative electrode current collecting tab 8a and the negative electrode terminal lead 36 are arranged in this order. Similar to the structure shown in FIG. 15, the structure shown in FIG. 16 has more compact reed wiring than those in FIGS. 5 and 6, but the lead thickness can be increased, so that the battery is suitable for a large current. Can be provided.

FIG. 17 shows a positive electrode portion of the battery 108, which is a modification of the battery 106 of the first embodiment. The negative electrode side is configured symmetrically with the positive electrode side and is not shown. In the battery 106 of FIG. 15, the electrode group side positive electrode lead 12 and the positive electrode external terminal 17 are in direct contact with each other. Further, in the battery 107 of FIG. 16, the positive electrode current collecting tab 7a or the backup positive electrode lead 11 sandwiching the positive electrode current collecting tab 7a is in contact with the positive electrode external terminal 17. On the other hand, in the battery 108 of FIG. 17, the positive electrode external terminal 17 is not in direct contact with any of the positive electrode current collecting tab 7a, the backup positive electrode lead 11 sandwiching the positive electrode current collecting tab 7a, and the current collector side positive electrode lead 12. The negative electrode side is the same as the positive electrode side. Similar to the structure shown in FIG. 15, the structure shown in FIG. 17 has more compact reed wiring as compared with FIGS. 5 and 6, but the lead thickness can be increased, so that the battery is suitable for a large current. Can be provided.

The battery of the first embodiment described above can increase the thickness of the reed in the exterior member 1 even if it is a thin battery, and is suitable for a large current.

The terminal portion may be applied to both the positive electrode terminal portion and the negative electrode terminal portion, but it can also 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 batteries of the first embodiment. Examples of the assembled battery of the battery of the first embodiment are shown in FIGS. 18 and 19.

As shown in FIG. 18, the battery pack 200 uses the batteries 100 to 108 of the first embodiment as the unit cell. The battery pack 200 may be covered with a laminate (not shown). A triangular columnar conductive connecting member 62 is arranged between the top surface of the negative electrode external terminal 32 of the first unit cell 60 and the top surface of the negative electrode external terminal 32 of the second unit cell 61. Further, a triangular columnar conductive connecting member 62 is arranged between the top surface of the positive electrode 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 each electrically connected by welding. For welding, for example, laser welding, arc welding, and resistance welding are used. As a result, 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. A battery pack can be obtained by connecting the unit 63 of the assembled batteries in series by the bus bar 64.

The battery pack 201 shown in FIG. 19 uses the battery 100 of the first embodiment as a unit cell. The unit 65 of the assembled battery is formed by connecting the first unit cell 60 and the second unit cell 61 in series by using the conductive connecting member 62, and the unit 65 of the assembled battery is connected in series by the bus bar 64. Configure the battery pack with. The method of electrically connecting the first unit cell 60 and the second unit cell 61 by using the conductive connecting member 62 is the same as that described with reference to FIG.

In the assembled batteries shown in FIGS. 18 and 19, adjacent first unit cells 60 and second unit cells 61 are laminated so that the main surfaces of the exterior members 1 face each other. For example, in the battery unit 63 shown in FIG. 18, the main surface of the first exterior portion 5 of the first unit cell 60 and the main surface of the first exterior portion 5 of the second unit cell 61 face each other. ing. Further, in the adjacent assembled battery units 63, the main surface of the second exterior portion 6 of the second unit cell 61 of the one assembled battery unit 63 and the second unit cell of the other assembled battery unit 63. The main surface of the second exterior portion 6 of 61 faces. By stacking the batteries so that the main surfaces of the exterior members face each other in this way, the volumetric energy density of the assembled battery can be increased.

Further, as shown in FIGS. 18 and 19, it is desirable that there is an insulating space between the unit cell 60 and the unit cell 61, or between the units cells 60, 60 and the unit cells 61, 61, and 0.03 mm or more. Insulation members (for example, polypropylene, polyphenylene sulfide, epoxy, fine ceramics, alumina, zirconia, etc.) can be sandwiched between the two.

Since the positive electrode external terminal 17 and the negative electrode external terminal 32 have a pyramidal trapezoidal head, the unit is in one of two places (for example, the first and second inclined surfaces) of one head (first inclined surface). A bus bar can be connected to the external terminal of the cell and the other (second inclined surface). That is, one head can be connected in two directions. As a result, the path for electrically connecting the batteries can be shortened, so that a large current can be easily passed through the battery pack with low resistance.

Since the battery pack of the second embodiment contains at least one battery of the first embodiment, the battery pack can be made thinner and more flexible, has excellent reliability, and can reduce the manufacturing cost. Can be provided.
The battery pack is used, for example, as a power source for electronic devices and vehicles (railroad vehicles, automobiles, motorized bicycles, light vehicles, trolley buses, etc.).
As described above, the assembled battery may include a plurality of batteries connected in series, in parallel, or in combination of series and parallel and electrically connected. Further, the battery pack may include a circuit such as a battery control unit (Battery Control Unit, BMU) in addition to the assembled battery, but the battery control unit includes a circuit included in a battery (for example, a vehicle) on which the assembled battery is mounted. Can be used as. The battery control unit has a function of monitoring the voltage and / or both of a single battery and an assembled battery to prevent overcharging and overdischarging.

(Third Embodiment)
The third embodiment relates to a power storage device. The battery packs 200 and 201 of the second embodiment can be mounted on the power storage device 300. The power storage device 300 shown in the conceptual diagram of FIG. 20 includes battery packs 200 and 201, an inverter 302, and a converter 301. The external AC power supply 303 is DC-converted by the converter 301, the battery packs 200 and 201 are charged, AC-converted by the DC power supply inverter 302 from the battery packs 200 and 201, and electricity is supplied to the load 304 connected to the power storage device 300. It is configured to. By using the power storage device 300 having the present configuration having the battery packs 200 and 201 of the embodiment, a power storage device having excellent battery characteristics is provided. Batteries 100 to 104 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 according to the present embodiment will be briefly described with reference to the schematic diagram of the vehicle 400 of FIG. The vehicle 400 has battery packs 200 and 201, a vehicle body 401, a motor 402, wheels 403, and a control unit 404. The battery packs 200 and 201, the motor 402, the wheels 403, and the control unit 404 are arranged in the vehicle body 401. The control unit 404 converts the electric power output from the battery packs 200 and 201 and adjusts the output. The motor 402 uses the electric power output from the battery packs 200 and 201 to rotate the wheels 403. The vehicle 400 also includes an electric vehicle such as a train and a hybrid vehicle having another drive source such as an engine. The battery packs 200 and 201 may be charged by the regenerative energy from the motor 402. Those driven by the electric energy from the battery packs 200 and 201 are not limited to the motor, and may be used as a power source for operating the electric equipment included in the vehicle 400. Further, it is preferable to obtain regenerative energy when the vehicle 400 is decelerated and to charge the battery packs 200 and 201 using the obtained regenerative energy. By using the vehicle 400 having the present configuration having the battery packs 200 and 201 of the embodiment, a vehicle having excellent battery characteristics is provided. Batteries 100 to 104 can be used instead of the battery packs 200 and 201.

(Fifth Embodiment)
A fifth embodiment relates to a projectile (eg, a multicopter). The projectile of the fifth embodiment uses the battery packs 200 and 201 of the second embodiment. The configuration of the flying object according to the present embodiment will be briefly described with reference to the schematic diagram of the flying object (quadcopter) 500 of FIG. The projectile 500 includes battery packs 200 and 201, an airframe 501, a motor 502, rotor blades 503, and a control unit 504. The battery packs 200 and 201, the motor 502, the rotor blades 503, and the control unit 504 are arranged on the fuselage frame 501. The control unit 504 converts the electric power output from the battery packs 200 and 201 and adjusts the output. The motor 502 uses the electric power output from the battery packs 200 and 201 to rotate the rotor blades 503. By using the flying object 500 having the battery packs 200 and 201 of the present embodiment, the flying object having excellent battery characteristics can be provided. Batteries 100 to 104 can be used instead of the battery packs 200 and 201.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, 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 also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Exterior member, 2 ... Electrode group, 3 ... Positive electrode terminal, 4 ... Negative terminal, 5 ... First exterior, 5a ... Opening, 5b ... Flange, 5c ... Bottom, 5d ... Inclined surface, 6 ... 2nd exterior part, 7 ... positive electrode, 7a ... positive electrode current collecting tab, 8 ... negative electrode, 8a ... negative electrode current collecting tab, 12 ... electrode group side positive electrode lead, 14 ... electrode group side negative electrode lead, 15, 30 ... Through holes in the exterior portion of 1, 16, 31 ... Burling portion, 17 ... Positive electrode external terminal, 18a ... Positive electrode insulating member, 18b ... Positive electrode reinforcing member, 19, 34 ... Insulating gasket, 20 ... Positive electrode terminal insulating member, 21 ... Head Unit, 23 ... positive electrode terminal lead, 24 ... first positive electrode insulating reinforcing member, 25 ... second positive electrode insulating reinforcing member, 32 ... negative electrode external terminal, 33a ... negative electrode insulating member, 33b ... negative electrode reinforcing member, 35 ... negative electrode terminal Insulating member, 36 ... Negative electrode terminal lead, 37 ... First negative electrode insulating reinforcing member, 38 ... Second insulating reinforcing member, 39 ... Guide hole, 40, 41, 43 ... Welded part, 42 ... Cut part, 60 ... No. 1 unit cell, 61 ... 2nd unit cell, 62 ... conductive connecting member, 63, 65 ... assembled battery unit, 64 ... bus bar 100 to 108 ... battery, 200, 201 ... battery pack, 300 ... power storage device, 301 ... converter, 302 ... inverter, 303 ... external AC power supply, 304 ... load, 400 ... vehicle, 401 ... body, 402 ... motor, 403 ... wheels, 404 ... control unit, 500 ... flying object, 501 ... body skeleton, 502 ... motor, 503 ... rotary blade, 504 ... control unit

Claims (14)

The positive electrode current collecting tab including a positive electrode, a positive electrode current collecting tab electrically connected to the positive electrode, a negative electrode, and a negative electrode current collecting tab electrically connected to the negative electrode, and the positive electrode current collecting tab wound in a flat shape is the first. A group of flat-shaped electrodes located on one end surface and having the negative electrode current collecting tab wound in a flat shape located on the second end face.
The electrode group side positive electrode lead electrically connected to the positive electrode current collector tab,
The electrode group side negative electrode lead electrically connected to the negative electrode current collector tab,
In a space formed by welding the flange portion and the second exterior portion of the first exterior portion, which includes a first exterior portion having a flange portion in the opening portion and a second exterior portion. The exterior member in which the electrode group is housed and
The first exterior portion has a through hole on the positive electrode current collecting tab side, and includes a positive electrode external terminal including a head and a shaft portion extending from the head, and a positive electrode terminal lead having a through hole. The head protrudes to the outside of the first exterior portion, the shaft portion is inserted into the through hole of the positive electrode terminal lead, and the shaft portion is caulked and fixed to the first exterior portion and the positive electrode terminal lead. With the terminal part
The first exterior portion has a through hole on the negative electrode current collecting tab side, includes a head and a negative electrode external terminal including a shaft portion extending from the head, and a negative electrode terminal lead having a through hole. A negative electrode whose head protrudes to the outside of the first exterior portion, the shaft portion is inserted into a through hole of the negative electrode terminal lead, and the shaft portion is caulked and fixed to the first exterior portion and the negative electrode terminal lead. With the terminal part
Including
The positive electrode terminal lead has a first extending portion extending toward the second exterior portion side.
The electrode group side positive electrode lead has a first extending portion of the electrode group side positive electrode lead on the side opposite to the electrode group side.
The first extension portion of the positive electrode terminal lead and the first extension portion of the positive electrode group side positive electrode lead are welded together.
The tips of the first extension of the welded positive electrode terminal lead and the first extension of the electrode group side positive electrode lead are of a second exterior portion parallel to the opening of the first exterior portion. Vertical or nearly perpendicular to the surface,
The negative electrode terminal lead has a first extending portion extending toward the second exterior portion side.
The electrode group side negative electrode lead has a first extending portion of the electrode group side negative electrode lead on the side opposite to the electrode group side.
The first extension portion of the negative electrode terminal lead and the first extension portion of the negative electrode group side negative electrode lead are welded together.
The tip of the first extension portion of the welded negative electrode terminal lead and the first extension portion of the negative electrode group side negative electrode lead is a second exterior portion parallel to the opening of the first exterior portion. A battery that is perpendicular or substantially perpendicular to a surface. The electrode group is one or more.
The thickness of the battery is 5 mm or more and 30 mm or less.
The thickness of the electrode group side positive electrode lead and the electrode group side negative electrode lead is 0.5 mm or more and 3.0 mm or less.
The battery according to claim 1, wherein the thickness of the positive electrode terminal lead and the negative electrode terminal lead is 0.5 mm or more and 3.0 mm or less. The tip of the first extension portion of the welded positive electrode terminal lead and the first extension portion of the positive electrode group side positive electrode lead is a second exterior portion parallel to the opening of the first exterior portion. 80 ° or more and 100 ° or less with respect to the surface of
The tip of the first extension portion of the welded negative electrode terminal lead and the first extension portion of the electrode group side negative electrode lead is a second exterior portion parallel to the opening of the first exterior portion. The battery according to claim 1 or 2, wherein the temperature is 80 ° or more and 100 ° or less with respect to the surface of. The first extending portion of the positive electrode terminal lead extends toward the electrode group side.
The battery according to any one of claims 1 to 3, wherein the first extending portion of the negative electrode terminal lead extends toward the electrode group side. The positive electrode terminal lead has a second extension portion and has a second extension portion.
The positive electrode current collecting tab is sandwiched between the second extension portion of the positive electrode terminal lead and the positive electrode group side positive electrode lead.
The second extending portion of the positive electrode terminal lead supports the side of the positive electrode current collecting tab opposite to the side where the positive electrode group side positive electrode lead exists.
The negative electrode terminal lead has a second extension portion and has a second extension portion.
The negative electrode current collecting tab is sandwiched between the second extension portion of the negative electrode terminal lead and the negative electrode group side negative electrode lead.
The battery according to any one of claims 1 to 4, wherein the second extending portion of the negative electrode terminal lead supports the side of the negative electrode current collecting tab opposite to the side where the negative electrode group side negative electrode lead exists. .. The positive electrode terminal lead has a second extension portion and has a second extension portion.
The positive electrode group side positive electrode lead is sandwiched between the positive electrode current collecting tab and the second extension portion of the positive electrode terminal lead.
The negative electrode terminal lead has a second extension portion and has a second extension portion.
The battery according to any one of claims 1 to 4, wherein the negative electrode group side negative electrode lead is sandwiched between the negative electrode current collecting tab and the second extending portion of the negative electrode terminal lead. The first extending portion of the positive electrode terminal lead extends to the side opposite to the electrode group side.
The battery according to any one of claims 1 to 3, wherein the first extending portion of the negative electrode terminal lead extends to a side opposite to the electrode group side. The positive electrode current collecting tab, the electrode group side positive electrode lead, and the positive electrode terminal lead are arranged in the order of the positive electrode current collecting tab, the electrode group side positive electrode lead, and the positive electrode terminal lead.
The battery according to claim 7, wherein the negative electrode current collecting tab, the electrode group side negative electrode lead, and the negative electrode terminal lead are arranged in the order of the negative electrode current collecting tab, the electrode group side negative electrode lead, and the negative electrode terminal lead. The positive electrode current collecting tab, the electrode group side positive electrode lead, and the positive electrode terminal lead are arranged in the order of the electrode group side positive electrode lead, the positive electrode current collecting tab, and the positive electrode terminal lead.
The battery according to claim 7, wherein the negative electrode current collecting tab, the electrode group side negative electrode lead, and the negative electrode terminal lead are arranged in the order of the electrode group side negative electrode lead, the negative electrode current collecting tab, and the negative electrode terminal lead. The first extension portion of the positive electrode terminal lead and the first extension portion of the positive electrode group side positive electrode lead are fitted to each other.
The battery according to any one of claims 1 to 7, wherein the first extending portion of the negative electrode terminal lead and the first extending portion of the negative electrode group side negative electrode lead are fitted. A battery pack containing one or more of the batteries according to claims 1 to 10. A power storage device including the battery according to claim 1 to 10 or the battery pack according to claim 9. A vehicle comprising the battery according to claim 1 to 10 or the battery pack according to claim 9. A projectile comprising the battery according to claims 1 to 10 or the battery pack according to claim 9.