Energy storage cell

Abstract

To provide a power storage cell capable of suppressing re-inversion of an inversion plate.SOLUTION: A power storage cell 1 includes an electrode body, a cell case, and an external terminal 300. The cell case has a case body and a lid. The lid has a lid body 222 charged positively or negatively, an inversion plate 224 that is able to short-circuit between the lid body and the external terminal, and a protrusion 226 protruding from the inversion plate toward the external terminal. The inversion plate 224 is deformable between a steady-state shape curved to be convex in a direction separated from the external terminal and an inverted shape curved to be convex toward the external terminal and contacting the external terminal. The external terminal 300 has a holding portion 333 that is separated from the protrusion when the inversion plate is in the steady-state shape and that holds the protrusion when the inversion plate is in the inverted shape.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an energy storage cell. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2015-204284 discloses a storage cell including an electrode assembly, a case that houses the electrode assembly, and a cap assembly connected to the case. The case opens upward. The cap assembly includes a cap plate fixed to the opening of the case, a pair of terminal plates connected to the upper surface of the cap plate, and an inversion plate connected to the cap plate. The cap plate is electrically connected to a positive terminal plate, and the inversion plate is electrically connected to the cap plate. A negative terminal plate is disposed above the inversion plate.

[0003] When the inversion plate is inverted in the above-mentioned storage cell, the inversion plate comes into contact with the negative terminal plate, and the positive terminal plate and the negative terminal plate are short-circuited via the inversion plate and the cap plate, causing a short-circuit current to flow through the inversion plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-204284 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the energy storage cell described in JP 2015-204284 A, there is a concern that the reversal plate may be reversed again in a direction away from the terminal plate due to vibration or the like.

[0006] An object of the present disclosure is to provide an energy storage cell capable of suppressing re-inversion of the inversion plate. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, there is provided a storage cell comprising an electrode body, a cell case that houses the electrode body, and an external terminal fixed to an upper surface of the cell case, the cell case having a case body that houses the electrode body and has an opening that opens upward, and a lid connected to the case body so as to close the opening of the case body, the lid having a lid body that is charged with a positive or negative electrode in the electrode body, an inversion plate that is connected to the lid body and is capable of shorting the lid body and the external terminal, and a protrusion that protrudes from the inversion plate toward the external terminal, the inversion plate being deformable between a stationary shape that is curved so as to be convex in a direction away from the external terminal and an inverted shape that is curved so as to be convex toward the external terminal and in contact with the external terminal, the external terminal being separated from the protrusion when the inversion plate is in the stationary shape, and having a holding portion that holds the protrusion when the inversion plate is in the inverted shape. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide an energy storage cell capable of suppressing re-inversion of the inversion plate. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view illustrating a storage cell according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded perspective view of the power storage cell shown in FIG. [Diagram 3] FIG. 2 is a cross-sectional view of the storage cell shown in FIG. [Figure 4] FIG. 2 is an enlarged cross-sectional view of the vicinity of the reversal plate. [Diagram 5] FIG. 11 is a cross-sectional view illustrating a schematic state of the reversal plate after operation. [Figure 6] FIG. 11 is an enlarged cross-sectional view of the vicinity of the reversal plate in the modified example. [Figure 7]FIG. 11 is an enlarged cross-sectional view of the vicinity of the reversal plate in the modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0011] Fig. 1 is a perspective view that shows a schematic diagram of a storage cell according to an embodiment of the present disclosure. Fig. 2 is an exploded perspective view of the storage cell shown in Fig. 1. Fig. 3 is a cross-sectional view of the storage cell shown in Fig. 1.

[0012] As shown in FIGS. 1 to 3, the energy storage cell 1 includes an electrode assembly 100, a cell case 200, an external terminal 300, a connecting member 400, and an insulating member 500. The electrode assembly 100 includes an electrode body 100, a cell case 200, an external terminal 300, a connecting member 400, and an insulating member 500.

[0013] The electrode assembly 100 has a plurality of unit electrode bodies 111, 112 and an insulating film 120. In this embodiment, the plurality of unit electrode bodies includes two unit electrode bodies 111, 112. Each unit electrode body 111, 112 includes a plurality of tabs, i.e., a plurality of positive electrode tabs 110P and a plurality of negative electrode tabs 110N. The unit electrode bodies 111, 112 have the same structure. Therefore, hereinafter, only the unit electrode body 111 will be described.

[0014] The electrode unit 111 includes a positive electrode sheet, a separator, and a negative electrode sheet. The positive electrode sheet, the negative electrode sheet, and the separator are formed into a long rectangular shape.

[0015] The positive electrode sheet includes a metal foil and a positive electrode composite layer provided on the metal foil. An uncoated portion where the positive electrode composite layer is not formed is formed on the upper long side of the metal foil, and the positive electrode tabs 110P are formed at intervals from each other in the uncoated portion.

[0016] The negative electrode sheet includes a metal foil and a negative electrode composite layer formed on the metal foil. An uncoated portion where the negative electrode composite layer is not formed is formed on the upper long side of the metal foil, and the negative electrode tabs 110N are formed at intervals from each other on the uncoated portion.

[0017] In a state where each sheet is wound, the positive electrode tabs 110P are arranged in the thickness direction (a direction perpendicular to the paper surface in FIG. 3), and the negative electrode tabs 110N are arranged in the thickness direction. The positive electrode tabs 110P and the negative electrode tabs 110N are arranged at intervals in the width direction (a direction perpendicular to both the thickness direction and the height direction).

[0018] The insulating film 120 has a shape that collectively covers the peripheral and bottom surfaces of the plurality of unit electrode bodies 111 and 112 .

[0019] The cell case 200 houses the electrode assembly 100. The cell case 200 also houses an electrolyte (not shown). The cell case 200 is sealed. The cell case 200 has a case body 210 and a lid 220.

[0020] The case body 210 has an opening 211 that opens upward. The case body 210 is made of a metal such as aluminum. The case body 210 has a bottom wall 212 and a peripheral wall 214. The bottom wall 212 is formed in a rectangular, flat plate shape. The peripheral wall 214 stands up from the bottom wall 212. The peripheral wall 214 is formed in a rectangular tube shape. The length of the peripheral wall 214 in the width direction is longer than the length of the peripheral wall 214 in the thickness direction. The length of the peripheral wall 214 in the height direction is longer than the length of the peripheral wall 214 in the thickness direction.

[0021] The lid 220 closes the opening 211 of the case body 210. The lid 220 is connected to the opening 211 by welding or the like. The lid 220 is formed in a flat plate shape. The lid 220 is made of a metal such as aluminum. The lid 220 has a lid body 222, an inversion plate 224, and a protrusion 226.

[0022] The lid body 222 is connected to the case body 210 by welding or the like. The lid body 222 is formed with a pressure release valve 222a, a liquid injection hole 222b, a sealing member 222c, and a pair of pin insertion holes 222d.

[0023] The pressure release valve 222a is formed in the center of the lid body 222. The pressure release valve 222a is formed to break when the internal pressure of the cell case 200 reaches or exceeds a predetermined pressure. When the pressure release valve 222a breaks, gas within the cell case 200 is released to the outside of the cell case 200 through the pressure release valve 222a, and the internal pressure of the cell case 200 decreases.

[0024] The liquid injection hole 222b is a through hole for injecting an electrolyte into the cell case 200 during the manufacturing process of the energy storage cell 1.

[0025] The sealing member 222c is a member that seals the liquid injection hole 222b. After the electrolyte is injected into the case body 210, the liquid injection hole 222b is sealed with the sealing member 222c.

[0026] The pair of pin insertion holes 222d are formed at an interval from each other in the width direction. Each of the pin insertion holes 222d is a through hole for inserting a connecting pin 420 described later.

[0027] The reversible plate 224 is connected to the lid body 222 by welding or the like. The reversible plate 224 is capable of short-circuiting the lid body 222 and the external terminal 300. As shown in Fig. 4, the reversible plate 224 has a base portion 224a and a reversible portion 224b.

[0028] The base 224a is connected to the lid body 222 by welding or the like. In this embodiment, the base 224a is connected to a portion of the lid body 222 that is located below a negative electrode terminal plate 330 (described later). The base 224a is formed in an annular shape, more specifically, in a circular ring shape.

[0029] The inverted portion 224b is connected to the inside of the base portion 224a. The inverted portion 224b is formed in a disk shape. The inverted portion 224b can be deformed between a normal shape (shape shown in FIG. 4) curved so as to be convex in a direction away from the negative electrode terminal plate 330 and an inverted shape (shape shown in FIG. 5) curved so as to be convex toward the negative electrode terminal plate 330 and in contact with the negative electrode terminal plate 330. When the internal pressure of the cell case 200 is less than a predetermined pressure (normal state), the inverted portion 224b has a normal shape as shown in FIG. 4. When the internal pressure of the cell case 200 becomes equal to or greater than the predetermined pressure, the inverted portion 224b is deformed from the normal shape to an inverted shape as shown in FIG. 5. As a result, the inverted portion 224b comes into contact with the negative electrode terminal plate 330.

[0030] The protrusion 226 is connected to the reversal plate 224. More specifically, the protrusion 226 has a shape that protrudes from the upper surface of the reversal portion 224b toward the negative electrode terminal plate 330. The protrusion 226 constitutes a part of a restricting portion that restricts the deformation of the reversal portion 224b from the inverted shape to a normal shape, i.e., the reversal of the reversal portion 224b. The protrusion 226 has an upright piece 226a and a claw portion 226b.

[0031] The upright piece 226 a stands from a portion of the reversal plate 224 that sandwiches the top portion 224 b 1 of the reversal plate 224 toward the negative electrode terminal plate 330 .

[0032] The claw portion 226b protrudes from the upper end portion of the standing piece 226a in a direction away from the top portion 224b1 of the reversible plate 224 (outward in the width direction).

[0033] The external terminal 300 is fixed to the upper surface of the cell case 200. A bus bar (not shown) is connected by welding or the like to the external terminal 300. The external terminal 300 has a positive electrode member 300P and a negative electrode member 300N.

[0034] The positive electrode member 300P is connected by welding or the like to the upper surface of the cell case 200. The positive electrode member 300P has a positive electrode terminal plate 310 and a terminal block 320.

[0035] The positive electrode terminal plate 310 is formed in a rectangular parallelepiped shape and is made of a metal such as aluminum.

[0036] The terminal block 320 is formed in a rectangular parallelepiped shape. The terminal block 320 is made of a metal (such as iron) different from the metal constituting the positive electrode terminal plate 310. The terminal block 320 is connected to the upper surface of the lid body 222 by welding, and the positive electrode terminal plate 310 is connected to the upper surface of the terminal block 320 by welding or the like. In other words, the case body 210 and the lid 220 are electrically connected to the positive electrode terminal plate 310 via the terminal block 320, and are charged with the same polarity as the positive electrode terminal plate 310. Each of the positive electrode terminal plate 310 and the terminal block 320 has a through hole formed therein for inserting a positive electrode connecting pin 420P described later.

[0037] The negative electrode member 300N is connected to the upper surface of the cell case 200 by welding or the like. The negative electrode member 300N is disposed at a distance in the width direction from the positive electrode member 300P. The negative electrode member 300N has a negative electrode terminal plate 330 and an insulating plate 340.

[0038] The negative electrode terminal plate 330 is formed in a substantially rectangular parallelepiped shape. The negative electrode terminal plate 330 is disposed above the reversal plate 224. As shown in Fig. 4, the negative electrode terminal plate 330 has a facing portion 332 facing the reversal plate 224. The facing portion 332 is formed flat.

[0039] In this embodiment, the negative electrode terminal plate 330 has a holding portion 333. The holding portion 333 has a shape that protrudes from the facing portion 332 toward the reversal plate 224. The holding portion 333 is separated from the protrusion 226 when the reversal plate 224 is in a normal shape, and holds the protrusion 226 when the reversal plate 224 is in an inverted shape. In other words, the holding portion 333, together with the protrusion 226, constitutes the regulating portion that regulates the reversal of the reversal plate 224. The holding portion 333 may be formed in an annular shape, or may have a pair of holding elements arranged at positions sandwiching the top portion 224b1 of the reversal portion 224b in the width direction. The holding portion 333 has a protrusion 333a and a holding claw 333b.

[0040] The protruding portion 333a protrudes toward the reversing plate 224 from a position that sandwiches a portion of the facing portion 332 that faces the top portion 224b1 of the reversing plate 224.

[0041] The holding claw 333b protrudes from the lower end of the protruding portion 333a toward the portion of the facing portion 332 facing the apex 224b1.

[0042] 4 and 5, the holding portion 333 has a contact surface 336 having a shape that follows the outer shape of the reversible plate 224 in the inverted shape. As described above, when the internal pressure of the cell case 200 is less than a predetermined pressure (normal), the reversible portion 224b of the reversible plate 224 is separated from the contact surface 336, whereas when the internal pressure of the cell case 200 is equal to or greater than the predetermined pressure, the reversible portion 224b comes into contact with the contact surface 336. As the reversible portion 224b is inverted, the claw portion 226b of the projection 226 engages with the holding claw 333b of the holding portion 333 from the inside in the width direction.

[0043] The insulating plate 340 is fixed to the upper surface of the lid 220. The insulating plate 340 holds the negative electrode terminal plate 330. The insulating plate 340 provides insulation between the lid 220 and the negative electrode terminal plate 330. A through hole for inserting a negative electrode connecting pin 420N described below is formed in each of the negative electrode terminal plate 330 and the insulating plate 340. As shown in Figs. 3 and 4, the insulating plate 340 has an exposure opening 342 that exposes the facing portion 332.

[0044] The connecting member 400 connects the plurality of tabs 110P, 110N to the external terminal 300. The connecting member 400 has a current collecting plate 410 and a connecting pin 420.

[0045] The current collector 410 is connected to a plurality of tabs. The current collector 410 includes a positive current collector 410P and a negative current collector 410N.

[0046] The positive electrode current collector 410P is connected to the multiple positive electrode tabs 110P by welding, etc. The positive electrode current collector 410P has a first flat plate portion 411 and a second flat plate portion 412.

[0047] A plurality of positive electrode tabs 110P are connected to the first flat plate portion 411 by ultrasonic welding or the like. Through holes are formed in the first flat plate portion 411. The plurality of positive electrode tabs 110P are connected to the lower surface of the first flat plate portion 411. However, the plurality of positive electrode tabs 110P may be connected to the upper surface of the first flat plate portion 411.

[0048] The second flat plate portion 412 is disposed on the outer side of the first flat plate portion 411 in the width direction. A connecting hole 412h and a fuse portion 412a are formed in the second flat plate portion 412. The fuse portion 412a is configured as a through hole that penetrates the second flat plate portion 412 in the thickness direction. As shown in FIG. 3, a thin portion may be formed between the second flat plate portion 412 and the first flat plate portion 411.

[0049] The negative current collector 410N is connected to a plurality of negative electrode tabs 110N by welding, etc. The configuration of the negative current collector 410N is substantially the same as the configuration of the positive current collector 410P.

[0050] The connecting pins 420 connect the current collecting plate 410 and the external terminal 300. The connecting pins 420 have a positive electrode connecting pin 420P and a negative electrode connecting pin 420N.

[0051] The positive electrode connecting pin 420P connects the positive electrode current collector plate 410P and the positive electrode terminal plate 310. The positive electrode connecting pin 420P is formed in a cylindrical shape. The lower end of the positive electrode connecting pin 420P is connected to the second flat plate portion 412 in a state where it is inserted into the connecting hole 412h. The upper end of the positive electrode connecting pin 420P is crimped to the positive electrode terminal plate 310.

[0052] The negative electrode connecting pin 420N connects the negative electrode current collector plate 410N and the negative electrode terminal plate 330. The negative electrode connecting pin 420N is formed in a cylindrical shape. The lower end of the negative electrode connecting pin 420N is connected to the second flat plate portion 412 in a state where it is inserted into the connecting hole 412h. The upper end of the negative electrode connecting pin 420N is crimped to the negative electrode terminal plate 330.

[0053] The insulating member 500 provides insulation between the connecting member 400 and the cell casing 200. The insulating member 500 includes an insulating sheet 510 and an insulator 520.

[0054] The insulating sheet 510 is connected to the lower surface of the lid main body 222. Through holes are formed in the insulating sheet 510 at a portion overlapping the pressure release valve 222a in the height direction, a portion overlapping the liquid injection hole 222b, a portion overlapping each pin insertion hole 222d, and a portion overlapping the reversal plate 224.

[0055] The insulator 520 has a shape that surrounds the connecting pin 420, and provides insulation between the connecting pin 420 and the cell case 200. The insulator 520 has a positive electrode side insulator 520P and a negative electrode side insulator 520N.

[0056] The positive electrode side insulator 520P covers the positive electrode connecting pin 420P. The positive electrode side insulator 520P is formed in a cylindrical shape. The positive electrode side insulator 520P insulates between the positive electrode connecting pin 420P and the lid main body 222.

[0057] The negative electrode side insulator 520N covers the negative electrode connecting pin 420N. The structure of the negative electrode side insulator 520N is the same as the structure of the positive electrode side insulator 520P.

[0058] In the energy storage cell 1 described above, when the internal pressure of the cell case 200 rises to or above the predetermined pressure due to the occurrence of an abnormality in the electrode assembly 100, the inverted portion 224b of the inverted plate 224 inverts (deforms from a normal shape to an inverted shape) and comes into contact with the contact surface 336 of the negative electrode terminal plate 330, as shown in FIG. 5. As a result, the external terminal 300, the connecting member 400, and the electrode assembly 100 form a closed circuit via the lid 220, and a large current flows through this circuit. Then, the fuse portion 412a formed in the second flat plate portion 412 melts. As a result, the electrical connection between the electrode assembly 100 and the cell case 200 is cut off.

[0059] Here, when the inversion plate 224 is inverted (deformed from a normal shape to an inverted shape), as shown in FIG. 5, the protrusion 226 is held by the holding portion 333, so that the deformation of the inversion plate 224 from the inverted shape to the normal shape, i.e., the re-inversion of the inversion plate 224, is suppressed.

[0060] Modifications to the above embodiment will now be described.

[0061] (First Modification) As shown in Fig. 6, the claw portion 226b of the projection 226 protrudes from the upper end of the standing piece 226a toward the top of the reversible plate 224. The holding claw 333b of the holding portion 333 protrudes from the lower end of the projection 333a in a direction away from the portion of the opposing portion 332 that faces the top of the reversible plate 224. In this example, the reversible portion 224b is inverted, so that the claw portion 226b engages with the holding claw 333b from the outside in the width direction. In Fig. 6, the reversible plate 224 and the projection 226 in the normal shape are indicated by two-dot chain lines.

[0062] Furthermore, in this example, when the reversible plate 224 tries to return to its normal shape from the inverted shape, the protrusion 226 tries to deform in a direction approaching the holding portion 333. Therefore, the reversible plate 224 is more reliably prevented from reversing.

[0063] The standing piece 226a has an upper end surface 226c having a curved shape that is convex upward. The protruding portion 333a has a lower end surface 333c having a curved shape that is convex downward. This prevents the standing piece 226a from interfering with the protruding portion 333a when the reversing portion 224b is inverted.

[0064] (Second Modification) As shown in Fig. 7, the standing piece 226a of the projection 226 projects upward from the top of the inverted portion 224b. The claw portion 226b has a shape that protrudes from the upper end of the standing piece 226a in a direction perpendicular to the axial direction of the standing piece 226a (for example, in the width direction). In Fig. 7, the inverted plate 224 and the projection 226 in their normal shape are indicated by two-dot chain lines.

[0065] A recess 334 recessed in a direction away from the reversal plate 224 is formed in the facing portion 332 of the negative electrode terminal plate 330, and a holding portion 333 is formed at the lower end of the recess 334. The holding portion 333 allows the claw portion 226b to pass when the reversal plate 224 is deformed from the normal shape to the inverted shape. On the other hand, the holding portion 333 abuts against the claw portion 226b when the reversal plate 224 is in the inverted shape, thereby restricting the deformation of the reversal plate 224 in the inverted shape toward the normal shape.

[0066] The length between the outer ends of the claw portions 226b in the width direction is greater than the length between the inner ends of the holding portion 333 in the width direction. However, when the inverted portion 224b deforms from the normal shape to the inverted shape, the claw portions 226b pass through the holding portion 333 by elastically deforming. Then, after the claw portions 226b pass through the holding portion 333 when the inverted portion 224b is inverted, the claw portions 226b come into contact with the holding portion 333.

[0067] The negative electrode terminal plate 330 has a protruding portion 335 that protrudes downward from the facing portion 332 , and the lower surface of this protruding portion 335 forms a contact surface 336 .

[0068] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0069] [Aspect 1] An electrode body; A cell case that accommodates the electrode assembly; an external terminal fixed to an upper surface of the cell case; The cell casing comprises: a case body that houses the electrode body and has an opening that opens upward; a lid connected to the case body so as to close the opening of the case body, The lid is A lid body connected to the opening of the case body and charged to the positive or negative electrode of the electrode body; an inversion plate connected to the lid body and capable of short-circuiting the lid body and the external terminal; a protrusion protruding from the reversal plate toward the external terminal; the reversible plate is deformable between a normal shape in which the reversible plate is curved so as to be convex in a direction away from the external terminal and an inverted shape in which the reversible plate is curved so as to be convex toward the external terminal and in contact with the external terminal, The external terminal has a holding portion that is spaced from the protrusion when the reversal plate is in the normal shape and that holds the protrusion when the reversal plate is in the inverted shape.

[0070] In this energy storage cell, when the reversal plate is inverted (deformed from a normal shape to an inverted shape), the protrusion is held by the holding portion, thereby suppressing the deformation of the reversal plate from the inverted shape to the normal shape, i.e., suppressing reversal of the reversal plate.

[0071] [Aspect 2] 2. The energy storage cell of claim 1, wherein the holding portion has a contact surface having a shape that fits along an upper surface of the inversion plate in the inverted shape.

[0072] In this embodiment, the contact area between the reversal plate and the external terminal is ensured, so that the contact resistance between the reversal plate and the external terminal is reduced, thereby suppressing heat generation in the reversal plate when current is applied to the reversal plate.

[0073] [Aspect 3] The protrusion is an upright piece that stands from a portion of the reversal plate that sandwiches a top portion of the reversal plate toward the external terminal; a claw portion protruding from an upper end of the upright piece toward the top side of the inversion plate, The holding portion is a protruding portion protruding toward the reversal plate from a position sandwiching a portion facing the top of the reversal plate; and a retaining claw protruding from a lower end of the protrusion in a direction away from the portion facing the apex.

[0074] In this embodiment, when the reversible plate tries to return to its normal shape from the inverted shape, the protrusion tries to deform in a direction approaching the holding portion, thereby more reliably preventing the reversible plate from reversing.

[0075] [Aspect 4] The upright piece has an upper end surface that is curved so as to be convex upward, 4. The energy storage cell according to aspect 3, wherein the protrusion has a lower end surface that is curved so as to be convex downward.

[0076] In this embodiment, the standing piece is prevented from interfering with the protruding portion when the reversing plate is reversed.

[0077] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0078] 1 storage cell, 100 electrode body, 110N negative electrode tab, 110P positive electrode tab, 111, 112 unit electrode body, 120 insulating film, 200 cell case, 210 case body, 211 opening, 220 lid, 222 lid body, 224 inversion plate, 224a base, 224b inversion portion, 226 protrusion, 226a standing piece, 226b claw portion, 226c upper end surface, 300 external terminal, 300N negative electrode member, 300P positive electrode member, 310 positive electrode terminal plate, 320 terminal block, 330 negative electrode terminal plate, 332 facing portion, 333 holding portion, 333a protrusion, 333b holding claw, 334 recess, 335 protrusion, 336 contact surface, 340 Insulating plate, 400 connecting member, 410 current collecting plate, 410N negative current collecting plate, 410P positive current collecting plate, 420 connecting pin, 420N negative connecting pin, 420P positive connecting pin, 422 covering portion, 422a fuse portion, 500 insulating member, 510 insulating sheet, 520 insulator, 520N negative side insulator, 520P positive side insulator.

Claims

1. An electrode body; A cell case that accommodates the electrode assembly; an external terminal fixed to an upper surface of the cell case; The cell casing comprises: a case body that houses the electrode body and has an opening that opens upward; a lid connected to the case body so as to close the opening of the case body, The lid is A lid body connected to the opening of the case body and charged to the positive or negative electrode of the electrode body; an inversion plate connected to the lid body and capable of short-circuiting the lid body and the external terminal; a protrusion protruding from the reversal plate toward the external terminal; the reversible plate is deformable between a normal shape in which the reversible plate is curved so as to be convex in a direction away from the external terminal and an inverted shape in which the reversible plate is curved so as to be convex toward the external terminal and in contact with the external terminal, the external terminal has a holding portion that is spaced from the protrusion when the reversal plate is in the normal shape and that holds the protrusion when the reversal plate is in the inverted shape.

2. The energy storage cell according to claim 1 , wherein the holding portion has a contact surface having a shape that fits along an upper surface of the inversion plate in the inverted shape.

3. The protrusion is an upright piece that stands from a portion of the reversal plate that sandwiches a top portion of the reversal plate toward the external terminal; a claw portion protruding from an upper end of the upright piece toward the top side of the inversion plate, The holding portion is a protruding portion protruding toward the reversal plate from a position sandwiching a portion facing the top of the reversal plate; The energy storage cell according to claim 1 , further comprising: a retaining claw that protrudes from a lower end of the protruding portion in a direction away from the portion facing the apex.

4. The upright piece has an upper end surface that is curved so as to be convex upward, The energy storage cell according to claim 3 , wherein the protrusion has a lower end surface that is curved so as to be convex downward.

Images