Prismatic secondary battery

Abstract

To provide a reliable square secondary battery.SOLUTION: A square secondary battery 20 includes: an electrode body including a positive electrode plate and a negative electrode plate; a rectangular exterior body having an opening and housing the electrode body; a sealing plate 2 that seals the opening of the rectangular exterior body; an external terminal 7 electrically connected to one of the positive electrode plate and the negative electrode plate and attached to the sealing plate 2; a current collecting member that electrically connects the one electrode plate and the external terminal and is arranged between the electrode body and the sealing plate 2; an insulating member 63 arranged between the current collecting member and the sealing plate 2; and a liquid injection hole 15 formed in the sealing plate 2. The insulating member 63 has an opening 63b formed in a region overlapping with the liquid injection hole 15, and the inner diameter of the opening 63b is larger than the inner diameter of the liquid injection hole 15.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a prismatic secondary battery. [Background technology]

[0002] BACKGROUND ART Prismatic secondary batteries such as alkaline secondary batteries and non-aqueous electrolyte secondary batteries are used as driving power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs, PHEVs), and the like.

[0003] In these prismatic secondary batteries, a battery case is formed by a cylindrical, rectangular exterior body with a bottom and an opening, and a sealing plate that seals the opening. An electrode assembly consisting of a positive electrode plate, a negative electrode plate, and a separator is housed inside the battery case, along with an electrolyte. A positive electrode terminal and a negative electrode terminal are attached to the sealing plate. The positive electrode terminal is electrically connected to the positive electrode plate via a positive electrode current collector, and the negative electrode terminal is electrically connected to the negative electrode plate via a negative electrode current collector.

[0004] The positive electrode plate includes a metallic positive electrode core and a positive electrode active material mixture layer formed on the surface of the positive electrode core. A positive electrode core exposed portion is formed in part of the positive electrode core, where the positive electrode active material mixture layer is not formed. A positive electrode current collector is connected to this positive electrode core exposed portion. The negative electrode plate includes a metallic negative electrode core and a negative electrode active material mixture layer formed on the surface of the negative electrode core. A negative electrode core exposed portion is formed in part of the negative electrode core, where the negative electrode active material mixture layer is not formed. A negative electrode current collector is connected to this negative electrode core exposed portion.

[0005] For example, Patent Documents 1 and 2 disclose disposing an insulating spacer between a sealing plate and an electrode body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-32477 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-76293 Summary of the Invention [Problem to be solved by the invention]

[0007] Although the above-mentioned Patent Documents 1 and 2 disclose disposing an insulating spacer between the sealing plate and the electrode body, further improvements are required.

[0008] An object of the present invention is to provide a highly reliable prismatic secondary battery. [Means for solving the problem]

[0009] A prismatic secondary battery according to one embodiment of the present invention includes an electrode assembly including a positive electrode plate and a negative electrode plate, a prismatic exterior body having an opening and housing the electrode assembly, a sealing plate that seals the opening, an external terminal that is electrically connected to one of the positive electrode plate and the negative electrode plate and attached to the sealing plate, a current collecting member that electrically connects the one electrode plate and the external terminal and is arranged between the electrode assembly and the sealing plate, an insulating member that is arranged between the current collecting member and the sealing plate, and a liquid injection hole formed in the sealing plate, wherein the insulating member has an opening formed in a region that overlaps with the liquid injection hole, and the sealing plate has a longitudinal direction and a lateral direction, and The body includes a first electrode body element including a positive electrode plate and a negative electrode plate, and a second electrode body element including a positive electrode plate and a negative electrode plate, the first electrode body element and the second electrode body element being aligned in the short direction, one electrode plate of the first electrode body element and one electrode plate of the second electrode body element each having an electrode tab group in which a plurality of tabs are stacked, the electrode tab group of the first electrode body element being joined to a first joint of the current collecting member, and the electrode tab group of the second electrode body element being joined to a second joint of the current collecting member, an opening being located between the first joint and the second joint in the short direction, and the inner diameter of the opening being larger than the inner diameter of the liquid inlet. [Effects of the Invention]

[0010] According to the present invention, a prismatic secondary battery with higher reliability can be provided. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a perspective view of a prismatic secondary battery according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a plan view of a positive electrode plate according to the embodiment. [Figure 4] FIG. 2 is a plan view of a negative electrode plate according to the embodiment. [Figure 5] FIG. 2 is a plan view of an electrode element according to an embodiment. [Figure 6] FIG. 10 is a bottom view of the sealing plate after the components have been attached. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] 8 is an enlarged view of the first positive electrode current collector, the second positive electrode current collector, and the current interrupt mechanism in the vicinity of the first positive electrode current collector, the second positive electrode current collector, and the current interrupt mechanism in FIG. [Figure 9] 8 is an enlarged view of the vicinity of the first negative electrode current collector and the second negative electrode current collector in FIG. 7. FIG. [Figure 10] FIG. 10 is a diagram showing a step of connecting a tab to a second current collector. [Figure 11] FIG. 2 is a perspective view of a first insulating member and a second insulating member. [Figure 12] 4 is a cross-sectional view taken along the short side direction of the sealing plate in the vicinity of the connection portion between the first insulating member and the second insulating member. FIG. [Figure 13] FIG. 4 is a top view of the second insulating member. [Figure 14] FIG. 2 is a cross-sectional view taken along the short side direction of the sealing plate in the vicinity of the connection portion between the negative electrode tab and the second negative electrode current collector. [Figure 15] 10 is a cross-sectional view taken along the short side direction of a sealing body, a shielding member, and a sealing plate of a second insulating member of a prismatic secondary battery according to Modification 1. FIG. [Figure 16] 10 is a top view of a second insulating member of a prismatic secondary battery according to Modification 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The configuration of the prismatic secondary battery 20 according to the embodiment will be described below. Note that the present invention is not limited to the following embodiment.

[0013] FIG. 1 is a perspective view of a prismatic secondary battery 20. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. As shown in FIGS. 1 and 2, the prismatic secondary battery 20 includes a battery case 100 made of a prismatic outer casing 1 in the shape of a bottomed rectangular cylinder having an opening, and a sealing plate 2 that seals the opening of the prismatic outer casing 1. The prismatic outer casing 1 and the sealing plate 2 are preferably made of metal, for example, aluminum or an aluminum alloy. The prismatic outer casing 1 contains a stacked electrode assembly 3, in which multiple positive electrode plates and multiple negative electrode plates are stacked with separators interposed between them, together with an electrolyte. A resin insulating sheet 14 is disposed between the electrode assembly 3 and the prismatic outer casing 1.

[0014] A positive electrode tab 40 and a negative electrode tab 50 are provided on the end of the electrode assembly 3 on the sealing plate 2 side. The positive electrode tab 40 is electrically connected to the positive electrode external terminal 7 via the second positive electrode current collector 6b and the first positive electrode current collector 6a. The negative electrode tab 50 is electrically connected to the negative electrode external terminal 9 via the second negative electrode current collector 8b and the first negative electrode current collector 8a. The first positive electrode current collector 6a and the second positive electrode current collector 6b form the positive electrode current collector 6. The first negative electrode current collector 8a and the second negative electrode current collector 8b form the negative electrode current collector 8. The positive electrode current collector 6 can be formed as a single component. The negative electrode current collector 8 can also be formed as a single component.

[0015] The positive electrode external terminal 7 is fixed to the sealing plate 2 via a resin external insulating member 11. The negative electrode external terminal 9 is fixed to the sealing plate 2 via a resin external insulating member 13. The positive electrode external terminal 7 is preferably made of metal, and more preferably made of aluminum or an aluminum alloy. The negative electrode external terminal 9 is preferably made of metal, and more preferably made of copper or a copper alloy. Furthermore, it is more preferable that the negative electrode external terminal 9 has a portion made of copper or a copper alloy on the inside side of the battery case 100, and a portion made of aluminum or an aluminum alloy on the outside side of the battery case 100. The surface of the negative electrode external terminal 9 is preferably plated with nickel or the like.

[0016] The conductive path between the positive electrode plate and the positive electrode external terminal 7 is preferably provided with a current interruption mechanism 60 that operates when the pressure inside the battery case 100 reaches or exceeds a predetermined value, and interrupts the conductive path between the positive electrode plate and the positive electrode external terminal 7. A current interruption mechanism may also be provided in the conductive path between the negative electrode plate and the negative electrode external terminal 9.

[0017] The sealing plate 2 is provided with a gas release valve 17 that breaks when the pressure inside the battery case 100 exceeds a predetermined value, thereby releasing gas inside the battery case 100 to the outside of the battery case 100. The gas release valve 17 is formed to be thinner than other parts of the sealing plate 2. The gas release valve 17 can be formed by pressing the sealing plate 2. Alternatively, a through-hole for the gas release valve can be formed in the sealing plate 2, and the through-hole can be closed with a thin valve to form the gas release valve 17. The operating pressure of the gas release valve 17 is set to a value higher than the operating pressure of the current-breaking mechanism 60.

[0018] The sealing plate 2 is provided with an electrolyte injection hole 15. After the electrolyte is injected into the battery case 100 through the electrolyte injection hole 15, the electrolyte injection hole 15 is sealed with a sealing plug 16.

[0019] Next, a method for manufacturing the prismatic secondary battery 20 will be described. [Preparation of positive electrode plate] A positive electrode slurry containing lithium nickel cobalt manganese composite oxide as the positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, a carbon material as a conductive agent, and N-methylpyrrolidone (NMP) as a dispersion medium is prepared. This positive electrode slurry is applied to both sides of a rectangular aluminum foil with a thickness of 15 μm as a positive electrode core. The positive electrode slurry is then dried to remove the N-methylpyrrolidone from the positive electrode slurry, forming a positive electrode active material mixture layer on the positive electrode core. The positive electrode active material mixture layer is then compressed to a predetermined thickness. The resulting positive electrode plate is then cut into a predetermined shape.

[0020] FIG. 3 is a plan view of a positive electrode plate 4 fabricated by the above-described method. As shown in FIG. 3, the positive electrode plate 4 has a main body portion in which a positive electrode active material mixture layer 4b is formed on both sides of a rectangular positive electrode core 4a. The positive electrode core 4a protrudes from the edge of the main body portion, and this protruding positive electrode core 4a constitutes a positive electrode tab 40. The positive electrode tab 40 may be a part of the positive electrode core 4a as shown in FIG. 3, or another member may be connected to the positive electrode core 4a to form the positive electrode tab 40. Furthermore, a positive electrode protective layer 4d having an electrical resistance greater than that of the positive electrode active material mixture layer 4b is preferably provided in a portion of the positive electrode tab 40 adjacent to the positive electrode active material mixture layer 4b. The positive electrode protective layer 4d preferably contains ceramic particles such as alumina, silica, or zirconia, and a binder. Furthermore, the positive electrode protective layer 4d more preferably contains conductive particles such as a carbon material.

[0021] [Preparation of negative electrode plate] A negative electrode slurry containing graphite as the negative electrode active material, styrene butadiene rubber (SBR) as a binder, carboxymethyl cellulose (CMC) as a thickener, and water is prepared. This negative electrode slurry is applied to both sides of a rectangular copper foil with a thickness of 8 μm as the negative electrode substrate. The negative electrode substrate is then dried to remove the water from the negative electrode slurry, forming a negative electrode active material mixture layer on the negative electrode substrate. The negative electrode active material mixture layer is then compressed to a predetermined thickness. The negative electrode plate thus obtained is cut into a predetermined shape.

[0022] FIG. 4 is a plan view of a negative electrode plate 5 produced by the above-described method. As shown in FIG. 4, the negative electrode plate 5 has a main body portion in which negative electrode active material mixture layers 5b are formed on both sides of a rectangular negative electrode core 5a. The negative electrode core 5a protrudes from the edge of the main body portion, and this protruding negative electrode core 5a constitutes a negative electrode tab 50. Note that the negative electrode tab 50 may be a part of the negative electrode core 5a as shown in FIG. 4, or another member may be connected to the negative electrode core 5a to form the negative electrode tab 50.

[0023] [Fabrication of electrode elements] Fifty positive electrode plates 4 and 51 negative electrode plates 5 are prepared by the method described above, and these are stacked with rectangular polyolefin separators in between to prepare stacked electrode body elements (3a, 3b). As shown in FIG. 5, the stacked electrode body elements (3a, 3b) are prepared so that the positive electrode tabs 40 of each positive electrode plate 4 are stacked at one end, and the negative electrode tabs 50 of each negative electrode plate 5 are stacked at the other end. Separators are placed on both outer surfaces of the electrode body elements (3a, 3b), and the electrode plates and separators can be fixed in a stacked state with tape or the like. Alternatively, an adhesive layer may be provided on the separator, so that the separator and positive electrode plate 4 and the separator and negative electrode plate 5 are adhered to each other.

[0024] The size of the separator in a plan view is preferably the same as or larger than the negative electrode plate 5. The positive electrode plate 4 may be placed between two separators, and the edges of the separators may be heat-welded, after which the positive electrode plate 4 and the negative electrode plate 5 may be stacked. When producing the electrode body elements (3a, 3b), a long separator may be used, and the positive electrode plate 4 and the negative electrode plate 5 may be stacked while the long separator is folded zigzag. Alternatively, a long separator may be used, and the positive electrode plate 4 and the negative electrode plate 5 may be stacked while the long separator is wound.

[0025] [Installing each part on the sealing plate] 2 and 6 to 8, a method for attaching the positive electrode external terminal 7 and the first positive electrode current collector 6a to the sealing plate 2 and the configuration of the current interrupt mechanism 60 will be described. The external insulating member 11 is disposed on the outer surface of the positive terminal mounting hole 2a provided in the sealing plate 2, and the internal insulating member 10 and cup-shaped conductive member 61 are disposed on the inner surface of the positive terminal mounting hole 2a. Next, the positive external terminal 7 is inserted into the through hole of the external insulating member 11, the positive terminal mounting hole 2a of the sealing plate 2, the through hole of the internal insulating member 10, and the through hole of the conductive member 61. The tip of the positive external terminal 7 is then crimped onto the conductive member 61. This fixes the positive external terminal 7, the external insulating member 11, the sealing plate 2, the internal insulating member 10, and the conductive member 61 together. Note that the crimped portion of the positive external terminal 7 and the conductive member 61 are preferably welded by laser welding or the like. Furthermore, the internal insulating member 10 and the external insulating member 11 are preferably made of resin.

[0026] The conductive member 61 has an opening on the side of the electrode body 3. The disk-shaped deformable plate 62 is arranged to close the opening of the conductive member 61, and the periphery of the deformable plate 62 is welded to the conductive member 61. In this way, the opening of the conductive member 61 is sealed by the deformable plate 62. It is preferable that the conductive member 61 and the deformable plate 62 are each made of metal, and more preferably aluminum or an aluminum alloy.

[0027] Next, a third insulating member 63 made of resin is placed on the electrode body 3 side of the deforming plate 62. The third insulating member 63 has a connection portion, and it is preferable that this connection portion is connected to the inner insulating member 10. It is also preferable that a claw-shaped hook-fixing portion is provided on the third insulating member 63, a flange portion, a recessed portion or a protruding portion is provided on the conductive member 61, and the hook-fixing portion of the third insulating member 63 is fixed to the flange portion, the recessed portion or the protruding portion of the conductive member 61.

[0028] A fixing protrusion is formed on the surface of the third insulating member 63 facing the electrode body 3. The third insulating member 63 preferably has an insulating member first region 63x disposed below the deformable plate 62, an insulating member second region 63y extending from an end of the insulating member first region 63x toward the sealing plate 2, and an insulating member third region 63z extending from an end of the insulating member second region 63y along the sealing plate 2. An insulating member opening 63b is provided in the insulating member third region 63z at a position facing the electrolyte injection hole 15 of the sealing plate 2. An insulating member protrusion 63c protruding toward the electrode body 3 is provided on the edge of the insulating member opening 63b.

[0029] Next, the first positive electrode current collector 6a is placed on the electrode body 3 side of the third insulating member 63. The first positive electrode current collector 6a has a fixing through-hole. Then, the fixing protrusions of the third insulating member 63 are inserted into the fixing through-holes of the first positive electrode current collector 6a, and the tips of the fixing protrusions are expanded in diameter to fix the third insulating member 63 and the first positive electrode current collector 6a. In this way, a fixing portion 70 is formed. As shown in FIG. 6, the fixing portions 70 are preferably provided in four locations so as to surround the connection portion between the deformable plate 62 and the first positive electrode current collector 6a.

[0030] Thereafter, the deformable plate 62 and the first positive electrode current collector 6a are welded together via a through hole provided in the third insulating member 63. The first positive electrode current collector 6a preferably has a thin portion 6c, and is welded together with the deformable plate 62 at this thin portion 6c. An opening is preferably provided in the center of the thin portion 6c, and the edge of this opening is preferably welded together with the deformable plate 62. More preferably, the thin portion 6c is provided with an annular notch portion that surrounds the connection portion between the first positive electrode current collector 6a and the deformable plate 62.

[0031] When the pressure inside the battery case 100 exceeds a predetermined value, the deformable plate 62 deforms so that the center of the deformable plate 62 moves upward (toward the positive electrode external terminal 7). As the deformable plate 62 deforms, the thin portion 6c of the first positive electrode current collector 6a breaks, thereby cutting the conductive path between the positive electrode plate 4 and the positive electrode external terminal 7.

[0032] A terminal through-hole 7b is provided in the positive electrode external terminal 7, and gas can be introduced into the current interrupt mechanism 60 through this terminal through-hole 7b to check for leaks at the connection between the conductive member 61 and the deformable plate 62. Alternatively, the deformable plate 62 and the first positive electrode current collector 6a can be welded together while the gas is pressing the deformable plate 62 against the first positive electrode current collector 6a. Finally, the terminal through-hole 7b is sealed with a terminal sealing member 7a. The terminal sealing member 7a preferably includes a metal member 7x and a rubber member 7y.

[0033] The first positive electrode current collector 6a has current collector protrusions 6x on the surface facing the electrode body 3.

[0034] 2, 6, 7, and 9, a method for attaching the negative electrode external terminal 9 and the first negative electrode current collector 8a to the sealing plate 2 will be described. The external insulating member 13 is placed on the outer surface of the negative electrode terminal mounting hole 2b provided in the sealing plate 2, and the internal insulating member 12 and the first negative electrode current collector 8a are placed on the inner surface of the negative electrode terminal mounting hole 2b. Next, the negative electrode external terminal 9 is inserted into the through hole of the external insulating member 13, the negative electrode terminal mounting hole 2b of the sealing plate 2, the through hole of the internal insulating member 12, and the through hole of the first negative electrode current collector 8a. The tip of the negative electrode external terminal 9 is then crimped onto the first negative electrode current collector 8a. This fixes the external insulating member 13, the sealing plate 2, the internal insulating member 12, and the first negative electrode current collector 8a. Note that the crimped portion of the negative electrode external terminal 9 and the first negative electrode current collector 8a are preferably welded by laser welding or the like. Furthermore, the internal insulating member 12 and the external insulating member 13 are preferably made of resin.

[0035] [Connection between the second current collector and the tab] FIG. 10 shows a method for connecting a positive electrode tab 40 to the second positive electrode current collector 6b and a method for connecting a negative electrode tab 50 to the second negative electrode current collector 8b. Two electrode body elements are fabricated using the method described above, designated as the first electrode body element 3a and the second electrode body element 3b, respectively. The first electrode body element 3a and the second electrode body element 3b may have the same configuration or different configurations. Here, the multiple positive electrode tabs 40 of the first electrode body element 3a constitute the first positive electrode tab group 40a. The multiple negative electrode tabs 50 of the first electrode body element 3a constitute the first negative electrode tab group 50a. The multiple positive electrode tabs 40 of the second electrode body element 3b constitute the second positive electrode tab group 40b. The multiple negative electrode tabs 50 of the second electrode body element 3b constitute the second negative electrode tab group 50b.

[0036] A second positive electrode current collector 6b and a second negative electrode current collector 8b are disposed between the first electrode body element 3a and the second electrode body element 3b. A first positive electrode tab group 40a consisting of a plurality of stacked positive electrode tabs 40 protruding from the first electrode body element 3a is disposed on the second positive electrode current collector 6b, and a first negative electrode tab group 50a consisting of a plurality of stacked negative electrode tabs 50 protruding from the first electrode body element 3a is disposed on the second negative electrode current collector 8b. A second positive electrode tab group 40b consisting of a plurality of stacked positive electrode tabs 40 protruding from the second electrode body element 3b is disposed on the second positive electrode current collector 6b, and a second negative electrode tab group 50b consisting of a plurality of stacked negative electrode tabs 50 protruding from the second electrode body element 3b is disposed on the second negative electrode current collector 8b. The first positive electrode tab group 40a and the second positive electrode tab group 40b are each welded to the second positive electrode current collector 6b to form welded connections 90. The first negative electrode tab group 50a and the second negative electrode tab group 50b are each welded to the second negative electrode current collector 8b to form welded connections 90. The welded connections can be performed as follows.

[0037] The stacked tabs (first positive electrode tab group 40a, second positive electrode tab group 40b, first negative electrode tab group 50a, second negative electrode tab group 50b) and the current collectors (second positive electrode current collector 6b, second negative electrode current collector 8b) are sandwiched between welding jigs from above and below, and welding is performed. Here, ultrasonic welding or resistance welding is preferred as the welding method. This more reliably welds and connects the stacked tabs and current collectors. When a large number of tabs are stacked, for example, when the number of stacked tabs is 20 or more, ultrasonic welding or resistance welding can form a more reliable welded connection than laser welding or the like, because welding can be performed while sandwiched between a pair of welding jigs. Note that the pair of welding jigs is a pair of resistance welding electrodes in the case of resistance welding, and a horn and anvil in the case of ultrasonic welding. The tabs (first positive electrode tab group 40a, second positive electrode tab group 40b, first negative electrode tab group 50a, second negative electrode tab group 50b) and the current collectors (second positive electrode current collector 6b, second negative electrode current collector 8b) can also be connected by laser welding.

[0038] The first positive electrode tab group 40a of the first electrode body element 3a is connected to the second positive electrode current collector 6b on one side of the center in the width direction of the second positive electrode current collector 6b. The second positive electrode tab group 40b of the second electrode body element 3b is connected to the second positive electrode current collector 6b on the other side of the center in the width direction of the second positive electrode current collector 6b. The first negative electrode tab group 50a of the second electrode body element 3b is connected to the second negative electrode current collector 8b on one side of the center in the width direction of the second negative electrode current collector 8b. The second negative electrode tab group 50b of the second electrode body element 3b is connected to the second positive electrode current collector 6b on the other side of the center in the width direction of the second positive electrode current collector 6b.

[0039] As shown in FIG. 10 , an opening 6z is provided in the second positive electrode current collector 6b. After the second positive electrode current collector 6b is connected to the first positive electrode current collector 6a, the opening 6z is positioned corresponding to the electrolyte injection hole 15 provided in the sealing plate 2. The first positive electrode tab group 40a of the first electrode body element 3a is connected to one side of the opening 6z in the width direction of the second positive electrode current collector 6b. The second positive electrode tab group 40b of the second electrode body element 3b is connected to the other side of the opening 6z in the width direction of the second positive electrode current collector 6b. When the second positive electrode current collector 6b, the first positive electrode tab group 40a, and the second positive electrode tab group 40b are viewed from a direction perpendicular to the sealing plate 2, it is preferable that the portions of the first positive electrode tab group 40a and the second positive electrode tab group 40b that are arranged approximately parallel to the second positive electrode current collector 6b do not overlap the opening 6z. This makes it possible to prevent the second positive electrode current collector 6b, the first positive electrode tab group 40a, and the second positive electrode tab group 40b from interfering with the injection of the electrolyte.

[0040] It is noted that the order in which the step of fixing the first positive electrode current collector 6a and the first negative electrode current collector 8a to the sealing plate 2 and the step of connecting the positive electrode tab 40 and the negative electrode tab 50 to the second positive electrode current collector 6b and the second negative electrode current collector 8b, respectively, can be performed is not critical.

[0041] [Connection between the first and second positive electrode current collectors] As shown in FIGS. 6 and 7, the first positive electrode current collector 6a has current collector protrusions 6x. As shown in FIG. 10, the second positive electrode current collector 6b has current collector openings 6y. As shown in FIGS. 7 and 8, the second positive electrode current collector 6b is placed on the third insulating member 63 so that the current collector protrusions 6x of the first positive electrode current collector 6a are positioned within the current collector openings 6y of the second positive electrode current collector 6b. The current collector protrusions 6x of the first positive electrode current collector 6a and the edge of the current collector opening 6y of the second positive electrode current collector 6b are then welded by irradiating an energy beam such as a laser. This connects the first positive electrode current collector 6a and the second positive electrode current collector 6b. A current collector first recess 6f is provided around the current collector opening 6y of the second positive electrode current collector 6b. That is, the current collector opening 6y is formed in the center of the current collector first recess 6f. In the current collector first recess 6f, the first positive electrode current collector 6a and the second positive electrode current collector 6b are connected by welding.

[0042] As shown in FIG. 8, the second positive electrode current collector 6b has a current collector first region 6b1, a current collector second region 6b2, and a current collector third region 6b3. A positive electrode tab 40 is connected to the current collector first region 6b1. The current collector third region 6b3 is connected to the first positive electrode current collector 6a. The current collector second region 6b2 connects the current collector first region 6b1 and the current collector third region 6b3. In addition, in a direction perpendicular to the sealing plate 2, the distance between the sealing plate 2 and the current collector first region 6b1 is smaller than the distance between the sealing plate 2 and the current collector third region 6b3. With this configuration, the space occupied by the current collector can be made smaller, resulting in a prismatic secondary battery with a higher volumetric energy density.

[0043] As shown in FIG. 10, target holes 6e are provided on both sides of the current collector opening 6y in the second positive electrode current collector 6b. When welding the first positive electrode current collector 6a and the second positive electrode current collector 6b by irradiating them with an energy beam such as a laser, it is preferable to use the target holes 6e as targets for image correction. It is preferable to image-detect the target holes 6e, correct their positions, and irradiate the energy beam along the shape of the current collector opening 6y. The target holes 6e may be recessed rather than through-holes. It is preferable that the area of ​​the target holes 6e in a plan view is smaller than the area of ​​the current collector opening 6y in a plan view. It is also preferable that the current collector opening 6y and the target holes 6e are arranged so as to be aligned on a straight line in the width direction of the second positive electrode current collector 6b.

[0044] 8, a current collector second recess 6w is formed on the surface of the first positive electrode current collector 6a facing the third insulating member 63, behind the current collector protrusion 6x. This is preferable because it makes it easier to form a larger welded connection between the first positive electrode current collector 6a and the second positive electrode current collector 6b. Furthermore, the formation of the current collector second recess 6w prevents the third insulating member 63 from being damaged by heat generated during welding when the first positive electrode current collector 6a and the second positive electrode current collector 6b are welded together.

[0045] As shown in Fig. 8, it is preferable that the lower (electrode body 3 side) tip of the insulating member protrusion 63c of the third insulating member 63 protrudes downward (toward the electrode body 3) further than the lower surface around the opening 6z of the second positive electrode current collector 6b. This reliably prevents contact between the sealing plug 16 and the second positive electrode current collector 6b. It is preferable that the insulating member protrusion 63c is annular. However, the insulating member protrusion 63c does not necessarily have to be annular, and may have a partially cut-out shape.

[0046] [Connection between the first negative electrode current collector and the second negative electrode current collector] As shown in FIGS. 6 and 7, the first negative electrode current collector 8a has current collector protrusions 8x. As shown in FIGS. 9 and 10, the second negative electrode current collector 8b has current collector openings 8y. As shown in FIG. 9, the second negative electrode current collector 8b is placed on the inner insulating member 12 so that the current collector protrusions 8x of the first negative electrode current collector 8a are positioned within the current collector openings 8y of the second negative electrode current collector 8b. The current collector protrusions 8x of the first negative electrode current collector 8a and the edge of the current collector opening 8y of the second negative electrode current collector 8b are then welded by irradiating an energy beam such as a laser. This connects the first negative electrode current collector 8a and the second negative electrode current collector 8b. As shown in FIG. 10, a current collector first recess 8f is provided around the current collector opening 8y of the second negative electrode current collector 8b. That is, a current collector opening 8y is formed in the center of the current collector first recess 8f. The first negative electrode current collector 8a and the second negative electrode current collector 8b are connected by welding in the current collector first recess 8f. In addition, a target hole 8e is formed in the second negative electrode current collector 8b, similar to the second positive electrode current collector 6b.

[0047] 9, a current collector second recess 8w is formed on the surface of the first negative electrode current collector 8a facing the inner insulating member 12 and behind the current collector protrusion 8x. This is preferable because it makes it easier to form a larger welded connection between the first negative electrode current collector 8a and the second negative electrode current collector 8b. Furthermore, the formation of the current collector second recess 8w prevents the inner insulating member 12 from being damaged by heat generated during welding when the first negative electrode current collector 8a and the second negative electrode current collector 8b are welded together.

[0048] As shown in FIG. 9, the second negative electrode current collector 8b has a current collector first region 8b1, a current collector second region 8b2, and a current collector third region 8b3. A negative electrode tab 50 is connected to the current collector first region 8b1. The current collector third region 8b3 is connected to the first negative electrode current collector 8a. The current collector second region 8b2 connects the current collector first region 8b1 and the current collector third region 8b3. In addition, in a direction perpendicular to the sealing plate 2, the distance between the sealing plate 2 and the current collector first region 8b1 is smaller than the distance between the sealing plate 2 and the current collector third region 8b3. With this configuration, the space occupied by the current collector can be made smaller, resulting in a prismatic secondary battery with a higher volumetric energy density.

[0049] The current collector protrusions 6x and 8x are preferably non-circular, and are preferably rectangular, elliptical, or track-shaped.

[0050] <Connection between the first insulating member and the second insulating member> As described above, it is preferable to electrically connect the positive electrode tab 40 and the positive electrode external terminal 7, and electrically connect the negative electrode tab 50 and the negative electrode external terminal 9, and then connect the first insulating member and the second insulating member.

[0051] FIG. 11 is a perspective view of an inner insulating member 12 and a second insulating member 80 as the first insulating member. The inner insulating member 12 has a first insulating member main body 12a that faces the inner surface of the sealing plate 2. The first insulating member main body 12a is preferably plate-shaped. The first insulating member main body 12a has a through hole 12d, into which the negative electrode external terminal 9 is inserted. A pair of first side walls 12b that protrude toward the electrode body 3 are provided at both ends in the short direction of the first insulating member main body 12a of the inner insulating member 12. A connection recess 12e is provided on the outer surface of each of the pair of first side walls 12b. Furthermore, a pair of second side walls 12c that protrude toward the electrode body 3 are provided at both ends in the long direction of the first insulating member main body 12a of the inner insulating member 12.

[0052] The second insulating member 80 has a second insulating member main body 80a disposed opposite the sealing plate 2. The second insulating member main body 80a is disposed between the sealing plate 2 and the electrode body 3. The second insulating member main body 80a has a wide portion 80a1 in the center in the longitudinal direction of the sealing plate 2, and narrow portions 80a2 on both sides of the wide portion 80a1, the narrow portions 80a2 having a width smaller than the width of the wide portion 80a1. A pair of side walls 80b extending from the second insulating member main body 80a toward the sealing plate 2 is provided at both ends of the wide portion 80a1 of the second insulating member main body 80a in the lateral direction of the sealing plate 2. Furthermore, a pair of connecting portions 80c extending from the second insulating member main body 80a toward the sealing plate 2 is provided at both ends of the wide portion 80a1 of the second insulating member main body 80a in the lateral direction of the sealing plate 2. It is preferable that the side walls 80b and the connecting portions 80c are spaced apart in the longitudinal direction of the sealing plate 2. This allows the pair of connecting portions 80c to be easily deformed, and therefore, when the connecting portions 80c are connected to the inner insulating member 12 as the first insulating member, it is possible to reliably prevent the second insulating member 80 from being damaged or broken.

[0053] It is preferable that the upper end of the side wall 80b contact the inner surface of the sealing plate 2. The height of the side wall 80b (the length from the second insulating member main body 80a to the upper end of the side wall 80b) can be made larger than the height of the connecting portion 80c (the length from the second insulating member main body 80a to the upper end of the connecting portion 80c).

[0054] FIG. 12 is a cross-sectional view taken along the short direction of the sealing plate near the connection point between the inner insulating member 12 (first insulating member) and the second insulating member 80. The connection portion 80c of the second insulating member 80 has a vertical wall 80c1 extending from the second insulating member main body 80a of the second insulating member 80 toward the sealing plate 2 and a protruding portion 80c2 protruding from the inner surface of the vertical wall 80c1 toward the inner insulating member 12 (first insulating member). The protruding portion 80c2 is fitted into the connection recess 12e of the inner insulating member 12 (first insulating member). This connects the inner insulating member 12 (first insulating member) to the second insulating member 80. Note that a connection recess may be provided at the end of the first side wall 12b of the inner insulating member 12 (first insulating member) on the sealing plate 2 side, and the protruding portion 80c2 may be disposed between the inner insulating member 12 (first insulating member) and the sealing plate 2.

[0055] In the second insulating member 80, a metal plate 81 is preferably disposed as a shielding member at a position facing the gas exhaust valve 17 provided on the sealing plate 2.

[0056] Fig. 13 is a top view of the second insulating member 80. The dashed line in Fig. 13 indicates the outer periphery of the metal plate 81. In the second insulating member 80, the metal plate 81 is molded inside the second insulating member 80 made of resin.

[0057] Metal plate 81 is preferably made of iron, an iron alloy such as stainless steel, copper, a copper alloy, aluminum, an aluminum alloy, or the like. The melting point of metal plate 81 is preferably higher than the melting point of sealing plate 2. For example, it is preferable that sealing plate 2 is made of aluminum or an aluminum alloy, and metal plate 81 is made of stainless steel.

[0058] <Electrode body production> The first positive electrode tab group 40a, the second positive electrode tab group 40b, the first negative electrode tab group 50a, and the second negative electrode tab group 50b are curved so that the upper surfaces of the first electrode body element 3a and the second electrode body element 3b in FIG. 10 are in contact with each other directly or via another member. This allows the first electrode body element 3a and the second electrode body element 3b to be combined into a single electrode body 3. It is preferable to combine the first electrode body element 3a and the second electrode body element 3b using tape or the like. Alternatively, it is preferable to combine the first electrode body element 3a and the second electrode body element 3b by placing them in an insulating sheet 14 formed into a box or bag shape.

[0059] <Assembly of prismatic secondary batteries> The electrode assembly 3 attached to the sealing plate 2 is covered with an insulating sheet 14 and inserted into the rectangular outer casing 1. Preferably, the insulating sheet 14 is a flat sheet that has been bent into a box or bag shape. The sealing plate 2 and the rectangular outer casing 1 are then joined by laser welding or the like, and the opening of the rectangular outer casing 1 is sealed. Thereafter, a nonaqueous electrolyte containing an electrolyte solvent and an electrolyte salt is poured through an electrolyte pouring hole 15 provided in the sealing plate 2. The electrolyte pouring hole 15 is then sealed with a sealing plug 16.

[0060] <Regarding the prismatic secondary battery 20> In the prismatic secondary battery 20, the second insulating member 80 is connected to the inner insulating member 12, which serves as a first insulating member fixed to the sealing plate 2. Therefore, when the prismatic secondary battery 20 is subjected to vibration or impact, the second insulating member 80 can be prevented from moving significantly inside the battery case 100. This reliably prevents unexpected short circuits that may occur due to misalignment of the second insulating member 80. Alternatively, it is possible to prevent the second insulating member 80 from moving inside the battery case 100 and damaging the positive electrode tab 40 or the negative electrode tab 50.

[0061] It is preferable that one narrow portion 80a2 of the second insulating member 80 is disposed between the first positive electrode tab group 40a and the second positive electrode tab group 40b, and the other narrow portion 80a2 of the second insulating member 80 is disposed between the first negative electrode tab group 50a and the second negative electrode tab group 50b. It is also preferable that the wide portion 80a1 of the second insulating member 80 is disposed between the first positive electrode tab group 40a and the second positive electrode tab group 40b and the first negative electrode tab group 50a and the second negative electrode tab group 50b in the longitudinal direction of the sealing plate 2. This configuration can more reliably prevent the second insulating member 80 from damaging the tabs. It is not necessary for the second insulating member 80 to have a wide portion and a narrow portion.

[0062] In the short direction of the sealing plate 2, a pair of side walls 80b extending from the second insulating member main body 80a toward the sealing plate 2 is provided at both ends of the wide portion 80a1 of the second insulating member main body 80a of the second insulating member 80. With this configuration, a gas flow path can be reliably secured between the second insulating member main body 80a of the second insulating member 80 and the sealing plate 2. That is, it is possible to more reliably prevent the second insulating member main body 80a from blocking the gas exhaust valve 17. This prevents the second insulating member 80 from obstructing gas exhaust from the gas exhaust valve 17. It is also possible to prevent the second insulating member 80 from coming into contact with the gas valve.

[0063] The length of the side wall 80b is preferably shorter than the length of the second insulating member main body 80a in the longitudinal direction of the sealing plate 2. This allows gas generated within the electrode body 3 to be more smoothly discharged to the outside of the battery case 100 when the gas discharge valve 17 is activated.

[0064] It is preferable that a metal plate 81 is disposed in the second insulating member 80 at a position facing the gas release valve 17 provided on the sealing plate 2. This prevents high-temperature gas ejected from the electrode body 3 from being directly sprayed onto the gas release valve 17 when an abnormality occurs in the prismatic secondary battery 20. This prevents high-temperature gas and sparks from being ejected from the gas release valve 17 when the gas release valve 17 breaks. It is particularly preferable that the metal plate 81 be made of stainless steel.

[0065] The method of attaching the metal plate 81 to the second insulating member 80 is not particularly limited. The metal plate 81 can be attached to the upper surface (the surface on the sealing plate 2 side) or the lower surface (the surface on the electrode body 3 side) of the second insulating member 80 by adhesive bonding, fitting, or the like. Alternatively, as shown in FIGS. 2 and 12, the metal plate 81 may be disposed inside the resin second insulating member 80. With such a configuration, unexpected short circuits between the positive and negative electrodes via the metal plate 81 can be more reliably prevented. Note that molding is a preferred method of disposing the metal plate 81 inside the resin second insulating member 80.

[0066] In the prismatic secondary battery 20, the second insulating member 80 that holds the metal plate 81 is connected to the inner insulating member 12, which serves as the first insulating member and is fixed to the sealing plate 2. This ensures that the metal plate 81 is positioned in a predetermined position, and also prevents the metal plate 81 from shifting out of position. This more reliably prevents high-temperature gas, sparks, and the like from being sealed in through the gas release valve 17. Furthermore, the provision of the side wall 80b on the second insulating member more reliably prevents an unexpected short circuit between the positive and negative electrodes via the metal plate 81.

[0067] It is not necessary to provide the side wall 80b and the connecting portion 80c separately. For example, in the second insulating member 80, a protrusion can be provided on the side wall 80b, which serves as a connecting portion that is connected to the inner insulating member 12, which serves as the first insulating member.

[0068] The inner insulating member 12 as the first insulating member and the second insulating member are preferably made of resin, such as polypropylene, polyethylene, perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), or ethylene-tetrafluoroethylene copolymer (ETFE).

[0069] A through hole can be provided in the second insulating member main body 80a of the second insulating member 80. The through hole is preferably provided at a position closer to the center of the electrolyte injection hole 15 provided in the sealing plate 2 in the longitudinal direction of the sealing plate 2 (on the gas release valve 17 side).

[0070] Fig. 14 is a cross-sectional view taken along the short direction of the sealing plate 2 near the connection portion between the first negative electrode tab group 50a and the second negative electrode tab group 50b and the second negative electrode current collector 8b. As shown in Fig. 14, the first negative electrode tab group 50a of the first electrode body element 3a and the second negative electrode tab group 50b of the second electrode body element 3b are each welded to the second negative electrode current collector 8b. The narrow width portion 80a2 of the second insulating member 80 is disposed between the first negative electrode tab group 50a and the second negative electrode tab group 50b.

[0071] With this configuration, a space S can be secured between the second negative electrode current collector 8b and the base of the first negative electrode tab group 50a, and between the second negative electrode current collector 8b and the base of the second negative electrode tab group 50b. The space S serves as a flow path for gas generated in the electrode assembly 3 to the gas release valve 17. Therefore, with the above configuration, if an abnormality occurs in the prismatic secondary battery, the gas can be smoothly released to the outside of the battery case, resulting in a prismatic secondary battery with higher reliability.

[0072] It is preferable that a corner C facing the first negative electrode tab group 50a to the second negative electrode tab group 50b be chamfered in the narrow width portion 80a2 of the second insulating member 80. This reliably prevents the first negative electrode tab group 50a to the second negative electrode tab group 50b from being damaged by the narrow width portion 80a2 of the second insulating member 80.

[0073] As with the negative electrode side, on the positive electrode side, the narrow width portion 80a2 of the second insulating member 80 is disposed between the first positive electrode tab group 40a of the first electrode body element 3a and the second positive electrode tab group 40b of the second electrode body element 3b. This ensures a space between the second positive electrode current collector 6b and the base of the first positive electrode tab group 40a, and between the second positive electrode current collector 6b and the base of the second positive electrode tab group 40b.

[0074] <<Variation 1>> FIG. 15 is a cross-sectional view of the sealing plate 2, a stainless steel metal plate 181 serving as a shielding member, and a resin second insulating member 180 in the short-side direction of the sealing plate 2 in a secondary battery according to Variation 1. As shown in FIG. 15, the metal plate 181 is disposed between the sealing plate 2 and the electrode body 3, facing the gas release valve 17. The metal plate 181 has a shielding member main body 181a disposed to face the sealing plate 2, and a pair of shielding member side walls 181b extending from both ends of the shielding member main body 181a toward the sealing plate 2. The shielding member main body 181a is disposed approximately parallel to the sealing plate 2. For example, the inclination of the shielding member main body 181a relative to the sealing plate 2 can be approximately −10° to 10°. The shielding member side walls 181b are provided at the ends of the shielding member main body 181a in the short-side direction of the sealing plate 2. In addition, in the shielding member main body 181a, no sidewalls are formed on either end side of the sealing plate 2 in the longitudinal direction.

[0075] The second insulating member 180 has a second insulating member main body 180a disposed opposite the sealing plate 2, and a pair of insulating member sidewalls 180b extending from both ends of the second insulating member main body 180a toward the sealing plate 2. The second insulating member main body 180a is disposed substantially parallel to the sealing plate 2. For example, the inclination of the second insulating member main body 180a relative to the sealing plate 2 can be approximately −10° to 10°. The insulating member sidewalls 180b are provided at the end of the second insulating member main body 180a in the short direction of the sealing plate 2. The shielding member main body 181a is disposed inside the second insulating member main body 180a, and the shielding member sidewalls 181b are disposed inside the insulating member sidewalls 180b. As shown in FIG. 15, the insulating member sidewalls 180b contact the sealing plate 2 at a position different from the gas release valve 17.

[0076] Metal plate 181 has a pair of shielding member sidewall portions 181b. Therefore, even if second insulating member 180 melts and metal plate 181 moves toward sealing plate 2 when high-temperature gas is ejected from electrode body 3, shielding member main body 181a comes into contact with sealing plate 2, and it is possible to reliably prevent shielding member main body 181a from blocking gas exhaust valve 17 and impeding gas exhaust.

[0077] <<Variation 2>> 16 is a top view (surface facing the sealing plate 2) of the second insulating member 280 in the secondary battery according to Modification 2. The second insulating member 280 has a second insulating member main body 280a arranged to face the sealing plate 2. The second insulating member main body 280a has a wide portion 280a1 and a pair of narrow portions 280a2 arranged on either side of the wide portion 280a1. The width of the wide portion 280a1 along the short side of the sealing plate 2 is larger than the width of the narrow portion 280a2 along the short side of the sealing plate 2. The wide portion 280a1 is arranged in a position facing the gas release valve 17 provided on the sealing plate 2.

[0078] The second insulating member main body 280a has an insulating member through-hole 285. The insulating member through-hole 285 is preferably provided at a position closer to the center of the sealing plate 2 in the longitudinal direction of the sealing plate 2 than the electrolyte injection hole 15 provided in the sealing plate 2. This configuration allows the electrolyte to more smoothly permeate the electrode body 3. The insulating member through-hole 285 is more preferably provided at a position facing the gas exhaust valve 17.

[0079] The second insulating member main body 280a is provided with a groove 286 that extends in the longitudinal direction of the sealing plate 2 and is connected to the insulating member through-hole 285. With this configuration, the electrode body 2, when the tab of the electrode plate (positive electrode tab 40 or negative electrode tab 50) is located near the bottom of the electrolyte injection hole 15 provided in the sealing plate 2 and the second insulating member is disposed below the electrolyte injection hole 15, it is preferable that the electrolyte injected from the electrolyte injection hole 15 moves inside the groove portion 286 and is injected into the electrode body 3 through the insulating member through-hole 285.

[0080] Like the second insulating member 80, the second insulating member main body 280a can be provided with a pair of side walls (corresponding to 80b) and a pair of connecting portions (corresponding to 80c).

[0081] <Other> A gap can be provided between the end of the separator constituting the electrode body 3 on the sealing plate 2 side and the second insulating member 80. In other words, the end of the separator constituting the electrode body 3 on the sealing plate 2 side can be prevented from contacting the second insulating member 80.

[0082] When the electrode body 3 is a stacked electrode body having multiple positive electrode plates and multiple negative electrode plates, or when the electrode body 3 is a wound electrode body arranged so that its winding axis is perpendicular to the sealing plate, the leading end of the positive electrode plate, the leading end of the negative electrode plate, and the leading end of the separator in the electrode body 3 are located on the sealing plate 2 side. With this configuration, when an electrolyte injection hole 15 is provided in the sealing plate 2, the injection of electrolyte into the electrode body 3 is improved. In such a case, it is preferable that the end of the separator on the sealing plate 2 side protrudes toward the sealing plate 2 further than the end of the negative electrode active material mixture layer on the sealing plate 2 side of the negative electrode plate. Also, in the electrode body 3, it is preferable that the end of the separator on the sealing plate 2 side protrudes toward the sealing plate 2 further than the end of the positive electrode active material mixture layer on the sealing plate 2 side of the positive electrode plate. Also, it is preferable that the positive electrode plate and the separator are bonded by an adhesive layer, and the negative electrode plate and the separator are bonded by an adhesive layer. With this configuration, it is possible to reliably prevent the positive electrode active material mixture layer or the negative electrode active material mixture layer from coming into contact with the second insulating member and damaging the positive electrode active material layer or the negative electrode active material layer.

[0083] A current interruption mechanism can be provided in only one of the conductive path between the positive electrode plate and the positive electrode external terminal 7 and the conductive path between the negative electrode plate and the negative electrode external terminal 9. In this case, the second insulating member can be connected only to the first insulating member on the side where the current interruption mechanism is not provided. This reduces the load on the fragile part of the current interruption mechanism. As shown in the above-described embodiment, it is preferable that a current interruption mechanism is formed in the conductive path between the positive electrode plate and the positive electrode external terminal 7. In such a case, the second insulating member can be connected only to the first insulating member on the negative electrode side.

[0084] As shown in the above-described embodiment, it is preferable that a current interruption mechanism be formed in the conductive path between the positive electrode plate and the positive electrode external terminal 7. In such a case, the entire second insulating member 80 can be positioned closer to the sealing plate 2 than the end of the positive electrode current collecting member 6 on the electrode body 3 side. With such a configuration, a prismatic secondary battery with a higher volumetric energy density can be obtained.

[0085] In the above embodiment, an example was shown in which the prismatic secondary battery was provided with a current interruption mechanism 60, but a current interruption mechanism need not be provided. Also, the inner insulating member 10 and the inner insulating member 12 can be integrated into a single component.

[0086] In the above-described embodiment, an example has been shown in which the inner insulating member 12, which is disposed between the sealing plate 2 and the first negative electrode current collector 8a and the second negative electrode current collector 8b that constitute the negative electrode current collector 8, is the first insulating member, and the second insulating member 80 is connected to this first insulating member. It is also possible to connect the second insulating member 80 to the third insulating member 63 or the inner insulating member 10 that is disposed between the sealing plate 2 and the positive electrode current collector 6.

[0087] In the above-described embodiment, an example has been shown in which the electrode body 3 is composed of two electrode body elements 3a, 3b, but this is not limiting. The electrode body 3 may be a single stacked electrode body. Furthermore, the electrode body 3 may be a single wound electrode body in which a long positive electrode plate and a long negative electrode plate are wound with a separator interposed therebetween. Furthermore, each of the two electrode body elements 3a, 3b is not limited to being a stacked electrode body, and may be a wound electrode body in which a long positive electrode plate and a long negative electrode plate are wound with a separator interposed therebetween.

[0088] In the above-described embodiment, an example has been shown in which the positive electrode current collecting member is made up of a first positive electrode current collector and a second positive electrode current collector, and the negative electrode current collecting member is made up of a first negative electrode current collector and a second negative electrode current collector. However, the positive electrode current collecting member may be made up of a single component, and the negative electrode current collecting member may be made up of a single component.

[0089] In the above embodiment, an example was shown in which the metal plate 81 was attached to the second insulating member 80. However, the metal plate 81 is not an essential component.

[0090] In the above-described embodiment, an example using a laminated electrode body has been shown, but a wound electrode body may also be used. Furthermore, the orientation of the wound electrode body arranged inside the rectangular exterior body is not particularly limited. [Explanation of symbols]

[0091] 20 Prismatic secondary battery, 1 Prismatic exterior body, 2 Sealing plate, 2a Positive electrode terminal mounting hole, 2b Negative electrode terminal mounting hole, 100 Battery case, 3 Electrode body, 3a First electrode body element, 3b Second electrode body element, 4 Positive electrode plate, 4a Positive electrode core, 4b Positive electrode active material mixture layer, 4d Positive electrode protective layer, 40 Positive electrode tab, 40a First positive electrode tab group, 40b Second positive electrode tab group, 5 Negative electrode plate, 5a Negative electrode core, 5b Negative electrode active material mixture layer, 50 Negative electrode tab, 50a First negative electrode tab group, 50b 6. Second negative electrode tab group, 6. Positive electrode current collecting member, 6a. First positive electrode current collecting member, 6c. Thin-walled portion, 6x. Current collecting member protrusion, 6w. Second current collecting member recess, 6b. Second positive electrode current collecting member, 6b1. First current collecting member region, 6b2. Second current collecting member region, 6b3. Third current collecting member region, 6e. Target hole, 6f. First current collecting member recess, 6y. Current collecting member opening, 6z. Opening, 7. Positive electrode external terminal, 7a. Terminal sealing member, 7x. Metal member, 7y. Rubber member, 7b. Terminal through-hole, 8. Negative electrode current collecting member, 8a. First negative electrode current collecting member, 8x. 8a...current collector projection, 8w...current collector second recess, 8b...second negative electrode current collector, 8b1...current collector first region, 8b2...current collector second region, 8b3...current collector third region, 8e...target hole, 8f...current collector first recess, 8y...current collector opening, 9...negative electrode external terminal, 10...internal insulating member, 11...external insulating member, 12...internal insulating member, 12a...first insulating member main body, 12b...first side wall, 12c...second side wall, 12d...through hole, 12e...connection recess, 13...external insulating member, 14...insulating sheet, 15... Electrolyte injection hole, 16... sealing plug, 17... gas exhaust valve, 60... current interruption mechanism, 61... conductive member, 62... deformable plate, 63... third insulating member, 63b... insulating member opening, 63c... insulating member protrusion, 63x... insulating member first region, 63y... insulating member second region, 63z... insulating member third region, 70... fixing portion, 80... second insulating member, 80a... second insulating member main body portion, 80a1... wide portion, 80a2... narrow portion, 80b... side wall, 80c... connection portion, 80c1... vertical wall, 80c2... protrusion portion, 81... metal plate,90 welded connection portion, 180 second insulating member, 180a second insulating member main body portion, 180b insulating member side wall portion, 181 metal plate, 181a shielding member main body portion, 181b shielding member side wall portion, 280 second insulating member, 280a second insulating member main body portion, 280a1 wide portion, 280a2 narrow portion, 285 insulating member through hole, 286 groove portion,

Claims

1. an electrode assembly including a positive electrode plate and a negative electrode plate; a rectangular exterior body having an opening and accommodating the electrode body; a sealing plate that seals the opening; an external terminal electrically connected to one of the positive electrode plate and the negative electrode plate and attached to the sealing plate; a current collecting member that electrically connects the one electrode plate and the external terminal and is disposed between the electrode body and the sealing plate; an insulating member disposed between the current collecting member and the sealing plate; a liquid injection hole formed in the sealing plate, the insulating member has an opening formed in a region overlapping the liquid injection hole, The sealing plate has a longitudinal direction and a lateral direction, the electrode body includes a first electrode body element including the positive electrode plate and the negative electrode plate, and a second electrode body element including the positive electrode plate and the negative electrode plate, The first electrode element and the second electrode element are aligned in the short-side direction, the one electrode plate of the first electrode body element and the one electrode plate of the second electrode body element each have an electrode tab group in which a plurality of tabs are stacked, a group of electrode tabs of the first electrode body element joined to a first joining portion of the current collecting member; an electrode tab group of the second electrode body element is joined to a second joint portion of the current collecting member, and the opening portion is located between the first joint portion and the second joint portion in the short-side direction; The inner diameter of the opening is larger than the inner diameter of the liquid injection hole.

2. the insulating member has a through hole located outside the first bonding portion and the second bonding portion in the longitudinal direction of the sealing plate, The prismatic secondary battery according to claim 1 , wherein the external terminal and the current collecting member are electrically connected via the through hole.

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