Secondary battery and method for manufacturing same

Abstract

The invention provides a secondary battery and a method for manufacturing the same. The first electrode body has a first electrode sheet and a second electrode sheet. The second electrode body has a third electrode sheet and a fourth electrode sheet. The first electrode sheet is joined to the first current collector. The second electrode sheet is joined to the second current collector. The third electrode sheet is joined to the third current collector. The fourth electrode sheet is joined to the fourth current collector. The first current collector and the third current collector are configured from separate members. The second current collector and the fourth current collector are configured from separate members.

Description

Technical Field

[0001] The present technology relates to a secondary battery and a method for manufacturing the same. Background Art

[0002] Japanese Patent No. 4537353 discloses a square secondary battery in which an electrode group (25) is housed in a casing (14) having openings (14a, 14b) at both ends and electrode terminals (21, 23) are respectively attached to cover plates (33, 33') for sealing the openings (14a, 14b).

[0003] In the secondary battery described in Japanese Patent No. 4537353, there is still room for improving the energy density and stably manufacturing the secondary battery. Summary of the invention

[0004] The present technology has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a secondary battery and a secondary battery that can improve energy density and can be manufactured stably.

[0005] The secondary battery based on the present technology comprises a first electrode body, a second electrode body and a shell. The first electrode body and the second electrode body respectively comprise a first electrode and a second electrode having a polarity different from that of the first electrode. The shell accommodates the first electrode body and the second electrode body. The shell comprises a cylindrical shell body, a first sealing plate and a second sealing plate. The shell body has a first opening located at an end of the first side and a second opening located at an end of the second side opposite to the end of the first side. The first sealing plate seals the first opening. The second sealing plate seals the second opening. A first electrode terminal electrically connected to the first electrode is provided on the first sealing plate. A second electrode terminal electrically connected to the second electrode is provided on the second sealing plate. The first electrode body has a first electrode sheet electrically connected to the first electrode at the end on the first sealing plate side, and has a second electrode sheet electrically connected to the second electrode at the end on the second sealing plate side. The second electrode body has a third electrode sheet electrically connected to the first electrode at the end on the first sealing plate side, and has a fourth electrode sheet electrically connected to the second electrode at the end on the second sealing plate side. The first electrode sheet is bonded to the first current collector. The second electrode sheet is bonded to the second current collector. The third electrode sheet is bonded to the third current collector. The fourth electrode sheet is bonded to the fourth current collector. The first current collector and the third current collector are composed of separate components. The second current collector and the fourth current collector are composed of separate components. The first current collector and the third current collector are respectively connected to the fifth current collector electrically connected to the first electrode terminal. The second current collector and the fourth current collector are respectively connected to the sixth current collector electrically connected to the second electrode terminal.

[0006] The secondary battery in the manufacturing method of the secondary battery based on the present technology comprises a first electrode body, a second electrode body and a shell. The first electrode body and the second electrode body respectively include a first electrode and a second electrode having a polarity different from that of the first electrode. The shell accommodates the first electrode body and the second electrode body. The shell includes a cylindrical shell body, a first sealing plate and a second sealing plate. The shell body has a first opening located at an end of the first side and a second opening located at an end of the second side opposite to the first end. The first sealing plate seals the first opening. The second sealing plate seals the second opening. A first electrode terminal electrically connected to the first electrode is provided on the first sealing plate. A second electrode terminal electrically connected to the second electrode is provided on the second sealing plate. The first electrode body has a first electrode sheet electrically connected to the first electrode at the end on the first sealing plate side, and has a second electrode sheet electrically connected to the second electrode at the end on the second sealing plate side. The second electrode body has a third electrode sheet electrically connected to the first electrode at the end on the first sealing plate side, and has a fourth electrode sheet electrically connected to the second electrode at the end on the second sealing plate side. The first electrode sheet is bonded to the first current collector. The second electrode sheet is bonded to the second current collector. The third electrode sheet is bonded to the third current collector. The fourth electrode sheet is bonded to the fourth current collector. The first current collector and the third current collector are composed of separate components. The second current collector and the fourth current collector are composed of separate components. The first current collector and the third current collector are respectively connected to the fifth current collector electrically connected to the first electrode terminal. The second current collector and the fourth current collector are respectively connected to the sixth current collector electrically connected to the second electrode terminal. The manufacturing method of a secondary battery comprises: a step of manufacturing a first electrode body and a second electrode body; a step of joining a first electrode sheet to a first current collector after the first electrode body and the second electrode body are manufactured; a step of joining a second electrode sheet to a second current collector after the first electrode body and the second electrode body are manufactured; a step of joining a third electrode sheet to a third current collector after the first electrode body and the second electrode body are manufactured; a step of joining a fourth electrode sheet to a fourth current collector after the first electrode body and the second electrode body are manufactured; a step of joining the first electrode sheet to the second current collector in a thickness direction of the first electrode body and the second electrode body; A process of overlapping the first electrode body and the second electrode body; a process of connecting the first current collector and the third current collector to the fifth current collector after overlapping the first electrode body and the second electrode body; a process of inserting the first electrode body and the second electrode body into the shell body from the first opening with the second electrode sheet and the fourth electrode sheet as the front end after connecting the first current collector and the third current collector to the fifth current collector; and a process of connecting the second current collector and the fourth current collector protruding from the second opening to the sixth current collector after inserting the first electrode body and the second electrode body into the shell body.

[0007] The so-called "overlapping the first electrode body with the second electrode body" may be made to overlap the first electrode body with the second electrode body directly, or another component may be arranged between the first electrode body and the second electrode body. In addition, the first electrode body and the second electrode body may be fixed by a belt component or the like, or may not be fixed.

[0008] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a front view showing the structure of the secondary battery according to the first embodiment of the present technology.

[0010] Figure 2 It means observing from the direction of arrow II Figure 1 A diagram showing the state of a secondary battery.

[0011] Figure 3 It means observing from the direction of arrow III Figure 1 A diagram showing the state of a secondary battery.

[0012] Figure 4 It means observing from the direction of arrow IV Figure 1 A diagram showing the state of a secondary battery.

[0013] Figure 5 It means when viewed from the direction of arrow V Figure 1 A diagram showing the state of a secondary battery.

[0014] Figure 6 yes Figure 1 A front cross-sectional view of a secondary battery is shown.

[0015] Figure 7 It is a front view showing a negative electrode original plate before forming a negative electrode plate.

[0016] Figure 8 yes Figure 7 The VIII-VIII cross-sectional view of the negative electrode original plate shown.

[0017] Fig. 9 It is a front view showing a negative electrode plate formed from a negative electrode original plate.

[0018] Fig.10 It is a front view showing a positive electrode original plate before forming a positive electrode plate.

[0019] Fig.11 yes Fig.10 XI-XI cross-sectional view of the positive electrode original plate shown.

[0020] Fig.12It is a front view showing a positive electrode plate formed from a positive electrode original plate.

[0021] Fig.13 yes Figure 1 XIII-XIII cross-sectional view of the secondary battery shown.

[0022] Fig.14 yes Figure 1 A XIV-XIV cross-sectional view of the secondary battery shown.

[0023] Fig.15 This is a flowchart showing the method for manufacturing the secondary battery according to the first embodiment.

[0024] Fig.16 It is a perspective view showing a state before two electrode bodies included in the secondary battery of Embodiment 1 are overlapped.

[0025] Fig.17 It is a cross-sectional view showing a state where the electrode sheet is bent.

[0026] Fig.18 It is a perspective view showing a state where a holder and a separator are attached to an electrode body.

[0027] Fig.19 It is a perspective view showing a state where the first sealing plate is attached to the first current collector.

[0028] Fig. 20 yes Fig.19 XX-XX cross-sectional view of the electrode body and the current collector shown.

[0029] Fig.21 It is a perspective view showing a state where the electrode body is inserted into the case body.

[0030] Fig. 22 It is a perspective view showing a state where the second sealing plate is attached to the second current collector.

[0031] Fig.23 yes Fig. 22 XXIII-XXIII cross-sectional view of the electrode body and the current collector shown.

[0032] Fig.24 It means observing from the direction of arrow XXIV Fig. 22 The diagram shows the state of the current collector.

[0033] Fig.25 yes Fig.24 XXV-XXV cross-sectional view of the current collector shown.

[0034] Fig.26 It is a perspective view showing the structure of the secondary battery according to the first embodiment.

[0035] Fig. 27 It is a cross-sectional view showing the structure of a secondary battery according to the second embodiment.

[0036] Fig.28 It is a perspective view showing the structure of a current collector included in a secondary battery according to a third embodiment.

[0037] Fig.29 yes Fig.28 XXIX-XXIX cross-sectional view of the current collector shown.

[0038] Fig.30 It is a perspective view showing the structure of a current collector included in a secondary battery according to a fourth embodiment.

[0039] Fig.31 yes Fig.30 XXXI-XXXI cross-sectional view of the current collector shown.

[0040] Fig.32 It is a perspective view showing the structure of a current collector included in a secondary battery according to the fifth embodiment.

[0041] Fig.33 yes Fig.32 XXXIII-XXXIII cross-sectional view of the current collector shown.

[0042] Fig.34 It is a perspective view showing the structure of a current collector included in a secondary battery according to the sixth embodiment.

[0043] Fig.35 yes Fig.34 XXXV-XXXV cross-sectional view of the current collector shown.

[0044] Fig.36 It is a cross-sectional view showing the structure of a current collector included in a secondary battery according to a seventh embodiment. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the present technology will be described. In addition, the same reference numerals are given to the same or corresponding parts, and the description thereof may not be repeated.

[0046] In addition, in the embodiments described below, when the number, amount, etc. are mentioned, the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, in the following embodiments, except for the cases where there are special records, each component is not necessarily essential to the present technology. In addition, the present technology is not necessarily limited to the technology that has all the effects mentioned in the present embodiment.

[0047] In addition, in this specification, the descriptions of "comprise", "include", and "have" are open forms. That is, when a certain structure is included, other structures other than the structure may or may not be included.

[0048] In addition, in this specification, when geometrical terms and terms indicating position and direction relationships are used, such as "parallel", "orthogonal", "oblique 45 degrees", "coaxial", "along", etc., these terms allow for manufacturing errors or some changes. In this specification, when terms such as "upper side" and "lower side" are used to indicate relative positional relationships, these terms are used to indicate relative positional relationships in one state, and the relative positional relationship can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, turning the entire mechanism upside down, etc.).

[0049] In this specification, "secondary battery" is not limited to lithium-ion batteries, and may include other secondary batteries such as nickel-hydrogen batteries and sodium-ion batteries. In this specification, "electrode" may be collectively referred to as positive electrode and negative electrode.

[0050] In addition, in the drawings, the direction along the winding axis of the electrode body of the secondary battery is set as the X direction, the short side direction of the electrode body when viewed from the X direction is set as the Y direction, and the long side direction of the electrode body when viewed from the X direction is set as the Z direction. In addition, in order to facilitate the understanding of the invention, there are parts in which the dimensions of each structure in the drawings are changed from the actual dimensions.

[0051] In this application specification, the X direction is sometimes referred to as the "width direction" of the secondary battery or the shell body, the Y direction is similarly referred to as the "thickness direction" of the secondary battery or the shell body, and the Z direction is similarly referred to as the "height direction" of the secondary battery or the shell body.

[0052] (Implementation Method 1)

[0053] (Overall structure of the battery)

[0054] Figure 1 It is a front view of the secondary battery 1 according to the present embodiment. Figure 2 to Figure 5 They are respectively viewed from the direction of arrow II, arrow III, arrow IV, and arrow V. Figure 1 The diagram shows the state of the secondary battery 1. Figure 6 yes Figure 1 The secondary battery 1 is shown in front cross-sectional view.

[0055] The secondary battery 1 can be mounted on an electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), etc. However, the use of the secondary battery 1 is not limited to vehicle-mounted use.

[0056] like Figure 1 to Figure 6 As shown, the secondary battery 1 includes a case 100 , an electrode body 200 , an electrode terminal 300 , and a current collector 400 . The case 100 includes a case body 110 , a first sealing plate 120 , and a second sealing plate 130 .

[0057] When forming a battery pack including secondary batteries 1, a plurality of secondary batteries 1 are stacked in their thickness direction. The stacked secondary batteries 1 may be constrained in the stacking direction (Y direction) by a constraining member to form a battery module, or the battery pack may be directly supported by the side surface of the battery pack housing without using a constraining member.

[0058] The case body 110 is formed of a cylindrical, preferably rectangular, member. This provides a rectangular secondary battery 1. The case body 110 is made of metal. Specifically, the case body 110 is made of aluminum, aluminum alloy, iron, or iron alloy.

[0059] like Figure 1 , Figure 2 As shown in FIG. 1 , a first sealing plate 120 and a second sealing plate 130 are provided at both ends of the housing body. The housing body 110 is formed by, for example, bringing the ends of the plate-like members subjected to bending into contact with each other (at Figure 2 The square tube shape can be formed by joining the two members (for example, laser welding) to each other as shown in the joining portion 115 illustrated in FIG. The corners of the "square tube shape" may also have an R shape.

[0060] In the present embodiment, the shell body 110 is formed in the width direction (X direction) of the secondary battery 1 to be longer than the thickness direction (Y direction) and the height direction (Z direction) of the secondary battery 1. The dimension (width) of the shell body 110 in the X direction is preferably more than 30 cm. Thus, a relatively large (high capacity) secondary battery 1 can be formed. The dimension (height) of the shell body 110 in the Z direction is preferably less than 20 cm, more preferably less than 15 cm, and further preferably less than 10 cm. Thus, a secondary battery 1 with a relatively low height (low height) can be formed, for example, the mountability on a vehicle is improved.

[0061] The housing body 110 includes a pair of first side portions 111 and a pair of second side portions 112. The pair of first side portions 111 constitute a portion of the side surface of the housing 100. The pair of second side portions 112 constitute the bottom surface portion and the upper surface portion of the housing 100. The pair of first side portions 111 and the pair of second side portions 112 are arranged to intersect each other. The pair of first side portions 111 and the pair of second side portions 112 are connected at their respective ends. The area of ​​each of the pair of first side portions 111 is preferably larger than the area of ​​each of the pair of second side portions 112.

[0062] like Figure 5 As shown, a second side surface 112A of one of the pair of second side surfaces 112 is provided with an exhaust valve 150. The exhaust valve 150 extends along the width direction (X direction) of the secondary battery 1. The exhaust valve 150 extends from the center of the housing body 110 in the X direction along the X direction to an extent that it does not reach both ends. The exhaust valve 150 can be appropriately changed.

[0063] The thickness of the plate-shaped member in the exhaust valve 150 is formed thinner than the thickness of the plate-shaped member of the housing body 110 other than the exhaust valve 150. Therefore, when the pressure in the housing 100 becomes equal to or higher than a predetermined value, the exhaust valve 150 breaks preferentially compared to other parts in the housing body 110, thereby exhausting the gas in the housing 100 to the outside.

[0064] like Figure 2 As shown, a joint portion 115 is formed on the other second side portion 112B of the pair of second side portions 112. The joint portion 115 extends along the width direction (X direction) of the secondary battery 1. In the joint portion 115, the edge sides of the plate-like members constituting the case body 110 are joined to each other.

[0065] like Figure 3 As shown, a first opening 113 is provided at the end of the first side of the shell body 110 in the first direction (X direction). The first opening 113 is sealed by a first sealing plate 120. A joint 115 is formed in the first opening 113 to seal the first opening 113. The first opening 113 and the first sealing plate 120 are formed into a roughly rectangular shape having a long side direction and a short side direction in a direction intersecting the first direction (X direction) in which the first opening 113 and the second opening 114 are arranged. The first opening 113 and the first sealing plate 120 in the present embodiment have a roughly rectangular shape in which the Y direction is the short side direction and the Z direction is the long side direction. In addition, as a roughly rectangular shape, a substantially rectangular shape such as a rectangular shape or a shape in which the corners of a rectangular shape are R-ed is included.

[0066] A negative electrode terminal 301 (first electrode terminal) is provided on the first sealing plate 120. The position of the negative electrode terminal 301 can be changed as appropriate.

[0067] like Figure 4 As shown, in the shell body 110, a second opening 114 is provided at the end of the second side opposite to the first side in the first direction (X direction). That is, the second opening 114 is located at the end opposite to the first opening 113. The second opening 114 is sealed by the second sealing plate 130. A joint 115 is formed in the second opening 114 to seal the second opening 114. The second opening 114 and the second sealing plate 130 are formed into a roughly rectangular shape having a long side direction and a short side direction in a direction intersecting the first direction (X direction) in which the first opening 113 and the second opening 114 are arranged. The second opening 114 and the second sealing plate 130 in this embodiment have a roughly rectangular shape in which the Y direction is the short side direction and the Z direction is the long side direction.

[0068] The second sealing plate 130 is provided with a positive electrode terminal 302 (second electrode terminal) and a liquid injection hole 134. The positions of the positive electrode terminal 302 and the liquid injection hole 134 can be changed as appropriate.

[0069] The first sealing plate 120 and the second sealing plate 130 are made of metal. Specifically, the first sealing plate 120 and the second sealing plate 130 are made of aluminum, aluminum alloy, iron, iron alloy, or the like.

[0070] The negative electrode terminal 301 is electrically connected to the negative electrode (first electrode) of the electrode body 200 . The negative electrode terminal 301 is attached to the first sealing plate 120 , that is, the case 100 .

[0071] The positive electrode terminal 302 is electrically connected to the positive electrode (second electrode) of the electrode body 200 . The positive electrode terminal 302 is attached to the second sealing plate 130 , that is, the case 100 .

[0072] The negative electrode terminal 301 is made of a conductive material (more specifically, a metal), for example, copper or a copper alloy, etc. A portion or layer made of aluminum or an aluminum alloy may be provided on the outer surface of the negative electrode terminal 301 .

[0073] The positive electrode terminal 302 is made of a conductive material (more specifically, a metal), and can be made of, for example, aluminum or an aluminum alloy.

[0074] The liquid injection hole 134 is sealed by a sealing member (not shown). As the sealing member, for example, a blind rivet or other metal member can be used.

[0075] The electrode body 200 is a flat electrode body having a positive electrode plate and a negative electrode plate described later. Specifically, the electrode body 200 is a wound electrode body formed by winding a strip-shaped positive electrode plate and a strip-shaped negative electrode plate together via a strip-shaped separator not shown. However, in this specification, the "electrode body" is not limited to a wound electrode body, and may also be a stacked electrode body formed by alternately stacking a plurality of positive plates and a plurality of negative plates. The strip-shaped separator can be composed of a polyolefin microporous film, for example. The electrode body includes a plurality of positive plates and a plurality of negative plates, and the positive electrode sheets arranged on each positive plate may also be stacked to form a positive electrode sheet group, and the negative electrode sheets arranged on each negative plate may also be stacked to form a negative electrode sheet group. In addition, the electrode body 200 may include a plurality of wound electrode bodies, or may include a plurality of stacked electrode bodies.

[0076] like Figure 6 As shown, the housing 100 accommodates the electrode body 200. Figure 6 In the embodiment, a first electrode body 201 described later is exemplified. The first electrode body 201 is housed in the case 100 so that its winding axis is parallel to the X direction.

[0077] Specifically, a single or a plurality of wound electrode bodies and an electrolyte (electrolyte) not shown are housed together inside an insulating sheet 700 to be described later and arranged in the housing 100. As the electrolyte (non-aqueous electrolyte), for example, an electrolyte obtained by dissolving LiPF6 at a concentration of 1.2 mol / L in a non-aqueous solvent obtained by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) in a volume ratio (25° C.) of 30:30:40 can be used. In addition, a solid electrolyte may be used instead of the electrolyte.

[0078] The first electrode body 201 includes a main body (a portion in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween), a first electrode sheet 220 (negative electrode sheet group), and a second electrode sheet 250 (positive electrode sheet group).

[0079] The main body is composed of a negative electrode plate 210 and a positive electrode plate 240 described later. The first electrode sheet 220 is located at an end portion of the first electrode body 201 on the first side in the first direction (X direction) relative to the main body. The first side in this embodiment is the first sealing plate 120 side. The second electrode sheet 250 is located at an end portion of the second side of the first electrode body 201 in the first direction (X direction) relative to the main body. The second side in this embodiment is the second sealing plate 130 side.

[0080] The first electrode sheet 220 and the second electrode sheet 250 are formed so as to protrude from the center portion of the electrode body 200 toward the first sealing plate 120 or the second sealing plate 130 , respectively.

[0081] The current collector 400 includes a negative electrode current collector 400A and a positive electrode current collector 400B. The negative electrode current collector 400A and the positive electrode current collector 400B are each formed of a plate-like member. The electrode body 200 is electrically connected to the negative electrode terminal 301 and the positive electrode terminal 302 via the current collector 400 .

[0082] The negative electrode current collector 400A is arranged on the first sealing plate 120 via an insulating member made of resin. The negative electrode current collector 400A is electrically connected to the first electrode sheet 220 and the negative electrode terminal 301. The negative electrode current collector 400A is made of a conductive material (more specifically, a metal), for example, copper or a copper alloy. In addition, the details of the negative electrode current collector 400A will be described later.

[0083] The positive electrode collector 400B is arranged on the second sealing plate 130 via an insulating member made of resin. The positive electrode collector 400B is electrically connected to the second electrode sheet 250 and the positive terminal 302. The positive electrode collector 400B is composed of a conductive material (more specifically, a metal), for example, it can be composed of aluminum or an aluminum alloy. In addition, the second electrode sheet 250 can also be electrically connected to the second sealing plate 130 directly, or electrically connected to the second sealing plate 130 via the positive electrode collector 400B. In this case, the second sealing plate 130 can also play the role of the positive terminal 302. In addition, the details of the positive electrode collector 400B will be described later.

[0084] (Structure of Electrode Body 200)

[0085] Figure 7 2 is a front view showing a negative electrode original plate 210S before forming a negative electrode plate 210 (first electrode). Figure 8 yes Figure 7 The VIII-VIII cross-sectional view of the negative electrode original plate 210S shown in FIG. Fig. 9 1 is a front view showing a negative electrode plate 210 formed from a negative electrode original plate 210S.

[0086] The negative electrode plate 210 is manufactured by processing a negative electrode original plate 210S. Figure 7 and Figure 8 As shown, the negative electrode original plate 210S includes a negative electrode core 211 and a negative electrode active material layer 212. The negative electrode core 211 is a copper foil or a copper alloy foil.

[0087] The negative electrode core 211 has a negative electrode active material layer 212 formed thereon except for one end portion of both surfaces. The negative electrode active material layer 212 is formed by applying a negative electrode active material layer slurry using a die coater.

[0088] The negative electrode active material layer slurry is prepared by kneading graphite as a negative electrode active material, styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as binders, and water as a dispersion medium so that the mass ratio of graphite:SBR:CMC is about 98:1:1.

[0089] The negative electrode core 211 coated with the negative electrode active material layer slurry is dried and the water contained in the negative electrode active material layer slurry is removed to form the negative electrode active material layer 212. Furthermore, the negative electrode original plate 210S including the negative electrode core 211 and the negative electrode active material layer 212 is formed by compressing the negative electrode active material layer 212. The negative electrode original plate 210S is cut into a predetermined shape to form the negative electrode plate 210. The negative electrode original plate 210S can be cut by laser processing based on energy line irradiation, metal mold processing, or tool processing.

[0090] like Fig. 9 As shown, at one end in the width direction of the negative electrode plate 210 formed by the negative electrode original plate 210S, a plurality of negative electrode sheets 230 formed by the negative electrode core 211 are provided. When the negative electrode plate 210 is wound, the plurality of negative electrode sheets 230 are stacked to form the first electrode sheet 220. Thus, the first electrode sheet 220 is connected to the negative electrode plate 210 (first electrode). The positions of the respective plurality of negative electrode sheets 230 and the lengths in the protruding direction are appropriately adjusted in consideration of the state in which the first electrode sheet 220 is connected to the negative electrode collector 400A. In addition, the shape of the negative electrode sheet 230 is not limited to Figure 8 The shape illustrated in .

[0091] Fig.10 2 is a front view showing a positive electrode original plate 240S before forming a positive electrode plate 240 (second electrode). Fig.11 yes Fig.10 The XI-XI cross-sectional view of the positive electrode original plate 240S shown in FIG. Fig.12 1 is a front view showing a positive electrode plate 240 formed of a positive electrode original plate 240S.

[0092] The positive electrode plate 240 as the second electrode has a different polarity from the negative electrode plate 210 as the first electrode. The positive electrode plate 240 is manufactured by processing a positive electrode original plate 240S. Fig.10 and Fig.11 As shown, the positive electrode original plate 240S includes a positive electrode core 241, a positive electrode active material layer 242, and a positive electrode protective layer 243. The positive electrode core 241 is an aluminum foil or an aluminum alloy foil.

[0093] The positive electrode core body 241 has a positive electrode active material layer 242 formed thereon except for one end portion of both surfaces. The positive electrode active material layer 242 is formed on the positive electrode core body 241 by applying a positive electrode active material layer slurry using a die coater.

[0094] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as a positive electrode active material, polyvinylidene fluoride (PVdF) as a binding material, a carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium in such a manner that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material becomes approximately 97.5:1:1.5.

[0095] The positive electrode protection layer 243 is in contact with the positive electrode core 241 and is formed at one end of the positive electrode active material layer 242 in the width direction. The positive electrode protection layer 243 is formed on the positive electrode core 241 by applying the positive electrode protection layer slurry using a die coater. The positive electrode protection layer 243 has a resistance greater than that of the positive electrode active material layer 242.

[0096] The positive electrode protective layer slurry was prepared by kneading alumina powder, a carbon material as a conductive material, PVdF as a binder, and NMP as a dispersion medium so that the mass ratio of alumina powder:carbon material:PVdF was about 83:3:14.

[0097] The positive electrode core 241 coated with the positive electrode active material layer slurry and the positive electrode protective layer slurry is dried and the NMP contained in the positive electrode active material layer slurry and the positive electrode protective layer slurry is removed to form the positive electrode active material layer 242 and the positive electrode protective layer 243. Furthermore, the positive electrode original plate 240S including the positive electrode core 241, the positive electrode active material layer 242 and the positive electrode protective layer 243 is formed by compressing the positive electrode active material layer 242. The positive electrode plate 240 is formed by cutting the positive electrode original plate 240S into a predetermined shape. The positive electrode original plate 240S can be cut by laser processing based on energy line irradiation, metal mold processing, or tool processing.

[0098] like Fig.12 As shown, at one end portion in the width direction of the positive electrode plate 240 formed by the positive electrode original plate 240S, a plurality of positive electrode sheets 260 formed by the positive electrode core 241 are provided. When the positive electrode plate 240 is wound, the plurality of positive electrode sheets 260 are stacked to form the second electrode sheet 250. Thus, the second electrode sheet 250 is connected to the positive electrode plate 240 (the second electrode). The positions of the respective plurality of positive electrode sheets 260 and the lengths in the protruding direction are appropriately adjusted in consideration of the state in which the second electrode sheet 250 is connected to the positive electrode collector 400B. In addition, the shape of the positive electrode sheet 260 is not limited to Fig.12 The shape illustrated in .

[0099] A positive electrode protection layer 243 is provided at the root of each of the plurality of positive electrode sheets 260. The positive electrode protection layer 243 does not necessarily need to be provided at the root of the positive electrode sheet 260.

[0100] In a typical example, the thickness of the negative electrode sheet 230 (one sheet) is smaller than the thickness of the positive electrode sheet 260 (one sheet). In this case, the thickness of the first electrode sheet 220 is smaller than the thickness of the second electrode sheet 250.

[0101] (Connection Structure of Electrode Body 200 and Current Collector 400)

[0102] Fig.13 yes Figure 1 The XIII-XIII cross-sectional view of the secondary battery shown in FIG. Fig.13 As shown, the electrode body 200 includes a first electrode body 201 and a second electrode body 202. The first electrode body 201 and the second electrode body 202 include a first electrode (negative electrode) and a second electrode (positive electrode), respectively. Alternatively, the electrode body 200 may be composed of three or more electrode bodies.

[0103] The electrode body 200 is formed by overlapping a first electrode body 201 and a second electrode body 202. The first electrode body 201 and the second electrode body 202 are arranged in the thickness direction (Y direction) of the first electrode body 201 and the second electrode body 202.

[0104] The first electrode body 201 includes a first electrode sheet 220. The first electrode sheet 220 is electrically connected to the first electrode at a first end 205 on the first sealing plate 120 side in the X direction. The second electrode body 202 includes a third electrode sheet 270. The third electrode sheet 270 is electrically connected to the first electrode at a third end 207 on the first sealing plate 120 side in the X direction.

[0105] The first electrode sheet 220 has a bent portion 221 and a front end portion 222. The bent portion 221 is a portion of the first electrode sheet 220 bent on the side connected to the first electrode relative to the front end portion 222. The front end portion 222 is a portion of the first electrode sheet 220 located on the side opposite to the side connected to the first electrode.

[0106] The third electrode sheet 270 has a bent portion 271 and a front end portion 272. The bent portion 271 is a portion of the third electrode sheet 270 bent on the side connected to the first electrode relative to the front end portion 272. The front end portion 272 is a portion of the third electrode sheet 270 located on the side opposite to the side connected to the first electrode.

[0107] The first electrode sheet 220 and the third electrode sheet 270 are bent in opposite directions so that the front ends 222 and 272 approach each other. In the present embodiment, the front ends 222 and 272 are separated, but the present invention is not limited to this structure, and the front ends 222 and 272 may be in contact with each other.

[0108] The negative electrode current collector 400A electrically connects the negative electrode terminal 301 to the first electrode sheet 220 and the third electrode sheet 270. The negative electrode current collector 400A in this embodiment is connected to the negative electrode terminal 301 between the electrode body 200 and the first sealing plate 120.

[0109] The negative electrode current collector 400A includes a first current collector 410 , a third current collector 430 , and a fifth current collector 450 .

[0110] The first current collector 410 is a plate-shaped component. The first current collector 410 has a long side direction in the Z direction and a short side direction in the Y direction. The third current collector 430 is a plate-shaped component. The third current collector 430 has a long side direction in the Z direction and a short side direction in the Y direction. The first current collector 410 and the third current collector 430 are arranged side by side in the Y direction. In this way, the first current collector 410 and the third current collector 430 are composed of independent components.

[0111] The first electrode sheet 220 is joined to the first current collector 410 at a joining portion 411 described later. The third electrode sheet 270 is joined to the third current collector 430 at a joining portion 431 described later. The joining portions 411 and 431 can be formed, for example, by ultrasonic welding, resistance welding, laser welding, riveting, etc. In the present embodiment, the first electrode sheet 220 and the first current collector 410, and the third electrode sheet 270 and the third current collector 430 are joined, for example, by ultrasonic bonding.

[0112] The fifth current collector 450 is electrically connected to the first current collector 410 and the third current collector 430 at a joint portion located at an end in the Z direction described later. The fifth current collector 450 is electrically connected to the negative electrode terminal 301. The connection between the fifth current collector 450 and the negative electrode terminal 301 can be formed by caulking and / or welding, for example.

[0113] The negative electrode terminal 301 is provided so as to be exposed outside the first sealing plate 120 and reach the fifth current collector 450 of the negative electrode current collector 400A provided on the inner surface side of the first sealing plate 120 . The negative electrode terminal 301 is connected to the first plate portion 303 .

[0114] The first plate portion 303 is located outside the first sealing plate 120. The first plate portion 303 is arranged along the first sealing plate 120. The first plate portion 303 has conductivity. The first plate portion 303 is arranged to ensure a connection area with a bus bar or the like that electrically connects the secondary battery 1 to other adjacent secondary batteries. The connection between the negative terminal 301 and the first plate portion 303 can be formed by, for example, laser welding or the like.

[0115] A first insulating member 510 is disposed between the first plate portion 303 and the first sealing plate 120 . A second insulating member 520 is disposed between the negative electrode terminal 301 and the first sealing plate 120 . A third insulating member 530 is disposed between the fifth current collector 450 and the first sealing plate 120 .

[0116] However, the negative electrode terminal 301 may be electrically connected to the first sealing plate 120 . In addition, the first sealing plate 120 may also function as the negative electrode terminal 301 .

[0117] A separator 600 is disposed between the first sealing plate 120 and the electrode body 200. The separator 600 is made of an insulating resin member. The separator 600 includes a first member 610 and a second member 620. The first member 610 and the second member 620 are engaged with each other at engaging portions (not shown) at both ends in the Z direction.

[0118] The end portions of the first member 610 and the second member 620 on the electrode body 200 side in the X direction protrude in the Y direction. Thus, the spacer 600 plays a guiding role when the bent portions 221 and 271 are bent, so that the bent portions 221 and 271 are easily bent.

[0119] An insulating sheet 700 (electrode body holder) made of resin is arranged between the electrode body 200 and the case body 110. The insulating sheet 700 may be made of resin, for example. More specifically, the material of the insulating sheet 700 may be polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0120] Fig.14 yes Figure 1 The XIV-XIV cross-sectional view of the secondary battery shown. The first electrode body 201 includes a second electrode sheet 250. The second electrode sheet 250 is electrically connected to the second electrode at a second end 206 on the second sealing plate 130 side in the X direction. The second electrode body 202 includes a fourth electrode sheet 280. The fourth electrode sheet 280 is electrically connected to the second electrode at a fourth end 208 on the second sealing plate 130 side in the X direction.

[0121] The second electrode sheet 250 has a bent portion 251 and a front end portion 252. The bent portion 251 is a portion of the second electrode sheet 250 bent on the side connected to the second electrode relative to the front end portion 252. The front end portion 252 is a portion of the second electrode sheet 250 located on the side opposite to the side connected to the second electrode.

[0122] The fourth electrode sheet 280 has a bent portion 281 and a front end portion 282. The bent portion 281 is a portion of the fourth electrode sheet 280 bent on the side connected to the second electrode relative to the front end portion 282. The front end portion 282 is a portion of the fourth electrode sheet 280 located on the side opposite to the side connected to the second electrode.

[0123] The second electrode sheet 250 and the fourth electrode sheet 280 are bent in opposite directions so that the front ends 252 and 282 approach each other. In this embodiment, the front ends 252 and 282 are separated, but the present invention is not limited to this structure, and the front ends 252 and 282 may be in contact with each other.

[0124] The positive electrode current collector 400B electrically connects the positive electrode terminal 302 to the second electrode sheet 250 and the fourth electrode sheet 280. The positive electrode current collector 400B in this embodiment is connected to the positive electrode terminal 302 between the electrode body 200 and the second sealing plate 130.

[0125] The positive electrode current collector 400B includes a second current collector 420 , a fourth current collector 440 , and a sixth current collector 460 .

[0126] The second current collector 420 is a plate-shaped component. The second current collector 420 has a long side direction in the Z direction and a short side direction in the Y direction. The fourth current collector 440 is a plate-shaped component. The fourth current collector 440 has a long side direction in the Z direction and a short side direction in the Y direction. The second current collector 420 and the fourth current collector 440 are arranged side by side in the Y direction. In this way, the second current collector 420 and the fourth current collector 440 are composed of independent components.

[0127] The second electrode sheet 250 is joined to the second current collector 420 at a joining portion 421 described later. The fourth electrode sheet 280 is joined to the fourth current collector 440 at a joining portion 441 described later. The joining portions 421 and 441 can be formed, for example, by ultrasonic welding, resistance welding, laser welding, riveting, etc. In the present embodiment, the second electrode sheet 250 and the second current collector 420, and the fourth electrode sheet 280 and the fourth current collector 440 are joined, for example, by ultrasonic bonding.

[0128] The sixth current collector 460 is electrically connected to the second current collector 420 and the fourth current collector 440 at a joint portion located at an end in the Z direction described later. The sixth current collector 460 is electrically connected to the positive electrode terminal 302. The connection between the sixth current collector 460 and the positive electrode terminal 302 can be formed by caulking and / or welding, for example.

[0129] The positive electrode terminal 302 is provided so as to be exposed outside the second sealing plate 130 and reach the sixth current collector 460 of the positive electrode current collector 400B provided on the inner surface side of the second sealing plate 130 . The positive electrode terminal 302 is connected to the second plate portion 304 .

[0130] The second plate portion 304 is located outside the second sealing plate 130. The second plate portion 304 is arranged along the second sealing plate 130. The second plate portion 304 has conductivity. The second plate portion 304 is arranged to ensure a connection area with a bus bar or the like that electrically connects the secondary battery 1 to other adjacent secondary batteries. The connection between the positive terminal 302 and the second plate portion 304 can be formed by, for example, laser welding or the like.

[0131] A first insulating member 510 is disposed between the second plate portion 304 and the second sealing plate 130 . A second insulating member 520 is disposed between the positive electrode terminal 302 and the second sealing plate 130 . A third insulating member 530 is disposed between the sixth current collector 460 and the second sealing plate 130 .

[0132] However, the positive electrode terminal 302 may be electrically connected to the second sealing plate 130 . In addition, the second sealing plate 130 may also play the role of the positive electrode terminal 302 .

[0133] A separator 600 is disposed between the second sealing plate 130 and the electrode body 200. The separator 600 is made of an insulating resin member. The separator 600 includes a first member 610 and a second member 620. The first member 610 and the second member 620 are engaged with each other at engaging portions (not shown) at both ends in the Z direction.

[0134] The end portions of the first member 610 and the second member 620 on the electrode body 200 side in the X direction protrude in the Y direction. Thus, the spacer 600 plays a guiding role when the bent portions 251 and 281 are bent, so that the bent portions 251 and 281 are easily bent.

[0135] An insulating sheet 700 (electrode body holder) made of resin is arranged between the electrode body 200 and the case body 110 .

[0136] (Manufacturing process of secondary battery 1)

[0137] Hereinafter, a method for manufacturing the secondary battery of this embodiment will be described. Fig.15 This is a flowchart showing the method for manufacturing the secondary battery according to the first embodiment. Fig.16 It is a perspective view showing a state before two electrode bodies included in the secondary battery of Embodiment 1 are overlapped.

[0138] like Fig.15As shown, in the manufacturing method of the secondary battery of the present embodiment, first, the first electrode body 201 and the second electrode body 202 are made (S1 process). For each of the first electrode sheet 220, the second electrode sheet 250, the third electrode sheet 270 and the fourth electrode sheet 280, a part of the front end is cut off so that the length of the front end becomes the same length when they are bundled.

[0139] like Fig.15 and Fig.16 As shown, after the first electrode body 201 and the second electrode body 202 are manufactured, the first electrode sheet 220 is joined to the first current collector 410 (S2 process). The first electrode sheet 220 is joined to the first current collector 410 at the joining portion 411. Next, the second electrode sheet 250 is joined to the second current collector 420 (S3 process). The second electrode sheet 250 is joined to the second current collector 420 at the joining portion 421. Next, the third electrode sheet 270 is joined to the third current collector 430 (S4 process). The third electrode sheet 270 is joined to the third current collector 430 at the joining portion 431. Next, the fourth electrode sheet 280 is joined to the fourth current collector 440 (S5 process). The fourth electrode sheet 280 is joined to the fourth current collector 440 at the joining portion 441.

[0140] In the height direction of the first electrode body 201 and the second electrode body 202, the first current collector 410, the second current collector 420, the third current collector 430 and the fourth current collector 440 are arranged offset to one side of the center of the first electrode body 201 and the second electrode body 202. Thus, since the current collector can be configured to be shorter, the current collector can be made small.

[0141] In addition, the first current collector 410, the second current collector 420, the third current collector 430, and the fourth current collector 440 are not limited to this structure. The first current collector 410, the second current collector 420, the third current collector 430, and the fourth current collector 440 may also be arranged at the center of the first electrode body 201 and the second electrode body 202 in the height direction of the first electrode body 201 and the second electrode body 202. In this case, in the height direction of the first electrode body 201 and the second electrode body 202, in coordination with the first current collector 410, the second current collector 420, the third current collector 430, and the fourth current collector 440, the first electrode sheet 220, the second electrode sheet 250, the third electrode sheet 270, and the fourth electrode sheet 280 are each arranged at the center of the first electrode body 201 and the second electrode body 202.

[0142] The order of the steps of joining the first current collector 410 , the second current collector 420 , the third current collector 430 , and the fourth current collector 440 to the first electrode body 201 and the second electrode body 202 , respectively, is not limited to the above-described order, and the order may be changed.

[0143] Fig.17 2 is a cross-sectional view showing a state where the electrode sheet is bent. Figure 15 to Figure 17 As shown in FIG. 1 , next, the first electrode body 201 and the second electrode body 202 are overlapped in the thickness direction of the first electrode body 201 and the second electrode body 202 (step S6 ). Fig.16 The first electrode body 201 and the second electrode body 202 are overlapped in the direction of the arrow. That is, the first electrode body 201 and the second electrode body 202 are combined into one.

[0144] The so-called "overlapping the first electrode body with the second electrode body" may be made to overlap the first electrode body with the second electrode body directly, or another component may be arranged between the first electrode body and the second electrode body. In addition, the first electrode body and the second electrode body may be fixed by a belt component or the like, or may not be fixed.

[0145] exist Fig.17 The first electrode sheet 220, the second electrode sheet 250, the third electrode sheet 270, and the fourth electrode sheet 280 are respectively bent in the direction of the arrow in FIG. Thus, the first electrode sheet 220 and the third electrode sheet 270 are arranged so that the front ends thereof face each other. In addition, the second electrode sheet 250 and the fourth electrode sheet 280 are arranged so that the front ends thereof face each other.

[0146] In addition, the process of overlapping the first electrode body 201 and the second electrode body 202 is preferably performed before the process of respectively joining the first current collector 410, the second current collector 420, the third current collector 430, and the fourth current collector 440 to the first electrode body 201 and the second electrode body 202. In addition, the process of overlapping the first electrode body 201 and the second electrode body 202 may also be performed in the middle of each of the processes of respectively joining the first current collector 410, the second current collector 420, the third current collector 430, and the fourth current collector 440.

[0147] Fig.18 1 is a perspective view showing a state where a retainer and a separator are installed on an electrode body. Fig.15 and Fig.18 As shown, next, the separator 600 and the insulating sheet 700 are assembled to the electrode body 200 (step S7 ).

[0148] In addition, the insulating sheet 700 does not necessarily need to cover the entire surface of the electrode body 200. The insulating sheet 700 preferably covers an area of ​​50% or more of the outer surface of the electrode body, and more preferably covers an area of ​​70% or more. The insulating sheet 700 preferably covers the entirety of at least four of the six surfaces of the substantially rectangular parallelepiped (flat) electrode body 200, excluding the two surfaces on which the first electrode sheet 220 and the second electrode sheet 250 are formed.

[0149] Fig.19 It is a perspective view showing a state where the first sealing plate is attached to the first current collector. Fig. 20 yes Fig.19 XX-XX cross-sectional view of the electrode body and the current collector shown.

[0150] like Fig.15 , Fig.19 and Fig. 20 As shown, after the first electrode body 201 and the second electrode body 202 are overlapped, the first current collector 410 and the third current collector 430 are connected to the fifth current collector 450 (step S8).

[0151] In addition, the S8 step can be performed before the S7 step. By performing the S8 step before the S7 step, when the negative terminal 301 is electrically connected to the first electrode sheet 220 and the third electrode sheet 270, it is easy to connect more stably. In addition, it is easy to form a structure with a smaller space between the first sealing plate 120 and the main body of the electrode body 200.

[0152] The first electrode sheet 220 and the third electrode sheet 270 are bent so that the front end portions 222 and 272 face each other.

[0153] The negative terminal 301 and the fifth current collector 450 are mounted on the first sealing plate 120 via an insulating member. The fifth current collector 450 is brought into contact with the first current collector 410 and the third current collector 430 in the X direction. The fifth current collector 450 is joined to the first current collector 410 and the third current collector 430 by laser welding between the first sealing plate 120 and the insulating sheet 700. In addition, the connection of the first plate portion 303 to the negative terminal 301 can be made at any time.

[0154] The first current collector 410 , the third current collector 430 , and the fifth current collector 450 may be connected by welding in the same manner as the second current collector 420 , the fourth current collector 440 , and the sixth current collector 460 described below.

[0155] Specifically, when viewed in the long side direction (Y direction) of the first sealing plate 120, the first current collector 410 and the fifth current collector 450 define a third overlapping region that overlaps each other at the end side (upper end in the Z direction) in the long side direction of the first sealing plate 120. In addition, when viewed in the long side direction (Y direction) of the first sealing plate 120, the third current collector 430 and the fifth current collector 450 define a fourth overlapping region that overlaps each other at the end side (upper end in the Z direction) in the long side direction of the first sealing plate 120.

[0156] In the third overlapping region, the first current collector 410 and the fifth current collector 450 are connected by welding. In addition, in the fourth overlapping region, the third current collector 430 and the fifth current collector 450 are connected by welding.

[0157] Fig.21 2 is a perspective view showing a state where an electrode body is inserted into a shell body. Fig.15 and Fig.21 As shown, after the first current collector 410 and the third current collector 430 are connected to the fifth current collector 450, the first electrode body 201 and the second electrode body 202 are inserted into the case body 110 from the first opening 113 with the second electrode sheet 250 and the fourth electrode sheet 280 side as the front (S9 process).

[0158] The first sealing plate 120 is brought into contact with the housing body 110. As a result, the first electrode sheet 220 and the third electrode sheet 270 are bent. Fig.13 As shown, the first electrode sheet 220 and the third electrode sheet 270 are bent along the shape of the separator 600 so that the folded-back portions of the bent portions 221 and 271 approach the case body 110 in the Y direction.

[0159] Thereafter, the first sealing plate 120 is temporarily joined to the case body 110. By temporarily joining, the first sealing plate 120 is partially joined to the first opening 113 of the case body 110. Thus, the first sealing plate 120 is positioned relative to the case body 110.

[0160] When the electrode body 200 is inserted into the case body 110, the electrode body 200 may be pulled from the second current collector 420 and the fourth current collector 440, or may be pressed from the first current collector 410 and the third current collector 430. When the electrode body 200 is pressed from the first current collector 410 and the third current collector 430, the first electrode sheet 220 and the third electrode sheet 270 may be bent at the same time.

[0161] Fig. 22 It is a perspective view showing a state where the second sealing plate is attached to the second current collector. Fig.23 yes Fig. 22XXIII-XXIII cross-sectional view of the electrode body and the current collector shown. Fig.24 It means observing from the direction of arrow XXIV Fig. 22 The diagram shows the state of the current collector. Fig.25 yes Fig.24 XXV-XXV cross-sectional view of the current collector shown in FIG. Fig.23 , the housing body 110 is omitted.

[0162] like Fig.15 and Figure 22 to Figure 25 As shown, after the first electrode body 201 and the second electrode body 202 are inserted into the case body 110 , the second current collector 420 and the fourth current collector 440 protruding from the second opening 114 are connected to the sixth current collector 460 (step S10 ).

[0163] Specifically, the positive electrode terminal 302 and the sixth current collector 460 are attached to the second sealing plate 130 via an insulating member. The sixth current collector 460 is brought into contact with the second current collector 420 in the X direction. The second plate portion 304 may be connected to the positive electrode terminal 302 at any time.

[0164] like Fig.24 and Fig.25 As shown, the second current collector 420, the fourth current collector 440, and the sixth current collector 460 in this embodiment have a folded portion F at the end in the Z direction. The folded portion F is along the X direction. By making the folded portion F along the X direction, the high energy line 2 can be irradiated from a direction parallel to the Z direction, so that the high energy line 2 can be less likely to interfere with the housing body 110 or the second sealing plate 130. The high energy line is, for example, a laser.

[0165] The second current collector 420 and the sixth current collector 460 overlap each other in a first overlapping region R11 at the ends in the longitudinal direction when viewed in the longitudinal direction (Y direction) of the second sealing plate 130. The first overlapping region R11 is formed by aligning the folded portions F in the Z direction.

[0166] Furthermore, the fourth current collector 440 and the sixth current collector 460 overlap each other in a second overlapping region R12 at the end sides in the longitudinal direction when viewed in the longitudinal direction (Y direction) of the second sealing plate 130. The second overlapping region R12 is formed by arranging the folded portions F in the Z direction.

[0167] When the second current collector 420 and the fourth current collector 440 are connected to the sixth current collector 460, the high energy line 2 is irradiated to at least one of the second current collector 420 and the sixth current collector 460 from between the second sealing plate 130 and the end of the case body 110 on the second opening 114 side to weld the second current collector 420 and the sixth current collector 460. In addition, the high energy line 2 is irradiated to at least one of the fourth current collector 440 and the sixth current collector 460 from between the second sealing plate 130 and the end of the case body 110 on the second opening 114 side to weld the fourth current collector 440 and the sixth current collector 460.

[0168] In the first overlapping region R11, the second current collector 420 and the sixth current collector 460 are connected by welding. In the present embodiment, the second current collector 420 and the sixth current collector 460 are connected by welding at the welding position P1 in the first overlapping region R11.

[0169] In the second overlapping region R12, the fourth current collector 440 and the sixth current collector 460 are connected by welding. In the present embodiment, the fourth current collector 440 and the sixth current collector 460 are connected by welding at the welding position P2 in the second overlapping region R12.

[0170] The second current collector 420 or the fourth current collector 440 and the sixth current collector 460 are welded by penetration welding, for example. The sixth current collector 460 may be provided with a thin wall portion and the current collectors may be welded together at the thin wall portion, or the sixth current collector 460 may be provided with a through hole and the current collectors may be welded together at a position away from the through hole.

[0171] The second electrode sheet 250 and the fourth electrode sheet 280 are bent so that the front end portions 252 and 282 face each other. The second sealing plate 130 is brought into contact with the housing body 110. Thus, the second electrode sheet 250 and the fourth electrode sheet 280 are bent. Fig.14 As shown, the second electrode sheet 250 and the fourth electrode sheet 280 are bent along the shape of the separator 600 so that the folded-back portions of the bent portions 251 and 281 approach the case body 110 in the Y direction.

[0172] Thereafter, the second sealing plate 130 is temporarily welded to the case body 110. By temporarily joining, the second sealing plate 130 is partially joined to the second opening 114 of the case body 110. Thus, the second sealing plate 130 is positioned relative to the case body 110.

[0173] Fig.26 1 is a perspective view showing the structure of a secondary battery according to Embodiment 1. Fig.15 and Fig.26As shown, next, the first sealing plate 120 and the second sealing plate 130 are joined to the housing body 110 (step S11). The first sealing plate 120 seals the first opening 113 of the housing body 110, and the second sealing plate 130 seals the second opening 114 of the housing body 110. Thus, the first electrode body 201 and the second electrode body 202 are accommodated in the housing 100.

[0174] After the above steps, a leakage check and other inspections are performed (S12 step). After the leakage check, the secondary battery 1 is dried to remove moisture in the shell 100. Then, the electrolyte is injected into the interior of the shell 100 from the injection hole 134. When injecting the electrolyte, the second sealing plate 130 is located at the top and the first sealing plate 120 is located at the bottom, so that the shell 100 is tilted, and the electrolyte is injected into the interior of the shell 100 from the injection hole 134 of the second sealing plate 130. After that, exhaust charging is performed. During exhaust charging, the injection hole 134 can also be temporarily sealed. After that, the injection hole is sealed, and the secondary battery 1 is completed.

[0175] In the secondary battery 1 and the manufacturing method thereof according to the first embodiment of the present technology, by providing the first electrode sheet 220 and the second electrode sheet 250 in the first electrode body 201 and providing the third electrode sheet 270 and the fourth electrode sheet 280 in the second electrode body 202, it is possible to form a structure in which the first electrode body 201 and the second electrode body 202 each have an electrode sheet. With this structure, the electrode sheet can be shortened compared to the case where the first electrode body 201 and the second electrode body 202 form an integral electrode sheet and the electrode sheet is bent. As a result, the volume occupied by the electrode sheet can be reduced, so the energy density of the secondary battery 1 can be improved. In addition, in the structure in which the electrode sheet is provided in the first electrode body 201 and the second electrode body 202, the electrode sheet is easy to bend compared to the case in which the first electrode body 201 and the second electrode body 202 form an integral electrode sheet, so it is easy to join the electrode sheet with the collector, and the secondary battery can be stably manufactured. In particular, by being able to stably manufacture the secondary battery 1, the reliability of the connection between the electrode sheet and the collector can be improved.

[0176] In the secondary battery 1 and the manufacturing method thereof according to the first embodiment of the present technology, by providing the first overlapping region R11 where the second current collector 420 overlaps with the sixth current collector 460, and the second overlapping region R12 where the fourth current collector 440 overlaps with the sixth current collector 460, it is possible to ensure the weldable region between the current collectors, thereby stably connecting the current collectors to each other. When the current collectors are connected to each other by irradiating the high energy line 2 from between the second opening 114 of the case body 110 and the second sealing plate 130, it is possible to easily ensure the weldable range between the current collectors for irradiation of the high energy line 2 from the second direction (Z direction) intersecting the first direction in which the first opening 113 and the second opening 114 are arranged.

[0177] In the secondary battery 1 and the manufacturing method thereof according to the first embodiment of the present technology, by providing the third overlapping region where the first current collector 410 overlaps with the fifth current collector 450 and the fourth overlapping region where the third current collector 430 overlaps with the fifth current collector 450, it is possible to ensure the weldable region between the current collectors, thereby stably connecting the current collectors to each other. When the current collectors are connected to each other by irradiating high-energy rays from between the first opening 113 of the case body 110 and the first sealing plate 120, it is possible to easily ensure the weldable range between the current collectors for irradiation of high-energy rays from the second direction (Z direction) intersecting the first direction in which the first opening 113 and the second opening 114 are arranged.

[0178] In the manufacturing method of the secondary battery 1 of the first embodiment of the present technology, the second current collector 420 and the sixth current collector 460 are welded by irradiating the high-energy line 2 from between the second sealing plate 130 and the end of the shell body 110 on the side of the second opening 114 to the second current collector 420 and the sixth current collector 460, and the fourth current collector 440 and the sixth current collector 460 are welded by irradiating the high-energy line 2 from between the second sealing plate 130 and the end of the shell body 110 on the side of the second opening 114 to the second current collector 420 and the sixth current collector 460, and the fourth current collector 440 and the sixth current collector 460 are welded to the fourth current collector 440 and the sixth current collector 460, so that the current collectors on the side of the second opening 114 can be stably connected to each other after the electrode body 200 is inserted into the shell body 110.

[0179] The secondary battery of Embodiment 2 is described below. Since the connection structure between the electrode body and the current collector is different from that of the secondary battery 1 of Embodiment 1 of the present technology, the same structure as that of the secondary battery 1 of Embodiment 1 of the present technology will not be described repeatedly.

[0180] (Implementation Method 2)

[0181] Fig. 27 2 is a cross-sectional view showing the structure of a secondary battery according to Embodiment 2. Fig. 27As shown, in the secondary battery of the second embodiment, the front end portions 222A and 272A of the first electrode sheet 220A and the third electrode sheet 270A are bent in the same direction in the Y direction.

[0182] After that, the first electrode body 201A and the second electrode body 202A are inserted into the housing body, and the first sealing plate 120 is brought into contact with the housing body. As a result, the first electrode sheet 220A and the third electrode sheet 270A are bent in the same direction in such a manner that the front end portions 222A and 272A located at the ends opposite to the side connected to the first electrode face the same direction. In order to make it easier for the front end portions 222A and 272A to bend in the same direction, the third component 630A of the separator 600A is provided between the first electrode sheet 220A and the third electrode sheet 270A.

[0183] By making the front end portions 222A and 272A of the first electrode sheet 220A and the third electrode sheet 270A bent in the same direction in the Y direction, and the front end portions of the second electrode sheet and the fourth electrode sheet bent in the same direction in the Y direction, the first electrode body 201A having the first current collector 410 and the second current collector 420 mounted thereon, and the second electrode body 202A having the third current collector 430 and the fourth current collector 440 mounted thereon can be prepared with the same structure. Thus, the first electrode body 201A having the first current collector 410 and the second current collector 420 mounted thereon, and the second electrode body 202A having the third current collector 430 and the fourth current collector 440 mounted thereon can be configured as one type and can be easily manufactured.

[0184] The following describes the secondary batteries of Embodiments 3 to 7. Since the connection structure between the current collectors of the secondary batteries of Embodiments 3 to 7 is different from that of the secondary battery 1 of Embodiment 1 of the present technology, the same structure as that of the secondary battery 1 of Embodiment 1 of the present technology and the same structure between Embodiments 3 to 7 will not be described repeatedly.

[0185] (Implementation 3)

[0186] Fig.28 It is a perspective view showing the structure of a current collector included in a secondary battery according to a third embodiment. Fig.29 yes Fig.28 XXIX-XXIX cross-sectional view of the current collector shown.

[0187] like Fig.28 and Fig.29 As shown, the second current collector 420B, the fourth current collector 440B, and the sixth current collector 460B in this embodiment each have a folded portion F on the end side in the Z direction. The folded portion F is folded back to be inclined from the YZ plane and to have a convex shape toward the case body 110 .

[0188] The second current collector 420B, the fourth current collector 440B, and the sixth current collector 460B each have a gap G1 in the flat plate portion except for the folded portion F. Thus, the current collectors are easily in contact with each other at the folded portion F. In addition, the reaction force generated by the bending of the electrode sheet is applied toward the current collectors. Thus, the current collectors can be brought into close contact with each other.

[0189] In the secondary battery and the manufacturing method thereof according to the third embodiment of the present technology, by providing the first overlapping region R31 where the second current collector 420B overlaps with the sixth current collector 460B, and the second overlapping region R32 where the fourth current collector 440B overlaps with the sixth current collector 460B, it is possible to ensure the weldable region between the current collectors and stably connect the current collectors to each other. In the case where the current collectors are connected to each other by irradiating the high energy line 2 from between the second opening 114 of the housing body 110 and the second sealing plate 130, it is possible to easily ensure the weldable range between the current collectors for irradiation of the high energy line 2 from a direction intersecting with the first direction in which the first opening 113 and the second opening 114 are arranged.

[0190] (Implementation 4)

[0191] Fig.30 It is a perspective view showing the structure of a current collector included in a secondary battery according to a fourth embodiment. Fig.31 yes Fig.30 XXXI-XXXI cross-sectional view of the current collector shown.

[0192] like Fig.30 and Fig.31 As shown in FIG. 1 , each current collector in the present embodiment has a folded portion F at an end portion side in the Z direction. At the tip of the folded portion F, an extended portion E extending in the Z direction is provided.

[0193] The sixth current collector 460C has a gap G2 in the extended portion E. Thus, since the distance between each current collector and the insulating member can be increased, heat generated when the current collectors are bonded together by a high-energy wire can be less likely to be transferred to the insulating member.

[0194] The extension E of the second collector 420C and the sixth collector 460C abuts against each other, forming a first abutting region R41 extending along a direction (Y direction and Z direction) intersecting the first direction (X direction) in which the first opening 113 and the second opening 114 are arranged, and the second collector 420C and the sixth collector 460C abut in the first direction (X direction). The first abutting region R41 includes a contact surface between the second collector 420C and the sixth collector 460C. The first abutting region R41 extends on a surface intersecting the first direction (X direction). The first abutting region R41 extends along the Y direction and the Z direction, respectively. The first abutting region R41 is preferably configured along the second sealing plate 130.

[0195] In addition, the extension portions E of the fourth collector 440C and the sixth collector 460C abut against each other, thereby forming a second abutting region R42 extending along directions (Y directions and Z directions) intersecting the first direction (X direction) and in which the fourth collector 440C abuts against the sixth collector 460C in the first direction (X direction).

[0196] At the end of the first contact region R41, the second current collector 420C and the sixth current collector 460C are connected by welding. At the end of the second contact region R42, the fourth current collector 440C and the sixth current collector 460C are connected by welding.

[0197] The connection configuration of the current collectors on the first sealing plate 120 side of the secondary battery is similar to the connection configuration of the current collectors on the second sealing plate 130 side.

[0198] Specifically, a third contact region is formed, which extends in a direction intersecting the first direction and in which the first current collector and the fifth current collector contact each other in the first direction (X direction). A fourth contact region is formed, which extends in a direction intersecting the first direction and in which the third current collector and the fifth current collector contact each other in the first direction. The first current collector and the fifth current collector are welded together at the end of the third contact region. The third current collector and the fifth current collector are welded together at the end of the fourth contact region.

[0199] In the secondary battery and the manufacturing method thereof of the fourth embodiment of the present technology, by providing the first contact region R41 and the second contact region R42, it is possible to ensure the areas where the collectors can be bonded to each other, thereby facilitating the stable connection of the collectors to each other. In particular, it is possible to ensure the bonding sites between the collectors without making the mutual positioning of the bonded collectors high-precision.

[0200] In the secondary battery and the manufacturing method thereof according to the fourth embodiment of the present technology, by providing the third contact region and the fourth contact region, a region where the first current collector or the third current collector and the fifth current collector can be bonded can be ensured, thereby facilitating stable connection of the current collectors.

[0201] (Implementation 5)

[0202] Fig.32 It is a perspective view showing the structure of a current collector included in a secondary battery according to the fifth embodiment. Fig.33 yes Fig.32 XXXIII-XXXIII cross-sectional view of the current collector shown.

[0203] like Fig.32 and Fig.33 As shown in FIG. 1 , the second current collector 420D, the fourth current collector 440D, and the sixth current collector 460D in this embodiment each have a folded portion F on the end side in the Z direction. An extension portion E extending along the Z direction is provided at the front end of the folded portion F. The front end of the extension portion E is bent in a direction of separation between the joined current collectors. Since the contact portion in the extension portion E becomes the inner side from the front end, it is difficult to cause a weld collapse.

[0204] (Implementation method 6)

[0205] Fig.34 It is a perspective view showing the structure of a current collector included in a secondary battery according to the sixth embodiment. Fig.35 yes Fig.34 XXXV-XXXV cross-sectional view of the current collector shown.

[0206] like Fig.34 and Fig.35 As shown, the thickness of the sixth current collector 460E in the present embodiment in the X direction is thicker than the thickness of the second current collector 420E and the fourth current collector 440E in the X direction. Thus, since the allowable amount of heat when the current collectors are joined together by the high-energy wire 2 can be ensured more in the sixth current collector 460E, the heat when the current collectors are joined together by the high-energy wire can be made difficult to be transferred to the insulating member.

[0207] The second current collector 420E and the fourth current collector 440E are provided with a fuse 422E. When the current collector is overheated, the current collector is preferentially melted at the fuse 422E as far away from the insulating member as possible in the positive electrode current collector.

[0208] (Implementation 7)

[0209] Fig.36 It is a cross-sectional view showing the structure of a current collector included in a secondary battery according to a seventh embodiment.

[0210] like Fig.36 As shown, the thickness of the sixth current collector 460F in the present embodiment in the X direction is thicker than the thickness of the second current collector 420F and the fourth current collector in the X direction. The sixth current collector 460F has a gap G3 in the extension portion E located at the front end side of the folded portion F. Thus, since the distance from the insulating member can be kept, it is possible to prevent heat from being transferred to the insulating member when the current collectors are joined together by the high-energy wire 2.

[0211] In the secondary battery and the manufacturing method thereof of the fifth to seventh embodiments of the present technology, by providing the first contact regions R51, R61, R71 and the second contact regions R52, R62, it is possible to ensure the areas where the collectors can be bonded to each other, thereby facilitating the stable connection of the collectors to each other. In particular, it is possible to ensure the bonding sites between the collectors without making the mutual positioning of the bonded collectors high-precision.

[0212] The first sealing plate 120 and the second sealing plate 130 preferably each have a pair of long sides arranged parallel to each other and short sides shorter than the pair of long sides arranged parallel to each other. In this case, the direction in which the pair of long sides extend is the long side direction.

[0213] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all changes within the meaning and scope equivalent to the claims.

Claims

1. A secondary battery, characterized in that: have: a first electrode body and a second electrode body, each of which includes a first electrode and a second electrode having a polarity different from that of the first electrode; and a housing for housing the first electrode body and the second electrode body, The housing comprises: a housing body having a cylindrical shape and having a first opening located at an end portion on a first side and a second opening located at an end portion on a second side opposite to the end portion on the first side; a first sealing plate for sealing the first opening; as well as a second sealing plate for sealing the second opening, The first sealing plate is provided with a first electrode terminal electrically connected to the first electrode. The second sealing plate is provided with a second electrode terminal electrically connected to the second electrode. The first electrode body has a first electrode sheet electrically connected to the first electrode at an end portion on the first sealing plate side, and has a second electrode sheet electrically connected to the second electrode at an end portion on the second sealing plate side. The second electrode body has a third electrode sheet electrically connected to the first electrode at an end portion on the first sealing plate side, and has a fourth electrode sheet electrically connected to the second electrode at an end portion on the second sealing plate side. The first electrode sheet is bonded to the first current collector. The second electrode sheet is bonded to the second current collector. The third electrode sheet is bonded to the third current collector. The fourth electrode sheet is bonded to the fourth current collector. The first current collector and the third current collector are composed of separate components. The second current collector and the fourth current collector are composed of separate components. The first current collector and the third current collector are respectively connected to a fifth current collector electrically connected to the first electrode terminal. The second current collector and the fourth current collector are respectively connected to a sixth current collector electrically connected to the second electrode terminal.

2. The secondary battery according to claim 1, characterized in that: have: a first contact region extending in a direction intersecting a first direction in which the first opening and the second opening are arranged, and wherein the second current collector and the sixth current collector contact each other in the first contact region; as well as a second contact region extending in a direction intersecting the first direction, wherein the fourth current collector and the sixth current collector contact each other in the second contact region, At the end of the first contact region, the second current collector and the sixth current collector are connected by welding. The fourth current collector and the sixth current collector are connected by welding at an end portion of the second contact region.

3. The secondary battery according to claim 2, characterized in that: have: a third contact region extending in a direction intersecting the first direction, wherein the first current collector and the fifth current collector contact each other in the third contact region; and a fourth contact region extending in a direction intersecting the first direction, wherein the third current collector and the fifth current collector contact each other in the fourth contact region, At the end of the third contact region, the first current collector and the fifth current collector are connected by welding. The third current collector and the fifth current collector are connected by welding at an end portion of the fourth contact region.

4. The secondary battery according to claim 1, characterized in that: The second sealing plate has a long side direction and a short side direction in a direction intersecting a first direction in which the first opening and the second opening are arranged. The secondary battery has: a first overlapping region formed by the second current collector and the sixth current collector overlapping each other at an end side in the long-side direction when viewed in the long-side direction; and a second overlapping region formed by the fourth current collector and the sixth current collector overlapping each other at the end side in the long side direction when viewed from the long side direction, In the first overlapping region, the second current collector and the sixth current collector are connected by welding. In the second overlapping region, the fourth current collector and the sixth current collector are connected by welding.

5. The secondary battery according to claim 4, characterized in that: have: a third overlapping region formed by the first current collector and the fifth current collector overlapping each other at an end side of the first sealing plate in the longitudinal direction when viewed in the longitudinal direction; as well as a fourth overlapping region formed by the third current collector and the fifth current collector overlapping each other at an end side of the first sealing plate in the longitudinal direction when viewed in the longitudinal direction, In the third overlapping region, the first current collector and the fifth current collector are connected by welding. In the fourth overlapping region, the third current collector and the fifth current collector are connected by welding.

6. A method for manufacturing a secondary battery, the secondary battery comprising: a first electrode body and a second electrode body, each of which includes a first electrode and a second electrode having a polarity different from that of the first electrode; and a housing for housing the first electrode body and the second electrode body, The housing comprises: a housing body having a cylindrical shape and having a first opening located at an end portion on a first side and a second opening located at an end portion on a second side opposite to the end portion on the first side; a first sealing plate for sealing the first opening; as well as a second sealing plate for sealing the second opening, The first sealing plate is provided with a first electrode terminal electrically connected to the first electrode. The second sealing plate is provided with a second electrode terminal electrically connected to the second electrode. The first electrode body has a first electrode sheet electrically connected to the first electrode at an end portion on the first sealing plate side, and has a second electrode sheet electrically connected to the second electrode at an end portion on the second sealing plate side. The second electrode body has a third electrode sheet electrically connected to the first electrode at an end portion on the first sealing plate side, and has a fourth electrode sheet electrically connected to the second electrode at an end portion on the second sealing plate side. The first electrode sheet is bonded to the first current collector. The second electrode sheet is bonded to the second current collector. The third electrode sheet is bonded to the third current collector. The fourth electrode sheet is bonded to the fourth current collector. The first current collector and the third current collector are composed of separate components. The second current collector and the fourth current collector are composed of separate components. The first current collector and the third current collector are respectively connected to a fifth current collector electrically connected to the first electrode terminal. The second current collector and the fourth current collector are respectively connected to a sixth current collector electrically connected to the second electrode terminal. The method for manufacturing the secondary battery is characterized by comprising the following steps: A step of manufacturing the first electrode body and the second electrode body; After the first electrode body and the second electrode body are manufactured, a step of joining the first electrode sheet to the first current collector; After the first electrode body and the second electrode body are manufactured, a step of joining the second electrode sheet to the second current collector; After the first electrode body and the second electrode body are manufactured, the step of joining the third electrode sheet to the third current collector; After the first electrode body and the second electrode body are manufactured, the fourth electrode sheet is joined to the fourth current collector; A step of overlapping the first electrode body and the second electrode body in a thickness direction of the first electrode body and the second electrode body; After the first electrode body and the second electrode body are overlapped, the first current collector and the third current collector are connected to the fifth current collector; After the first current collector and the third current collector are connected to the fifth current collector, the first electrode body and the second electrode body are inserted into the case body from the first opening with the second electrode sheet and the fourth electrode sheet as the leading end; as well as A step of connecting the second current collector and the fourth current collector protruding from the second opening to the sixth current collector after the first electrode body and the second electrode body are inserted into the case body.

7. The method for manufacturing a secondary battery according to claim 6, characterized in that: When the second current collector and the fourth current collector are connected to the sixth current collector, irradiating at least one of the second current collector and the sixth current collector with high energy radiation from between the second sealing plate and the end of the case body on the second opening side to weld the second current collector and the sixth current collector, The fourth current collector and the sixth current collector are welded by irradiating at least one of the fourth current collector and the sixth current collector with high energy radiation from between the second sealing plate and the end portion of the case body on the second opening side.

8. The method for manufacturing a secondary battery according to claim 6 or 7, characterized in that: have: a first contact region extending in a direction intersecting a first direction in which the first opening and the second opening are arranged, and wherein the second current collector and the sixth current collector contact each other in the first contact region; as well as a second contact region extending in a direction intersecting the first direction, wherein the fourth current collector and the sixth current collector contact each other in the second contact region, At the end of the first contact region, the second current collector and the sixth current collector are connected by welding. The fourth current collector and the sixth current collector are connected by welding at an end portion of the second contact region.

9. The method for manufacturing a secondary battery according to claim 6 or 7, characterized in that: The second sealing plate has a long side direction and a short side direction in a direction intersecting a first direction in which the first opening and the second opening are arranged. The secondary battery has: a first overlapping region formed by the second current collector and the sixth current collector overlapping each other at an end side in the long-side direction when viewed in the long-side direction; and a second overlapping region formed by the fourth current collector and the sixth current collector overlapping each other at the end side in the long side direction when viewed from the long side direction, In the first overlapping region, the second current collector and the sixth current collector are connected by welding. In the second overlapping region, the fourth current collector and the sixth current collector are connected by welding.

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