Manufacturing equipment for secondary batteries

Abstract

To provide a method for manufacturing a secondary battery in which the volume density energy of the secondary battery is improved.SOLUTION: An apparatus 10 for manufacturing a secondary battery 20 includes: a conveying section 5 that conveys the secondary battery 20 having an outer package 22; plural contact rollers (for example, a first upstream side contact roller 30, a second upstream side contact roller 130 and a third upstream side contact roller 230) which are provided on a conveying path of the conveying section 5, the plural contact rollers having different contact angles with respect to an edge part 28 of the outer package 22 being conveyed; and opposition rollers (for example, a first upstream side opposition roller 40, a second upstream side opposition roller 140 and a third upstream side opposition roller 240) which are respectively disposed in opposition to the contact rollers, and which, together with the contact rollers, fold the edge part 28 of the outer package 22.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This disclosure relates to a secondary battery manufacturing apparatus, a secondary battery manufacturing method, and a secondary battery. [Background technology]

[0002] A secondary battery in which the electrode body is covered by an outer casing is known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a method for manufacturing a secondary battery having a laminated outer casing with a bent portion at at least one end. This method for manufacturing a secondary battery includes the steps of: bringing a pressing plate into contact with the starting point of the bend at the end of the outer casing; and, after the contact step, sliding the pressing plate and a pressing plate positioned opposite the pressing plate so as to sandwich the end, thereby bending the end around the starting point and forming the bent portion by sandwiching the end between the pressing plate and the pressing plate. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-200973 [Overview of the project] [Problems that the invention aims to solve]

[0005] In secondary batteries having an outer casing, it is preferable to improve the volume density energy of the secondary battery. "Volume density energy" refers to the ratio of the volume of electrodes contained in the secondary battery to the total volume of the secondary battery.

[0006] If the electrodes in a secondary battery are subjected to impact, they may be damaged, potentially preventing the battery from performing optimally. Therefore, there is a need for secondary batteries with shock resistance.

[0007] The problem to be solved by one embodiment of the present disclosure is to provide a manufacturing apparatus for a secondary battery and a manufacturing method for a secondary battery that can manufacture a secondary battery having excellent volumetric density energy. The problem to be solved by another embodiment of the present disclosure is to provide a secondary battery having excellent volumetric density energy and impact resistance.

Means for Solving the Problem

[0008] The manufacturing apparatus for a secondary battery according to the first aspect of the present disclosure includes a transport unit that transports a laminated-type secondary battery having a laminated exterior body, and a plurality of contact rollers provided in the transport path of the transport unit and having different contact angles that contact the edge seal portion of the laminated exterior body being transported. Opposing rollers are arranged opposite to each of the contact rollers, and together with the contact rollers, bend the edge seal portion of the laminated exterior body.

[0009] In the present disclosure, the "laminated-type secondary battery" refers to a secondary battery having a laminated exterior body. The "laminated exterior body" refers to a case made of a laminated sheet. The "laminated sheet" refers to a sheet having at least a metal layer, a first resin layer laminated on one main surface of the metal layer, and a second resin layer laminated on the other main surface of the metal layer. The "edge seal portion" refers to a portion formed by welding the ends of the laminated sheets to seal the electrode body.

[0010] According to the manufacturing apparatus for a secondary battery according to the first aspect, by providing a plurality of contact rollers having different contact angles that contact the edge seal portion of the laminated exterior body being transported, the edge seal portion of the laminated exterior body is bent step by step. Therefore, the springback amount of the edge seal portion of the bent laminated exterior body is suppressed. As a result, the volumetric density energy of the secondary battery can be improved. That is, the manufacturing apparatus of the first aspect can manufacture a secondary battery having excellent volumetric density energy.

[0011] A secondary battery manufacturing apparatus according to a second embodiment forms a bent portion on at least one edge seal portion of the laminated outer casing of a laminated secondary battery. The manufacturing apparatus includes a transport unit for transporting the secondary battery in one direction, and a plurality of pairs of rollers for bending the edge seal portion. Each of the plurality of pairs of rollers includes a contact roller and a counter roller positioned opposite the contact roller. The manufacturing apparatus passes the edge seal portion of the secondary battery being transported by the transport unit between the plurality of pairs of rollers, bending the edge seal portion in stages to form the bent portion.

[0012] According to the secondary battery manufacturing apparatus of the second embodiment, the amount of springback of the bent portion of the edge seal is suppressed. As a result, the manufacturing apparatus of the second embodiment can manufacture secondary batteries with excellent volume density energy.

[0013] In a secondary battery manufacturing apparatus according to a third aspect of the present disclosure, in the secondary battery manufacturing apparatus of the first or second aspect, the contact roller provided on the downstream side in the transport direction is an elastic pressing roller that presses from the outside toward the opposing roller positioned in the gap of the edge seal portion of the bent laminate outer casing.

[0014] According to the secondary battery manufacturing apparatus of the third embodiment, in the secondary battery manufacturing apparatus of the first or second embodiment, the contact roller provided on the downstream side in the conveying direction is a pressing roller that presses from the outside toward an opposing roller positioned in the gap of the edge seal portion of the folded laminate outer casing, so that the edge seal portion of the laminate outer casing is pressed along the outer shape of the opposing roller. Therefore, the edge seal portion of the laminate outer casing can be brought into the desired folded position.

[0015] In a secondary battery manufacturing apparatus according to a fourth aspect of this disclosure, in the secondary battery manufacturing apparatus described in any one of the first to third aspects, one of the contact roller and the opposing roller is provided with a restricting part that restricts movement in a direction perpendicular to the conveying direction of the laminate outer casing.

[0016] According to the secondary battery manufacturing apparatus of the fourth embodiment, one of the contact roller and the opposing roller is equipped with a restricting part that restricts movement in a direction perpendicular to the conveying direction of the laminated casing, thereby restricting the movement of the laminated casing in a direction perpendicular to the conveying direction. As a result, the edge seal portion of the laminated casing can be bent at the desired position.

[0017] In the secondary battery manufacturing apparatus according to the fifth aspect of this disclosure, in the secondary battery manufacturing apparatus described in any one of the first to fourth aspects, the edge sealing portion of the laminate outer casing contacts at least one of the contact roller and the opposing roller on the base side of the bending base.

[0018] According to the secondary battery manufacturing apparatus of the fifth aspect of this disclosure, the edge seal portion of the laminated casing contacts at least one of the contact roller and the opposing roller at the base side of the bending point, thereby suppressing the occurrence of a difference in frictional force at the contact surface between the contact roller and the opposing roller on the edge seal portion of the laminated casing. Therefore, damage to the edge seal portion of the laminated casing can be suppressed.

[0019] In the secondary battery manufacturing apparatus according to the sixth aspect of this disclosure, in the secondary battery manufacturing apparatus described in any one of the first to fifth aspects, the plurality of pairs of rollers bend the edge sealing portion at least twice in stages to form the bent portion.

[0020] According to the secondary battery manufacturing apparatus of the sixth aspect of this disclosure, a secondary battery can be obtained having a bent portion formed by folding the edge seal portion at least twice. As a result, the manufacturing apparatus of the seventh aspect can manufacture a secondary battery with excellent volume density energy and impact resistance.

[0021] In a method for manufacturing a secondary battery according to a seventh aspect of the present disclosure, the laminated casing of the secondary battery is conveyed between a plurality of contact rollers with different contact angles that contact the edge seal portion of the laminated casing, and a counter roller that faces the contact roller, thereby bending the edge seal portion of the laminated casing in stages.

[0022] According to the seventh embodiment of the method for manufacturing a secondary battery, the laminated casing of the secondary battery is conveyed between a plurality of contact rollers with different contact angles that contact the edge seal portion of the laminated casing, and a counter roller that faces the contact rollers, thereby gradually bending the edge seal portion of the laminated casing. This suppresses the amount of springback of the bent edge seal portion of the laminated casing. As a result, the volume density energy of the secondary battery can be improved. In other words, the manufacturing method of the seventh embodiment can produce a secondary battery with superior volume density energy.

[0023] A secondary battery according to an eighth aspect of the present disclosure comprises an electrode body and a laminated casing made of a laminate sheet that covers the electrode body. The laminated casing has a housing portion for housing the electrode body and an edge sealing portion formed by welding the ends of the laminate sheet together. The edge sealing portion has a bent portion formed by folding it relative to the main surface of the electrode body. The bent portion is formed by folding the edge sealing portion at least twice.

[0024] In this disclosure, "the edge sealing portion is folded at least twice" indicates that the edge sealing portion has at least two fold lines.

[0025] In the secondary battery according to the eighth embodiment, the bent portion is formed by folding the edge sealing portion two or more times. Therefore, the impact resistance of the secondary battery according to the eighth embodiment is superior to that of conventional secondary batteries. As a result, the secondary battery according to the eighth embodiment has excellent volume density energy and impact resistance.

[0026] In the secondary battery according to the ninth aspect of this disclosure, the first pressing load is 6.0 MPa or more in the secondary battery of the eighth aspect. The bent portion has an opposing surface that faces the first side surface of the housing portion. The first pressing load represents the load required to press a part of the bent portion toward the side surface of the housing portion, thereby bringing the opposing surface into contact with the side surface of the housing portion.

[0027] In the secondary battery according to the ninth embodiment, the first pressing load is 6.0 MPa or higher. A first pressing load of 6.0 MPa or higher indicates superior rigidity of the bent portion in the housing. As a result, the secondary battery according to the ninth embodiment has superior impact resistance.

[0028] A secondary battery according to a tenth aspect of the present disclosure further comprises a terminal electrically connected to the electrode body, in the secondary battery of the eighth or ninth aspect. The laminate casing further has a terminal sealing portion that seals the terminal extending to the outside of the laminate casing. The bent portion has an opposing surface that faces the side surface of the housing portion and the terminal sealing portion. The terminal sealing portion has a convex welded portion formed by welding the overlapping portion of the laminate sheet to the side surface of the terminal sealing portion. The convex welded portion protrudes from the side surface toward the opposing surface.

[0029] In the secondary battery according to the tenth embodiment, the terminal seal portion has a convex welded portion on its side surface. The convex welded portion functions as a cushioning material against the displacement of the bent portion. Therefore, the impact resistance of the secondary battery according to the tenth embodiment is superior to that of the case in which the terminal seal portion does not have a convex welded portion. As a result, the secondary battery according to the tenth embodiment has excellent volume density energy and impact resistance.

[0030] In the secondary battery according to the 11th aspect of this disclosure, the second pressing load is 12.0 MPa or more. The second pressing load represents the load required to press the entire bent portion toward the side surface of the terminal seal portion, thereby crushing the convex welded portion and bringing the opposing surface into contact with the side surface of the terminal seal portion.

[0031] In the secondary battery according to the 11th aspect of this disclosure, the second pressing load is 12.0 MPa or higher. A second pressing load of 12.0 MPa or higher indicates superior rigidity of the bent portion in the terminal seal. As a result, the secondary battery according to the 11th aspect has superior impact resistance. [Effects of the Invention]

[0032] According to this disclosure, it is possible to provide a secondary battery manufacturing apparatus and a secondary battery manufacturing method that can produce secondary batteries with excellent volume density energy. According to this disclosure, it is possible to provide a secondary battery that is excellent in volume density energy and shock resistance. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 is a schematic side view showing a secondary battery manufacturing apparatus according to the first embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of a secondary battery according to the first embodiment, showing the AA cross-section of Figure 1. [Figure 3] Figure 3 is a schematic cross-sectional view showing the upstream roller pair according to the first embodiment, and shows the BB cross-section of Figure 1. [Figure 4] Figure 4 is a schematic cross-sectional view showing the intermediate roller pair according to the first embodiment, and shows the CC cross-section of Figure 1. [Figure 5] Figure 5 is a schematic cross-sectional view showing the downstream roller pair according to the first embodiment, and shows the DD cross-section of Figure 1. [Figure 6] Figure 6 is a perspective view of a secondary battery according to the first embodiment. [Figure 7] Figure 7 is a cross-sectional view taken along line VII-VII in Figure 6. [Figure 8] Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 6. [Figure 9] Figure 9 is a diagram illustrating the method for measuring the first pressing load. [Figure 10]Figure 10 is a diagram illustrating the method for measuring the third pressing load. [Figure 11] Figure 11 is a diagram illustrating the method for measuring the second pressing load. [Figure 12] Figure 12 is a schematic cross-sectional view showing an example of a unit electrode in the first embodiment of this disclosure. [Figure 13] Figure 13 is a schematic cross-sectional view showing the upstream roller pair according to the second embodiment. [Modes for carrying out the invention]

[0034] In this disclosure, a numerical range indicated using "~" means a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced by the upper or lower limit of another numerical range described in stages. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, the term "process" is included not only in the sense of an independent process, but also in the sense of a process that is not clearly distinguishable from other processes, as long as its intended purpose is achieved.

[0035] Hereinafter, with reference to the drawings, the manufacturing apparatus for secondary batteries, the method for manufacturing secondary batteries, and embodiments of the secondary batteries of this disclosure will be described. In the drawings, the same or corresponding parts are denoted by the same reference numerals and will not be repeated in the description.

[0036] (1) First Embodiment Hereinafter, a secondary battery manufacturing apparatus according to the first embodiment will be described with reference to the drawings. In the first embodiment, the laminate-type secondary battery manufacturing apparatus 10 will be described as an apparatus for bending the edge sealing portion 28 (hereinafter also referred to as "edge portion 28") of the laminate outer casing 22 (hereinafter also referred to as "outer casing 22") of the secondary battery 20.

[0037] (1.1) Configuration of the secondary battery 20 As shown in Figures 1 and 2, the laminate-type secondary battery 20 comprises an electrode body 21 and an outer casing 22 that covers the electrode body 21. The outer casing 22 is composed of two laminate sheets 24. The laminate sheet 24 is composed of a laminate in which an outer insulating layer 25, a metal layer 26, and an inner insulating layer 27 are laminated together. The electrode body 21 is sandwiched between the two laminate sheets 24, and the inner insulating layers 27 are joined together at the periphery to form the edge portion 28 of the outer casing 22. The edge portion 28 is formed by folding the end portion back by approximately 180° and then bending it by approximately 90°. Details of the secondary battery 20 will be described later.

[0038] (1.2) Configuration of the secondary battery 20 manufacturing apparatus 10 The secondary battery manufacturing apparatus 10 comprises a conveying section 5, an upstream roller group S1, an intermediate roller group S2, a downstream roller group S3, and a downstream roller group S4. The upstream roller group S1, intermediate roller group S2, downstream roller group S3, and downstream roller group S4 are examples of multiple pairs of rollers.

[0039] (1.2.1) Conveyor unit 5 As shown in Figure 1, the transport unit 5 is configured to transport the secondary battery 20 in the transport direction (to the right in Figure 1) R.

[0040] (1.2.2) Upstream roller group S1 The upstream roller group S1 is provided along the transport path of the transport section 5, on one side in the width direction of the transport path. The upstream roller group S1 is positioned upstream of the intermediate roller group S2 in the transport direction R. The upstream roller group S1 comprises a first upstream roller pair 30A, a second upstream roller pair 130A, and a third upstream roller pair 230A.

[0041] The first upstream roller pair 30A comprises a first upstream contact roller 30 and a first upstream opposing roller 40 positioned opposite the first upstream contact roller 30. The second upstream roller pair 130A comprises a second upstream contact roller 130 and a second upstream opposing roller 140 positioned opposite the second upstream contact roller 130. The third upstream roller pair 230A comprises a third upstream contact roller 230 and a third upstream opposing roller 240 positioned opposite the third upstream contact roller 230.

[0042] The first upstream roller pair 30A, the second upstream roller pair 130A, and the third upstream roller pair 230A have the same configuration except for the difference in the inclination angle of the contact surface that abuts the edge 28 of the outer casing 22. Below, the second upstream roller pair 130A will be described in detail.

[0043] (1.2.2.1) Second upstream roller pair 130A (1.2.2.1.1) Second upstream contact roller 130 As shown in Figure 3, the second upstream contact roller 130 is configured to be rotatable with respect to a horizontal rotation axis C1 perpendicular to the conveying direction R. The second upstream contact roller 130 is made of, for example, metal or resin, and has a small diameter section 131, a large diameter section 132, and an intermediate section 133.

[0044] The small-diameter section 131 is located on the conveying section 5 side of the large-diameter section 132. The large-diameter section 132 has a larger outer diameter than the small-diameter section 131. The intermediate section 133 is located between the large-diameter section 132 and the small-diameter section 131. The intermediate section 133 is formed in the shape of a frustoconical cone, expanding in diameter from the small-diameter section 131 toward the large-diameter section 132, so as to connect the outer shapes of the large-diameter section 132 and the small-diameter section 131. The outer circumferential surface 133A of the intermediate section 133 is an inclined surface tilted at an angle α (for example, 60°) with respect to the horizontal direction. The outer circumferential surface 133A of the intermediate section 133 and the outer circumferential surface 131A of the small-diameter section 131 are contact surfaces that abut against the edge 28 of the outer casing 22 conveyed by the conveying section 5.

[0045] (1.2.2.1.2) Second upstream opposing roller 140 The second upstream opposing roller 140 is configured to be rotatable with respect to a horizontal rotation axis C2 perpendicular to the conveying direction R. The second upstream opposing roller 140 is positioned above the second upstream contact roller 130 and opposite to the second upstream contact roller 130. The second upstream opposing roller 140 is made of, for example, metal or resin, and has a small diameter section 141, a large diameter section 142, and an intermediate section 143.

[0046] The large-diameter section 142 is located on the conveying section 5 side of the small-diameter section 141. The large-diameter section 142 has a larger outer diameter than the small-diameter section 141. The intermediate section 143 is located between the large-diameter section 142 and the small-diameter section 141. The intermediate section 143 is formed in the shape of a frustoconical cone, expanding in diameter from the small-diameter section 141 toward the large-diameter section 142, so as to connect the outer shapes of the large-diameter section 142 and the small-diameter section 141. The outer circumferential surface 143A of the intermediate section 143 is an inclined surface tilted at an angle α (for example, 60°) with respect to the horizontal direction. The outer circumferential surface 143A of the intermediate section 143 and the outer circumferential surface 142A of the large-diameter section 142 are contact surfaces that abut against the edge 28 of the outer casing 22 conveyed by the conveying section 5.

[0047] The second upstream contact roller 130 and the second upstream opposing roller 140 are configured to bend the edge 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle α (for example, 60°).

[0048] (1.2.2.2) First upstream roller pair 30A In the first upstream roller pair 30A, the outer circumferential surface of the intermediate portion of the first upstream contact roller 30 is an inclined surface tilted at an angle α (for example, 30°) with respect to the horizontal direction. The outer circumferential surface of the intermediate portion of the first upstream opposing roller 40 is an inclined surface tilted at an angle α (for example, 30°) with respect to the horizontal direction. The first upstream contact roller 30 and the first upstream opposing roller 40 are configured to bend the edge portion 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle α (for example, 30°).

[0049] (1.2.2.3) Third upstream roller pair 230A In the third upstream roller pair 230A, the outer circumferential surface of the middle portion of the third upstream contact roller 230 is an inclined surface tilted at an angle α (for example, 90°) with respect to the horizontal direction. The outer circumferential surface of the middle portion of the third upstream opposing roller 240 is an inclined surface tilted at an angle α (for example, 90°) with respect to the horizontal direction. The third upstream contact roller 230 and the third upstream opposing roller 240 are designed to bend the edges 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle α (for example, 90°).

[0050] In other words, the first upstream roller pair 30A, the second upstream roller pair 130A, and the third upstream roller pair 230A have different contact angles of the contact surfaces that come into contact with the edge 28 of the outer casing 22 being conveyed.

[0051] (1.2.3) Intermediate roller group S2 As shown in Figure 1, the intermediate roller group S2 is provided along the transport path of the transport section 5, on one side in the width direction of the transport path. The intermediate roller group S2 is positioned downstream of the upstream roller group S1 in the transport direction R. The intermediate roller group S2 comprises a first intermediate roller pair 50A, a second intermediate roller pair 150A, and a third intermediate roller pair 250A.

[0052] The first intermediate roller pair 50A comprises a first intermediate contact roller 50 as a contact roller and a first intermediate opposing roller 60 as an opposing roller positioned opposite the first intermediate contact roller 50. The second intermediate roller pair 150A comprises a second intermediate contact roller 150 as a contact roller and a second intermediate opposing roller 160 as an opposing roller positioned opposite the second intermediate contact roller 150. The third intermediate roller pair 250A comprises a third intermediate contact roller 250 as a contact roller and a third intermediate opposing roller 260 as an opposing roller positioned opposite the third intermediate contact roller 250.

[0053] The first intermediate roller pair 50A, the second intermediate roller pair 150A, and the third intermediate roller pair 250A have the same configuration except for the difference in the inclination angle of the contact surface that abuts against the edge 28 of the outer casing 22. Below, the second intermediate roller pair 150A will be described in detail.

[0054] (1.2.3.1) Second intermediate roller vs. 150A (1.2.3.1.1) Second intermediate contact roller 150 As shown in Figure 4, the second intermediate contact roller 150 is configured to be rotatable with respect to a horizontal rotation axis C3 perpendicular to the conveying direction R. The second intermediate contact roller 150 is made of, for example, metal or resin, and is a stepped roller having a small diameter section 151 and a large diameter section 152.

[0055] The large-diameter portion 152 is positioned on the conveying portion 5 side of the small-diameter portion 151. The large-diameter portion 152 has a larger outer diameter than the small-diameter portion 151. The outer circumferential surface 152A of the large-diameter portion 152 is a contact surface that abuts against the edge 28 of the outer casing 22 that is conveyed by the conveying portion 5.

[0056] 《Second Intermediate Opposing Roller 160》 The second intermediate opposing roller 160 is configured to be rotatable with respect to a horizontal rotation axis C4 perpendicular to the conveying direction R. The second intermediate opposing roller 160 is positioned above the second intermediate contact roller 150 and opposite to the second intermediate contact roller 150. The second intermediate opposing roller 160 is made of, for example, metal or resin, and is a stepped roller having a large diameter section 161 and a small diameter section 162.

[0057] The small-diameter portion 162 is positioned on the conveying portion 5 side of the large-diameter portion 161. The large-diameter portion 161 has a larger outer diameter than the small-diameter portion 162. The small-diameter portion 162 is formed in a frustoconical shape that widens toward the large-diameter portion 161. The outer circumferential surface 162A of the small-diameter portion 162 is an inclined surface tilted at an angle β (for example, 150°) with respect to the horizontal direction. The outer circumferential surface 162A of the small-diameter portion 162 and the end face 161A of the large-diameter portion 161 on the conveying portion 5 side are contact surfaces that abut against the edge 28 of the outer casing 22 conveyed by the conveying portion 5. The end face 161A of the large-diameter portion 161 constitutes a restricting portion that restricts the movement of the outer casing 22 in a direction perpendicular to the conveying direction R.

[0058] The second intermediate contact roller 150 and the second intermediate opposing roller 160 are configured to bend the edges 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle β (for example, 150°).

[0059] (1.2.3.2) First intermediate roller vs. 50A In the first intermediate roller pair 50A, the outer surface of the small-diameter portion of the first intermediate opposing roller 60 is an inclined surface tilted at an angle β (for example, 120°) with respect to the horizontal direction. The first intermediate contact roller 50 and the first intermediate opposing roller 60 are designed to bend the edge portion 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle β (for example, 120°).

[0060] (1.2.3.3) Third intermediate roller vs. 250A In the third intermediate roller pair 250A, the outer circumferential surface of the small-diameter portion of the third intermediate opposing roller 260 is an inclined surface tilted at an angle β (for example, 180°) with respect to the horizontal direction. The third intermediate contact roller 250 and the third intermediate opposing roller 260 are designed to bend the edge portion 28 of the outer casing 22 being conveyed by the conveying unit 5 at an angle β (for example, 180°). In other words, the first intermediate roller pair 50A, the second intermediate roller pair 150A, and the third intermediate roller pair 250A have different contact angles of the contact surfaces that contact the edge portion 28 of the outer casing 22 being conveyed.

[0061] (1.2.4) Downstream roller group S3 As shown in Figure 1, the downstream roller group S3 has the same configuration as the upstream roller group S1 and is provided along the transport path of the transport section 5, on one side in the width direction of the transport path. The downstream roller group S3 is positioned downstream of the intermediate roller group S2 in the transport direction R.

[0062] The downstream roller group S3 comprises a first downstream roller pair 70A, a second downstream roller pair 170A, and a third downstream roller pair 270A.

[0063] The first downstream roller pair 70A comprises a first downstream contact roller 70 as a contact roller and a first downstream opposing roller 80 positioned opposite the first downstream contact roller 70. The second downstream roller pair 170A comprises a second downstream contact roller 170 as a contact roller and a second downstream opposing roller 180 positioned opposite the second downstream contact roller 170. The third downstream roller pair 270A comprises a third downstream contact roller 270 as a contact roller and a third downstream opposing roller 280 positioned opposite the third downstream contact roller 270.

[0064] The first downstream roller pair 70A, the second downstream roller pair 170A, and the third downstream roller pair 270A have the same configuration except for the difference in the inclination angle of the contact surface that abuts against the edge 28 of the outer casing 22.

[0065] (1.2.4.1) First downstream roller pair 70A In the first downstream roller pair 70A, the outer circumferential surface of the intermediate portion of the first downstream contact roller 70 is an inclined surface tilted at an angle α (for example, 30°) with respect to the horizontal direction. The outer circumferential surface of the intermediate portion of the first downstream opposing roller 80 is an inclined surface tilted at an angle α (for example, 30°) with respect to the horizontal direction. The first downstream contact roller 70 and the first downstream opposing roller 80 are designed to bend the edge portion 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle α (for example, 30°).

[0066] (1.2.4.2) Second downstream roller pair 170A In the second downstream roller pair 170A, the outer circumferential surface of the middle portion of the second downstream contact roller 170 is an inclined surface tilted at an angle α (for example, 60°) with respect to the horizontal direction. The outer circumferential surface of the middle portion of the second downstream opposing roller 180 is an inclined surface tilted at an angle α (for example, 60°) with respect to the horizontal direction. The second downstream contact roller 170 and the second downstream opposing roller 180 are designed to bend the edges 28 of the outer casing 22, which is conveyed by the conveying unit 5, at an angle α (for example, 60°).

[0067] (1.2.4.3) Third downstream roller pair 270A In the third downstream roller pair 270A, the outer circumferential surface of the middle portion of the third downstream contact roller 270 is an inclined surface tilted at an angle α (for example, 90°) with respect to the horizontal. The outer circumferential surface of the middle portion of the third downstream opposing roller 280 is an inclined surface tilted at an angle α (for example, 90°) with respect to the horizontal. The third downstream contact roller 270 and the third downstream opposing roller 280 are designed to bend the edge portion 28 of the outer casing 22 being conveyed by the conveying unit 5 at an angle α (for example, 90°). In other words, the first downstream roller pair 70A, the second downstream roller pair 170A, and the third downstream roller pair 270A have different contact angles of the contact surfaces that contact the edge portion 28 of the outer casing 22 being conveyed.

[0068] (1.2.5) Downstream roller group S4 As shown in Figure 1, the downstream roller group S4 is provided along the transport path of the transport section 5, on one side in the width direction of the transport path. The downstream roller group S4 is positioned downstream of the downstream roller group S3 in the transport direction R. The downstream roller group S4 includes a downstream roller pair 90A. The downstream roller pair 90A includes a downstream contact roller 90 as a contact roller and a downstream opposing roller 96 as an opposing roller.

[0069] (1.2.5.1) Downstream contact roller 90 As shown in Figure 5, the downstream contact roller 90 is configured to be rotatable with respect to a vertical rotation axis C5 perpendicular to the conveying direction R. At least the surface layer of the downstream contact roller 90 is made of an elastic material. The downstream contact roller 90 is biased by a spring or the like in the direction F approaching the conveying section 5 in the width direction of the conveying section 5. The downstream contact roller 90 presses the edge 28 of the outer casing 22 conveyed by the conveying section 5 from the outside toward the downstream opposing roller 96.

[0070] (1.2.5.2) Downstream opposing roller 96 The downstream opposing roller 96 is made of, for example, metal or resin. The downstream opposing roller 96 is positioned to the side of the downstream contact roller 90, facing the downstream contact roller 90. The downstream opposing roller 96 is positioned with its lower end inserted into the gap U in the edge 28 of the bent outer casing 22. The downstream opposing roller 96 is configured to be rotatable with respect to a rotation axis C6 that is inclined at a predetermined angle θ with respect to the horizontal direction perpendicular to the conveying direction R. The downstream opposing roller 96 is positioned so that the corner 96A at the lower end of the downstream opposing roller 96 contacts the edge 28. As a result, the edge 28 of the outer casing 22 conveyed by the conveying unit 5 is bent with the position where the corner 96A contacts it as the bending base point. That is, the corner 96A of the downstream opposing roller 96 is in contact with the bending base point of the edge 28 of the outer casing 22.

[0071] (1.3) Method for manufacturing secondary battery 20 As shown in Figure 1, a secondary battery 20 with its outer casing 22's edges 28 not bent is placed on the transport unit 5.

[0072] Next, the transport unit 5 transports the secondary battery 20 in the transport direction R. Then, as shown in Figure 3, the edges 28 of the casing 22 are bent at 30° by the first upstream roller pair 30A, at 60° by the second upstream roller pair 130A, and at 90° by the third upstream roller pair 230A. In other words, the casing 22 of the secondary battery 20 is transported by the first upstream roller pair 30A, the second upstream roller pair 130A, and the third upstream roller pair 230A, each having different contact angles that abut the edges 28 of the casing 22, thereby bending the edges 28 of the casing 22 in stages.

[0073] Next, as shown in Figure 4, the edges 28 of the outer casing 22 are bent at 120° by the first intermediate roller pair 50A, at 150° by the second intermediate roller pair 150A, and at 180° by the third intermediate roller pair 250A. At this time, the end faces of the large diameter portions of each opposing roller (in the case of the second intermediate roller pair 150A, the end face 161A of the large diameter portion 161 of the second intermediate opposing roller 160) restrict the movement of the outer casing 22 in a direction perpendicular to the transport direction R.

[0074] Next, the edge 28 of the outer casing 22, which has been bent at 180°, is bent at 30° by the first downstream roller pair 70A, bent at 60° by the second downstream roller pair 170A, and bent at 90° by the third downstream roller pair 270A.

[0075] Next, as shown in Figure 5, the edge 28 of the outer casing 22, which has been folded 180° and then 90°, is pressed from the outside by the downstream contact roller 90 toward the downstream opposing roller 96. Through the above process, the edge 28 of the outer casing 22 of the secondary battery 20 is folded, as shown in Figure 2.

[0076] (1.4) Secondary battery As shown in Figure 6, the secondary battery 20 comprises an electrode body 21, an outer casing 22, and a pair of terminals 29. One of the pair of terminals 29 is the positive terminal. The other of the pair of terminals 29 is the negative terminal. The electrode body 21 is a rectangular parallelepiped.

[0077] In the first embodiment, one side of the main surface of the electrode body 21 in the longitudinal direction is defined as the positive X-axis direction, and the opposite side as the negative X-axis direction. One side of the main surface of the electrode body 21 in the short direction is defined as the positive Y-axis direction, and the opposite side as the negative Y-axis direction. One side of the thickness direction of the electrode body 21 is defined as the positive Z-axis direction, and the opposite side as the negative Z-axis direction. The X-axis, Y-axis, and Z-axis are all orthogonal to each other. Note that these orientations do not limit the orientation of the secondary battery when it is used.

[0078] The pair of terminals 29 are arranged facing each other via the electrode body 21. More specifically, the pair of terminals 29 are arranged so as to sandwich the electrode body 21 in the X-axis direction. Each of the pair of terminals 29 is electrically connected to the electrode body 21. The outer casing 22 covers the electrode body 21. The electrode body 21 is sealed by the pair of terminals 29 and the outer casing 22.

[0079] In the first embodiment, the secondary battery 20 is a laminate-type lithium secondary battery using a solid electrolyte. Applications of the secondary battery 20 include, for example, in-vehicle power supplies, power supplies for information processing devices (e.g., personal computers, smartphones, etc.), and power supplies for energy storage.

[0080] (1.4.1) Terminals Terminal 29 is a rectangular parallelepiped. The shape of terminal 29, as viewed from the Z-axis direction, is U-shaped. Terminal 29 has its longitudinal direction along the Y-axis and its transverse direction along the X-axis. The material of terminal 29 may be metal (for example, stainless steel (SUS)).

[0081] (1.4.2) Laminated outer casing The outer casing 22 covers the electrode body 21 and seals the electrode body 21 together with the pair of terminals 29. The outer casing 22 is made up of two laminate sheets 24. The two laminate sheets 24 are folded together to function as the outer casing 22.

[0082] As shown in Figure 1, the outer casing 22 has a housing portion R22A, an edge portion 28 (hereinafter also referred to as the "edge sealing portion R22B"), and a pair of terminal sealing portions R22C. The housing portion R22A is located in the center of the secondary battery 20 in the X-axis direction. The edge sealing portion R22B is located on the edge of the secondary battery 20 in the negative Y-axis direction. The pair of terminal sealing portions R22C are arranged so as to sandwich the housing portion R22A in the X-axis direction.

[0083] (1.4.2.1) Storage section The housing section R22A houses the electrode body 21. The shape of the housing section R22A conforms to the shape of the electrode body 21.

[0084] (1.4.2.2) Edge seal section The edge seal portion R22B is formed by welding the edges of the laminate sheet 24 together. The edge seal portion R22B is a portion that has been heat-pressed by a heating device (e.g., a heat bar).

[0085] The edge sealing portion R22B has a bent portion R22B0. The bent portion R22B0 is bent relative to the main surface D20 (XY plane) of the electrode body 21.

[0086] In the first embodiment, the bent portion R22B0 is formed by bending the edge sealing portion R22B twice. In other words, the edge sealing portion R22B has three bend lines FL. Specifically, the bent portion R22B0 has a first bent portion R22B1, a second bent portion R22B2, and a third bent portion R22B3. The first bent portion R22B1, the second bent portion R22B2, and the third bent portion R22B3 are formed in this order. Each of the first bent portion R22B1, the second bent portion R22B2, and the third bent portion R22B3 is flat. The bending angle of the first bent portion R22B1 with respect to the main surface D20 of the electrode body 21 is 90°. The bending angle of the second bent portion R22B2 with respect to the main surface D20 of the electrode body 21 is 180°. The bending angle of the third bent portion R22B3 with respect to the main surface D20 of the electrode body 21 is 270°.

[0087] The bent portion R22B0 has an opposing surface SR22B that faces the side surface SR22A of the housing portion R22A and the first side surface SR22CA of the terminal sealing portion R22C. In the first embodiment, the opposing surface SR22B is formed by a third bent portion R22B3.

[0088] (1.4.2.3) Terminal seal section The terminal seal portion R22C seals the terminal 29 that extends to the outside of the outer casing 22 by sandwiching it between them. The terminal seal portion R22C is welded to the terminal 29. The shape of the terminal seal portion R22C conforms to the shape of the terminal 29.

[0089] A pair of terminal seal portions R22C have three convex welded portions SR22C0. One convex welded portion SR22C0 is formed on the Z-axis positive edge of the first side surface SR22CA of the terminal seal portion R22C. Two convex welded portions SR22C0 are formed on both Z-axis positive edges of the second side surface SR22CB of the terminal seal portion R22C. The convex welded portions SR22C0 are formed by welding the overlapping portions of the laminate sheet 24. The convex welded portions SR22C0 are areas that are heat-pressed by a heating device (e.g., a heat bar). The convex welded portions SR22C0 extend along the X-axis direction.

[0090] The terminal sealing portion R22C may be welded to the terminal 29 via a known resin material (e.g., a tab film).

[0091] (1.4.2.4) Rigidity of the folded portion of the storage section (edge ​​pressure) In the first embodiment, the first pressing load is 6.0 MPa or higher. The first pressing load represents the load required to press a portion of the bent portion R22B0 toward the side surface SR22A of the housing portion R22A (along direction F), as shown in Figure 9, and to bring the opposing surface SR22B into contact with the side surface SR22A of the housing portion R22A. Direction F is parallel to the positive Y-axis direction. The contact surface S80 of the indenter 80A that presses a portion of the bent portion R22B0 against the bent portion R22B is a flat surface. The contact surface S80 of the indenter 80A is in contact with a portion of the bent portion R22B0 in the Z-axis direction. A load measuring instrument is used to measure the first pressing load. The movement speed of the indenter 80A is 10 mm / min.

[0092] (1.4.2.5) Rigidity of the folding section of the storage compartment (overall pressure) In the first embodiment, the third pressing load is 6.5 MPa or higher. The third pressing load represents the load required to press the entire bent portion R22B0 toward the side surface SR22A of the housing portion R22A (along direction F), as shown in Figure 10, so that the opposing surface SR22B comes into contact with the side surface SR22A of the housing portion R22A. The contact surface S80 of the indenter 80B that presses a portion of the bent portion R22B0 against the bent portion R22B is flat. The contact surface S80 of the indenter 80B is in contact with the entire bent portion R22B0 in the Z-axis direction. A load measuring instrument is used to measure the third pressing load. The movement speed of the indenter 80B is 10 mm / min.

[0093] (1.4.2.6) Rigidity of the bent portion of the terminal seal (overall pressure) In the first embodiment, the second pressing load is 12.0 MPa or higher. The second pressing load represents the load required to press the entire bent portion R22B0 toward the side surface SR22CA of the terminal seal portion R22C (along direction F), as shown in Figure 11, thereby crushing the convex welded portion R22C0 and bringing the opposing surface SR22B into contact with the side surface SR22CA of the terminal seal portion R22C. The contact surface S80 of the indenter 80B that presses a portion of the bent portion R22B0 with the bent portion R22B is flat. The contact surface S80 of the indenter 80B is in contact with the entire bent portion R22B0 in the Z-axis direction. A load measuring instrument is used to measure the second pressing load. The movement speed of the indenter 80B is 10 mm / min.

[0094] (1.4.2.7) Material As shown in Figure 2, the laminate sheet 24 has an outer insulating layer 25, a metal layer 26, and an inner insulating layer 27. The thickness of the laminate sheet 24 may be 70 μm to 220 μm.

[0095] The outer insulating layer 25 functions as a protective layer for the metal layer 26. Examples of materials for the protective layer include polyethylene terephthalate (PET) and nylon. The thickness of the outer insulating layer 25 may be 20 μm to 60 μm.

[0096] The metal layer 26 blocks the exchange of gases (e.g., moisture, air, etc.) between the outside and inside of the secondary battery 20. Examples of materials for the metal layer 26 include aluminum, aluminum alloy, and stainless steel. The thickness of the metal layer 26 may be 30 μm to 60 μm or less.

[0097] The inner insulating layer 27 electrically insulates the pair of terminals 29 and electrode body 21 from the metal layer 26. Examples of materials for the inner insulating layer 27 include olefin resins such as polypropylene (PP) and polyethylene (PE). The thickness of the inner insulating layer 27 may be 40 μm to 100 μm.

[0098] (1.5) Electrode body The electrode body 21 functions as a power generation element of the secondary battery 20.

[0099] The electrode body 21 has a plurality of unit electrode bodies 210 and a pair of current collecting tabs (not shown). One of the pair of current collecting tabs is the positive electrode current collecting tab. The positive electrode current collecting tab is electrically connected to the positive terminal (one of the pair of terminals 29). The other of the pair of current collecting tabs is the negative electrode current collecting tab. The negative electrode current collecting tab is electrically connected to the negative terminal (the other of the pair of terminals 29). Each of the pair of current collecting tabs is electrically connected to the plurality of unit electrode bodies 210.

[0100] Multiple unit electrodes 210 are in the shape of a rectangular parallelepiped. The unit electrodes 210 include a so-called all-solid-state battery (where the electrolyte content is less than 5% by mass of the total electrolyte amount) using an inorganic solid electrolyte as the electrolyte. The structure of the unit electrode 210 may be a structure in which a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector are stacked in this order along the Z-axis direction, for example, the structure shown in Figure 12. The solid electrolyte layer B in Figure 12 may be a two-layer structure. Figure 12 is a schematic cross-sectional view showing an example of the unit electrode 210. The unit electrode 210 shown in Figure 12 comprises a negative electrode, a solid electrolyte layer B, and a positive electrode. The negative electrode includes a negative electrode current collector 211 and a negative electrode layer A. The positive electrode includes a positive electrode current collector 212 and a positive electrode layer C. The negative electrode layer A includes a negative electrode active material 213, a conductive additive 214, a binder 215, and a solid electrolyte 216. The positive electrode layer C includes a positive electrode active material 217, a conductive additive 218, a binder 219, and a solid electrolyte 220.

[0101] Multiple unit electrode bodies 210 may be connected in series or in parallel.

[0102] Multiple unit electrode bodies 210 may be constructed by sealing the laminated end faces (sides) of the laminated structure of the positive electrode layer / solid electrolyte layer / negative electrode layer with resin.

[0103] (1.5.1) Solid electrolyte layer The unit electrode body 210 comprises a solid electrolyte layer. The solid electrolyte layer preferably contains one selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes.

[0104] The sulfide solid electrolyte preferably contains sulfur (S) as the main component of the anionic element, and more preferably contains, for example, Li and A. Element A is at least one selected from the group consisting of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In. The sulfide solid electrolyte may further contain O and at least one of a halogen element. Examples of halogen elements (X) include F, Cl, Br, and I. The composition of the sulfide solid electrolyte is not particularly limited, and examples include xLi2S·(100-x)P2S5 (70≦x≦80) and yLiI·zLiBr·(100-yz)(xLi2S·(1-x)P2S5) (0.7≦x≦0.8, 0≦y≦30, 0≦z≦30). The sulfide solid electrolyte may have a composition represented by the following general formula (1). Equation (1): Li 4-x Ge 1-x P x S4(0 <x<1) In formula (1), at least a portion of Ge may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. At least a portion of P may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. A portion of Li may be substituted with at least one selected from the group consisting of Na, K, Mg, Ca, and Zn. A portion of S may be substituted with a halogen. The halogen is at least one of F, Cl, Br, and I.

[0105] As the oxide solid electrolyte, it is preferable to contain oxygen (O) as the main component of the anion element. For example, it may contain Li, Q element (Q represents at least one of Nb, B, Al, Si, P, Ti, Zr, Mo, W and S), and O. Examples of the oxide solid electrolyte include garnet-type solid electrolyte, perovskite-type solid electrolyte, NASICON-type solid electrolyte, Li-P-O-based solid electrolyte, Li-B-O-based solid electrolyte, etc. Examples of the garnet-type solid electrolyte include, for example, Li7La3Zr2O 12 、Li 7-x La3(Zr 2-x Nb x )O 12 (0 ≦ x ≦ 2), Li5La3Nb2O 12 and the like. Examples of the perovskite-type solid electrolyte include, for example, (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, etc. Examples of the NASICON-type solid electrolyte include, for example, Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, etc. Examples of the Li-P-O-based solid electrolyte include Li3PO4, LIPON (a compound in which a part of O in Li3PO4 is replaced by N), and examples of the Li-B-O-based solid electrolyte include Li3BO3, a compound in which a part of O in Li3BO3 is replaced by C, etc.

[0106] As the halide solid electrolyte, a solid electrolyte containing Li, M and X (M represents at least one of Ti, Al and Y, and X represents F, Cl or Br) is suitable. Specifically, Li 6-3z Y z X6 (X represents Cl or Br, and z satisfies 0 < z < 2), Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≦ 1.5) is preferable. Among Li 6-3z Y z X6, Li3YX6 (X represents Cl or Br) is more preferable in terms of excellent lithium ion conductivity, and further Li3YCl6 is preferable. Li 6-(4-x)b (Ti 1-x Al x ) bF6 (0 < x < 1, 0 < b ≤ 1.5) is preferably included together with a solid electrolyte such as a sulfide solid electrolyte from the viewpoint of suppressing oxidative decomposition of the sulfide solid electrolyte and the like.

[0107] The solid electrolyte layer may have a single-layer structure or a multi-layer structure of two or more layers.

[0108] The solid electrolyte layer may contain a binder or may not contain a binder. Examples of the binder that can be included in the solid electrolyte layer include, for example, vinyl halide resins, rubbers, polyolefin resins, and the like. Examples of the vinyl halide resin include polyvinylidene fluoride (PVdF), a copolymer of polyvinylidene fluoride and hexafluoropropylene (PVdF-HFP), and the like. Examples of the polyolefin resin include butadiene rubber (BR), acrylate butadiene rubber (ABR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (isobutylene-isoprene rubber), and the like. Examples of the polyolefin resin include polyethylene, polypropylene, and the like. The binder (C) may be a diene-based rubber containing a double bond in the main chain, for example, a butadiene-based rubber in which butadiene occupies 30 mol% or more of the whole.

[0109] (1.5.2) Positive electrode layer The unit electrode body 210 includes a positive electrode layer. The positive electrode layer contains a positive electrode active material. The positive electrode layer may contain at least one of a solid electrolyte for positive electrode, a conductive assistant, and a binder, if necessary.

[0110] Preferably, the positive electrode active material contains a lithium composite oxide. The lithium composite oxide may contain at least one selected from the group consisting of F, Cl, N, S, Br, and I. The lithium composite oxide may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc (also referred to as P63mc, P6 / mmc). The main arrangement of transition metal, oxygen, and lithium in the lithium composite oxide may be an O2-type structure.

[0111] Examples of lithium composite oxides having a crystal structure belonging to R-3m include Li x Me y O α X β Examples of compounds represented by (Me represents at least one selected from the group consisting of Mn, Co, Ni, Fe, Al, Cu, V, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, W, B, Si, and P, and X represents at least one selected from the group consisting of F, Cl, N, S, Br, and I, satisfying 0.5≦x≦1.5, 0.5≦y≦1.0, 1≦α<2, and 0<β≦1) include.

[0112] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 2(satisfying 1.5 ≤ x1 ≤ 2.3, M 1 It includes at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, A 1 It contains at least oxygen, A 1 The proportion of oxygen in it is 85 atomic percent or more. (Examples of complex oxides represented by ) (Li2NiO2), Li x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0≦x2≦0.5, 0≦y≦0.3, and at least one of x2 and y is not 0, M 1A represents at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, M 1B A1 represents at least one element selected from the group consisting of Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta, and W, and A2 represents at least one element selected from the group consisting of F, Cl, Br, S, and P. Examples of composite oxides represented by this formula include:

[0113] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include M1x M2 y O2 (M1 represents an alkali metal (at least one of Na and K is preferred), M2 represents a transition metal (at least one selected from the group consisting of Mn, Ni, Co, and Fe is preferred), and x + y satisfies 0 < x + y ≤ 2.) The composite oxide represented by is mentioned.

[0114] As the lithium composite oxide having an O2-type structure, for example, Li x [Li α (Mn a Co b M c ) 1-α O2 (0.5 < x < 1.1, 0.1 < α < 0.33, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi.) The composite oxide represented by is mentioned, and specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 and the like.

[0115] The solid electrolyte for the positive electrode preferably contains one selected from the group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte. As the sulfide solid electrolyte, those similar to those exemplified as the sulfide solid electrolyte contained in the solid electrolyte are mentioned. As the oxide solid electrolyte, those similar to those exemplified as the oxide solid electrolyte contained in the solid electrolyte are mentioned. As the halide solid electrolyte, those similar to those exemplified as the halide solid electrolyte contained in the solid electrolyte are mentioned.

[0116] Examples of conductive additives include carbon materials, metallic materials, and conductive polymer materials. Examples of carbon materials include carbon black (e.g., acetylene black, furnace black, Ketjen black, etc.), fibrous carbon (e.g., vapor-processed carbon fibers, carbon nanotubes, carbon nanofibers, etc.), graphite, and carbon fluoride. Examples of metallic materials include metal powders (e.g., aluminum powder), conductive whiskers (e.g., zinc oxide, potassium titanate, etc.), and conductive metal oxides (e.g., titanium oxide, etc.). Examples of conductive polymer materials include polyaniline, polypyrrole, and polythiophene. Conductive additives may be used individually or in mixtures of two or more types.

[0117] Examples of binders include those similar to those exemplified as binders contained in the solid electrolyte layer.

[0118] (1.5.3) Positive electrode current collector The unit electrode body 210 includes a positive electrode current collector. The positive electrode current collector collects current from the positive electrode layer. The positive electrode current collector is positioned on the opposite side of the solid electrolyte layer from the positive electrode layer. Examples of materials for the positive electrode current collector include stainless steel, aluminum, copper, nickel, iron, titanium, and carbon, with aluminum alloy foil or aluminum foil being preferred. Aluminum alloy foil and aluminum foil may be manufactured using powder. The shape of the positive electrode current collector can be, for example, foil-like or mesh-like. The positive electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer on its surface.

[0119] (1.5.4) Negative electrode layer The unit electrode 210 comprises a negative electrode layer. The negative electrode layer contains a negative electrode active material. The negative electrode layer may optionally contain at least one of a negative electrode solid electrolyte, a conductive additive, and a binder. Examples of negative electrode active materials include Li-based active materials such as metallic lithium, carbon-based active materials such as graphite, oxide-based active materials such as lithium titanate, and Si-based active materials such as elemental Si. Examples of conductive additives, negative electrode solid electrolytes, and binders used in the negative electrode layer are the same as those exemplified as the conductive additive contained in the positive electrode layer, the solid electrolyte contained in the solid electrolyte layer, and the binder (C).

[0120] (1.5.5) Negative electrode current collector The unit electrode body 210 includes a negative electrode current collector. The negative electrode current collector collects current from the negative electrode layer. The negative electrode current collector is positioned on the opposite side of the solid electrolyte layer from the negative electrode layer. Examples of materials for the negative electrode current collector include stainless steel, aluminum, copper, nickel, iron, titanium, and carbon, with copper being preferred. The shape of the negative electrode current collector can be, for example, foil-like or mesh-like. The negative electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer on its surface.

[0121] (1.6) Effect Next, the operation and effects of the first embodiment will be described.

[0122] By providing multiple contact rollers with different contact angles that contact the edges 28 of the transported outer casing 22, the edges 28 of the outer casing 22 are bent in stages. As a result, springback of the bent edges 28 of the outer casing 22 is suppressed. Consequently, the volume density energy of the secondary battery 20 can be improved.

[0123] By providing multiple contact rollers with different contact angles that contact the edge 28 of the transported outer casing 22, the thickness of each contact roller and each opposing roller is formed to be different. That is, the contact rollers and opposing rollers with steeper contact angles can be made thinner than the contact rollers and opposing rollers with gentler contact angles. Therefore, by gradually reducing the thickness of the contact rollers and opposing rollers, the gap formed at the edge 28 of the bent outer casing 22 can be reduced. As a result, the volume density energy of the secondary battery 20 can be improved.

[0124] The downstream contact roller 90, located on the downstream side of the conveying direction R, is an elastic pressing roller that presses from the outside toward the downstream opposing roller 96, which is positioned in the gap of the edge 28 of the bent outer casing 22. As a result, the edge 28 of the outer casing 22 is pressed against the outer shape of the downstream opposing roller 96. Therefore, the edge 28 of the outer casing 22 can be positioned in the desired bent position.

[0125] Because the pressing roller is an elastic body, when it presses against the edge 28 of the outer casing 22, the elastic body deforms elastically. Therefore, even if there are variations in thickness on the edge 28 of the outer casing 22, the variations in thickness are absorbed, and the edge 28 of the outer casing 22 can be bent into the desired position. In other words, the edge 28 of the outer casing 22 can be bent into the desired position regardless of its thickness. Moreover, damage to the outer casing 22 can be suppressed.

[0126] The opposing roller (for example, the second intermediate opposing roller 160) is equipped with an end face 161A that restricts the movement of the outer casing 22 in a direction perpendicular to the conveying direction R, thereby restricting the movement of the outer casing 22 in a direction perpendicular to the conveying direction R. As a result, the edge 28 of the outer casing 22 can be bent at the desired position.

[0127] The outer casing 22 of the secondary battery 20 is transported between multiple contact rollers with different contact angles that contact the edge 28 of the outer casing 22, and opposing rollers that are opposite to the contact rollers, thereby gradually bending the edge 28 of the outer casing 22. This suppresses the springback of the bent edge 28 of the outer casing 22. As a result, the volume density energy of the secondary battery 20 can be improved.

[0128] As explained with reference to Figures 1 to 5, the manufacturing apparatus 10 forms a bent portion R22B0 on ​​one edge 28 of the outer casing 22 of the secondary battery 20. The manufacturing apparatus 10 includes a conveying unit 5, an upstream roller group S1, an intermediate roller group S2, a downstream roller group S3, and a downstream roller group S4. The manufacturing apparatus 10 passes the edge 28 of the secondary battery 20, which is being conveyed by the conveying unit 5, through the upstream roller group S1, the intermediate roller group S2, the downstream roller group S3, and the downstream roller group S4, bending the edge 28 in stages to form the bent portion R22B0. This suppresses the amount of springback in the bent portion R22B0 of the edge 28. As a result, the manufacturing apparatus 10 can produce a secondary battery 20 with excellent volume density energy.

[0129] As explained with reference to Figures 1 to 5, in the manufacturing apparatus 10, the upstream roller group S1, the intermediate roller group S2, the downstream roller group S3, and the downstream roller group S4 bend the edge portion 28 twice in stages to form the bent portion R22B0. This results in a secondary battery 20 having a folded portion R22B0 formed by folding the edge 28 twice. As a result, the manufacturing apparatus 10 can produce a secondary battery 20 that is excellent in volume density energy and impact resistance.

[0130] As explained with reference to Figures 6 to 12, the secondary battery 20 comprises an electrode body 21 and an outer casing 22. The outer casing 22 has a housing portion R22A and an edge sealing portion R22B. The edge sealing portion R22B has a bent portion R22B0. The bent portion R22B0 is formed by bending the edge sealing portion R22B twice. Therefore, the shock resistance of the secondary battery 20 is superior to that of conventional batteries. As a result, the secondary battery 20 has excellent volume density energy and shock resistance.

[0131] As explained with reference to Figures 6 to 12, the first pressing load of the secondary battery 20 is 6.0 MPa or higher. The fact that the first pressing load is 6.0 MPa or higher indicates that the rigidity of the bent portion R22B0 in the housing portion R22A is excellent. As a result, the secondary battery 20 has superior impact resistance.

[0132] A secondary battery 20, as shown in Figures 1 to 6, was manufactured using the manufacturing apparatus 10 of the first embodiment. The first pressing load of the secondary battery 20 was 6.05 MPa. The third pressing load of the secondary battery 20 was 6.65 MPa. A conventional secondary ionization system was prepared. The first pressing load of the conventional secondary battery was 0.64 MPa. The third pressing load of the conventional secondary battery was 2.16 MPa. These results show that the external force required to destroy the electrode body 21 of the secondary battery 20 from the bent portion R22B0 in the housing portion R22A is approximately 3 to 10 times the external force required to destroy the electrode body of a conventional cell. In other words, the secondary battery 20 is found to have superior impact resistance.

[0133] As explained with reference to Figures 6 to 12, the secondary battery 20 further comprises a pair of terminals 29. The casing 22 further comprises a terminal sealing portion R22C. The terminal sealing portion R22C has a convex welded portion R22C0 on its side surface SR22CA. The convex welded portion R22C0 functions as a cushion against the displacement of the bent portion R22B0. Therefore, the impact resistance of the secondary battery 20 is superior to that of the terminal seal portion R22C when it does not have the convex welded portion R22C0. As a result, the secondary battery 20 has excellent volume density energy and impact resistance.

[0134] As explained with reference to Figures 6 to 12, the second pressing load of the secondary battery 20 is 12.0 MPa or higher. A second pressing load of 12.0 MPa or higher indicates that the rigidity of the bent portion R22B0 in the terminal seal portion R22C is excellent. As a result, the secondary battery 20 has superior impact resistance.

[0135] The secondary battery 20 shown in Figures 1 to 6 was manufactured using the manufacturing apparatus 10 of the first embodiment. The second pressing load of the secondary battery 20 was 16.5 MPa. As described above, the first pressing load of the secondary battery 20 was 6.65 MPa. These results show that the external force required to destroy the electrode body 21 of the secondary battery 20 from the bent portion R22B0 in the terminal seal portion R22C is approximately 2.5 times the external force required to destroy the electrode body 21 of the secondary battery 20 from the bent portion R22B0 in the housing portion R22A. In other words, the secondary battery 20 is found to have superior impact resistance compared to the case where the terminal seal portion R22C does not have a convex welded portion R22C0.

[0136] (2) Second Embodiment The secondary battery manufacturing apparatus of the second embodiment differs from the secondary battery manufacturing apparatus of the first embodiment in that the configuration of the contact surfaces between the upstream roller group, intermediate roller group, and downstream roller group and the outer casing is different.

[0137] The manufacturing apparatus for a secondary battery according to the second embodiment will be described below. In addition, the same terms or reference numerals will be used to describe parts that are the same as or equivalent to those described in the first embodiment.

[0138] The following describes the second upstream roller pair 330A of the upstream roller group S1, but the same method can be applied to other roller pairs.

[0139] As shown in Figure 13, the second upstream roller pair 330A comprises a second upstream contact roller 330 and a second upstream opposing roller 340 positioned opposite the second upstream contact roller 330.

[0140] (2.1) Second upstream roller pair 330A (2.1.1) Second upstream contact roller 330 The second upstream contact roller 330 is made of, for example, metal or resin, and has a small diameter portion 331, a large diameter portion 332, and an intermediate portion 333.

[0141] The small-diameter section 331 is located on the conveying section 5 side of the large-diameter section 332. The large-diameter section 332 has a larger outer diameter than the small-diameter section 331. The intermediate section 333 is located between the large-diameter section 332 and the small-diameter section 331. The intermediate section 333 is formed by expanding in diameter from the small-diameter section 331 toward the large-diameter section 332 so as to connect the outer shapes of the large-diameter section 332 and the small-diameter section 331. The outer circumferential surface of the intermediate section 333 is formed by a first inclined surface 332A tilted at an angle α (for example, 60°) with respect to the horizontal direction, and a first inclined surface 332B tilted at an angle k smaller than α with respect to the horizontal direction.

[0142] The outer circumferential surface 331A of the small diameter portion 331 and the outer circumferential surface 332A of the intermediate portion 333 are contact surfaces that come into contact with the edge portion 28 of the outer casing 22 being conveyed by the conveying unit 5. In other words, the edge portion 28 of the outer casing 22 being conveyed by the conveying unit 5 is in contact with the second upstream contact roller 330 at a point on the base side of the bending base portion of the edge portion 28 (near the base point of the bending point).

[0143] (2.1.2) Second upstream opposing roller 340 The second upstream opposing roller 340 is configured to be rotatable with respect to a rotation axis C7 that is inclined at a predetermined angle θ with respect to a horizontal direction perpendicular to the conveying direction R. The second upstream opposing roller 340 is made of, for example, metal or resin, and has a small diameter portion 341 and a large diameter portion 342. The large diameter portion 342 is positioned on the conveying portion 5 side of the small diameter portion 341. The large diameter portion 342 has a larger outer diameter than the small diameter portion 341. The corner portion 342C at the lower end of the large diameter portion 342 is positioned to abut against the edge portion 28. As a result, the edge portion 28 of the outer casing 22 conveyed by the conveying portion 5 is bent with the position where the corner portion 342C abuts as the bending base point. The outer circumferential surface 342A and the corner portion 342C of the large diameter portion 342 are contact surfaces that abut against the edge portion 28 of the outer casing 22 conveyed by the conveying portion 5. In other words, the edge 28 of the outer casing 22 being transported by the transport unit 5 is in contact with the second upstream opposing roller 340 at the base side of the bending point of the edge 28. That is, the part of the edge 28 of the outer casing 22 being transported by the transport unit 5 that is on the tip side of the bending point is not in contact with the second upstream contact roller 330 and the second upstream opposing roller 340.

[0144] (2.2) Effect Next, the operation and effects of the second embodiment will be described.

[0145] The rotational speed differs between the radially inner and radially outer sides of the roller. Therefore, when the edge 28 of the outer casing 22 comes into contact with the side end face of the roller, the difference in frictional force between the radially inner and outer sides of the roller may damage the edge 28 of the outer casing 22.

[0146] In the second embodiment, the edge 28 of the outer casing 22 contacts the contact roller and the opposing roller at the base side of the bending point, thereby suppressing the occurrence of a difference in frictional force at the contact surface between the edge 28 of the outer casing 22 and the contact roller and the opposing roller. Therefore, damage to the edge 28 of the outer casing 22 can be suppressed.

[0147] Furthermore, the other configurations and effects are substantially the same as those of the first embodiment described above, so their explanation will be omitted.

[0148] (4) Variations The secondary battery manufacturing apparatus of this disclosure has been described above based on the first and second embodiments. However, the specific configuration is not limited to these embodiments, and changes to the design are permitted as long as they do not deviate from the gist of the invention as described in each claim.

[0149] In the first embodiment, an example was shown in which the opposing roller was configured to be rotatable with respect to a rotation axis in a horizontal direction perpendicular to the conveying direction R. However, the opposing roller may also be configured to be rotatable with respect to a rotation axis that is inclined at a predetermined angle with respect to the horizontal direction perpendicular to the conveying direction R. In this case, the corner of the opposing roller can be brought into contact with the edge 28. This concentrates stress at the bending point of the edge 28, allowing the edge 28 to be bent.

[0150] In the first and second embodiments, the contact roller and the opposing roller were shown to rotate driven by the casing 22 of the secondary battery 20 being transported by the transport unit 5. However, at least one of the contact roller and the opposing roller may be rotationally driven.

[0151] In the first and second embodiments, an example was shown in which an end face 161A, which serves as a restricting portion to restrict the movement of the outer casing 22 in a direction perpendicular to the transport direction R, is provided on the opposing roller. However, this end face can also be provided on the contact roller.

[0152] In the first and second embodiments, examples were shown in which the contact roller and the opposing roller are rotatably fixed. However, at least one of the contact roller and the opposing roller may be biased toward the edge 28.

[0153] In the first and second embodiments, the contact roller and the opposing roller were shown to be provided along the transport path of the transport unit 5, on one side in the width direction of the transport path. However, the contact roller and the opposing roller may also be provided along the transport path of the transport unit 5, on both sides in the width direction of the transport path.

[0154] In the first and second embodiments, a plurality of pairs of rollers (i.e., upstream roller group S1, intermediate roller group S2, downstream roller group S3, and downstream roller group S4) bend the edge portion 28 twice in stages to form the bent portion R22B0. The disclosure is not limited thereto, and the plurality of pairs of rollers (i.e., upstream roller group S1, intermediate roller group S2, downstream roller group S3, and downstream roller group S4) may also form the bent portion by bending the edge portion 28 once in stages, or by bending the edge portion 28 at least three times in stages.

[0155] In the first and second embodiments, the first pressing load is 6.0 MPa or greater, but the disclosure is not limited thereto. The first pressing load of the secondary battery of the disclosure may be less than 6.0 MPa.

[0156] In the first and second embodiments, the terminal seal portion R22C has a convex welded portion R22C0 on the side surface SR22CA of the terminal seal portion R22C, but the disclosure is not limited thereto. In the secondary battery of the disclosure, the terminal seal portion R22C does not have to have a convex welded portion R22C0 on the side surface SR22CA of the terminal seal portion R22C.

[0157] In the first and second embodiments, the second pressing load is 12.0 MPa or greater, but the disclosure is not limited thereto. The second pressing load of the secondary battery of the disclosure may be less than 12.0 MPa.

[0158] In the first and second embodiments, the electrode body 21 has a plurality of unit electrode bodies 210, but it may also have only one unit electrode body 210. In the first and second embodiments, the unit electrode body 210 has a solid electrolyte layer, but a non-aqueous electrolyte may be used instead of a solid electrolyte layer. In the first and second embodiments, the secondary battery 20 is a laminate-type lithium secondary battery using a solid electrolyte, but it may also be a secondary battery such as a nickel-metal hydride battery.

[0159] The secondary battery manufacturing apparatus of this disclosure can be applied to secondary batteries having a laminated outer casing. [Explanation of Symbols]

[0160] 5. Conveying section 10 Manufacturing equipment 20 Secondary battery 21 Electrode body 22 Exterior 29 terminals 30. First upstream contact roller (an example of a contact roller) 40. First upstream opposing roller (an example of an opposing roller) 90. Downstream contact roller (an example of a contact roller) 96. Downstream Opposing Roller (An example of an opposing roller) 130 Second upstream contact roller (an example of a contact roller) 140 Second upstream opposing roller (an example of an opposing roller) 151A End face (an example of a regulated section) 230 Third upstream contact roller (an example of a contact roller) 240 Third upstream opposing roller (an example of an opposing roller) R Conveying direction

Claims

1. A conveying unit that conveys laminate-type secondary batteries having a laminate outer casing along the conveying direction, Multiple contact rollers with different contact angles are provided in the transport path of the transport section and contact the edge sealing portion of the laminate exterior body being transported, Opposing each of the aforementioned contact rollers are opposing rollers that, together with the contact rollers, bend the edge sealing portion of the laminated outer casing, A secondary battery manufacturing apparatus comprising: The plurality of contact rollers include a downstream contact roller located at the downstream end in the conveying direction, The opposing roller includes a downstream opposing roller positioned opposite the downstream contact roller, The downstream opposing roller has a portion of the same diameter having the same outer diameter, When viewed from the aforementioned transport direction, the edge seal portion of the laminate outer casing contacts one radial end of the portion of the same diameter with the base portion of the edge seal portion from the bending point. When viewed from the aforementioned transport direction, the rotation axis of the downstream contact roller is parallel to the thickness direction of the electrode body included in the secondary battery. A secondary battery manufacturing apparatus, wherein, when viewed from the aforementioned transport direction, the other radial end of the portion of the same diameter is located on the electrode body side relative to the one end of the portion of the same diameter, and the rotation axis perpendicular to the radial direction of the downstream opposing roller is inclined with respect to a direction perpendicular to the rotation axis of the downstream contact roller.

2. The downstream contact roller is an elastic pressing roller that presses from the outside toward the downstream opposing roller positioned in the gap of the edge seal portion of the folded laminate exterior body. The apparatus for manufacturing a secondary battery according to claim 1.

3. One of the contact roller and the opposing roller is provided with a restricting portion that restricts movement in a direction perpendicular to the conveying direction of the laminated outer casing. A secondary battery manufacturing apparatus according to claim 1 or claim 2.

4. The secondary battery manufacturing apparatus is an apparatus for forming a bent portion in the edge sealing portion, The secondary battery having the aforementioned bent portion, The electrode body and, The laminated outer casing, which is made of a laminate sheet, covers the electrode body, Equipped with, The laminated outer casing is A housing section for housing the electrode body, The edge seal portion is formed by welding the edges of the laminate sheets together, It has, The edge sealing portion has the bent portion which is formed by bending it relative to the main surface of the electrode body, The aforementioned folded portion is formed by folding the edge sealing portion at least twice. The first pressing load is 6.0 MPa or more. The folded portion has a facing surface that is opposite to the side surface of the housing portion, The secondary battery manufacturing apparatus according to claim 1 or claim 2, wherein the first pressing load represents the load required to press a part of the bent portion toward the side surface of the housing portion, thereby bringing the opposing surface into contact with the side surface of the housing portion.

5. The electrode body further comprises a terminal electrically connected to it, The laminated outer casing further includes a terminal sealing portion that encloses and seals the terminals extending to the outside of the laminated outer casing, The bent portion has a facing surface that is opposite to the side surface of the housing portion and the terminal sealing portion, The terminal sealing portion has a convex welded portion formed by welding the overlapping portion of the laminate sheet to the side surface of the terminal sealing portion. The convex welded portion protrudes from the side surface toward the opposing surface, The second pressing load is 12.0 MPa or higher. The secondary battery manufacturing apparatus according to claim 4, wherein the second pressing load represents the load necessary to press the entire bent portion toward the side surface of the terminal seal portion, thereby crushing the convex welded portion and bringing the opposing surface into contact with the side surface of the terminal seal portion.

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