JP7373544B2 - Batteries and battery manufacturing methods - Google Patents

Description

The present invention relates to a battery and a method for manufacturing the battery.

Patent Documents 1 and 2 disclose a composite material laminated portion in which an electrode composite material layer is laminated on the surface of the current collector foil, and a composite material laminated portion in which the electrode composite material layer is not laminated on the surface of the current collector foil. a laminated electrode body including a plurality of electrode plates having a current collecting tab extending from the electrode, and a laminated electrode body having an electrode laminated portion in which a plurality of the composite laminated portions are laminated in the lamination direction with a separator interposed therebetween; It is made of a laminate film having a structure in which both sides are covered with resin films, and is connected to a battery case housing the laminated electrode body and a plurality of current collecting tabs of the laminated electrode body, and is connected to the battery case to connect the battery case from the inside to the outside. A battery is disclosed that includes a current collector terminal that extends into the battery.

Japanese Patent Application Publication No. 2012-54029 Japanese Patent Application Publication No. 2012-164470

The current collector terminal has an L-shape when viewed from the side, and includes a first portion that extends in the stacking direction and is housed in the battery case, and a first portion that extends in the stacking direction and a first portion that extends in the stacking direction. A second portion extending from the inside of the battery case to the outside is connected to the second portion. The plurality of current collecting tabs are overlapped with each other without gaps in their thickness direction, and form a tab overlap that extends in the length direction from the electrode stack side to the tip side. The first portion of the current collector terminal has a first end that extends in the stacking direction and is located farthest from the second portion.

The tab overlapping portion extends from the first end toward the second portion along a first surface of the first portion of the current collector terminal facing the electrode lamination portion. There is. A portion of the tab overlapping portion that extends from the first end side toward the second portion along the first surface of the first portion is welded to the first surface of the first portion. ing. The electrode plate is a positive electrode plate or a negative electrode plate, the current collector tab is a positive electrode current collector tab or a negative electrode current collector tab, and the current collector terminal is a positive electrode current collector terminal or a negative electrode current collector terminal. .

By the way, if the corner of the first end of the current collector terminal, which is L-shaped in side view, comes into direct contact with the battery case made of a laminate film, there is a risk that the laminate film forming the battery case will be damaged. Furthermore, the part of the resin film of the laminate film that the corner of the first end comes into contact with breaks, and the first end of the first part directly contacts the metal film inside the laminate film. There is also a possibility that a problem may occur in which the metal film and the current collector terminal are electrically connected. In order to prevent such problems, in the batteries of Patent Documents 1 and 2 mentioned above, the first end of the first portion of the current collector terminal is covered with an insulating covering member (insulating sheet or insulating tape). was. However, preparing a separate insulating covering member and covering the first end of the current collector terminal with this covering member increases manufacturing time and manufacturing cost.

The present invention has been made in view of the current situation, and the present invention has been made in such a way that the corner of the first end of the current collector terminal is directly connected to the battery case made of a laminate film without using an insulating covering member. An object of the present invention is to provide a battery that can prevent contact, and a method for manufacturing the same.

One aspect of the present invention includes a composite material laminated part in which an electrode composite material layer is laminated on the surface of the current collector foil, and a composite material laminated part in which the electrode composite material layer is not laminated on the surface of the current collector foil. a laminated electrode body including a plurality of electrode plates having an extending current collecting tab, and an electrode lamination part in which a plurality of the composite material lamination parts are laminated in the lamination direction with a separator interposed therebetween; and both sides of a metal film. is made of a laminate film having a structure covered with a resin film, and is bonded to a battery case housing the laminated electrode body and a plurality of current collecting tabs of the laminated electrode body, and is connected to the battery case from the inside to the outside of the battery case. a first portion of the current collecting terminal that is L-shaped in side view and extends in the stacking direction and is accommodated in the battery case; and a second portion that extends in a direction perpendicular to the stacking direction and extends from the inside of the battery case to the outside, and the plurality of current collecting tabs have a shape that extends in the thickness direction of the second portion. The tab overlap portion is overlapped without a gap and extends in the length direction from the electrode laminated portion side to the tip end side, and the first portion of the current collector terminal is connected to the first portion. The portion has a first end that extends in the stacking direction and is located farthest from the second portion, and the tab overlapping portion faces toward the electrode stacking portion of the first portion. The first portion of the first portion extends along the first surface from the second portion side toward the first end portion, and is folded back toward the second portion side in a manner that covers the first end portion. The tabs extend toward the second portion along a second surface facing opposite to the second surface, and of the tab overlapping portion, the second portion side extends along the first surface of the first portion. A welded portion included in a portion extending from the battery toward the first end portion is welded to the first surface of the first portion.

In the battery described above, the tab overlapping portion extends from the second portion side toward the first end portion along the first surface of the first portion of the current collector terminal facing the electrode lamination portion side of the laminated electrode body, and extends from the second portion side toward the first end portion. It is folded back toward the second portion in such a manner as to cover one end, and extends toward the second portion along a second surface of the first portion that faces opposite to the first surface. Therefore, the first end of the first portion of the current collector terminal is covered by the tab overlapping portion. Thereby, the corner of the first end of the current collector terminal can be prevented from coming into direct contact with the battery case made of the laminate film, without using an insulating covering member. This can prevent damage to the laminate film constituting the battery case due to contact with the corner of the first end of the current collector terminal. Furthermore, ``the part of the resin film of the laminate film that the corner of the first end touched broke, and the first end of the first part directly contacted the metal film inside the laminate film. It is possible to prevent the occurrence of "a problem in which electrical conduction occurs between the metal film and the current collector terminal."

Note that the electrode plate is a positive electrode plate or a negative electrode plate, the current collector tab is a positive electrode current collector tab or a negative electrode current collector tab, and the current collector terminal is a positive electrode current collector terminal or a negative electrode current collector terminal. In addition, the tab overlapping portion is a region where multiple current collecting tabs (positive electrode current collecting tabs or negative electrode current collecting tabs) are overlapped without any gaps in the thickness direction, and the same electrode (positive electrode or negative electrode) included in the laminated electrode body. Not only where all current collecting tabs (all positive current collecting tabs or all negative current collecting tabs) overlap, but also where at least two or more current collecting tabs (positive current collecting tabs or negative current collecting tabs) overlap. Including the part where it is.

Another aspect of the present invention is the method for manufacturing the battery, in which a plurality of the composite material laminated parts among the plurality of electrode plates are laminated with the separator interposed therebetween, and the battery having the electrode laminated part is a laminated electrode body forming step of forming a laminated electrode body; and a laminated electrode body forming step in which the plurality of current collecting tabs of the laminated electrode body are stacked without any gaps in the thickness direction without trimming the tips of the plurality of current collecting tabs, and the electrode lamination is performed. a tab overlapping portion forming step of forming the tab overlapping portion extending in a direction perpendicular to the stacking direction from the top side, and aligning the direction in which the first portion of the current collector terminal extends with the direction in which the tab overlapping portion extends; , the tip of the tab overlapping portion is disposed further from the second portion than the first end of the first portion; a welding step of welding the welded portion included in a portion extending from the second portion side toward the first end portion along the first surface to the first surface of the first portion; and the tab overlap portion. A portion of the first portion that is located farther from the second portion than the first end portion is folded back toward the second portion so as to cover the first end portion. a folding step of forming a portion of one portion extending toward the second portion along a second surface facing opposite to the first surface; and a step of folding the first portion of the current collector terminal into the battery case. manufacturing a battery, comprising: housing the laminated electrode body in the battery case made of the laminate film in such a manner that the second portion extends from the inside of the battery case to the outside; It's a method.

In the above-mentioned manufacturing method, in the folding process, the portion of the tab overlapping portion that is located farther from the second portion than the first end of the first portion of the current collector terminal is replaced with the first portion of the current collector terminal. Fold it back toward the second part so as to cover the first end of the. As a result, the first end of the first portion of the current collector terminal is covered by the tab overlapping portion. Therefore, in the battery manufactured by the above-mentioned manufacturing method, the corner of the first end of the current collector terminal can directly contact the battery case made of the laminate film without using an insulating covering member. can be prevented. This can prevent damage to the laminate film constituting the battery case due to contact with the corner of the first end of the current collector terminal. Furthermore, ``the part of the resin film of the laminate film that the corner of the first end touched broke, and the first end of the first part directly contacted the metal film inside the laminate film. It is possible to prevent the occurrence of "a problem in which electrical conduction occurs between the metal film and the current collector terminal."

Furthermore, in the above-described manufacturing method, the tab overlapping portions are formed by overlapping the plurality of current collecting tabs in the stacked electrode body without cutting the ends thereof in the thickness direction without any gaps. Therefore, in the above-described manufacturing method, the cutting step of trimming the ends of the plurality of current collecting tabs can be omitted compared to the conventional manufacturing method, so that the manufacturing cost can be reduced. Furthermore, by omitting the cutting step, there is no possibility that foreign matter such as metal powder generated in the cutting step will enter the battery.

FIG. 1 is a front view of a battery according to an embodiment. 2 is a sectional view taken along line FF in FIG. 1. FIG. 2 is a sectional view taken along line GG in FIG. 1. FIG. FIG. 3 is an enlarged view of part J in FIG. 2; FIG. 2 is a plan view of a laminated electrode body according to an embodiment. 6 is a sectional view taken along line BB in FIG. 5. FIG. FIG. 2 is a plan view of a positive electrode plate according to an embodiment. 8 is a sectional view taken along the line CC in FIG. 7. FIG. FIG. 2 is a plan view of a negative electrode plate according to an embodiment. 9 is a sectional view taken along line DD in FIG. 9. FIG. 3 is an enlarged view of section E in FIG. 2. FIG. 4 is an enlarged view of part H in FIG. 3. FIG. It is a side view of a current collection terminal. 1 is a flowchart showing the flow of a battery manufacturing method according to an embodiment. It is a figure explaining a welding process. It is a figure explaining a folding process. It is a figure explaining an accommodation process.

Next, embodiments of the present invention will be described. The battery 1 of this embodiment is a lithium ion secondary battery, and includes a stacked electrode body 50, a battery case 10 that accommodates the stacked electrode body 50, and current collector terminals (a positive current collector terminal 20 and a negative current collector terminal 30). (See Figures 1 to 3). Among these, the laminated electrode body 50 includes a plurality of positive electrode plates 60 (electrode plates), a plurality of negative electrode plates 70 (electrode plates), and a plurality of separators 80.

The positive electrode plate 60 includes a rectangular flat positive electrode composite material laminated portion 61 in which a positive electrode composite material layer 62 (electrode composite material layer) is laminated on the surface (in this embodiment, both surfaces) of a positive electrode current collector foil 66, and a positive electrode current collector. The foil 66 includes a positive electrode current collector tab 65 that extends from the positive electrode composite material laminated portion 61 without being laminated with the positive electrode composite material layer 62 (see FIGS. 7 and 8). The negative electrode plate 70 includes a rectangular flat negative electrode composite material laminated portion 71 in which a negative electrode composite material layer 72 (electrode composite material layer) is laminated on the surface (in this embodiment, both surfaces) of a negative electrode current collector foil 76, and a negative electrode current collector. The foil 76 includes a negative electrode current collector tab 75 that extends from the negative electrode composite material laminated portion 71 without being laminated with the negative electrode composite material layer 72 (see FIGS. 9 and 10).

The laminated electrode body 50 has an electrode laminated portion 51 in which a plurality of positive electrode composite material laminated portions 61 and a plurality of negative electrode composite material laminated portions 71 are laminated in the lamination direction DL via a rectangular flat plate-shaped separator 80 (see FIG. 2, see Figures 3, 5, and 6). Note that FIGS. 5 and 6 show the laminated electrode body 50 before the positive electrode current collecting tab 65 and the negative electrode current collecting tab 75 are attached to the positive electrode current collecting terminal 20 and the negative electrode current collecting terminal 30.

The battery case 10 is made of a laminate film 15 having a structure in which both sides of a metal film 12 are covered with resin films (inner resin film 11 and outer resin film 13). That is, the battery case 10 includes an inner resin film 11 located at the innermost side of the battery case 10, a metal film 12 located adjacent to the outside of the inner resin film 11, and a metal film 12 located adjacent to the outside of the metal film 12. It is formed of a laminate film 15 on which an outer resin film 13 is laminated (see FIG. 4).

The positive electrode current collector terminal 20 is joined to a plurality of (all) positive electrode current collector tabs 65 of the laminated electrode body 50 and extends from the inside of the battery case 10 to the outside (see FIG. 3). This positive electrode current collector terminal 20 is formed by bending a rectangular flat metal plate, and has an L-shape in side view. This positive electrode current collector terminal 20 has a first portion 21 that extends in the stacking direction DL and is housed in the battery case 10, and a first portion 21 that extends in the stacking direction DL and is accommodated in the battery case 10. It has a form in which a second portion 22 extending from the inside to the outside is connected (see FIGS. 3 and 13). The first portion 21 of the positive electrode current collector terminal 20 has a first end portion 21b that is an end in the stacking direction DL in which the first portion 21 extends and is located farthest from the second portion 22 (FIG. 3, (See Figures 12 and 13).

The negative electrode current collector terminal 30 is joined to a plurality of (all) negative electrode current collector tabs 75 of the laminated electrode body 50 and extends from the inside of the battery case 10 to the outside (see FIG. 2). This negative electrode current collector terminal 30 is formed by bending a rectangular flat metal plate, and has an L-shape in side view. This negative electrode current collector terminal 30 has a first portion 31 that extends in the stacking direction DL and is accommodated in the battery case 10, and a first portion 31 that extends in the orthogonal direction DC perpendicular to the stacking direction DL and is housed in the battery case 10. It has a form in which a second portion 32 extending from the inside to the outside is connected (see FIGS. 2 and 13). The first portion 31 of the negative electrode current collector terminal 30 has a first end portion 31b that is an end in the stacking direction DL in which the first portion 31 extends and is located farthest from the second portion 32 (FIG. 3, (See Figures 12 and 13).

The plurality of positive electrode current collecting tabs 65 are overlapped in the thickness direction to form a positive electrode tab overlapping portion 67 (see FIGS. 3 and 12). This positive electrode tab overlapping portion 67 extends in its length direction from the electrode laminated portion 51 side to the tip side. Note that the positive electrode tab overlapping portion 67 is a portion where a plurality of positive electrode current collecting tabs 65 are overlapped without any gaps in the thickness direction, and is a portion where all positive electrode current collecting tabs 65 included in the laminated electrode body 50 overlap. It also includes a portion where at least two or more positive electrode current collecting tabs 65 overlap.

The positive electrode tab overlapping portion 67 extends from the second portion 22 side (the left side in FIGS. 3 and 12) along the first surface 21c of the first portion 21 of the positive electrode current collector terminal 20 facing the electrode laminated portion 51 side. It extends toward the end portion 21b, is folded back toward the second portion 22 side in a manner to cover the entire first end portion 21b, and extends along a second surface 21d of the first portion 21 facing opposite to the first surface 21c. and extends toward the second portion 22. Note that the width dimension of the positive electrode tab overlapping portion 67 (the dimension in the direction perpendicular to the plane of paper in FIG. 12) is smaller than the width dimension of the first portion 21 of the positive electrode current collector terminal 20 (the dimension in the direction perpendicular to the plane of paper in FIG. 12). is also large, and the position of the center in the width direction of the positive electrode tab overlapping portion 67 is aligned with the center position of the first portion 21 in the width direction.

Therefore, the first end portion 21b of the first portion 21 of the positive electrode current collector terminal 20 is covered by the positive electrode tab overlapping portion 67. Thereby, the corner of the first end 21b of the positive electrode current collector terminal 20 can be prevented from directly contacting the battery case 10 made of the laminate film 15 without using an insulating covering member. This can prevent "damage to the laminate film 15 constituting the battery case 10 due to contact with the corner of the first end 21b of the positive electrode current collector terminal 20." Furthermore, "the part of the inner resin film 11 of the laminate film 15 that the corner of the first end 21b comes into contact with is broken, and the first end 21b of the first portion 21 is damaged by the metal film 12 inside the laminate film 15. It is possible to prevent the occurrence of a problem in which the metal film 12 and the positive electrode current collector terminal 20 are electrically connected due to direct contact with the metal film 12.

Further, the plurality of negative electrode current collecting tabs 75 are overlapped in the thickness direction to form a negative electrode tab overlapping portion 77 (see FIGS. 2 and 11). This negative electrode tab overlapping portion 77 extends in its length direction from the electrode laminated portion 51 side to the tip side. Note that the negative electrode tab overlapping portion 77 is a portion where a plurality of negative electrode current collecting tabs 75 are overlapped without any gaps in the thickness direction, and is only a portion where all negative electrode current collecting tabs 75 included in the laminated electrode body 50 overlap. It also includes a portion where at least two or more negative electrode current collecting tabs 75 overlap.

The negative electrode tab overlapping portion 77 extends from the second portion 32 side (left side in FIGS. 2 and 11) to the first surface 31c of the first portion 31 of the negative electrode current collector terminal 30 facing the electrode laminated portion 51 side. It extends toward the end portion 31b, is folded back toward the second portion 32 side in a manner to cover the entire first end portion 31b, and extends along a second surface 31d of the first portion 31 facing the opposite side to the first surface 31c. It has a shape that extends toward the second portion 32. Note that the width dimension of the negative electrode tab overlapping portion 77 (the dimension in the direction perpendicular to the plane of paper in FIG. 11) is smaller than the width dimension of the first portion 31 of the negative electrode current collector terminal 30 (the dimension in the direction perpendicular to the plane of paper in FIG. 12). is also large, and the widthwise center position of the negative electrode tab overlapping portion 77 is aligned with the widthwise center position of the first portion 21 .

Therefore, the first end portion 31b of the first portion 31 of the negative electrode current collector terminal 30 is covered by the negative electrode tab overlapping portion 77. Thereby, the corner of the first end 31b of the negative electrode current collector terminal 30 can be prevented from directly contacting the battery case 10 made of the laminate film 15 without using an insulating covering member. This can prevent damage to the laminate film 15 that constitutes the battery case 10 due to contact with the corner of the first end 31b of the negative electrode current collector terminal 30. Furthermore, "the part of the inner resin film 11 of the laminate film 15 that the corner of the first end 31b comes into contact with is broken, and the first end 31b of the first portion 31 touches the metal film 12 inside the laminate film 15. It is possible to prevent the occurrence of "a problem in which the metal film 12 and the negative electrode current collector terminal 30 are electrically connected due to direct contact with the negative electrode current collector terminal 30."

In addition, in the positive electrode tab overlapping portion 67, a welded portion included in a portion 67c extending from the second portion 22 side toward the first end portion 21b along the first surface 21c of the first portion 21 of the positive electrode current collector terminal 20. 67b is welded to the first surface 21c of the first portion 21 (see FIG. 12). Further, in the negative electrode tab overlapping portion 77, a welded portion included in a portion 77c extending from the second portion 32 side toward the first end portion 31b along the first surface 31c of the first portion 31 of the negative electrode current collector terminal 30. 77b is welded to the first surface 31c of the first portion 31 (see FIG. 11).

A battery case 10 made of a laminate film 15 accommodates therein a laminated electrode body 50 to which a positive current collector terminal 20 and a negative current collector terminal 30 are bonded, and a part of the second portion 22 of the positive current collector terminal 20 and With a part of the second portion 32 of the negative electrode current collector terminal 30 protruding to the outside of the battery case 10, the approximately U-shaped weld sealing portion 15b (three edges of the battery case 10) is thermally welded. It is formed by being sealed (see FIGS. 1 to 3). Note that a part of the second portion 22 of the positive electrode current collector terminal 20 is covered with a resin film 25, and by thermally welding the resin film 25 and the welding sealing portion 15b of the battery case 10, the positive electrode current collector A terminal 20 is joined to the battery case 10. In addition, a part of the second portion 32 of the negative electrode current collector terminal 30 is also covered with a resin film 35, and this resin film 35 and the welding sealing part 15b of the battery case 10 are thermally welded, so that the negative electrode current collector A terminal 30 is joined to the battery case 10.

Next, a method for manufacturing the battery 1 according to the embodiment will be described. In this embodiment, a lithium ion secondary battery is manufactured as the battery 1. FIG. 14 is a flowchart showing the flow of the method for manufacturing the battery 1 according to the embodiment. First, in step S1 (stacked electrode body forming step), a stacked electrode body 50 (see FIGS. 5 and 6) is formed. Specifically, a plurality of positive electrode plates 60, a plurality of negative electrode plates 70, and a plurality of separators 80 are prepared, and the positive electrode composite material laminated portion 61 of the positive electrode plate 60 and the negative electrode composite material laminated portion 71 of the negative electrode plate 70 are prepared. The laminated electrode body 50 having the electrode laminated portion 51 is produced by laminating these with the separator 80 interposed between them.

Next, in step S2 (tab overlapping portion forming step), the plurality of (all) negative electrode current collecting tabs 75 included in the laminated electrode body 50 are formed without trimming their ends and without gaps in the thickness direction. By overlapping them, a negative electrode tab overlapping portion 77 is formed that extends from the electrode laminated portion 51 side (lower side in FIG. 15) in the orthogonal direction DC (upper side in FIG. 15) perpendicular to the lamination direction DL (see FIG. 15). Similarly, the plurality of (all) positive electrode current collecting tabs 65 included in the laminated electrode body 50 are stacked on top of each other in the thickness direction without any gaps, without trimming their tips to the electrode laminated portion 51 side. A positive electrode tab overlapping portion 67 extending from the stacking direction DL in a perpendicular direction DC perpendicular to the stacking direction DL is formed.

Next, in step S3 (welding step), the negative electrode tab overlapping portion 77 and the negative electrode current collector terminal 30 are ultrasonically welded. Specifically, as shown in FIG. 15, the direction in which the first portion 31 of the negative electrode current collector terminal 30 extends is made to match the direction in which the negative electrode tab overlapping portion 77 extends (orthogonal direction DC, the vertical direction in FIG. 15), The tip portion 77f of the negative electrode tab overlapping portion 77 is disposed on the side farther from the second portion 32 than the first end portion 31b of the first portion 31 (upper side in FIG. 15). The negative electrode tab overlapping portion 77 is brought into contact with the first surface 31c of the first portion 31.

In this state, the ultrasonic horn 91 and the ultrasonic anvil 92 move the negative electrode tab overlapping portion 77 along the first surface 31c of the negative electrode current collector terminal 30 from the second portion 32 side toward the first end portion 31b. The welding portion 77b included in the extending portion 77c and the first portion 31 of the negative electrode current collector terminal 30 are sandwiched and pressed together. In this state, the ultrasonic horn 91 is ultrasonically vibrated to weld the welded portion 77b of the negative electrode tab overlapping portion 77 to the first surface 31c of the first portion 31 of the negative electrode current collector terminal 30. In the same manner, the welded portion 67b of the positive electrode tab overlap portion 67 is ultrasonically welded to the first surface 21c of the first portion 21 of the positive electrode current collector terminal 20.

Next, in step S4 (folding step), in the negative electrode tab overlapping portion 77, the side farther from the second portion 32 than the first end 31b of the first portion 31 of the negative electrode current collector terminal 30 (the upper side in FIG. 15) The portion 77d located at A portion 77g extending toward the second portion 32 is formed along the second surface 31d facing the opposite side (see FIGS. 15 and 16).

Furthermore, in step S4 (folding step), the negative electrode current collector terminal 30 is rotated 90 degrees clockwise from the position shown in FIG. A portion 77c extending from the second portion 32 side toward the first end portion 31b along the first surface 31c of the negative electrode current collector terminal 30 is bent on the second portion 32 side, and the direction in which the first portion 31 of the negative electrode current collector terminal 30 extends. corresponds to the stacking direction DL, and the first surface 31c of the first portion 31 is brought into a state opposite to the end surface (the upper end surface in FIG. 16) of the electrode stack 51.

Furthermore, in step S4 (folding step), similarly to the negative electrode tab overlapping portion 77, in the positive electrode tab overlapping portion 67, the second portion 22 of the positive electrode current collecting terminal 20 is further away from the first end portion 21b of the first portion 21 of the positive electrode tab overlapping portion 67. The part disposed on the far side is folded back toward the second part 22 side so as to cover the first end part 21b, and is folded along the second surface 21d of the first part 21 facing opposite to the first surface 21c. A portion 67g extending toward the second portion 22 is formed. Thereafter, the positive electrode current collector terminal 20 is rotated by 90 degrees together with the positive electrode tab overlapping portion 67, and the first end is moved from the second portion 22 side along the first surface 21c of the positive electrode current collector terminal 20 through the positive electrode tab overlapping portion 67. The portion 67c extending toward the portion 21b is bent on the second portion 22 side, and the direction in which the first portion 21 of the positive electrode current collector terminal 20 extends coincides with the stacking direction DL (see FIG. 12).

Next, in step S5 (housing step), the laminated electrode body 50 is housed in the battery case 10 made of the laminate film 15. Specifically, the first portion 21 of the positive electrode current collector terminal 20 and the first portion 31 of the negative electrode current collector terminal 30 are housed in the battery case 10, and the second portion 22 of the positive electrode current collector terminal 20 and the negative electrode collector terminal 30 are housed in the battery case 10. The laminated electrode body 50 is housed in the battery case 10 made of the laminate film 15 in such a manner that the second portion 32 of the electrical terminal 30 extends from the inside of the battery case 10 to the outside (FIG. 17, FIGS. 1 to 3 reference).

Specifically, the laminated electrode body 50 is placed inside the battery case 10 made of the laminate film 15 before sealing, and the first portion 21 of the positive electrode current collector terminal 20 and the first portion 31 of the negative electrode current collector terminal 30 are connected to each other. The second portion 22 of the positive current collector terminal 20 and the second portion 32 of the negative current collector terminal 30 extend from the inside of the battery case 10 before sealing to the outside. It is in the state where it is released. In this state, the approximately U-shaped welding sealing portions 15b (three edges of the battery case 10) are heated while being pressurized in the thickness direction to thermally weld the inner resin films 11 together (FIG. 17, (See Figures 1 to 3).

However, at this time, a part of the welding sealing part 15b is not thermally welded (sealed), but instead is used as a liquid injection port (not shown) for injecting the electrolyte. Further, a part of the second portion 22 of the positive electrode current collector terminal 20 is covered with a resin film 25, and this resin film 25 and the weld sealing portion 15b (inner resin film 11) of the battery case 10 are thermally welded. By doing so, the positive electrode current collector terminal 20 is joined to the battery case 10. Further, a part of the second portion 32 of the negative electrode current collector terminal 30 is also covered with a resin film 35, and this resin film 35 and the welding sealing portion 15b (inner resin film 11) of the battery case 10 are thermally welded. By doing so, the negative electrode current collector terminal 30 is joined to the battery case 10.

Next, in step S6 (liquid injection step), a non-aqueous electrolyte (not shown) is injected into the battery case 10 through a liquid injection port (not shown). Thereafter, the battery case 10 is sealed by closing the liquid injection port by thermal welding, and the battery 1 is completed.

As described above, in the manufacturing method of the present embodiment, in the folding process (step S4), the second end portion 31b of the first portion 31 of the negative electrode current collector terminal 30 is The portion 77d located far from the portion 32 (upper side in FIG. 15) is folded back toward the second portion 32 so as to cover the first end portion 31b (see FIGS. 15 and 16). As a result, the first end portion 31b of the first portion 31 of the negative electrode current collector terminal 30 is covered by the negative electrode tab overlapping portion 77. Further, a portion of the positive electrode tab overlapping portion 67 that is located farther from the second portion 22 than the first end portion 21b of the first portion 21 of the positive electrode current collector terminal 20 covers the first end portion 21b. In this way, fold it back toward the second portion 22 side. As a result, the first end portion 21b of the first portion 21 of the positive electrode current collector terminal 20 is also covered by the positive electrode tab overlapping portion 67 (see FIG. 3).

Therefore, according to the manufacturing method of the present embodiment, "the corners of the first end 31b of the negative electrode current collector terminal 30 and the first end 21b of the positive electrode current collector terminal 20 are It is possible to manufacture a battery 1 in which the corners can be prevented from coming into direct contact with the battery case 10 made of the laminate film 15 (see FIGS. 2 and 3). This can prevent damage to the laminate film 15 constituting the battery case 10 due to contact between the corners of the first ends 21b and 31b of the positive current collector terminal 20 and the negative current collector terminal 30. . Furthermore, "the part of the resin film (inner resin film 11) of the laminate film 15 that the corners of the first ends 21b, 31b are in contact with breaks, and the first ends 21b, 31b of the first parts 21, 31 may come into direct contact with the metal film 12 inside the laminate film 15, causing a problem in which the metal film 12 and the current collector terminals (the positive electrode current collector terminal 20 and the negative electrode current collector terminal 30) are electrically connected. can be prevented.

Furthermore, in the manufacturing method of the present embodiment, the tips of the plurality of (all) negative electrode current collecting tabs 75 included in the laminated electrode body 50 are not trimmed and are stacked without any gaps in the thickness direction, A negative electrode tab overlapping portion 77 is formed (see FIG. 15). Similarly, the plurality of (all) positive electrode current collecting tabs 65 included in the laminated electrode body 50 are overlapped in the thickness direction without any gaps without trimming their ends to form the positive electrode tab overlapping portion 67. form.

Therefore, in the manufacturing method of this embodiment, compared to the conventional manufacturing method, the cutting step of trimming the ends of the plurality of current collecting tabs (positive electrode current collecting tab and negative electrode current collecting tab) can be omitted, so the manufacturing method Cost can be reduced. Furthermore, by omitting the cutting step, there is no problem that foreign matter such as metal powder generated by the cutting step gets mixed into the battery, which is preferable.

Although the present invention has been described above based on the embodiments, it goes without saying that the present invention is not limited to the embodiments, and can be applied with appropriate modifications without departing from the gist thereof.

1 Battery 10 Battery case 11 Inner resin film 12 Metal film 13 Outer resin film 15 Laminate film 20 Positive electrode current collector terminal 21, 31 First portion 21b, 31b First end portion 21c, 31c First surface 21d, 31d Second surface 22 , 32 Second portion 30 Negative current collector terminal 50 Laminated electrode body 51 Electrode laminated portion 60 Positive electrode plate (electrode plate)
61 Positive electrode composite material laminated part 62 Positive electrode composite material layer (electrode composite material layer)
65 Positive electrode current collector tab 66 Positive electrode current collector foil 67 Positive electrode tab overlapping part 67b, 77b Welding part 70 Negative electrode plate (electrode plate)
71 Negative electrode composite material laminated part 72 Negative electrode composite material layer (electrode composite material layer)
75 Negative electrode current collector tab 76 Negative electrode current collector foil 77 Negative electrode tab overlapping portion 80 Separator

Claims (2)

A composite material laminated part in which an electrode composite material layer is laminated on the surface of the current collector foil, and a current collector tab that extends from the composite material laminated part without the electrode composite material layer being laminated on the current collector foil. A laminated electrode body comprising a plurality of electrode plates having a plurality of electrode plates, and having an electrode lamination part in which a plurality of the composite material lamination parts are laminated in the lamination direction with a separator interposed therebetween;
a battery case that is made of a laminate film having a structure in which both sides of a metal film are covered with a resin film, and that houses the laminated electrode body;
A battery comprising: a current collecting terminal connected to a plurality of the current collecting tabs of the laminated electrode body and extending from the inside of the battery case to the outside;
The current collector terminal has an L-shape when viewed from the side, and includes a first portion that extends in the stacking direction and is housed in the battery case, and a first portion that extends in the stacking direction and a first portion that extends in the stacking direction. and a second portion extending from the inside of the battery case to the outside,
The plurality of current collecting tabs are overlapped with each other without gaps in their thickness direction, forming a tab overlapping part extending from the electrode lamination part side to the tip side in the length direction,
The first portion of the current collector terminal has a first end that extends in the stacking direction and is located farthest from the second portion,
The tab overlapping portion extends from the second portion side toward the first end portion along a first surface of the first portion facing the electrode lamination portion side, and covers the first end portion. It is folded back toward the second portion and extends toward the second portion along a second surface of the first portion that faces opposite to the first surface;
A welded portion included in a portion of the tab overlapping portion that extends from the second portion side toward the first end portion along the first surface of the first portion is Batteries welded to the surface. A method for manufacturing a battery according to claim 1, comprising:
a laminated electrode body forming step of laminating a plurality of the composite material laminated parts of the plurality of electrode plates via the separator to form the laminated electrode body having the electrode laminated parts;
The plurality of current collecting tabs of the laminated electrode body are overlapped without gaps in the thickness direction without trimming the tips thereof, and the plurality of current collecting tabs are arranged so as to extend from the electrode lamination part side in a direction perpendicular to the lamination direction. a tab overlapping portion forming step of forming a tab overlapping portion;
The direction in which the first portion of the current collector terminal extends is made to match the direction in which the tab overlapping portion extends, and the tip of the tab overlapping portion is further away from the second portion than the first end of the first portion. The tab is included in a portion of the tab overlapping portion that extends from the second portion side toward the first end portion along the first surface of the first portion in a state where the tab is disposed on the far side. a welding step of welding a welding portion to the first surface of the first portion;
A portion of the tab overlapping portion that is located farther from the second portion than the first end of the first portion is folded back toward the second portion so as to cover the first end. a folding step of forming a portion of the first portion that extends toward the second portion along a second surface facing opposite to the first surface;
The laminated electrode body is connected to the laminated electrode body made of the laminate film in such a manner that the first portion of the current collector terminal is housed in the battery case and the second portion extends from the inside of the battery case to the outside. A method of manufacturing a battery, comprising: housing the battery in a battery case.

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