Button cell

Abstract

The invention provides a button cell. The button cell comprises a shell and a laminated cell. The shell comprises a bottom shell, a pole and a top cover. The top cover is hermetically connected with the bottom shell. And the pole is connected with the top cover. And the bottom shell and the pole lead out different polarities. The laminated battery cell is arranged in the shell; along the stacking direction of the laminated battery cell, the laminated battery cell comprises a first single-sided pole piece and a second single-sided pole piece which are positioned on the outermost side. And the first single-sided pole piece and the second single-sided pole piece are opposite in polarity. The first single-sided pole piece comprises a first current collector and a first active material layer; along the stacking direction of the laminated cell, the surface, facing the pole, of the first current collector is directly and electrically connected with the pole. The first active material layer is arranged on the surface, back to the pole, of the first current collector. And the second single-sided pole piece comprises a second current collector and a second active material layer. And the surface of the second current collector back to the pole is directly and electrically connected with the bottom shell. The second active material layer is arranged on the surface, facing the pole, of the second current collector.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a button battery. Background Art

[0002] Button batteries are widely used in electronic devices, such as computers, clocks, calculators, etc. In the development of button battery technology, how to improve the energy density of button batteries is one of the research directions in battery technology. Summary of the invention

[0003] In view of the above problems, the present application provides a button battery, which can help improve the energy density of the button battery.

[0004] The present application provides a button battery, which includes a shell and a laminated battery cell. The shell includes a bottom shell, a pole and a top cover. The top cover is sealed and connected to the bottom shell. The pole is connected to the top cover. The bottom shell and the pole lead out different polarities. The laminated battery cell is arranged in the shell. Along the stacking direction of the laminated battery cell, the laminated battery cell includes a first single-sided pole sheet and a second single-sided pole sheet located at the outermost side. The first single-sided pole sheet has opposite polarity to the second single-sided pole sheet. The first single-sided pole sheet includes a first current collector and a first active material layer. Along the stacking direction of the laminated battery cell, the surface of the first current collector facing the pole is directly electrically connected to the pole. The first active material layer is arranged on the surface of the first current collector facing away from the pole. The second single-sided pole sheet includes a second current collector and a second active material layer. The surface of the second current collector facing away from the pole is directly electrically connected to the bottom shell. The second active material layer is arranged on the surface of the second current collector facing away from the pole.

[0005] The button battery of the embodiment of the present application includes a shell and a laminated battery cell arranged in the shell. The outermost first single-sided pole piece and the second single-sided pole piece in the laminated battery cell are directly electrically connected to the pole and the bottom shell respectively, so that there is no need to use an additional adapter for switching between the laminated battery cell and the shell. In the stacking direction of the laminated battery cell, there is no need to reserve space between the laminated battery cell and the shell to avoid the adapter, so that the structural compactness of the button battery can be improved in the stacking direction of the laminated battery cell. The above-mentioned structural design can be beneficial to reducing the overall size of the button battery in the stacking direction of the laminated battery cell, so as to reduce the overall volume of the button battery, which is beneficial to improve the energy density of the button battery.

[0006] In one or more optional embodiments above, the button battery includes a first adhesive member, and the first adhesive member bonds the first current collector and the electrode.

[0007] The first adhesive can fix the position of the laminated battery core in the housing, thereby reducing the possibility that the laminated battery core shakes in the housing and causes the pole and the first current collector to be out of electrical connection.

[0008] In one or more of the above optional embodiments, the pole includes a first wall and a first protrusion, the first wall is arranged facing the laminated battery cell, the first protrusion protrudes from the first wall, the first protrusion abuts against the surface of the first current collector facing the pole, and along the stacking direction of the laminated battery cell, there is a first distance between the first wall and the first current collector.

[0009] The method of directly contacting the first protrusion with the first current collector is conducive to reducing the difficulty of achieving electrical connection between the pole and the first current collector on the one hand, and on the other hand, it is conducive to ensuring that the pole and the first current collector maintain a stable electrical connection state in the assembled button battery, reducing the possibility of poor contact problems such as false connection between the pole and the first current collector.

[0010] In one or more of the above optional embodiments, the value range of the first spacing is greater than 0 micrometers and less than or equal to 50 micrometers.

[0011] In one or more optional embodiments above, the first adhesive is disposed between the pole and the first current collector, the first adhesive has a first avoidance channel, and the first protrusion passes through the first avoidance channel and abuts against the first current collector.

[0012] The first avoidance channel is used to avoid the first protrusion, reducing the possibility that the first adhesive is located between the first protrusion and the first current collector and affects the electrical connection state of the first protrusion and the first current collector. The shell of the button battery can be filled with electrolyte. The first protrusion can be surrounded by the first adhesive so that the first adhesive can prevent the electrolyte from infiltrating the connection area between the first protrusion and the first current collector, reducing the possibility that the first protrusion and the first current collector corrode in the connection area and cause the electrical connection state of the first protrusion and the first current collector to become unstable.

[0013] In one or more optional embodiments above, the pole includes a first wall and a first recess, the first wall is arranged facing the laminated battery cell, the first recess is arranged on the first wall, the first recess includes an opening located on the first wall, a first adhesive is arranged in the first recess, the first wall is abutted against the surface of the first current collector facing the pole, and the first adhesive bonds the first current collector to the pole.

[0014] The first wall surface of the pole is in direct contact with the surface of the first current collector facing the pole. The distance between the first wall surface and the first current collector is zero. The above structural design is conducive to reducing the overall size of the button battery in the stacking direction of the laminated battery core, so as to reduce the overall volume of the button battery, thereby facilitating the improvement of the energy density of the button battery.

[0015] In one or more of the above optional embodiments, the first adhesive member is a conductive adhesive and / or a pressure-sensitive adhesive.

[0016] The first adhesive may be a conductive adhesive. The first adhesive itself has conductivity, so the pole and the first current collector can also be electrically connected through the first adhesive.

[0017] The first adhesive may be a pressure-sensitive adhesive and may not require heating, solvent activation or complicated curing process. The first adhesive can be bonded by applying relatively small pressure to the first adhesive by the pole and the first current collector, thereby reducing the difficulty of connection.

[0018] In one or more optional embodiments above, the first current collector includes a first pole ear and a first main body connected to each other. The first pole ear and the first main body are integrally formed. The first active material layer is disposed on the first main body, and the surface of the first main body facing the pole is directly electrically connected to the pole.

[0019] The laminated battery cell is electrically connected to the pole through the first main body, which can help reduce the distance between the laminated battery cell and the pole in the stacking direction of the laminated battery cell, and help reduce the overall size of the button battery in the stacking direction of the laminated battery cell, so as to reduce the overall volume of the button battery, thereby helping to improve the energy density of the button battery. The area of ​​the first main body itself is relatively large, which helps to reduce the difficulty of achieving electrical connection between the first current collector and the pole.

[0020] In one or more optional embodiments above, the button battery includes a first adhesive member, and the first adhesive member bonds the pole and the first main body.

[0021] The area of ​​the first main body itself is relatively large. The first main body and the pole are bonded by the first adhesive, which is conducive to reducing the difficulty of connecting the first adhesive and the first current collector, and is also conducive to increasing the connection area between the first current collector and the pole, and improving the connection stability between the first current collector and the pole.

[0022] In one or more optional embodiments above, the first current collector includes a first pole ear, a first main body, and a first folded portion connected to each other. The first pole ear, the first main body, and the first folded portion are integrally formed. The first active material layer is disposed on the first main body, the first folded portion is folded relative to the first main body, the first folded portion is located between the first main body and the pole, and the surface of the first folded portion facing the pole is directly electrically connected to the pole.

[0023] The manner in which the first current collector is provided with the first folding portion can realize the operation of first connecting and fixing the laminated battery cell to the pole and then covering the top cover, thereby helping to reduce the difficulty of connecting the laminated battery cell and the pole and improve the connection stability and connection efficiency between the laminated battery cell and the pole.

[0024] In one or more optional embodiments above, the first folded portion is welded to the pole; or the button battery includes a first adhesive member, and the first adhesive member bonds the first folded portion to the pole.

[0025] The first folded portion and the pole are connected by welding, which is beneficial to improving the connection strength and connection stability between the first folded portion and the pole, and reducing the possibility of the first folded portion and the pole being disconnected during the use of the button battery.

[0026] By bonding the first folded portion to the pole, the connection difficulty between the first folded portion and the pole can be reduced, and it is also convenient to observe and detect the bonding state of the first folded portion and the pole. In addition, there is no need to consider the problems of over-welding and cold welding caused by welding, and there is no need to consider the weld marks left by welding.

[0027] In one or more of the above optional embodiments, the area of ​​the first folded portion is greater than or equal to the area of ​​the first main body portion.

[0028] When the laminated battery cell expands, when the first main body portion contacts the first folded portion, the first folded portion can support the first main body portion as a whole and exert a reaction force on the first main body portion as a whole, which can help to evenly stress the first main body portion as a whole, reduce the possibility of uneven stress on the first main body portion causing stress concentration areas, and cause the first active material layer to peel off and fall off the first main body portion in the stress concentration area.

[0029] In one or more of the above optional embodiments, the surface area of ​​the pole facing the laminated core is greater than or equal to the area of ​​the first main body.

[0030] When the laminated battery cell expands, the pole and the first folded portion can simultaneously support the first main body as a whole and apply a reaction force to the first main body as a whole, which can help to evenly load the first main body as a whole, reduce the possibility of uneven force on the first main body causing stress concentration areas, and cause the first active material layer to peel off and fall off the first main body in the stress concentration area.

[0031] In one or more optional embodiments above, the bottom shell has a bottom wall, the button cell includes a second adhesive, and the second adhesive bonds the second current collector to the bottom wall.

[0032] The second adhesive can fix the position of the laminated battery core in the housing, thereby reducing the possibility that the laminated battery core shakes in the housing and causes the bottom wall and the second current collector to lose electrical connection.

[0033] In one or more optional embodiments above, the bottom wall has a second wall surface, the bottom shell includes a second convex portion, the second wall surface is arranged facing the laminated battery cell, the second convex portion protrudes from the second wall surface, the second convex portion abuts against the surface of the second current collector facing the bottom wall, and along the stacking direction of the laminated battery cell, there is a second distance between the second wall surface and the second current collector.

[0034] The method of directly contacting the second protrusion with the second current collector is conducive to reducing the difficulty of achieving electrical connection between the bottom shell and the second current collector on the one hand, and is conducive to ensuring that the bottom shell and the second current collector maintain a stable electrical connection state in the assembled button battery on the other hand, thereby reducing the possibility of poor contact problems such as false connection between the bottom shell and the second current collector.

[0035] In one or more of the above optional embodiments, the value range of the second spacing is greater than 0 micrometers and less than or equal to 50 micrometers.

[0036] In one or more optional embodiments above, the second adhesive member is disposed between the bottom wall and the second current collector, the second adhesive member has a second avoidance channel, and the second protrusion passes through the second avoidance channel and abuts against the second current collector.

[0037] The second protrusion may be surrounded by the second adhesive so that the second adhesive can prevent the electrolyte from wetting the connection area between the second protrusion and the second current collector, thereby reducing the possibility of corrosion of the second protrusion and the second current collector in the connection area, which may cause an unstable electrical connection state between the second protrusion and the second current collector.

[0038] In one or more optional embodiments above, the second current collector includes a second pole ear and a second main body connected to each other. The second pole ear and the second main body are integrally formed. The second active material layer is disposed on the second main body, and the surface of the second main body facing away from the pole is directly electrically connected to the bottom shell.

[0039] The laminated battery cell is electrically connected to the bottom shell through the second main body, which can help reduce the distance between the laminated battery cell and the bottom shell in the stacking direction of the laminated battery cell, and help reduce the overall size of the button battery in the stacking direction of the laminated battery cell, so as to reduce the overall volume of the button battery, thereby helping to improve the energy density of the button battery. The area of ​​the second main body itself is relatively large, which helps to reduce the difficulty of achieving electrical connection between the second current collector and the bottom shell.

[0040] In one or more optional embodiments above, the bottom shell has a bottom wall, the button battery includes a second adhesive, and the second adhesive bonds the second main body to the bottom wall.

[0041] The area of ​​the second main body itself is relatively large. The second main body and the bottom wall are bonded by the second adhesive, which is conducive to reducing the difficulty of connecting the second adhesive and the second current collector, and is also conducive to increasing the connection area between the second current collector and the bottom wall, and improving the connection stability between the second current collector and the bottom wall.

[0042] In one or more optional embodiments above, the second current collector includes a second pole ear, a second main body, and a second folded portion connected to each other. The second pole ear, the second main body, and the second folded portion are integrally formed. The second active material layer is disposed on the second main body, the second folded portion is folded relative to the second main body, the second folded portion is located between the second main body and the bottom shell, and the surface of the second folded portion facing away from the pole is directly electrically connected to the bottom shell.

[0043] The second current collector is provided with a second folded portion, so that the laminated battery cell can be first connected and fixed to the bottom shell, and then the laminated battery cell can be installed into the bottom shell, thereby reducing the difficulty of connecting the laminated battery cell and the bottom shell and improving the connection stability and connection efficiency between the laminated battery cell and the bottom shell.

[0044] In one or more optional embodiments above, the bottom shell has a bottom wall, and the second folded portion is welded to the bottom wall; or, the button battery includes a second adhesive, and the second adhesive bonds the second folded portion to the bottom wall.

[0045] The second folded portion and the bottom wall are connected by welding, which is beneficial to improving the connection strength and connection stability between the second folded portion and the bottom wall, and reducing the possibility of the second folded portion and the bottom wall being disconnected during the use of the button battery.

[0046] By bonding the second folded portion to the bottom wall, the connection difficulty between the second folded portion and the bottom wall can be reduced, and it is also convenient to observe and detect the bonding state of the second folded portion and the bottom wall.

[0047] In one or more of the above optional embodiments, the area of ​​the second folded portion is greater than or equal to the area of ​​the second main body portion.

[0048] When the laminated battery cell expands, when the second main body contacts the second folded portion, the second folded portion can support the second main body as a whole and apply a reaction force to the second main body as a whole, which can help to evenly stress the second main body as a whole, reduce the possibility of uneven stress on the second main body and cause stress concentration areas, and cause the second active material layer to peel off and fall off the second main body in the stress concentration area.

[0049] In one or more of the above optional embodiments, the stacked battery cell includes a first double-sided pole piece and a second double-sided pole piece, and the first double-sided pole piece and the second double-sided pole piece are alternately stacked between the first single-sided pole piece and the second single-sided pole piece, the first single-sided pole piece and the first double-sided pole piece have the same polarity, the first single-sided pole piece and each first double-sided pole piece are electrically connected, the second single-sided pole piece and the second double-sided pole piece have the same polarity, and the second single-sided pole piece and each second double-sided pole piece are electrically connected.

[0050] In one or more optional embodiments above, the first single-sided pole piece includes a first pole ear, the first double-sided pole piece includes a third pole ear, the first pole ear and each third pole ear are gathered and welded along the stacking direction of the laminated battery cell to form a first gathered portion, and the first gathered portion is a one-section structure.

[0051] The first folding portion is a one-stage structure. The first pole ear and the third pole ear can be folded toward the bottom wall and welded along the stacking direction of the laminated battery cell, or can be folded toward the top cover and welded. The first folding portion is a one-stage structure, which means that the first pole ear and the third pole ear do not need to be folded toward the bottom wall and then folded toward the top cover, or folded toward the top cover and then folded toward the bottom wall, which is conducive to reducing the space occupied by the first pole ear and the third pole ear, and is conducive to reducing the overall size of the button battery, so as to reduce the overall volume of the button battery, thereby facilitating improving the energy density of the button battery.

[0052] In one or more optional embodiments above, the second single-sided pole piece includes a second pole ear, the second double-sided pole piece includes a fourth pole ear, the second pole ear and each fourth pole ear are gathered along the stacking direction of the laminated battery cell and welded to form a second gathered portion, and the second gathered portion is a one-section structure.

[0053] The second folding portion is a one-stage structure. The second pole lug and the fourth pole lug can be folded toward the bottom wall and welded along the stacking direction of the laminated battery cell, or they can be folded toward the top cover and welded. The second folding portion is a one-stage structure, which means that the second pole lug and the fourth pole lug do not need to be folded toward the bottom wall and then folded toward the top cover, or folded toward the top cover and then folded toward the bottom wall, which is conducive to reducing the space occupied by the second pole lug and the fourth pole lug, and is conducive to reducing the overall size of the button battery, so as to reduce the overall volume of the button battery, thereby facilitating improving the energy density of the button battery.

[0054] In one or more optional embodiments above, the first single-sided pole piece is a cathode pole piece, and the second single-sided pole piece is an anode pole piece.

[0055] In one or more optional embodiments above, the top cover is directly electrically connected to the bottom shell, the shell includes an insulating member, the insulating member connects the pole and the top cover, and the pole and the top cover are insulated and isolated by the insulating member.

[0056] The insulator connects the pole and the top cover. The pole and the top cover are insulated and separated by the insulator. The pole and the top cover are in a non-electrical connection state. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0058] Figure 1 is a schematic diagram of the structure of a button battery provided in one embodiment of the present application;

[0059] Figure 2 is a schematic diagram of the structure of a button battery provided in one embodiment of the present application;

[0060] Figure 3 is a schematic diagram of a partial cross-sectional structure of a button battery provided in one embodiment of the present application;

[0061] Figure 4 It is a schematic diagram of a partial exploded structure of a button battery provided in one embodiment of the present application;

[0062] Figure 5 It is a partial structural schematic diagram of a laminated battery cell provided in one embodiment of the present application;

[0063] Figure 6 It is a partial structural schematic diagram of a laminated battery cell provided in one embodiment of the present application;

[0064] Figure 7 It is a partial structural schematic diagram of a laminated battery cell provided in one embodiment of the present application;

[0065] Figure 8 is a schematic diagram of a partial cross-sectional structure of a button battery provided in one embodiment of the present application;

[0066] Fig. 9 is a schematic diagram of a partial cross-sectional structure of a button battery provided in one embodiment of the present application;

[0067] Fig.10 It is a schematic diagram of a partial exploded structure of a button battery provided in one embodiment of the present application;

[0068] Fig.11 It is a partial structural schematic diagram of a laminated battery cell provided in one embodiment of the present application;

[0069] Fig.12 It is a schematic diagram of the structural changes of a laminated battery cell provided in one embodiment of the present application;

[0070] Fig.13This is a schematic diagram of the assembly process of a button battery provided in one embodiment of the present application;

[0071] Fig.14 is a schematic diagram of a partial cross-sectional structure of a button battery provided in one embodiment of the present application;

[0072] Fig.15 is a schematic diagram of a partial cross-sectional structure of a button battery provided in one embodiment of the present application;

[0073] Fig.16 It is a partial structural schematic diagram of a laminated battery cell provided in one embodiment of the present application;

[0074] Fig.17 is a schematic diagram of a partial cross-sectional structure of a button battery provided in one embodiment of the present application;

[0075] Fig.18 yes Fig.17 The enlarged schematic diagram of the M in the middle;

[0076] Fig.19 yes Fig.17 The enlarged schematic diagram of the middle W;

[0077] Fig. 20 It is a schematic diagram of the partial structure of a button battery provided in one embodiment of the present application.

[0078] Description of reference numerals:

[0079] 10. button cell; 20. shell; 201. first convex portion; 202. second convex portion; 21. bottom shell; 21a. second wall surface; 21b. second concave portion; 211. bottom wall; 22. pole; 22a. first wall surface; 22b. first concave portion; 212. side wall; 221. base; 222. boss; 23. top cover; 231. center via; 24. insulator; 30. laminated cell; 31. first single-sided pole piece; 311. first current collector; 3111. first pole ear; 3112. first main body; 3113. first folding portion; 3 12. First active material layer; 32. Second single-sided pole piece; 321. Second current collector; 3211. Second pole ear; 3212. Second main body; 3213. Second folding portion; 322. Second active material layer; 33. First double-sided pole piece; 331. Third pole ear; 34. Second double-sided pole piece; 341. Fourth pole ear; 35. Diaphragm; 40. First adhesive; 50. Second adhesive; 60. First gathering portion; 70. Second gathering portion; 80. Insulating tape; 100. First avoidance channel; 110. Second avoidance channel; X, stacking direction. DETAILED DESCRIPTION

[0080] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0081] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0082] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0083] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0084] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0085] In the related art, a button battery includes a shell and a battery cell. The battery cell is arranged in the shell. The battery cell includes a plurality of first pole tabs and a plurality of second pole tabs. The button battery includes a switching plate. The first pole tab and the second pole tab are respectively welded to the corresponding switching plate. The first pole tab and the second pole tab are respectively led out through the corresponding switching plate. The additionally arranged switching plate will occupy the space in the shell, resulting in a decrease in the space utilization rate in the shell, thereby causing the button battery itself to have a relatively low energy density. Energy density refers to the ratio between the discharge energy of the button battery and the volume of the button battery.

[0086] The button battery of the embodiment of the present application can help improve the structural compactness of the button battery and improve the energy density of the button battery.

[0087] See also Figures 1 to 7 As shown, an embodiment of the present application provides a button battery 10, which includes a shell 20 and a laminated battery 30. The shell 20 includes a bottom shell 21, a pole 22 and a top cover 23. The top cover 23 is sealed and connected to the bottom shell 21. The pole 22 is connected to the top cover 23. The laminated battery 30 is arranged in the shell 20. Along the stacking direction X of the laminated battery 30, the laminated battery 30 includes a first single-sided pole piece 31 and a second single-sided pole piece 32 located at the outermost side. The first single-sided pole piece 31 has opposite polarity to the second single-sided pole piece 32. The first single-sided pole piece 31 includes a first current collector 311 and a first active material layer 312. Along the stacking direction X of the laminated battery 30, the surface of the first current collector 311 facing the pole 22 is directly electrically connected to the pole 22. The first active material layer 312 is arranged on the surface of the first current collector 311 facing away from the pole 22. The second single-sided pole piece 32 includes a second current collector 321 and a second active material layer 322. The surface of the second current collector 321 facing away from the pole 22 is directly electrically connected to the bottom case 21. The second active material layer 322 is disposed on the surface of the second current collector 321 facing the pole 22.

[0088] In the present application examples, see Figure 4 As shown, the shell 20 can form a protection for the laminated battery 30. The bottom shell 21 may include a storage space. The laminated battery 30 is arranged in the storage space. The stacking direction X of the laminated battery 30 may be the same as the depth direction of the storage space. In some achievable ways, along the stacking direction X of the laminated battery 30, the bottom wall 211 of the bottom shell 21 and the top cover 23 are correspondingly arranged. The surface of the second current collector 321 facing away from the pole 22 is directly electrically connected to the bottom wall 211. In some achievable ways, the laminated battery 30 includes a diaphragm 35. The stacking direction X of the laminated battery 30 may refer to the direction in which the pole piece and the diaphragm 35 are stacked on each other.

[0089] In the present application examples, see Figure 4 and Figure 7 As shown, the first single-sided pole piece 31 and the second single-sided pole piece 32 are arranged opposite to each other. The first single-sided pole piece 31 and the second single-sided pole piece 32 each include a first current collector 311 and a second current collector 321. The first current collector 311 and the second current collector 321 are directly electrically connected to the pole 22 and the bottom shell 21, respectively, so that the pole 22 and the shell 20 can serve as two electrodes of the button battery 10, respectively. The direct electrical connection between the first current collector 311 and the pole 22 means that the first current collector 311 does not need to be electrically connected to the pole 22 through an additional transition structure. The direct electrical connection between the second current collector 321 and the bottom shell 21 means that the second current collector 321 does not need to be electrically connected to the bottom shell 21 through an additional transition structure.

[0090] In the embodiment of the present application, the first single-sided pole piece 31 refers to the first current collector 311 having only one surface facing away from the pole 22 and provided with the first active material layer 312. The second single-sided pole piece 32 refers to the second current collector 321 having only one surface facing the pole 22 and provided with the second active material layer 322.

[0091] The button cell 10 of the embodiment of the present application includes a shell 20 and a laminated battery cell 30 disposed in the shell 20. The outermost first single-sided electrode sheet 31 and the second single-sided electrode sheet 32 ​​in the laminated battery cell 30 are directly electrically connected to the pole 22 and the bottom shell 21, respectively, so that there is no need to use an additional adapter for switching between the laminated battery cell 30 and the shell 20. In the stacking direction X of the laminated battery cell 30, there is no need to reserve a space between the laminated battery cell 30 and the shell 20 for avoiding the adapter, so that the structural compactness of the button cell 10 can be improved in the stacking direction X of the laminated battery cell 30. The above structural design can be beneficial to reducing the overall size of the button cell 10 in the stacking direction X of the laminated battery cell 30, so as to reduce the overall volume of the button cell 10, thereby helping to improve the energy density of the button cell 10.

[0092] In addition, in the related art, the button battery includes a wound cell. The wound cell is a cell formed by winding pole pieces and diaphragms with opposite polarities. The wound cell is a cylindrical structure, and its own structural form has applicability deviations. The button battery 10 of the embodiment of the present application includes a laminated cell 30. The structural form of the laminated cell 30 itself is related to the shape of the pole piece and the diaphragm 35. According to the shape design requirements of the button battery 10, the pole piece and the diaphragm 35 can be relatively easily designed in shape so that the shape of the laminated cell 30 matches the shape of the shell 20, so that the shape of the laminated cell 30 is not limited to a circle, but can also be other non-circular structures, so it can be beneficial to improve the applicability of the structural form of the laminated cell 30. In addition, the laminated cell 30 has a higher space utilization rate than the wound cell, and it is easier to manufacture the first single-sided pole piece 31 or the second single-sided pole piece 32 for direct electrical connection with the pole 22 or the bottom shell 21.

[0093] In some possible implementations, see Figure 4 and Figure 7 As shown, the button battery 10 includes a first adhesive 40. The first adhesive 40 bonds the first current collector 311 and the pole 22, which helps to reduce the difficulty of connecting the first current collector 311 and the pole 22. The first adhesive 40 connects the pole 22 and the first current collector 311. The first adhesive 40 can fix the position of the laminated battery 30 in the housing 20, reducing the possibility that the laminated battery 30 shakes in the housing 20 and causes the pole 22 and the first current collector 311 to be out of electrical connection. Exemplarily, the first adhesive 40 can be formed of an adhesive, for example, the first adhesive 40 can be an adhesive glue.

[0094] Exemplarily, the first adhesive member 40 may be an insulating adhesive member. The first adhesive member 40 itself does not have a conductive capability. For example, the first adhesive member 40 may be an adhesive having insulating properties.

[0095] For example, the first adhesive 40 may be a pressure-sensitive adhesive. The first adhesive 40 does not need to be heated, solvent activated or subjected to a complicated curing process, and can be bonded by only applying relatively small pressure to the first adhesive 40 by the pole 22 and the first current collector 311, thereby reducing the difficulty of connection.

[0096] For example, the first adhesive 40 may be a conductive adhesive. The first adhesive 40 itself has conductivity, so that the pole 22 and the first current collector 311 may also be electrically connected through the first adhesive 40. For example, the first adhesive 40 may be a conductive glue.

[0097] In some possible implementations, see Figure 8 As shown, the pole 22 includes a first wall 22a and a first convex portion 201. The first wall 22a is arranged facing the laminated battery cell 30, and the first convex portion 201 protrudes from the first wall 22a. The first convex portion 201 abuts against the surface of the first current collector 311 facing the pole 22 to achieve electrical connection between the pole 22 and the first current collector 311. Along the stacking direction X of the laminated battery cell 30, there is a first spacing L1 between the first wall 22a and the first current collector 311. The abutment of the first convex portion 201 against the first current collector 311 means that the first convex portion 201 and the first current collector 311 are in direct contact and have compressive stress between each other. The method of directly contacting the first protrusion 201 with the first current collector 311 is, on the one hand, conducive to reducing the difficulty of achieving electrical connection between the pole 22 and the first current collector 311, and on the other hand, is conducive to ensuring that in the assembled button battery 10, the pole 22 and the first current collector 311 maintain a stable electrical connection state, thereby reducing the possibility of poor contact problems such as false connection between the pole 22 and the first current collector 311.

[0098] In some examples, the first interval L1 has a value range of greater than 0 μm and less than or equal to 50 μm.

[0099] For some examples, see Figure 3 and Figure 4As shown, the top cover 23 and the bottom shell 21 can be directly electrically connected. The shell 20 includes an insulating member 24. The insulating member 24 connects the pole 22 and the top cover 23. The pole 22 and the top cover 23 are insulated and isolated by the insulating member 24. The pole 22 and the top cover 23 are in a non-electrically connected state. Exemplarily, the insulating member 24 can be an insulating adhesive. For example, the insulating member 24 can be an insulating adhesive glue. The insulating member 24 bonds the pole 22 and the top cover 23 to fix the pole 22 on the top cover 23.

[0100] For some examples, see Figure 4 and Figure 8 As shown, the top cover 23 includes a central through hole 231. The pole 22 includes a base 221 and a boss 222. The base 221 is connected to the top cover 23. The boss 222 is arranged corresponding to the central through hole 231. An insulating member 24 is arranged between the base 221 and the top cover 23. The surface of the first current collector 311 facing the pole 22 is directly electrically connected to the base 221. The base 221 may be provided with a first convex portion 201.

[0101] For example, see Figure 8 As shown, the first adhesive 40 is disposed between the pole 22 and the first current collector 311. The first adhesive 40 has a first avoidance channel 100. The pole 22 includes a first convex portion 201. The first convex portion 201 passes through the first avoidance channel 100 and abuts against the first current collector 311. The first avoidance channel 100 is used to avoid the first convex portion 201, reducing the possibility that the first adhesive 40 is located between the first convex portion 201 and the first current collector 311 and affects the electrical connection state of the first convex portion 201 and the first current collector 311. The shell 20 of the button battery 10 can be filled with electrolyte. The first convex portion 201 can be surrounded by the first adhesive 40 on all sides, so that the first adhesive 40 can prevent the electrolyte from infiltrating the connection area between the first convex portion 201 and the first current collector 311, reducing the possibility that the first convex portion 201 and the first current collector 311 are corroded in the connection area, resulting in an unstable electrical connection state between the first convex portion 201 and the first current collector 311.

[0102] Exemplarily, the first protrusion 201 may be in a conical, semicircular or other shape, with the top being narrower than the bottom, so that it is easier for the first protrusion 201 to pass through the first adhesive member 40 .

[0103] In some possible implementations, see Fig. 9 As shown, the pole 22 includes a first wall 22a and a first recess 22b. The first wall 22a is arranged facing the laminated core 30. The first recess 22b includes an opening located on the first wall 22a. A first adhesive 40 is arranged in the first recess 22b. The first wall 22a abuts against the surface of the first current collector 311 facing the pole 22. The first adhesive 40 bonds the first current collector 311 and the pole 22.

[0104] The first wall surface 22a of the pole 22 is in direct contact with the surface of the first current collector 311 facing the pole 22. The distance between the first wall surface 22a and the first current collector 311 is zero. The above structural design is conducive to reducing the overall size of the button battery 10 in the stacking direction X of the laminated battery 30, so as to reduce the overall volume of the button battery 10, thereby facilitating the improvement of the energy density of the button battery 10.

[0105] In some examples, there may be a plurality of first recesses 22 b, and a first adhesive member 40 is disposed in each first recess 22 b.

[0106] In some possible implementations, see Figure 5 and Figure 7 As shown, the first current collector 311 includes a first pole ear 3111 and a first main body 3112 connected to each other. The first pole ear 3111 and the first main body 3112 are integrally formed. The first active material layer 312 is arranged on the first main body 3112. The first active material layer 312 is not arranged on the surface of the first main body 3112 facing the pole 22. The surface of the first main body 3112 facing the pole 22 is directly electrically connected to the pole 22. The first active material layer 312 is not arranged on the first pole ear 3111. In the laminated battery cell 30, the first single-sided pole sheet 31 can be electrically connected to other pole sheets of the same polarity through the first pole ear 3111. The first single-sided pole sheet 31 is located at the outermost side of the laminated battery cell 30 as a whole.

[0107] The laminated battery cell 30 is electrically connected to the pole 22 through the first main body 3112, which can help reduce the distance between the laminated battery cell 30 and the pole 22 in the stacking direction X of the laminated battery cell 30, and help reduce the overall size of the button battery 10 in the stacking direction X of the laminated battery cell 30, so as to reduce the overall volume of the button battery 10, thereby helping to improve the energy density of the button battery 10. The area of ​​the first main body 3112 itself is relatively large, which helps to reduce the difficulty of achieving electrical connection between the first current collector 311 and the pole 22.

[0108] For some examples, see Figure 4 and Figure 7 As shown, the button battery 10 includes a first adhesive 40. The first adhesive 40 is disposed between the pole 22 and the first main body 3112. The first adhesive 40 bonds the first main body 3112 to the pole 22. The area of ​​the first main body 3112 itself is relatively large. The first main body 3112 and the pole 22 are bonded by the first adhesive 40, which is conducive to reducing the difficulty of connecting the first adhesive 40 and the first current collector 311, and is also conducive to increasing the connection area between the first current collector 311 and the pole 22, and improving the connection stability between the first current collector 311 and the pole 22.

[0109] In some examples, the pole 22 includes a first protrusion 201 . The first protrusion 201 abuts against a surface of the first body portion 3112 facing the pole 22 , so as to achieve electrical connection between the pole 22 and the first current collector 311 .

[0110] In some examples, the pole 22 includes a first wall surface 22 a that abuts against a surface of the first body portion 3112 facing the pole 22 to achieve electrical connection between the pole 22 and the first current collector 311 .

[0111] In some examples, the surface area of ​​the pole 22 facing the laminated battery cell 30 is greater than or equal to the area of ​​the first main body 3112. The pole 22 can cover the entire first main body 3112. In the case of expansion of the laminated battery cell 30, the pole 22 can support the first main body 3112 as a whole and apply a reaction force to the first main body 3112 as a whole, which can help the first main body 3112 to be uniformly stressed as a whole, reduce the stress concentration area caused by uneven stress on the first main body 3112, and cause the first active material layer 312 to peel off and fall off from the first main body 3112 in the stress concentration area.

[0112] In some possible implementations, see Fig.10 , Fig.11 and Fig.12 As shown, the first current collector 311 includes a first pole ear 3111, a first main body 3112 and a first folded portion 3113 connected to each other. The first pole ear 3111, the first main body 3112 and the first folded portion 3113 are integrally formed. The first active material layer 312 is disposed on the first main body 3112. The first folded portion 3113 is folded relative to the first main body 3112. The first folded portion 3113 is located between the first main body 3112 and the pole 22. The surface of the first folded portion 3113 facing the pole 22 is directly electrically connected to the pole 22.

[0113] The first active material layer 312 is not provided on the surface of the first main body 3112 facing the pole 22. The first active material layer 312 is not provided on the first pole ear 3111 and the first folded portion 3113. The first pole ear 3111 and the first folded portion 3113 are both empty foil areas. The first pole ear 3111 and the first folded portion 3113 are connected to different positions on the first main body 3112. The first single-sided pole piece 31 can be electrically connected to other pole pieces of the same polarity through the first pole ear 3111. The first current collector 311 is directly electrically connected to the pole 22 through the first folded portion 3113.

[0114] See also Fig.13As shown, after the laminated battery cell 30 is loaded into the bottom shell 21, the first folded portion 3113 located outside the bottom shell 21 is connected to the pole 22, and then the pole 22 and the top cover 23 are covered on the bottom shell 21. During the covering process, the first folded portion 3113 is folded toward the first main body 3112. The covered top cover 23 and the bottom shell 21 are connected, and the first folded portion 3113 is located between the pole 22 and the first main body 3112.

[0115] The first current collector 311 is provided with the first folding portion 3113, so that the laminated battery cell 30 can be first connected and fixed to the pole 22, and then the top cover 23 is closed, which is beneficial to reduce the connection difficulty between the laminated battery cell 30 and the pole 22, and improve the connection stability and connection efficiency between the laminated battery cell 30 and the pole 22.

[0116] When the first current collector 311 is directly electrically connected to the pole 22 through the first main body 3112, after the laminated battery cell 30 is loaded into the shell, the top cover 23 with the pole 22 is covered on the bottom shell 21. Under the condition that the connection position of the top cover 23 and the bottom shell 21 is ensured to be in a predetermined position, the pole 22 can abut against the first current collector 311 to ensure that the pole 22 and the first current collector 311 have a good electrical connection state. If the connection position of the top cover 23 and the bottom shell 21 deviates, there is a possibility that the pole 22 cannot abut against the first main body 3112, resulting in a non-electrical connection state between the pole 22 and the first main body 3112. When the first current collector 311 is directly electrically connected to the pole 22 through the first main body 3112, the connection position accuracy requirement of the top cover 23 and the bottom shell 21 is relatively high.

[0117] The first current collector 311 is provided with the first folding portion 3113, and the position of the first folding portion 3113 can be flexibly adjusted, and the first folding portion 3113 first completes the connection operation with the pole 22, and then the connection operation is performed on the top cover 23 and the bottom shell 21, so that the connection position between the top cover 23 and the bottom shell 21 will not affect the connection state between the first current collector 311 and the pole 22, which is beneficial to reduce the possibility of the above-mentioned problems and reduce the accuracy requirements of the connection position between the top cover 23 and the bottom shell 21.

[0118] In some examples, the surface of the first folded portion 3113 facing away from the pole 22 and the surface of the first main body portion 3112 facing the pole 22 can contact each other to reduce the space occupied by the laminated battery cell 30 in the stacking direction X of the laminated battery cell 30 and improve the structural compactness of the laminated battery cell 30.

[0119] In some examples, the first folded portion 3113 is welded to the pole 22. The way in which the first current collector 311 is connected to the pole 22 through the first folded portion 3113 can facilitate the welding operation of the first folded portion 3113 and the pole 22. The first folded portion 3113 located outside the bottom shell 21 can first fix the relative position with the pole 22, and then weld the first folded portion 3113 and the pole 22 on one side of the first folded portion 3113 to reduce the difficulty of connecting the first folded portion 3113 and the pole 22. The first folded portion 3113 and the pole 22 are connected by welding, which is conducive to improving the connection strength and connection stability between the first folded portion 3113 and the pole 22, and reducing the possibility of the first folded portion 3113 and the pole 22 being out of the connection state during the use of the button battery 10.

[0120] Exemplarily, a laser welding process may be used to weld the first folded portion 3113 and the pole 22. The thickness of the pole 22 is greater than the thickness of the first folded portion 3113. The laser cannot melt-weld the first folded portion 3113 and the pole 22 from one side of the pole 22. The first current collector 311 is connected to the pole 22 via the first folded portion 3113. The laser can be used to weld the first folded portion 3113 and the pole 22 on one side of the first folded portion 3113, thereby reducing the difficulty of connecting the first folded portion 3113 and the pole 22.

[0121] In some examples, the first folded portion 3113 is bonded to the pole 22. The first current collector 311 is bonded to the pole 22 through the first folded portion 3113, which can help reduce the difficulty of connecting the first folded portion 3113 and the pole 22, and is also convenient for observing and detecting the bonding state of the first folded portion 3113 and the pole 22. In addition, there is no need to consider the problems of over-welding and cold welding caused by welding, and there is no need to consider the weld marks left by welding. When the bonding state of the first folded portion 3113 and the pole 22 meets the requirements, the top cover 23 with the pole 22 is sealed and connected to the bottom shell 21.

[0122] Exemplarily, the first folded portion 3113 and the pole 22 may be bonded using a first adhesive 40. Exemplarily, the first adhesive 40 may be formed of an adhesive, for example, the first adhesive 40 may be adhesive glue. Exemplarily, the first adhesive 40 may cover the surface of the first folded portion 3113 facing the pole 22.

[0123] In some examples, the pole 22 includes a first protrusion 201 . The first protrusion 201 abuts against a surface of the first folded portion 3113 facing the pole 22 , so as to achieve electrical connection between the pole 22 and the first current collector 311 .

[0124] In some examples, the pole 22 includes a first wall surface 22 a that abuts against a surface of the first folded portion 3113 facing the pole 22 to achieve electrical connection between the pole 22 and the first current collector 311 .

[0125] In some examples, the area of ​​the first folded portion 3113 is greater than or equal to the area of ​​the first main body 3112. The first folded portion 3113 can cover the entire first main body 3112. When the laminated battery cell 30 expands, when the first main body 3112 contacts the first folded portion 3113, the first folded portion 3113 can support the first main body 3112 as a whole and apply a reaction force to the first main body 3112 as a whole, which can be beneficial to the uniform force on the first main body 3112 as a whole, reduce the possibility of uneven force on the first main body 3112 and the generation of stress concentration areas, and cause the first active material layer 312 to peel off and fall off from the first main body 3112 in the stress concentration area.

[0126] Exemplarily, the shape and size of the first folding portion 3113 are respectively the same as the shape and size of the first main body portion 3112 .

[0127] Exemplarily, the surface area of ​​the pole 22 facing the laminated battery cell 30 may be greater than or equal to the area of ​​the first folded portion 3113. The pole 22 may cover the entire first folded portion 3113. When the laminated battery cell 30 expands, the pole 22 and the first folded portion 3113 may simultaneously support the first main body 3112 as a whole and apply a reaction force to the first main body 3112 as a whole, which may be beneficial for uniform force on the first main body 3112 as a whole, reduce the possibility of uneven force on the first main body 3112 and the generation of stress concentration areas, and cause the first active material layer 312 to peel off and fall off from the first main body 3112 in the stress concentration areas.

[0128] In some achievable embodiments, the bottom shell 21 has a bottom wall 211. The button battery 10 includes a second adhesive 50. The second adhesive 50 bonds the second current collector 321 to the bottom wall 211, which helps to reduce the difficulty of connecting the second current collector 321 to the bottom wall 211. The second adhesive 50 connects the bottom wall 211 and the second current collector 321. The second adhesive 50 can fix the position of the laminated battery 30 in the housing 20, reducing the possibility that the laminated battery 30 shakes in the housing 20 and causes the bottom wall 211 and the second current collector 321 to be out of electrical connection.

[0129] Exemplarily, the second adhesive member 50 may be formed of an adhesive, for example, the second adhesive member 50 may be an adhesive glue.

[0130] For example, the second adhesive member 50 may be an insulating adhesive member. The second adhesive member 50 itself does not have the ability to conduct electricity. For example, the second adhesive member 50 may be an adhesive having insulating properties.

[0131] For example, the second adhesive 50 may be a pressure-sensitive adhesive, which does not need to be heated, solvent activated, or subjected to a complicated curing process, and can be bonded by applying relatively small pressure to the second current collector 321 and the bottom wall 211, thereby reducing the difficulty of connection.

[0132] For example, the second adhesive member 50 may be a conductive adhesive member. The second adhesive member 50 itself has conductivity, so that the bottom case 21 and the second current collector 321 may also be electrically connected through the second adhesive member 50. For example, the second adhesive member 50 may be a conductive glue.

[0133] In some possible implementations, see Fig.14 As shown, the bottom wall 211 has a second wall surface 21a. The bottom shell 21 includes a second protrusion 202. The second protrusion 202 is arranged on the bottom wall 211. The second wall surface 21a is arranged facing the laminated battery core 30. The second protrusion 202 is protrudingly arranged on the second wall surface 21a. The second protrusion 202 abuts against the surface of the second current collector 321 facing the bottom wall 211 to achieve electrical connection between the bottom shell 21 and the second current collector 321. Along the stacking direction X of the laminated battery core 30, there is a second spacing L2 between the second wall surface 21a and the second current collector 321. The second protrusion 202 abutting against the second current collector 321 means that the second protrusion 202 and the second current collector 321 are in direct contact and have compressive stress with each other. The method of directly contacting the second protrusion 202 with the second current collector 321 is conducive to reducing the difficulty of achieving electrical connection between the bottom shell 21 and the second current collector 321 on the one hand, and is conducive to ensuring that in the assembled button battery 10, a stable electrical connection state is maintained between the bottom shell 21 and the second current collector 321, thereby reducing the possibility of poor contact problems such as false connection between the bottom shell 21 and the second current collector 321.

[0134] In some examples, the second interval L2 has a value range of greater than 0 μm and less than or equal to 50 μm.

[0135] Exemplarily, the second adhesive 50 is disposed between the bottom wall 211 and the second current collector 321. The second adhesive 50 has a second avoidance channel 110. The bottom wall 211 is provided with a second convex portion 202. The second convex portion 202 passes through the second avoidance channel 110 and abuts against the second current collector 321. The second avoidance channel 110 is used to avoid the second convex portion 202, reducing the possibility that the second adhesive 50 is located between the second convex portion 202 and the second current collector 321 and affects the electrical connection state of the second convex portion 202 and the second current collector 321. The shell 20 of the button battery 10 can be filled with electrolyte. The second convex portion 202 can be surrounded by the second adhesive 50, so that the second adhesive 50 can prevent the electrolyte from infiltrating the connection area between the second convex portion 202 and the second current collector 321, reducing the possibility that the second convex portion 202 and the second current collector 321 are corroded in the connection area, resulting in an unstable electrical connection state between the second convex portion 202 and the second current collector 321.

[0136] Exemplarily, the second protrusion 202 may be in a conical, semicircular or other shape, with the top being narrower than the bottom, so that the second protrusion 202 can pass through the second adhesive member 50 more conveniently.

[0137] In some possible implementations, see Fig.15 As shown, the bottom wall 211 has a second wall surface 21a and a second recess 21b. The second wall surface 21a is arranged facing the laminated core 30. The second recess 21b includes an opening located at the second wall surface 21a. A second adhesive 50 is arranged in the second recess 21b, and the second wall surface 21a abuts against the surface of the second current collector 321 facing the bottom wall 211. The second adhesive 50 bonds the second current collector 321 to the pole 22.

[0138] The second wall surface 21a is in direct contact with the surface of the second current collector 321 facing the bottom wall 211. The distance between the second wall surface 21a and the second current collector 321 is zero. The above structural design is conducive to reducing the overall size of the button battery 10 in the stacking direction X of the laminated battery 30, so as to reduce the overall volume of the button battery 10, thereby facilitating the improvement of the energy density of the button battery 10.

[0139] In some examples, there may be a plurality of second recesses 21 b , and a second adhesive member 50 is disposed in each second recess 21 b .

[0140] In some possible implementations, see Figure 6 and Figure 7 As shown, the second current collector 321 includes a second pole tab 3211 and a second main body 3212 connected to each other. The second pole tab 3211 and the second main body 3212 are integrally formed. The second active material layer 322 is disposed on the second main body 3212. The surface of the second main body 3212 facing away from the pole 22 is directly electrically connected to the bottom shell 21.

[0141] The second active material layer 322 is not provided on the surface of the second main body 3212 facing the bottom wall 211. The bottom shell 21 may include a bottom wall 211. The surface of the second main body 3212 facing the bottom wall 211 may be directly electrically connected to the bottom wall 211. The second active material layer 322 is not provided on the second pole ear 3211. In the laminated battery 30, the second single-sided pole piece 32 may be electrically connected to other pole pieces of the same polarity through the second pole ear 3211. The second single-sided pole piece 32 is located at the outermost side of the laminated battery 30 as a whole.

[0142] The laminated battery cell 30 is electrically connected to the bottom shell 21 through the second main body 3212, which can help reduce the distance between the laminated battery cell 30 and the bottom shell 21 in the stacking direction X of the laminated battery cell 30, and help reduce the overall size of the button battery 10 in the stacking direction X of the laminated battery cell 30, so as to reduce the overall volume of the button battery 10, thereby helping to improve the energy density of the button battery 10. The area of ​​the second main body 3212 itself is relatively large, which helps to reduce the difficulty of achieving electrical connection between the second current collector 321 and the bottom shell 21.

[0143] For some examples, see Figure 4 and Figure 7 As shown, the button battery 10 includes a second adhesive 50. The second adhesive 50 is disposed between the bottom wall 211 and the second main body 3212. The second adhesive 50 bonds the second main body 3212 to the bottom wall 211. The area of ​​the second main body 3212 itself is relatively large. The second main body 3212 and the bottom wall 211 are bonded by the second adhesive 50, which is conducive to reducing the difficulty of connecting the second adhesive 50 and the second current collector 321, and is also conducive to increasing the connection area between the second current collector 321 and the bottom wall 211, and improving the connection stability between the second current collector 321 and the bottom wall 211.

[0144] In some examples, the bottom case 21 includes a second protrusion 202 . The second protrusion 202 abuts against a surface of the second body portion 3212 facing the bottom wall 211 to achieve electrical connection between the bottom wall 211 and the second current collector 321 .

[0145] In some examples, the bottom wall 211 has a second wall surface 21 a that abuts against a surface of the second main body 3212 facing the bottom wall 211 to achieve electrical connection between the bottom wall 211 and the second current collector 321 .

[0146] For some examples, see Fig.12 and Fig.16As shown, the second current collector 321 includes a second pole ear 3211, a second main body 3212, and a second folded portion 3213 connected to each other. The second pole ear 3211, the second main body 3212, and the second folded portion 3213 are integrally formed. The second active material layer 322 is disposed on the second main body 3212. The second folded portion 3213 is folded relative to the second main body 3212. The second folded portion 3213 is located between the second main body 3212 and the bottom shell 21. The surface of the second folded portion 3213 facing away from the pole 22 is directly electrically connected to the bottom shell 21.

[0147] The second active material layer 322 is not provided on the surface of the second main body 3212 facing the bottom shell 21. The second active material layer 322 is not provided on the second pole ear 3211 and the second folded portion 3213. The second pole ear 3211 and the second folded portion 3213 are both empty foil areas. The second pole ear 3211 and the second folded portion 3213 are connected to different positions on the second main body 3212. The second single-sided pole piece 32 can be electrically connected to other pole pieces of the same polarity through the second pole ear 3211. The second current collector 321 is directly electrically connected to the bottom shell 21 through the second folded portion 3213.

[0148] Before the laminated battery cell 30 is installed in the bottom case 21, the second folded portion 3213 can be connected to the bottom case 21, and then the rest of the laminated battery cell 30 is installed in the bottom case 21, and then the pole 22 and the top cover 23 are covered on the bottom case 21. In the process of installing the rest of the laminated battery cell 30 in the bottom case 21, the second folded portion 3213 is folded relative to the second main body 3212. After the laminated battery cell 30 is installed in the bottom case 21, the second folded portion 3213 is located between the bottom case 21 and the second main body 3212.

[0149] The second current collector 321 is provided with the second folding portion 3213, so that the laminated battery cell 30 can be first connected and fixed to the bottom wall 211, and then the laminated battery cell 30 can be installed into the bottom shell 21, thereby reducing the difficulty of connecting the laminated battery cell 30 and the bottom shell 21, and improving the connection stability and connection efficiency between the laminated battery cell 30 and the bottom shell 21.

[0150] In some examples, the surface of the second folded portion 3213 facing away from the bottom wall 211 and the surface of the second main body portion 3212 facing the bottom wall 211 may contact each other, so as to reduce the space occupied by the laminated battery cell 30 in the stacking direction X of the laminated battery cell 30 and improve the structural compactness of the laminated battery cell 30.

[0151] In some examples, the bottom shell 21 has a bottom wall 211. The second folded portion 3213 is welded to the bottom wall 211. The second current collector 321 adopts the method of connecting the second folded portion 3213 to the bottom wall 211, which can facilitate the welding operation of the second folded portion 3213 and the bottom wall 211. The second folded portion 3213 located in the bottom shell 21 is first fixed to the relative position with the bottom wall 211, and then the second folded portion 3213 and the bottom wall 211 are welded on one side of the second folded portion 3213 to reduce the difficulty of connecting the second folded portion 3213 and the bottom wall 211. The second folded portion 3213 and the bottom wall 211 are connected by welding, which is conducive to improving the connection strength and connection stability between the second folded portion 3213 and the bottom wall 211, and reducing the possibility of the second folded portion 3213 and the bottom wall 211 being out of the connection state during the use of the button battery 10.

[0152] Exemplarily, a laser welding process may be used to weld the second folded portion 3213 and the bottom wall 211. The thickness of the bottom shell 21 is greater than the thickness of the second folded portion 3213. The laser cannot melt-weld the second folded portion 3213 and the bottom wall 211 from the outside of the bottom shell 21. The second current collector 321 is connected to the bottom wall 211 via the second folded portion 3213. The laser can be used to weld the second folded portion 3213 and the bottom wall 211 on one side of the second folded portion 3213, thereby reducing the difficulty of connecting the second folded portion 3213 and the bottom wall 211.

[0153] In some examples, the second folded portion 3213 is bonded to the bottom wall 211. The second current collector 321 is bonded to the bottom wall 211 by the second folded portion 3213, which can help reduce the difficulty of connecting the second folded portion 3213 and the bottom wall 211, and is also convenient for observing and detecting the bonding state of the second folded portion 3213 and the bottom wall 211. In addition, there is no need to consider the problems of over-welding and cold welding caused by welding, nor is there any need to consider the welding marks left by welding. While ensuring that the bonding state of the second folded portion 3213 and the bottom wall 211 meets the requirements, the other parts of the laminated battery cell 30 are then installed into the bottom shell 21, and then the top cover 23 is covered on the bottom shell 21 and the top cover 23 and the bottom shell 21 are connected.

[0154] Exemplarily, the second folded portion 3213 and the bottom wall 211 may be bonded using a second adhesive 50. Exemplarily, the second adhesive 50 may be formed of an adhesive, for example, the second adhesive 50 may be adhesive glue. Exemplarily, the second adhesive 50 may cover the surface of the second folded portion 3213 facing the bottom wall 211.

[0155] In some examples, the bottom shell 21 includes a second protrusion 202 . The second protrusion 202 abuts against a surface of the second folded portion 3213 facing the bottom wall 211 , so as to achieve electrical connection between the bottom wall 211 and the second current collector 321 .

[0156] In some examples, the bottom wall 211 has a second wall surface 21 a that abuts against a surface of the second folded portion 3213 facing the bottom wall 211 to achieve electrical connection between the bottom wall 211 and the second current collector 321 .

[0157] In some examples, the area of ​​the second folded portion 3213 is greater than or equal to the area of ​​the second main body 3212. The second folded portion 3213 can cover the entire second main body 3212. When the laminated battery cell 30 expands, when the second main body 3212 contacts the second folded portion 3213, the second folded portion 3213 can support the second main body 3212 and apply a reaction force to the second main body 3212 as a whole, which can be beneficial to the uniform force on the second main body 3212 as a whole, reduce the possibility of uneven force on the second main body 3212 and the generation of stress concentration areas, and cause the second active material layer 322 to peel off and fall off from the second main body 3212 in the stress concentration area.

[0158] Exemplarily, the shape and size of the second folding portion 3213 are the same as the shape and size of the second main body portion 3212 .

[0159] In some possible implementations, see Figure 7 , Fig.17 and Fig.18 As shown, the laminated battery cell 30 includes a first double-sided pole piece 33 and a second double-sided pole piece 34. The first double-sided pole piece 33 and the second double-sided pole piece 34 are alternately stacked between the first single-sided pole piece 31 and the second single-sided pole piece 32. The first single-sided pole piece 31 and the first double-sided pole piece 33 have the same polarity. The first single-sided pole piece 31 and each first double-sided pole piece 33 are electrically connected. The second single-sided pole piece 32 and the second double-sided pole piece 34 have the same polarity. The second single-sided pole piece 32 and each second double-sided pole piece 34 are electrically connected.

[0160] In the embodiment of the present application, the first double-sided pole piece 33 refers to a current collector having two opposite surfaces on which an active material layer is disposed. The second double-sided pole piece 34 refers to a current collector having two opposite surfaces on which an active material layer is disposed.

[0161] The first single-sided pole piece 31, the second double-sided pole piece 34, the first double-sided pole piece 33 and the second single-sided pole piece 32 are stacked along the stacking direction X. The pole piece adjacent to the first single-sided pole piece 31 is the second double-sided pole piece 34. A diaphragm 35 may be provided between the first single-sided pole piece 31 and the second double-sided pole piece 34. The pole piece adjacent to the second single-sided pole piece 32 is the first double-sided pole piece 33. A diaphragm 35 may be provided between the second single-sided pole piece 32 and the first double-sided pole piece 33. A diaphragm 35 may be provided between the first double-sided pole piece 33 and the second double-sided pole piece 34.

[0162] For some examples, see Figure 2 , Figure 3 and Figure 4 As shown, the first pole tab 3111 and the third pole tab 331 are gathered toward the bottom wall 211 and then folded back toward the top cover 23 to form a two-stage structure. The first pole tab 3111 and the third pole tab 331 are welded to form a welding portion on the area folded toward the top cover 23. The first pole tab 3111 and the third pole tab 331 adopt this structural design, so that the first pole tab 3111 and the third pole tab 331 will occupy a relatively large space.

[0163] See also Figure 7 , Fig.17 and Fig.18 As shown, the first single-sided pole piece 31 includes a first pole ear 3111. The first double-sided pole piece 33 includes a third pole ear 331. The first pole ear 3111 and each third pole ear 331 are folded along the stacking direction X of the laminated battery core 30, and can be folded toward the bottom wall 211 of the bottom shell 21, or folded toward the top cover 23 and welded, and welded to form a first folded portion 60. The first folded portion 60 is a one-stage structure. That is, the first pole ear 3111 and the third pole ear 331 are folded toward the bottom wall 211 or the top cover 23 and welded, and the first pole ear 3111 and the third pole ear 331 do not need to be folded toward the bottom wall 211 or the top cover 23 and then folded in the opposite direction, which is conducive to reducing the space occupied by the first pole ear 3111 and the third pole ear 331, and is conducive to reducing the overall size of the button battery 10, so as to reduce the overall volume of the button battery 10, thereby facilitating the improvement of the energy density of the button battery 10. The first pole tab 3111 and the third pole tab 331 are folded together and then folded once, which can be called a two-stage structure. On this basis, folding once more can be called a three-stage structure.

[0164] The bottom shell 21 includes a side wall 212. The bottom wall 211 and the side wall 212 are connected to form a connection portion. The first gathering portion 60 is close to the connection portion between the bottom wall 211 and the side wall 212.

[0165] For some examples, see Figure 2 , Figure 3 and Figure 4As shown, the second pole lug 3211 and the fourth pole lug 341 are folded toward the bottom wall 211 and then folded back toward the top cover 23 to form a two-stage structure. The second pole lug 3211 and the fourth pole lug 341 are welded on the area folded toward the top cover 23 to form a welding portion. The second pole lug 3211 and the fourth pole lug 341 adopt this structural design, so that the second pole lug 3211 and the fourth pole lug 341 will occupy a relatively large space. The present application can eliminate the need for an adapter by connecting the topmost single-sided pole piece to the pole 22 and the bottommost single-sided pole piece to the bottom shell 21. In the prior art, it is necessary to reconnect the folded welding portion with the adapter, so the size of the welding portion needs to be enlarged. In the present application, the folded portion after welding can be directly sheared, so that the welding portion can be close to the bottom wall 211 or the top cover 23, without the need for secondary folding, which greatly improves the space occupancy rate of the battery cell.

[0166] See also Figure 7 , Fig.17 and Fig.19 As shown, the second single-sided pole piece 32 includes a second pole ear 3211. The second double-sided pole piece 34 includes a fourth pole ear 341. The second pole ear 3211 and each fourth pole ear 341 can be gathered and welded toward the bottom wall 211 along the stacking direction X of the laminated battery cell 30, or can be gathered and welded toward the top cover 23 to form a second gathered portion 70. The second gathered portion 70 is a one-stage structure. The second pole ear 3211 and the fourth pole ear 341 are gathered and welded toward the top cover 23 or the bottom wall 211. The second pole ear 3211 and the fourth pole ear 341 do not need to be gathered toward the bottom wall 211 or the top cover 23 and then folded in the opposite direction, which is conducive to reducing the space occupied by the second pole ear 3211 and the fourth pole ear 341, which is conducive to reducing the overall size of the button battery 10, so as to reduce the overall volume of the button battery 10, thereby facilitating the improvement of the energy density of the button battery 10. The second pole tab 3211 and the fourth pole tab 341 are folded together and then folded once, which can be called a two-stage structure. On this basis, they are folded once more to form a three-stage structure.

[0167] The bottom shell 21 includes a side wall 212. The bottom wall 211 and the side wall 212 are connected to form a connection portion. The second gathering portion 70 is close to the connection portion between the bottom wall 211 and the side wall 212.

[0168] In some achievable embodiments, the first single-sided electrode sheet 31 is a cathode electrode sheet. The material of the pole 22 may include aluminum or an aluminum alloy. The second single-sided electrode sheet 32 ​​is an anode electrode sheet. The material of the bottom shell 21 may include stainless steel. The material of the top cover 23 may include stainless steel. The outer edge of the top cover 23 and the top of the bottom shell 21 are welded and sealed. Fig.18 or Fig. 20As shown, after the first pole tab 3111 and each third pole tab 331 are folded and welded, an insulating tape 80 can be attached to the outer sides of the first pole tab 3111 and the third pole tab 331. The insulating tape 80 can insulate and isolate the first pole tab 3111 and the third pole tab 331 from the bottom shell 21, respectively, to reduce the possibility of electrical connection between the first pole tab 3111 and the third pole tab 331 and the bottom shell 21.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A button battery, characterized in that: include: The housing comprises a bottom shell, a pole and a top cover, wherein the top cover is sealed and connected to the bottom shell, the pole is connected to the top cover, and the bottom shell and the pole lead out different polarities; A laminated battery cell is arranged in the shell. Along the stacking direction of the laminated battery cell, the laminated battery cell includes a first single-sided pole sheet and a second single-sided pole sheet located at the outermost side. The first single-sided pole sheet and the second single-sided pole sheet have opposite polarity. The first single-sided pole sheet includes a first current collector and a first active material layer. Along the stacking direction of the laminated battery cell, the surface of the first current collector facing the pole is directly electrically connected to the pole, and the first active material layer is arranged on the surface of the first current collector facing away from the pole. The second single-sided pole sheet includes a second current collector and a second active material layer. The surface of the second current collector facing away from the pole is directly electrically connected to the bottom shell, and the second active material layer is arranged on the surface of the second current collector facing the pole.

2. The button battery according to claim 1, characterized in that: The button cell includes a first adhesive member, and the first adhesive member bonds the first current collector and the pole.

3. The button battery according to claim 2, characterized in that: The pole includes a first wall and a first protrusion, the first wall is arranged to face the laminated battery cell, the first protrusion protrudes from the first wall, the first protrusion abuts against the surface of the first current collector facing the pole, and along the stacking direction of the laminated battery cell, there is a first distance between the first wall and the first current collector.

4. The button battery according to claim 3, characterized in that: The value range of the first spacing is greater than 0 micrometers and less than or equal to 50 micrometers.

5. The button battery according to claim 3, characterized in that: The first adhesive is disposed between the pole and the first current collector, the first adhesive has a first escape channel, and the first protrusion passes through the first escape channel and abuts against the first current collector.

6. The button battery according to claim 2, characterized in that: The pole includes a first wall and a first recess, the first wall is arranged facing the laminated battery core, the first recess is arranged on the first wall, the first recess includes an opening located on the first wall, the first adhesive is arranged in the first recess, the first wall is abutted against the surface of the first current collector facing the pole, and the first adhesive bonds the first current collector to the pole.

7. The button battery according to claim 2, characterized in that: The first adhesive member is conductive adhesive and / or pressure-sensitive adhesive.

8. The button battery according to claim 1, characterized in that: The first current collector includes a first pole tab and a first main body that are connected to each other. The first pole tab and the first main body are integrally formed. The first active material layer is disposed on the first main body. A surface of the first main body that faces the pole is directly electrically connected to the pole.

9. The button battery according to claim 8, characterized in that: The button battery includes a first adhesive member, and the first adhesive member bonds the pole and the first main body.

10. The button battery according to claim 1, characterized in that: The first current collector includes a first pole ear, a first main body and a first folded portion that are connected to each other. The first pole ear, the first main body and the first folded portion are integrally formed. The first active material layer is arranged on the first main body. The first folded portion is folded relative to the first main body. The first folded portion is located between the first main body and the pole. The surface of the first folded portion facing the pole is directly electrically connected to the pole.

11. The button battery according to claim 10, characterized in that: The first folded portion is welded to the pole; or the button battery includes a first adhesive, and the first adhesive adheres the first folded portion to the pole.

12. The button battery according to claim 10, characterized in that: The area of ​​the first folded portion is greater than or equal to the area of ​​the first main body portion.

13. The button battery according to claim 8 or 12, characterized in that: The surface area of ​​the pole facing the laminated battery core is greater than or equal to the area of ​​the first main body.

14. The button battery according to any one of claims 1 to 12, characterized in that: The bottom shell has a bottom wall, and the button cell includes a second adhesive member, and the second adhesive member bonds the second current collector to the bottom wall.

15. The button battery according to claim 14, characterized in that: The bottom wall has a second wall surface, and the bottom shell includes a second convex portion. The second wall surface is arranged facing the laminated battery core, and the second convex portion is protruding from the second wall surface. The second convex portion abuts against the surface of the second current collector facing the bottom wall. Along the stacking direction of the laminated battery core, there is a second distance between the second wall surface and the second current collector.

16. The button battery according to claim 15, characterized in that: The second spacing has a value range of greater than 0 micrometers and less than or equal to 50 micrometers.

17. The button battery according to claim 15, characterized in that: The second adhesive member is disposed between the bottom wall and the second current collector, the second adhesive member has a second avoidance channel, and the second protrusion passes through the second avoidance channel and abuts against the second current collector.

18. The button battery according to claim 14, characterized in that: The bottom wall has a second wall surface and a second recess, the second wall surface is arranged facing the laminated battery core, the second recess includes an opening located on the second wall surface, the second adhesive is arranged in the second recess, the second wall surface abuts against the surface of the second current collector facing the bottom wall, and the second adhesive bonds the second current collector to the pole.

19. The button battery according to claim 18, characterized in that: The second adhesive member is conductive adhesive or pressure-sensitive adhesive.

20. The button battery according to any one of claims 1 to 12, characterized in that: The second current collector includes a second pole ear and a second main body that are connected. The second pole ear and the second main body are integrally formed. The second active material layer is arranged on the second main body. The surface of the second main body that faces away from the pole is directly electrically connected to the bottom shell.

21. The button battery according to claim 20, characterized in that: The bottom shell has a bottom wall, and the button battery includes a second adhesive member, and the second adhesive member is bonded to the second main body and the bottom wall.

22. The button battery according to any one of claims 1 to 12, characterized in that: The second current collector includes a second pole ear, a second main body and a second folded portion that are connected to each other. The second pole ear, the second main body and the second folded portion are integrally formed. The second active material layer is arranged on the second main body. The second folded portion is folded relative to the second main body. The second folded portion is located between the second main body and the bottom shell. The surface of the second folded portion facing away from the pole is directly electrically connected to the bottom shell.

23. The button battery according to claim 22, characterized in that: The bottom shell has a bottom wall, and the second folded portion is welded to the bottom wall; or, the button battery includes a second adhesive, and the second adhesive adheres the second folded portion to the bottom wall.

24. The button cell according to claim 22, characterized in that: The area of ​​the second folded portion is greater than or equal to the area of ​​the second main body portion.

25. The button battery according to any one of claims 1 to 12, characterized in that: The laminated battery cell includes a first double-sided pole piece and a second double-sided pole piece, the first double-sided pole piece and the second double-sided pole piece are alternately stacked between the first single-sided pole piece and the second single-sided pole piece, the first single-sided pole piece and the first double-sided pole piece have the same polarity, the first single-sided pole piece and each of the first double-sided pole pieces are electrically connected, the second single-sided pole piece and the second double-sided pole piece have the same polarity, and the second single-sided pole piece and each of the second double-sided pole pieces are electrically connected.

26. The button cell according to claim 25, characterized in that: The first single-sided pole piece includes a first pole ear, the first double-sided pole piece includes a third pole ear, the first pole ear and each of the third pole ears are gathered along the stacking direction of the laminated battery core and welded to form a first gathered portion, and the first gathered portion is a one-stage structure.

27. The button cell according to claim 25, characterized in that: The second single-sided pole piece includes a second pole ear, the second double-sided pole piece includes a fourth pole ear, the second pole ear and each of the fourth pole ears are gathered along the stacking direction of the laminated battery core and welded to form a second gathered portion, and the second gathered portion is a one-stage structure.

28. The button battery according to any one of claims 1 to 12, characterized in that: The first single-sided pole piece is a cathode pole piece, and the second single-sided pole piece is an anode pole piece.

29. The button cell according to any one of claims 1 to 12, characterized in that: The top cover is directly electrically connected to the bottom shell, the shell includes an insulating member, the insulating member connects the pole and the top cover, and the pole and the top cover are insulated and isolated by the insulating member.

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