Energy Storage Devices

Abstract

To realize a technique facilitating securement of a size of a connection plane of a terminal member.SOLUTION: A battery 1 comprises: a case 10 having a metal lid member 30 having an insertion hole 33h; a terminal member 50 inserted in the insertion hole 33h; and a resin member 70 insulating the case 10 and the terminal member 50 from one another. The terminal member 50 comprises: an internal terminal part 52 that is provided inside the case 10; and an external terminal part 51 that is provided outside the case 10 and has a connection plane 53. The terminal member is formed by bending a flat metal member. The external terminal part 51 comprise: an external body 51a that extends to one side in the thickness direction of the internal terminal part 52 from a portion communicating with the internal terminal part 52, and occupies more than half of the connection plane 53; and an external overhanging part 51b that extends to the other side in the thickness direction of the internal terminal part 52, and occupies the remaining part of the connection plane 53. The terminal part 50 has a T-shaped cross-section at a region including a portion where the internal terminal part 52 and the external terminal part 51 are communicated with one another.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The technical field disclosed in this specification relates to electricity storage devices. [Background technology]

[0002] As an electricity storage device, a rectangular battery in which positive and negative terminal members are fixed to a rectangular box-shaped case via a resin member is known. In such an electricity storage device, for example, the case is made up of a bottomed rectangular cylindrical main body member having a rectangular annular opening, and a rectangular plate-shaped lid member laser-welded to the main body member over the entire circumference in a form that closes the opening. The positive and negative terminal members are inserted into a pair of insertion holes provided in the lid member, respectively, and extend from the inside of the case to the outside of the case. The resin member insulates between the lid member and the positive and negative terminal members, respectively, while joining to the lid member and the terminal members, respectively, and seals them to maintain airtightness. For example, Patent Document 1 can be cited as a related prior art. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-086813 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in Patent Document 1, a terminal member is known that has an L-shaped cross section and is provided with a connection plane facing the outside of a case. Such a terminal member is formed, for example, by bending a flat metal member into an L-shape. However, simply bending the metal member also forms an R-surface that continues to the connection plane at the bent portion. Therefore, there are cases in which the size of the connection plane is not sufficiently secured. [Means for solving the problem]

[0005] The electricity storage device devised for solving the above-mentioned problems is as follows: A metal case member having an insertion hole; A terminal member inserted into the insertion hole; an electrode body housed in the case member and connected to the terminal member; a resin member that insulates the case member from the terminal members and is in contact with the case member and the terminal members; A power storage device comprising: The terminal member is an internal terminal portion connected to the electrode body in the case member and extending from the case member through the insertion hole to the outside of the case member; a flat-plate-shaped external terminal portion located outside the case member, including a connecting plane facing the outside of the case member, and an inner surface facing the inside of the case member being connected to an upper end of the internal terminal portion; the internal terminal portion and the external terminal portion are formed by bending a flat metal member, The external terminal portion is a main body portion extending from a portion connected to an upper end of the internal terminal portion to one side in a thickness direction of the internal terminal portion and constituting a majority of the connection plane; a protruding portion that protrudes from a portion connected to an upper end of the internal terminal portion toward the other side in a thickness direction of the internal terminal portion and forms a remainder of the connection plane; a cross section of the terminal member at a portion including a portion where an upper end of the internal terminal portion and the inner surface of the external terminal portion are connected to each other is T-shaped; It is configured as follows.

[0006] According to the above-described energy storage device, the terminal member is a bent flat metal member, but the external terminal portion constituting the connection plane has a protrusion on the opposite side to the external main body portion extending from the point where it is bent to connect with the internal terminal portion, thereby ensuring a wider connection plane compared to a connection plane that is simply bent without any protrusion and where the R surface remains as it is after bending. Effect of the Invention

[0007] The technique disclosed in this specification makes it possible to easily ensure the size of the connection plane of the terminal member in an electricity storage device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a battery according to an embodiment. [Diagram 2] 1 is a cross-sectional view of a battery according to an embodiment taken along a battery height direction and a battery width direction. [Diagram 3] 4 is a view showing the upper side of the lid member, in the vicinity of the opening of the body member and the peripheral edge of the lid member of the battery according to the embodiment; FIG. [Figure 4] 4 is a partially enlarged cross-sectional view (cross-sectional view taken along line AA in FIG. 3) of the vicinity of the opening of the body member and the peripheral edge of the lid member of the battery according to the embodiment, taken along the battery height direction and battery width direction. [Diagram 5] 4 is a partially enlarged cross-sectional view (cross-sectional view taken along line BB in FIG. 3) of the vicinity of the opening of the body member and the peripheral edge of the lid member of the battery according to the embodiment, taken along the battery height direction and the battery width direction. [Figure 6] 2 is a flowchart of a method for manufacturing a battery according to an embodiment. [Figure 7] 5 is an explanatory diagram showing a state in which an external terminal portion is forged in a terminal forging process. FIG. [Figure 8] FIG. 4 is a schematic diagram showing a state in which the surface of the lid member according to the embodiment is roughened. [Figure 9] 11A-11C are diagrams showing the lid assembly formed in the lid assembly forming step. [Figure 10] 13 is an explanatory diagram showing the state in which molten resin is injected into a mold in the lid assembly forming process. FIG. [Figure 11] 1 is a partially enlarged cross-sectional view of the vicinity of an opening of a body member and a peripheral portion of a lid member of a battery according to a comparative example, taken along the battery height direction and battery width direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a battery 1 according to an embodiment will be described with reference to Figs. 1 to 5. The battery 1 is an example of an electricity storage device. In the following description, the battery height direction AH, battery width direction BH, and battery thickness direction CH of the battery 1 will be defined as the directions shown in Figs. 1 to 5. The battery 1 is a rectangular (rectangular) sealed lithium ion secondary battery that is mounted on vehicles such as hybrid cars, plug-in hybrid cars, and electric cars.

[0010] [Battery configuration] 1 and 2, the battery 1 has a rectangular parallelepiped case 10 and an electrode assembly 40 housed in the case 10, and further has a positive electrode terminal member 50 supported via a resin member 70 and a negative electrode terminal member 60 supported via a resin member 80 at an upper portion 11 constituting a portion of the upper side AH1 of the case 10 in the battery height direction AH. The electrode assembly 40 is covered in a bag-shaped insulating holder 5 made of an insulating film inside the case 10. An electrolyte 3 is housed in the case 10, a portion of which is immersed in the electrode assembly 40, and the remainder is collected in a bottom portion 12 constituting a portion of the lower side AH2 of the case 10 in the battery height direction AH.

[0011] The case 10 is composed of a main body member 20 and a lid member 30. The main body member 20 is in the shape of a rectangular cylinder with a bottom having a rectangular annular opening 21 on the upper side AH1 in the battery height direction AH. Specifically, the main body member 20 forms a bottom 12 of the case 10, a long side portion 13 constituting a portion of one side CH1 of the case 10 in the battery thickness direction CH, a long side portion 14 constituting a portion of the other side CH2 of the case 10 in the battery thickness direction CH, a short side portion 15 constituting a portion of one side BH1 of the case 10 in the battery width direction BH, and a short side portion 16 constituting a portion of the other side BH2 of the case 10 in the battery width direction BH. On the other hand, the lid member 30 is in the shape of a rectangular plate and forms the upper portion 11 of the case 10. The lid member 30 is in a form that closes the opening 21 of the main body member 20, and the peripheral portion 31 of the lid member 30 is laser welded around the entire circumference of the opening 21 of the main body member 20, and a molten and solidified portion 18 is formed between the lid member 30 and the main body member 20.

[0012] The cover member 30 is provided with a safety valve 19 that breaks and opens when the internal pressure of the case 10 exceeds a valve opening pressure. Furthermore, the cover member 30 is formed with a liquid injection hole 30k that penetrates from the inside to the outside of the case 10, and a disk-shaped sealing member 39 made of aluminum is inserted into the liquid injection hole 30k to provide an airtight seal.

[0013] In addition, a rectangular insertion hole 33h penetrating in the lid thickness direction DH is provided near the end of one side BH1 of the battery width direction BH of the lid member 30, and a rectangular insertion hole 34h penetrating in the lid thickness direction DH is provided near the end of the other side BH2 of the battery width direction BH. A positive electrode terminal member 50 made of aluminum is inserted into the insertion hole 33h, and the positive electrode terminal member 50 is fixed to the lid member 30 in a state insulated from the lid member 30 via a resin member 70. A negative electrode terminal member 60 made of copper is inserted into the insertion hole 34h, and the negative electrode terminal member 60 is fixed to the lid member 30 in a state insulated from the lid member 30 via a resin member 80.

[0014] The terminal members 50, 60 are each formed by punching out a metal plate (in this embodiment, the positive terminal member 50 is an aluminum plate, and the negative terminal member 60 is a copper plate) into a predetermined shape and then bending the metal plate, etc. Specifically, as shown in Figs. 3 to 5, the positive terminal member 50 has an external terminal portion 51 located on the outside of the cover member 30, and an internal terminal portion 52 located mainly inside the case 10 and connected to the external terminal portion 51 via the inside of the insertion hole 33h.

[0015] The external terminal portion 51 is in the shape of a rectangular plate, and is provided with a connection plane 53 that faces the outside DH1 in the lid thickness direction DH of the lid member 30. There are no resin burrs on the connection plane 53, and the entire connection plane 53 is exposed. The entire connection plane 53 of the external terminal portion 51 can be used as a surface for connecting to an external terminal such as a bus bar. In addition, the external terminal portion 51 has an inner surface 54 that faces the inside DH2 in the lid thickness direction DH of the lid member 30, which is connected to the upper end of the internal terminal portion 52. The inner surface 54 of the external terminal portion 51 is located on the upper side AH1 of the surface 33 that faces the outside DH1 in the lid thickness direction DH of the lid member 30 in the battery height direction AH.

[0016] The internal terminal portion 52 is bent at a plurality of locations. Specifically, as shown in FIG. 5, the internal terminal portion 52 has a first inner portion 52a extending from the inner surface 54 of the external terminal portion 51 to the lower side AH2 in the battery height direction AH, a second inner portion 52b bending at the lower end of the first inner portion 52a and extending to one side CH1 in the battery thickness direction CH, and a third inner portion 52c bending at the end of the one side CH1 in the battery thickness direction CH of the second inner portion 52b and extending to the lower side AH2 in the battery height direction AH. Of these, the first inner portion 52a is inserted into the insertion hole 33h, and the resin member 70 is in contact with the first inner portion 52a. The third inner portion 52c is connected to the positive electrode current collector of the electrode body 40 at the end of the lower side AH2 in the battery height direction AH.

[0017] Also, the upper end of the first inner portion 52a of the inner terminal portion 52 is connected to a portion of the inner surface 54 of the external terminal portion 51 that is slightly inward (the other side CH2) from the end portion 51bn of one side CH1 of the external terminal portion 51 in the battery thickness direction CH. In other words, the terminal member 50 is bent at the portion where the external terminal portion 51 and the internal terminal portion 52 are connected, and at the connected portion, the external terminal portion 51 slightly protrudes toward the one side CH1 in the battery thickness direction CH. Therefore, the cross section of the terminal member 50 is T-shaped at the portion where the external terminal portion 51 and the internal terminal portion 52 are connected, that is, by the external terminal portion 51 and the first inner portion 52a of the internal terminal portion 52, as shown in FIG. In this specification, the portion of the external terminal portion 51 on one side CH1 in the battery thickness direction CH from the point where it is connected to the internal terminal portion 52 is referred to as the external main body portion 51a, and the portion of the external terminal portion 51 on the other side CH2 in the battery thickness direction CH from the point where it is connected to the internal terminal portion 52 is referred to as the external protrusion portion 51b.

[0018] The external protrusion 51b is a portion that protrudes slightly from the portion connected to the internal terminal 52, and the majority of the external terminal 51 constitutes the external main body 51a. In other words, the majority of the connection plane 53 of the external terminal 51 also constitutes the external main body 51a, and the remainder constitutes the external protrusion 51b.

[0019] The connecting plane 53 of the external terminal portion 51 is parallel to the battery thickness direction CH, and the first interior 52a extends in the battery height direction AH perpendicular to the battery thickness direction CH. Therefore, the thickness direction of the first interior 52a constituting the portion having a T-shaped cross section is the same as the battery thickness direction CH. Therefore, it can be said that the external terminal portion 51 is composed of an external main body portion 51a extending from a portion connected to the upper end of the first interior 52a to one side in the thickness direction of the first interior 52a, and an external protruding portion 51b extending to the other side in the thickness direction of the first interior 52a.

[0020] In addition, the surface 33 of the cover member 30 has a recessed portion 33k, which is a region recessed inward in the cover thickness direction DH2 in the region from the insertion hole 33h to the other side CH2 in the battery thickness direction CH. The thickness of the portion where the recessed portion 33k is present (the length of the cover member 30 in the cover thickness direction DH) is about half the thickness of the portion where the recessed portion 33k is not present. The width of the recessed portion 33k in the battery thickness direction CH is from the insertion hole 33h to the other side CH2 beyond the end 51an of the other side CH2 in the battery thickness direction CH of the external terminal portion 51. Due to the recessed portion 33k, a part of the surface 33 of the cover member 30 and a part of the inner surface 54 of the external main body portion 51a overlap without contacting each other in the battery thickness direction CH.

[0021] Like the positive terminal member 50, the negative terminal member 60 has an external terminal portion 61 located on the outside of the cover member 30, and an internal terminal portion 62 located mainly inside the case 10 and connected to the external terminal portion 61 via the insertion hole 34h. The detailed shape of the negative terminal member 60 is similar to that of the positive terminal member 50, and a description thereof will be omitted.

[0022] As shown in Figs. 1 and 2, the electrode body 40 is a flat rectangular parallelepiped, and is a laminated electrode body in which a plurality of positive electrode plates 41 and a plurality of negative electrode plates 42, each of which has a rectangular shape extending in the battery height direction AH and the battery width direction BH, are alternately laminated in the battery thickness direction CH via a separator 43 made of a porous resin film. Each positive electrode plate 41 has a positive electrode current collector 41r extending to one side BH1 of the battery width direction BH, and the positive electrode current collectors 41r overlap each other in the thickness direction to form the above-mentioned positive electrode tab 40a. This positive electrode tab 40a is connected to the internal terminal portion 52 of the positive electrode terminal member 50 as described above. Each negative electrode plate 42 has a negative electrode current collector 42r extending to the other side BH2 of the battery width direction BH, and the negative electrode current collectors 42r overlap each other in the thickness direction to form the above-mentioned negative electrode tab 40b. This negative electrode tab 40b is connected to the internal terminal portion 62 of the negative electrode terminal member 60 as described above.

[0023] The positive electrode resin member 70 contacts the cover member 30 and the terminal member 50 while providing insulation between the cover member 30 and the terminal member 50, and portions of the positive electrode resin member 70 are fixed to the cover member 30 and the terminal member 50. Similarly, the negative electrode resin member 80 contacts the cover member 30 and the terminal member 60 while providing insulation between the cover member 30 and the terminal member 60, and portions of the negative electrode resin member 80 are fixed to the cover member 30 and the terminal member 50.

[0024] The resin member 70 is made of polyphenylene sulfide (PPS) and has an external insulating part 71 arranged on the lid member 30 and an internal insulating part 72 arranged inside the case 10 and in the insertion hole 33h of the lid member 30, the internal insulating part 72 being connected to the external insulating part 71 via the insertion hole 33h of the lid member 30. The resin member 80 is also made of PPS and has an external insulating part 81 arranged on the lid member 30 and an internal insulating part 82 arranged inside the case 10 and in the insertion hole 34h of the lid member 30, the internal insulating part 82 being connected to the external insulating part 81 via the insertion hole 34h of the lid member 30.

[0025] 3 to 5, the external insulating portion 71 of the resin member 70 is in the shape of a frame surrounding the external terminal portion 51. The external insulating portion 71 is connected to the internal insulating portion 72. The external insulating portion 71 has a shape having a protrusion 71mG that protrudes from a part of the external insulating portion 71 toward the other side BH2 in the battery width direction BH. The resin member 70 is formed by insert molding, which will be described later, and the protrusion 71mG is a location where a gate member GT (see FIG. 10) into which molten resin is injected during the insert molding is disposed.

[0026] Furthermore, the surface of the lid member 30 in the bonding region 30S (the surface of the lid member 30 indicated by the thick line in Figs. 4 and 5) that is in contact with the resin member 70 is roughened to form fine irregularities. In such a roughened bonding region 30S, the adhesion between the metal lid member 30 and the resin member 70 is increased, and the adhesive strength between the lid member 30 and the resin member 70 is further increased by the anchor effect. This roughening does not need to be performed on the entire bonding region 33S that is in contact with the resin member 70, and it is sufficient that the roughening is performed so as to surround at least the insertion hole 33h. The resin member 70 is hermetically fixed to the lid member 30 by the region that has been roughened.

[0027] In addition, the surface of the positive electrode terminal member 50 is also roughened to form fine irregularities in the bonding area 50S (the surface of the terminal member 50 shown by the thick line in Figures 4 and 5) that is in contact with the resin member 70, and such roughening is performed all around the surface of the terminal member 50, thereby hermetically fixing the positive electrode terminal member 50 and the resin member 70 together.

[0028] In addition, the surface of the cover member 30 in the bonding area in contact with the resin member 80 on the negative electrode terminal member 60 side is also roughened to form fine irregularities, thereby increasing the adhesive strength between the cover member 30 and the resin member 80. Furthermore, the negative electrode terminal member 60 also has an area in which a part of the surface in contact with the resin member 80 is roughened to form fine irregularities, thereby hermetically fixing the negative electrode terminal member 60 and the resin member 80 together.

[0029] [Battery manufacturing] Next, a method for manufacturing the battery 1 will be described with reference to the flowchart of Fig. 6. First, in a "preparation step S0", the lid member 30 and the terminal members 50 and 60 are prepared. An aluminum plate is used for the lid member 30, and the liquid injection hole 30k, the insertion holes 33h and 34h, and the safety valve 19 are formed in advance by pressing or the like to obtain the lid member 30. The positive electrode terminal member 50 is made of an aluminum plate, and the negative electrode terminal member 60 is made of a copper plate, and each is obtained by pressing or the like.

[0030] Specifically, a process for forming the external terminal portion 51 and the first inner portion 52a of the internal terminal portion 52 of the positive electrode terminal member 50 will be described. First, in a "terminal bending process S01", a flat terminal member press-punched from an aluminum plate is bent by coining so that the bending angle is approximately 90 degrees, i.e., into an L-shape. At this stage, the external protrusion portion 51b of the external terminal portion 51 has not been formed.

[0031] Next, in the "terminal forging process S02", the end of the external terminal portion 51, i.e., the tip of one side of the external terminal portion 51 in the thickness direction of the internal terminal portion 52 (battery thickness direction CH shown in Figure 5), is hammered to the other side in the thickness direction of the internal terminal portion while fixing the internal terminal portion 52, to form an external protrusion portion 51b in the external terminal portion 51.

[0032] The terminal forging process S02 is performed, for example, according to the procedure shown in FIG. 7. First, as shown in FIG. 7(a), the inner surface 50a of the terminal member 50 formed in an L-shape is placed so as to contact the lower die FE2. Next, as shown in FIG. 7(b), the upper die FE1 is placed so as to contact the outer surface 50b of the terminal member 50. Note that the end of the external terminal portion 51, i.e., the tip surface 50c of one side EH1 in the thickness direction EH of the internal terminal portion 52 of the external terminal portion 51, is exposed from the die FE consisting of the upper die FE1 and the lower die FE2. The upper die FE1 and the lower die FE2 are in pressure contact with the internal terminal portion 52, whereby the internal terminal portion 52 of the terminal member 50 is fixed to the die FE.

[0033] In addition, the upper mold FE1 has a recess FE10 corresponding to the shape of the external protrusion 51b at the location where the L-shape of the external terminal portion 51 is formed, i.e., on the other side EH2 in the thickness direction EH of the internal terminal portion 52 of the external terminal portion 51, and when the upper mold FE1 is placed on the terminal member 50, there is a space FC within the mold FE that is surrounded by the recess FE10 of the upper mold FE1 and the outer surface 50b of the terminal member 50.

[0034] 7(c), the tip surface 50c of the external terminal portion 51 is struck by a hammer FH toward the other side EH2 in the thickness direction EH of the internal terminal portion. This causes the external terminal portion 51 to be pressed toward the other side EH2 in the thickness direction EH of the internal terminal portion, and to be deformed so as to fill the space FC. By repeatedly striking the tip surface 50c with the hammer FH, the external terminal portion 51 is deformed, and the space FC is filled with the external terminal portion 51, resulting in the formation of an external protruding portion 51b. Moreover, by deforming the external terminal portion 51, the length of the external terminal portion 51 in the thickness direction EH can be adjusted.

[0035] Next, in the "roughening process S03", a roughening process is performed to roughen a portion of the terminal member 50 that has been subjected to the forging process (a region corresponding to the joining region 50S that comes into contact with the resin member 70 after insert molding, which will be described later). Specifically, the following procedure is performed for each region to be roughened. First, a laser beam is irradiated onto a first region in the region to be roughened, and the first region is melted. As the metal terminal member 50 melts, metal particles are generated from the metal vapor or plasma released into the atmosphere, and the metal particles are deposited again in the first region or its periphery.

[0036] Then, a laser beam is irradiated to a second region adjacent to the first region, the second region is melted, and metal particles are deposited in the same manner as in the first region. By irradiating the laser beam in this manner over the entire region to be roughened, as shown in FIG. 8, a plurality of depressions 53L due to the laser beam and a plurality of protrusions 53R due to the deposition of metal particles are formed in the region to be roughened, and fine irregularities of the nm order are formed on the surface of the entire region to be roughened. Similarly, the negative electrode terminal member 60 is also subjected to a roughening treatment in a predetermined region. Similarly, the cover member 30 is also subjected to a roughening treatment in a part of the region (a region corresponding to a bonding region 30S that contacts the resin member 70 after insert molding, which will be described later).

[0037] In addition, the roughening process S03 may be performed before the lid assembly forming process S1 described later, and may be performed, for example, before the terminal bending process S01, or after the terminal bending process S01 and before the terminal forging process S02.

[0038] Next, in the "lid assembly forming step S1", a lid assembly 7 as shown in Fig. 9 is formed. The lid assembly 7 is a member in which the surface-roughened lid member 30, the surface-roughened terminal members 50, 60, the resin members 70, 80, and the electrode body 40 of the battery 1 are integrated together, and the electrode body 40 is wrapped in an insulating holder 5. In the lid assembly forming step S1, the lid member 30 and the terminal members 50, 60 are prepared, and the resin members 70, 80 are insert-molded to integrate the terminal members 50, 60 with the lid member 30 via the resin members 70, 80.

[0039] Specifically, in the lid assembly forming step S1, as shown in FIG. 10, the lid member 30 is placed at a predetermined position in the lower die DE2 of the die DE having an upper die DE1 and a lower die DE2. Then, the terminal members 50 and 60 are inserted into the insertion holes 33h and 34h of the lid member 30 placed in the lower die DE2, respectively. Then, the upper die DE1 is placed on the lower die DE2 and the die DE is closed. Next, the molten resin MR is injected into the die DE and then cooled to form the resin members 70 and 80. Then, the upper die DE1 is moved upward, and the composite molded product in which the terminal members 50 and 60 are integrated with the lid member 30 via the resin members 70 and 80 is taken out from the lower die DE2.

[0040] In this embodiment, since the resin member 70 is formed by insert molding, a region that connects to a gate member GT through which molten resin MR is injected into the mold DE is provided in the resin member 70. A protrusion 71mG provided on the outer insulating portion 71 of the resin member 70 becomes the region that connects to this gate member GT.

[0041] Next, an electrode body 40 formed by stacking a positive electrode plate 41, a negative electrode plate 42, and a separator 43 is prepared, and the internal terminal portions 52, 62 of the terminal members 50, 60 of the above-mentioned composite molded product are connected by welding to the positive electrode tab 40a and the negative electrode tab 40b of the electrode body 40, respectively. After that, the electrode body 40 is wrapped in a bag-shaped insulating holder 5. In this way, a lid assembly 7 consisting of the lid member 30, the terminal members 50, 60, the resin members 70, 80, the electrode body 40, and the insulating holder 5 is formed.

[0042] Next, in the "closing process S2", a main body member 20 is prepared, and the electrode body 40 covered with an insulating holder 5 of the lid assembly 7 formed in the lid assembly formation process S1 is inserted into the main body member 20, and the peripheral portion 31 of the lid member 30 is used to close the opening 21 of the main body member 20.

[0043] Next, in the "welding process S3", laser light is irradiated from the outside DH1 in the lid thickness direction DH of the lid member 30 (upper side AH1 in the battery height direction AH) to the opening 21 of the main body member 20 and the peripheral portion 31 of the lid member 30 to form a molten and solidified portion 18, performing laser welding around the entire circumference to form the case 10.

[0044] Next, in a "pouring and sealing process S4", the electrolyte 3 is poured into the case 10 through the pouring hole 30k, and the electrolyte 3 is impregnated into the electrode body 40. Thereafter, the pouring hole 30k is covered from the outside with a sealing member 39, and the sealing member 39 is welded to the lid member 30 around its entire periphery to hermetically seal the gap between the sealing member 39 and the lid member 30.

[0045] Next, in the "initial charging and aging step S5", a charging device (not shown) is connected to the battery 1 to perform an initial charge on the battery 1. After that, the initially charged battery 1 is left for a predetermined period of time to age the battery 1. In this way, the battery 1 is completed.

[0046] According to the battery 1 of the embodiment, the terminal member 50 is formed by bending a flat metal member to form the connection plane 53, but the external terminal portion 51 having the connection plane 53 has an external main body portion 51a extending from a portion where the external terminal portion 51 is bent and connected to the internal terminal portion 52, and also has an external protrusion portion 51b on the opposite side from the connection portion, and the connection plane 53 is formed by the external main body portion 51a and the external protrusion portion 51b. That is, the cross section at the portion where the external terminal portion 51 and the internal terminal portion 52 are connected is T-shaped. As a result, the terminal member 50 of this embodiment has a wider connection plane 53 than a connection plane in which there is no external protrusion portion 51b and the R surface remains as it is after bending.

[0047] 11, if the cross section of the connecting portion between external terminal portion 51 and internal terminal portion 52 is L-shaped as if the R surface remained after bending, the length of connecting plane 53 in battery thickness direction CH may be shortened, and the size of connecting plane 53 may not be sufficiently ensured. In battery 1 of the embodiment, the length of connecting plane 53 in battery thickness direction CH is longer by the amount of external protrusion 51b, and the size of connecting plane 53 is sufficiently ensured.

[0048] On the other hand, the size of the connection plane 53 can be secured by arranging the first inner portion 52a of the inner terminal portion 52 on one side CH1 of the battery thickness direction CH and widening the insertion hole 33h on one side CH1 of the battery thickness direction CH, as compared with the battery 1 of this embodiment. However, such a configuration shortens the length from the insertion hole 33h of the lid member 30 to the end on one side CH1 of the battery thickness direction CH, which causes the following problem. That is, in order to secure the size of the joining area 30S that seals the resin member 70 and the lid member 30 by the amount of widening the insertion hole 33h on one side CH1 of the battery thickness direction CH, it is necessary to widen the external insulating portion 71 of the resin member 70 on one side CH1 of the battery thickness direction CH. In that case, the distance between the resin member 70 and the welding point (the portion that becomes the melted and solidified portion 18) is shortened, and as a result, the external insulating portion 71 may be burned when the lid member 30 and the body member 20 are welded. On the other hand, if the external insulating portion 71 of the resin member 70 is left as it is, the size of the bonding area 30S that seals the resin member 70 and the lid member 30 will be reduced, and as a result, the bond between the resin member 70 and the lid member 30 will be easily broken, which may cause internal gas to leak.

[0049] In the battery 1 of this embodiment, since the terminal member 50 is T-shaped, the insertion hole 33h of the cover member 30 can be disposed on the other side CH2 of the battery thickness direction CH while ensuring the size of the connection plane 53, as compared with the comparative example. For example, in this embodiment, as shown in FIG. 5, the end 51bn of one side CH1 of the external protruding portion 51b of the external terminal portion 51 and the side surface 33h1 of one side CH1 of the insertion hole 33h in the battery thickness direction CH are located at approximately the same position in the battery thickness direction CH. This ensures the size of the bonding area 30S that seals the resin member 70 and the cover member 30, making the bond between the resin member 70 and the cover member 30 less likely to break. In addition, in the battery 1 of this embodiment, since it is not necessary to spread the external insulating portion 71 of the resin member 70 to one side CH1 of the battery thickness direction CH, the external insulating portion 71 is less likely to burn during welding.

[0050] It should be noted that this embodiment is merely an example and does not limit the present invention in any way. Therefore, the present invention can be naturally improved and modified in various ways without departing from the scope of the present invention. For example, in the embodiment, a laminated electrode body 40 is exemplified as the electrode body housed in the case 10, but the electrode body may be a flat wound electrode body. Also, a plurality of electrode bodies may be housed in the case.

[0051] Furthermore, although the embodiment is applied to a lithium ion battery, the present invention can be applied to any general power storage device, for example, a nickel-metal hydride battery or a nickel-cadmium battery.

[0052] In addition, in the embodiment, as a roughening treatment, a metal deposit (anchor) is formed on the metal surface by a laser beam, but any general roughening treatment can be applied, for example, pores may be formed on the metal surface by an acid-based etching agent.

[0053] 5, in the embodiment, the end 51bn of one side CH1 in the battery thickness direction CH of the external protruding portion 51b of the external terminal portion 51 and the side surface 33h1 of one side CH1 in the battery thickness direction CH of the insertion hole 33h are located at substantially the same position in the battery thickness direction CH, but the distance from the insertion hole 33h to the end of one side CH1 in the battery thickness direction CH of the lid member 30 may be increased so that the side surface 33h1 of one side CH1 in the battery thickness direction CH of the insertion hole 33h is located at the other side CH2 in the battery thickness direction CH. This increases the area where the resin member 70 and the lid member 30 contact each other, and increases the area of ​​the roughened bonding region 30S of the lid member 30, making it more difficult to break the bond between the resin member 70 and the lid member 30. [Explanation of symbols]

[0054] 1. Battery (energy storage device) 10 Cases 20 Main body parts 30 Lid member 30S Joint area (seal area) 33h Through hole 50 Terminal material 51 External terminal section 51a External body part (body part) 51b External overhang (overhang) 52 Internal terminal section 53 Connection Plane 70 Resin parts

Claims

1. A metal case member having an insertion hole; A terminal member inserted into the insertion hole; an electrode body housed in the case member and connected to the terminal member; a resin member that insulates the case member from the terminal members and is in contact with the case member and the terminal members; A power storage device comprising: The terminal member is an internal terminal portion connected to the electrode body in the case member and extending from the case member through the insertion hole to the outside of the case member; a flat-plate-shaped external terminal portion located outside the case member, including a connecting plane facing the outside of the case member, and an inner surface facing the inside of the case member that is connected to an upper end of the internal terminal portion; the internal terminal portion and the external terminal portion are formed by bending a flat metal member, The external terminal portion is a main body portion extending from a portion connected to an upper end of the internal terminal portion to one side in a thickness direction of the internal terminal portion and constituting a majority of the connection plane; a protruding portion that protrudes from a portion connected to an upper end of the internal terminal portion toward the other side in a thickness direction of the internal terminal portion and forms a remainder of the connection plane; a portion of the terminal member including a portion where an upper end of the internal terminal portion and the inner surface of the external terminal portion are connected has a T-shaped cross section; The power storage device is configured as follows.

2. A method for producing the electricity storage device according to claim 1, comprising the steps of: The terminal member is The flat metal member is bent into an L-shape to form the internal terminal portion and the external terminal portion, and then, while fixing the internal terminal portion, a tip end of the external terminal portion on one side in the thickness direction of the internal terminal portion is struck against the other side in the thickness direction of the internal terminal portion, thereby forming the main body portion and the protruding portion of the external terminal portion into a T-shape. The method for manufacturing an electricity storage device configured as above is also provided.

3. The electricity storage device according to claim 1 , At least a part of the surface of the case member that is in contact with the resin member has a seal area that is a roughened area. The power storage device is configured as follows.

4. The electricity storage device according to claim 3, the sealing area is in a region of the outer surface of the case member that is in contact with the resin member and is located on the other side of the insertion hole in a thickness direction of the internal terminal portion; The power storage device is configured as follows.

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