Button cell

Abstract

The application provides a button cell. The button cell comprises a shell and a laminated core. The shell comprises a bottom shell, a pole and a top cover. The top cover is sealingly connected with the bottom shell. The pole is connected with the top cover. The bottom shell and the pole lead out different polarities. The laminated core is arranged in the shell. Along the stacking direction of the laminated core, the laminated core comprises a first single-face pole piece and a second single-face pole piece located at the outermost side. The first single-face pole piece and the second single-face pole piece are opposite in polarity. The first single-face pole piece comprises a first current collector and a first active material layer. Along the stacking direction of the laminated core, the surface of the first current collector facing the pole is directly electrically connected with the pole. The first active material layer is arranged on the surface of the first current collector away from the pole. The second single-face pole piece comprises a second current collector and a second active material layer. The surface of the second current collector away from the pole is directly electrically connected with the bottom shell. The second active material layer is arranged on the surface of the second current collector facing the pole.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a button cell. BACKGROUND

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

[0003] In view of the above problems, the present application provides a button cell, which can be beneficial to improve the energy density of the button cell.

[0004] The present application provides a button cell, which comprises a shell and a jelly-roll. The shell comprises a bottom shell, a pole and a top cover. The top cover is sealingly connected with the bottom shell. The pole is connected with the top cover. The bottom shell and the pole are of different polarities. The jelly-roll is arranged in the shell. In the stacking direction of the jelly-roll, the jelly-roll comprises a first single-sided pole piece and a second single-sided pole piece located at the outermost side. The first single-sided pole piece and the second single-sided pole piece are of opposite polarities. The first single-sided pole piece comprises a first current collector and a first active material layer. In the stacking direction of the jelly-roll, the surface of the first current collector facing the pole is directly electrically connected with the pole. The first active material layer is arranged on the surface of the first current collector away from the pole. The second single-sided pole piece comprises a second current collector and a second active material layer. The surface of the second current collector away from the pole is directly electrically connected with the bottom shell. The second active material layer is arranged on the surface of the second current collector facing the pole.

[0005] The button cell of the present application comprises a shell and a jelly-roll arranged in the shell. The first single-sided pole piece and the second single-sided pole piece located at the outermost side of the jelly-roll are directly electrically connected with the pole and the bottom shell respectively, so that the jelly-roll and the shell no longer need to use an adapter piece for switching. In the stacking direction of the jelly-roll, the jelly-roll and the shell do not need to reserve space for avoiding the adapter piece, so that the structural compactness of the button cell in the stacking direction of the jelly-roll can be improved. The above structural design can be beneficial to reduce the overall size of the button cell in the stacking direction of the jelly-roll, so as to reduce the overall volume of the button cell, thereby being beneficial to improve the energy density of the button cell.

[0006] In one or more optional embodiments above, the button cell comprises a first adhesive member, which adhesively connects the first current collector with the pole.

[0007] The first adhesive member can fix the position of the jelly-roll in the shell, so as to reduce the possibility that the jelly-roll shakes in the shell and causes the pole and the first current collector to be disconnected.

[0008] In one or more optional embodiments above, the pole post comprises a first wall surface and a first protrusion, the first wall surface is arranged to face the jelly-roll, the first protrusion protrudes from the first wall surface, the first protrusion abuts a surface of the first current collector facing the pole post, and a first spacing is provided between the first wall surface and the first current collector in the stacking direction of the jelly-roll.

[0009] By directly abutting the first protrusion against the first current collector, on one hand, it is beneficial to reduce the difficulty of electrical connection between the pole post and the first current collector, and on the other hand, it is beneficial to ensure that the pole post and the first current collector maintain a stable electrical connection state in the completed button cell, thereby reducing the possibility of poor contact such as virtual connection between the pole post and the first current collector.

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

[0011] In one or more optional embodiments above, a first adhesive member is arranged between the pole post and the first current collector, the first adhesive member has a first avoiding passage, and the first protrusion passes through the first avoiding passage and abuts the first current collector.

[0012] The first avoiding passage is used to avoid the first protrusion, thereby reducing the possibility that the first adhesive member located between the first protrusion and the first current collector affects the electrical connection state of the first protrusion and the first current collector. The shell of the button cell can be filled with electrolyte. The periphery of the first protrusion can be surrounded by the first adhesive member, so that the first adhesive member can block the electrolyte from infiltrating the connection region between the first protrusion and the first current collector, thereby reducing the possibility that the first protrusion and the first current collector are corroded in the connection region, causing the electrical connection state of the first protrusion and the first current collector to be unstable.

[0013] In one or more optional embodiments above, the pole post comprises a first wall surface and a first recess, the first wall surface is arranged to face the jelly-roll, the first recess is arranged on the first wall surface, the first recess comprises an opening on the first wall surface, a first adhesive member is arranged in the first recess, the first wall surface abuts a surface of the first current collector facing the pole post, and the first adhesive member bonds the first current collector and the pole post.

[0014] The first wall surface of the pole post directly contacts the surface of the first current collector facing the pole post. The spacing between the first wall surface and the first current collector is zero. The above structure design is beneficial to reduce the overall size of the button cell in the stacking direction of the jelly-roll, thereby reducing the overall volume of the button cell, and thus beneficial to improve the energy density of the button cell.

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

[0016] The first adhesive can be conductive glue. The first adhesive itself has the ability to conduct electricity, so the pole and the first current collector can also be electrically connected through the first adhesive.

[0017] The first adhesive can be pressure sensitive adhesive. The first adhesive can not need to be treated by heating, solvent activation or complex curing process, and only needs the pole and the first current collector to apply relatively small pressure to the first adhesive to achieve adhesion, thereby reducing the connection difficulty.

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

[0019] The first main body part is relatively large in area. The first main body part and the pole are connected by the first adhesive, which is conducive to reducing the connection difficulty between the first current collector and the pole, 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.

[0020] In one or more optional embodiments above, the first current collector includes a first tab, a first main body part and a first folding part connected to each other. The first tab, the first main body part and the first folding part are integrally formed. The first active material layer is arranged on the first main body part, and the first folding part is folded relative to the first main body part. The first folding part is located between the first main body part and the pole, and a surface of the first folding part facing the pole is directly electrically connected to the pole.

[0021] The first main body part is relatively large in area. The first main body part and the pole are connected by the first adhesive, which is conducive to reducing the connection difficulty between the first current collector and the pole, 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 tab, a first main body part and a first folding part connected to each other. The first tab, the first main body part and the first folding part are integrally formed. The first active material layer is arranged on the first main body part, and the first folding part is folded relative to the first main body part. The first folding part is located between the first main body part and the pole, and a surface of the first folding part facing the pole is directly electrically connected to the pole.

[0023] The first current collector is provided with the first folding part, which can realize the operation of first connecting and fixing the pole and the first current collector, and then covering the top cover, thereby facilitating the reduction of the connection difficulty between the pole and the first current collector, and improving the connection stability and connection efficiency between the pole and the first current collector.

[0024] In one or more optional embodiments above, the first folded portion is welded to the pole; or the button cell comprises a first adhesive, and the first adhesive adheres the first folded portion to the pole.

[0025] The first folded portion and the pole are connected by welding, which can improve the connection strength and stability between the first folded portion and the pole, and reduce the possibility of disconnection between the first folded portion and the pole during use of the button cell.

[0026] The first folded portion and the pole are connected by welding, which can improve the connection strength and stability between the first folded portion and the pole, and reduce the possibility of disconnection between the first folded portion and the pole during use of the button cell.

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

[0028] In the case of expansion of the laminated core, when the first main body portion contacts the first folded portion, the first folded portion can support the entire first main body portion and apply a counterforce to the entire first main body portion, which can help the entire first main body portion to bear force evenly, reduce the possibility of stress concentration area on the first main body portion due to uneven force, and cause the first active material layer to peel off and fall off from the first main body portion in the stress concentration area.

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

[0030] In the case of expansion of the laminated core, the pole and the first folded portion can simultaneously support the entire first main body portion and apply a counterforce to the entire first main body portion, which can help the entire first main body portion to bear force evenly, reduce the possibility of stress concentration area on the first main body portion due to uneven force, and cause the first active material layer to peel off and fall off from the first main body portion in the stress concentration area.

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

[0032] The second adhesive can fix the position of the laminated core in the shell, and reduce the possibility of disconnection between the bottom wall and the second current collector due to shaking of the laminated core in the shell.

[0033] In one or more optional embodiments above, the bottom wall has a second wall surface, the bottom shell includes a second protrusion, the second wall surface is arranged to face the jelly-roll, and the second protrusion is arranged to protrude from the second wall surface, the second protrusion is arranged to abut against a surface of the second current collector facing the bottom wall, and the second wall surface and the second current collector have a second spacing therebetween in the stacking direction of the jelly-roll.

[0034] In one or more optional embodiments above, the second protrusion is arranged to directly abut against the second current collector, which is conducive to reducing the difficulty of electrical connection between the bottom shell and the second current collector and ensuring stable electrical connection between the bottom shell and the second current collector in the assembled button cell.

[0035] In one or more optional embodiments above, 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 is arranged between the bottom wall and the second current collector, and the second adhesive has a second avoiding passage through which the second protrusion is arranged to abut against the second current collector.

[0037] The second protrusion can be surrounded by the second adhesive, so that the second adhesive can block the electrolyte from infiltrating a connection region between the second protrusion and the second current collector, thereby reducing the possibility of unstable electrical connection between the second protrusion and the second current collector due to corrosion of the second protrusion and the second current collector in the connection region.

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

[0039] The jelly-roll is electrically connected to the bottom shell through the second main body portion, which can be conducive to reducing the spacing between the jelly-roll and the bottom shell in the stacking direction of the jelly-roll, reducing the overall size of the button cell in the stacking direction of the jelly-roll, and reducing the overall volume of the button cell, thereby improving the energy density of the button cell. The second main body portion has a relatively large area, which is conducive to reducing the difficulty of 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, and the button cell includes a second adhesive arranged to bond the second main body portion to the bottom wall.

[0041] The second main body part has a relatively large area. The second main body part and the bottom wall are bonded by the second bonding member, which is conducive to reducing the connection difficulty between the second bonding member 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 tab, a second main body part, and a second folded part connected in series. The second tab, the second main body part, and the second folded part are integrally formed. The second active material layer is arranged on the second main body part, the second folded part is folded relative to the second main body part, the second folded part is located between the second main body part and the bottom shell, and the surface of the second folded part facing away from the pole is directly electrically connected with the bottom shell.

[0043] The second current collector is provided with the second folded part, which can realize the operation of first connecting and fixing the laminated battery cell with the bottom shell and then assembling the laminated battery cell into the bottom shell, thereby facilitating to reduce the connection difficulty between the laminated battery cell and the bottom shell and improve 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 part is welded with the bottom wall; or the button cell includes a second bonding member bonding the second folded part with the bottom wall.

[0045] The second folded part and the bottom wall are connected by welding, which is conducive to improving the connection strength and connection stability between the second folded part and the bottom wall and reducing the possibility of disconnection between the second folded part and the bottom wall during use of the button cell.

[0046] The second folded part and the bottom wall are connected by bonding, which is conducive to reducing the connection difficulty between the second folded part and the bottom wall and facilitating observation and detection of the bonding state between the second folded part and the bottom wall.

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

[0048] In the case of swelling of the laminated battery cell, when the second main body part contacts the second folded part, the second folded part can support and apply a reaction force to the entire second main body part, which is conducive to uniform stress of the entire second main body part and reduces the possibility of stress concentration area on the second main body part and the second active material layer peeling off and falling off from the second main body part.

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

[0050] In one or more optional embodiments above, the first single-sided tab includes a first lug, the first double-sided tab includes a third lug, the first lug and each of the third lugs are folded and welded in a stacking direction of the laminated cell to form a first folded portion, and the first folded portion has a one-piece structure.

[0051] The first folded portion has a one-piece structure. The folding of the first lug and the third lug in the stacking direction of the laminated cell can be towards the bottom wall or towards the top cover. The first folded portion having a one-piece structure means that the first lug and the third lug do not need to be folded towards the bottom wall and then folded towards the top cover, or folded towards the top cover and then folded towards the bottom wall. This is beneficial to reduce the space occupied by the first lug and the third lug, and to reduce the overall size of the button cell, thereby reducing the overall volume of the button cell and improving the energy density of the button cell.

[0052] In one or more optional embodiments above, the second single-sided tab includes a second lug, the second double-sided tab includes a fourth lug, the second lug and each of the fourth lugs are folded and welded in a stacking direction of the laminated cell to form a second folded portion, and the second folded portion has a one-piece structure.

[0053] The second folded portion has a one-piece structure. The folding of the second lug and the fourth lug in the stacking direction of the laminated cell can be towards the bottom wall or towards the top cover. The second folded portion having a one-piece structure means that the second lug and the fourth lug do not need to be folded towards the bottom wall and then folded towards the top cover, or folded towards the top cover and then folded towards the bottom wall. This is beneficial to reduce the space occupied by the second lug and the fourth lug, and to reduce the overall size of the button cell, thereby reducing the overall volume of the button cell and improving the energy density of the button cell.

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

[0055] In one or more optional embodiments above, the top cover is directly electrically connected to the bottom shell, the outer 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 separated by the insulating member.

[0056] The insulating member connects the pole and the top cover. The pole and the top cover are insulated and separated by the insulating member. The pole and the top cover are in a non-electrically connected state. BRIEF DESCRIPTION OF DRAWINGS

[0057] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The detailed description is merely meant to teach a person of ordinary skill a way to make and use the application. It is not meant to be limiting in any way. Still further, the same reference numerals are intended to denote the same components throughout the text. In the drawings:

[0058] Figure 1 is a structural schematic diagram of a button cell provided by an embodiment of the present application;

[0059] Figure 2 is a structural schematic diagram of a button cell provided by an embodiment of the present application;

[0060] Figure 3 is a partial sectional structural schematic diagram of a button cell provided by an embodiment of the present application;

[0061] Figure 4 is a partial sectional structural schematic diagram of a button cell provided by an embodiment of the present application;

[0062] Figure 5 is a partial structural schematic diagram of a laminated cell provided by an embodiment of the present application;

[0063] Figure 6 is a partial structural schematic diagram of a laminated cell provided by an embodiment of the present application;

[0064] Figure 7 is a partial structural schematic diagram of a laminated cell provided by an embodiment of the present application;

[0065] Figure 8 is a partial sectional structural schematic diagram of a button cell provided by an embodiment of the present application;

[0066] Figure 9 is a partial sectional structural schematic diagram of a button cell provided by an embodiment of the present application;

[0067] Figure 10 is a partial sectional structural schematic diagram of a button cell provided by an embodiment of the present application;

[0068] Figure 11 is a partial structural schematic diagram of a laminated cell provided by an embodiment of the present application;

[0069] Figure 12 is a structural variation schematic diagram of a laminated cell provided by an embodiment of the present application;

[0070] Figure 13is a schematic diagram of an assembling process of a button cell provided by an embodiment of the present application;

[0071] Figure 14 is a schematic diagram of a partial cross-sectional structure of a button cell provided by an embodiment of the present application;

[0072] Figure 15 is a schematic diagram of a partial cross-sectional structure of a button cell provided by an embodiment of the present application;

[0073] Figure 16 is a schematic diagram of a partial structure of a laminated cell provided by an embodiment of the present application;

[0074] Figure 17 is a schematic diagram of a partial cross-sectional structure of a button cell provided by an embodiment of the present application;

[0075] Figure 18 is Figure 17 is an enlarged schematic diagram of M in FIG. 1;

[0076] Figure 19 is Figure 17 is an enlarged schematic diagram of W in FIG. 1;

[0077] Figure 20 is a schematic diagram of a partial structure of a button cell provided by an embodiment of the present application.

[0078] Legend of Reference Signs:

[0079] 10, button cell; 20, shell; 201, first protrusion; 202, second protrusion; 21, bottom shell; 21a, second wall surface; 21b, second recess; 211, bottom wall; 22, pole post; 22a, first wall surface; 22b, first recess; 212, side wall; 221, base; 222, boss; 23, top cover; 231, center via hole; 24, insulating piece; 30, laminated cell; 31, first single-face pole piece; 311, first current collector; 3111, first tab; 3112, first main body part; 3113, first folding part; 312, first active material layer; 32, second single-face pole piece; 321, second current collector; 3211, second tab; 3212, second main body part; 3213, second folding part; 322, second active material layer; 33, first double-face pole piece; 331, third tab; 34, second double-face pole piece; 341, fourth tab; 35, separator; 40, first adhesive piece; 50, second adhesive piece; 60, first gathering part; 70, second gathering part; 80, insulating tape; 100, first avoiding passage; 110, second avoiding passage; X, stacking direction. DETAILED DESCRIPTION

[0080] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, but cannot limit the protection scope 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 be understood as the usual meaning understood by the skilled person in the field to which the embodiments of the present application belong.

[0082] In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0083] In addition, the technical terms "first", "second" and the like are only for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0084] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0085] In the related art, the button cell includes a shell and a cell. The cell is arranged in the shell. The cell includes a plurality of first tabs and a plurality of second tabs. The button cell includes a transition sheet. Each of the first tabs and the second tabs is welded with a corresponding transition sheet. Each of the first tabs and the second tabs is led out through the corresponding transition sheet. The additional transition sheet occupies the space in the shell, resulting in a decrease in the space utilization in the shell, thereby causing the button cell to have a relatively low energy density. The energy density refers to the ratio between the discharge energy of the button cell and the volume of the button cell.

[0086] The button cell of the embodiments of the present application can be beneficial to improve the compactness of the button cell and improve the energy density of the button cell.

[0087] Referring to Figures 1 to 7 As shown in the figure, the embodiment of the application provides a button cell 10, which comprises a shell 20 and a laminated cell 30. The shell 20 comprises a bottom shell 21, a pole 22 and a top cover 23. The top cover 23 is sealingly connected with the bottom shell 21. The pole 22 is connected with the top cover 23. The laminated cell 30 is arranged in the shell 20. Along the stacking direction X of the laminated cell 30, the laminated cell 30 comprises 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 and the second single-sided pole piece 32 are opposite in polarity. The first single-sided pole piece 31 comprises a first current collector 311 and a first active material layer 312. Along the stacking direction X of the laminated cell 30, the surface of the first current collector 311 facing the pole 22 is directly electrically connected with the pole 22. The first active material layer 312 is arranged on the surface of the first current collector 311 away from the pole 22. The second single-sided pole piece 32 comprises a second current collector 321 and a second active material layer 322. The surface of the second current collector 321 away from the pole 22 is directly electrically connected with the bottom shell 21. The second active material layer 322 is arranged on the surface of the second current collector 321 facing the pole 22.

[0088] In the embodiment of the application, referring to Figure 4 As shown in the figure, the shell 20 can form a protection for the laminated cell 30. The bottom shell 21 can comprise a containing space. The laminated cell 30 is arranged in the containing space. The stacking direction X of the laminated cell 30 can be the same as the depth direction of the containing space. In some realizable modes, along the stacking direction X of the laminated cell 30, the bottom wall 211 of the bottom shell 21 is correspondingly arranged with the top cover 23. The surface of the second current collector 321 away from the pole 22 is directly electrically connected with the bottom wall 211. In some realizable modes, the laminated cell 30 comprises a separator 35. The stacking direction X of the laminated cell 30 can refer to the direction in which the pole pieces and the separator 35 are stacked with each other.

[0089] In the embodiment of the application, referring to Figure 4 and Figure 7 As shown in the figure, the first single-sided pole piece 31 and the second single-sided pole piece 32 are oppositely arranged. The first single-sided pole piece 31 and the second single-sided pole piece 32 each comprise 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 with the pole 22 and the bottom shell 21 respectively, so that the pole 22 and the shell 20 can be respectively used as two electrodes of the button cell 10. 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 with the pole 22 through an additionally arranged adapter 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 with the bottom shell 21 through an additionally arranged adapter structure.

[0090] In this embodiment, the first single-sided electrode 31 refers to the first active material layer 312 being disposed on only one surface of the first current collector 311 facing away from the electrode post 22. The second single-sided electrode 32 refers to the second active material layer 322 being disposed on only one surface of the second current collector 321 facing the electrode post 22.

[0091] The button cell 10 of this embodiment includes a casing 20 and stacked cells 30 disposed within the casing 20. The outermost first single-sided electrode 31 and second single-sided electrode 32 of the stacked cells 30 are directly electrically connected to the terminal post 22 and the bottom shell 21, respectively, eliminating the need for an additional adapter plate between the stacked cells 30 and the casing 20. In the stacking direction X of the stacked cells 30, no space is required between the stacked cells 30 and the casing 20 to avoid the adapter plate, thereby improving the structural compactness of the button cell 10 in the stacking direction X. This structural design helps to reduce the overall size of the button cell 10 in the stacking direction X, thereby reducing the overall volume of the button cell 10 and thus improving its energy density.

[0092] In addition, in related technologies, button batteries include wound cells. Wound cells are cells formed by winding electrodes and separators with opposite polarities. Wound cells have a cylindrical structure, which has limited applicability. The button battery 10 of this application embodiment includes a stacked cell 30. The structural form of the stacked cell 30 is related to the shape of the electrodes and separator 35. According to the shape design requirements of the button battery 10, the electrodes and separator 35 can be relatively easily shaped so that the shape of the stacked cell 30 matches the shape of the casing 20. Therefore, the shape of the stacked cell 30 is not limited to a circle, but can also be other non-circular structures. This can help improve the applicability of the structural form of the stacked cell 30. In addition, the stacked cell 30 has a higher space utilization rate than the wound cell, and it is easier to manufacture the first single-sided electrode 31 or the second single-sided electrode 32 for direct electrical connection with the terminal post 22 or the bottom casing 21.

[0093] See also some of the possible implementation methods. Figure 4 and Figure 7 As shown, the button cell 10 includes a first adhesive member 40. The first adhesive member 40 bonds the first current collector 311 to the terminal post 22, which helps to reduce the difficulty of connecting the first current collector 311 and the terminal post 22. The first adhesive member 40 connects the terminal post 22 and the first current collector 311. The first adhesive member 40 can fix the position of the stacked cell 30 within the housing 20, reducing the possibility that the stacked cell 30 may shake within the housing 20, causing the terminal post 22 and the first current collector 311 to lose their electrical connection. Exemplarily, the first adhesive member 40 can be formed of an adhesive, for example, the first adhesive member 40 can be an adhesive glue.

[0094] Exemplarily, the first adhesive 40 can be an insulating adhesive. The first adhesive 40 itself does not have the electrically conductive capability. For example, the first adhesive 40 can be an adhesive glue with insulating performance.

[0095] Exemplarily, the first adhesive 40 can be a pressure sensitive adhesive. The first adhesive 40 can not need to be processed by heating, solvent activation or complex curing process, and only needs to apply a relatively small pressure on the first adhesive 40 by the pole 22 and the first current collector 311 to achieve adhesion, thereby reducing the connection difficulty.

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

[0097] In some implementable manners, referring to Figure 8 As shown, the pole 22 includes a first wall surface 22a and a first protrusion 201. The first wall surface 22a is arranged to face the laminated battery cell 30, and the first protrusion 201 protrudes from the first wall surface 22a. The first protrusion 201 abuts against a 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, the first wall surface 22a and the first current collector 311 have a first spacing L1. The abutting of the first protrusion 201 against the first current collector 311 means that the first protrusion 201 and the first current collector 311 are in direct contact and have a compressive stress therebetween. By directly abutting the first protrusion 201 against the first current collector 311, on the one hand, it is beneficial to reduce the connection difficulty of achieving electrical connection between the pole 22 and the first current collector 311, and on the other hand, it is beneficial to ensure that the pole 22 and the first current collector 311 maintain a stable electrical connection state in the completed button cell 10, thereby reducing the possibility of poor contact problems such as virtual connection between the pole 22 and the first current collector 311.

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

[0099] In some examples, referring to Figure 3 and Figure 4As shown, the top cover 23 and the bottom shell 21 can be directly electrically connected. The shell 20 comprises an insulating member 24. The insulating member 24 connects the pole post 22 and the top cover 23. The pole post 22 and the top cover 23 are insulated and isolated by the insulating member 24. The pole post 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. The insulating member 24 bonds the pole post 22 and the top cover 23 to fix the pole post 22 on the top cover 23.

[0100] In some examples, referring to Figure 4 and Figure 8 As shown, the top cover 23 comprises a center through hole 231. The pole post 22 comprises a base 221 and a boss 222. The base 221 is connected with the top cover 23. The boss 222 is correspondingly arranged with the center through hole 231. The 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 post 22 is directly electrically connected with the base 221. The base 221 can be provided with a first protrusion 201.

[0101] Exemplarily, referring to Figure 8 As shown, the first adhesive 40 is arranged between the pole post 22 and the first current collector 311. The first adhesive 40 has a first avoiding passage 100. The pole post 22 comprises the first protrusion 201. The first protrusion 201 passes through the first avoiding passage 100 and abuts against the first current collector 311. The first avoiding passage 100 is used for avoiding the first protrusion 201, reducing the possibility that the first adhesive 40 located between the first protrusion 201 and the first current collector 311 affects the electrically connected state of the first protrusion 201 and the first current collector 311. The shell 20 of the button cell 10 can be filled with electrolyte. The periphery of the first protrusion 201 can be surrounded by the first adhesive 40, so that the first adhesive 40 can block the electrolyte from infiltrating the connecting area between the first protrusion 201 and the first current collector 311, reducing the possibility that the first protrusion 201 and the first current collector 311 are corroded in the connecting area to cause the instability of the electrically connected state of the first protrusion 201 and the first current collector 311.

[0102] Exemplarily, the first protrusion 201 can be a shape with a narrower top than bottom, such as a conical shape, a semicircular shape, etc., which is more convenient for the first protrusion 201 to pass through the first adhesive 40.

[0103] In some implementable manners, referring to Figure 9 As shown, the pole post 22 comprises a first wall surface 22a and a first recess 22b. The first wall surface 22a is arranged facing the laminated cell 30. The first recess 22b comprises an opening on the first wall surface 22a. The first adhesive 40 is arranged in the first recess 22b. The first wall surface 22a abuts against the surface of the first current collector 311 facing the pole post 22. The first adhesive 40 bonds the first current collector 311 and the pole post 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 spacing between the first wall surface 22a and the first current collector 311 is zero. The above structure design is conducive to reducing the overall size of the button cell 10 in the stacking direction X of the jelly-roll 30, reducing the overall volume of the button cell 10, and thus improving the energy density of the button cell 10.

[0105] In some examples, the number of first recesses 22b can be multiple. The first adhesive 40 is arranged in each of the first recesses 22b.

[0106] In some implementable manners, referring to Figure 5 and Figure 7 The first current collector 311 includes a first tab 3111 and a first body portion 3112 connected to each other. The first tab 3111 and the first body portion 3112 are integrally formed. The first active material layer 312 is arranged on the first body portion 3112. The surface of the first body portion 3112 facing the pole 22 is not provided with the first active material layer 312. The surface of the first body portion 3112 facing the pole 22 is directly electrically connected to the pole 22. The first tab 3111 is not provided with the first active material layer 312. In the jelly-roll 30, the first single-sided pole piece 31 can be electrically connected to other pole pieces of the same polarity through the first tab 3111. The first single-sided pole piece 31 is located at the outermost side of the jelly-roll 30 as a whole.

[0107] The first body portion 3112 of the jelly-roll 30 is electrically connected to the pole 22, which can be conducive to reducing the spacing between the jelly-roll 30 and the pole 22 in the stacking direction X of the jelly-roll 30, reducing the overall size of the button cell 10 in the stacking direction X of the jelly-roll 30, reducing the overall volume of the button cell 10, and thus improving the energy density of the button cell 10. The first body portion 3112 has a relatively large area, which is conducive to reducing the connection difficulty between the first current collector 311 and the pole 22.

[0108] In some examples, referring to Figure 4 and Figure 7 The button cell 10 includes the first adhesive 40. The first adhesive 40 is arranged between the pole 22 and the first body portion 3112. The first adhesive 40 adheres the first body portion 3112 to the pole 22. The first body portion 3112 has a relatively large area. The first adhesive 40 is arranged between the first body portion 3112 and the pole 22, which is conducive to reducing the connection difficulty between the first adhesive 40 and the first current collector 311, 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 post 22 includes a first protrusion 201. The first protrusion 201 abuts the surface of the first body portion 3112 facing the pole post 22 to realize the electrical connection between the pole post 22 and the first current collector 311.

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

[0111] In some examples, the surface area of the pole post 22 facing the jelly-roll battery cell 30 is greater than or equal to the area of the first body portion 3112. The pole post 22 can cover the entire first body portion 3112. In the case of swelling of the jelly-roll battery cell 30, the pole post 22 can support the entire first body portion 3112 and apply a reaction force to the entire first body portion 3112, which can help the entire first body portion 3112 to bear force uniformly, reduce the possibility of stress concentration area on the first body portion 3112 due to uneven force, and cause the first active material layer 312 to peel off and fall off from the first body portion 3112 in the stress concentration area.

[0112] In some realizable ways, referring to Figure 10 , Figure 11 and Figure 12 , the first current collector 311 includes the first tab 3111, the first body portion 3112 and the first folded portion 3113 connected together. The first tab 3111, the first body portion 3112 and the first folded portion 3113 are integrally formed. The first active material layer 312 is arranged on the first body portion 3112. The first folded portion 3113 is folded relative to the first body portion 3112. The first folded portion 3113 is located between the first body portion 3112 and the pole post 22. The surface of the first folded portion 3113 facing the pole post 22 is directly electrically connected with the pole post 22.

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

[0114] Referring to Figure 13As shown, after the jelly-roll 30 is loaded into the bottom shell 21, the first folded portion 3113 located outside the bottom shell 21 is connected with 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 towards the first main body portion 3112. After the covering, the 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 portion 3112.

[0115] The first current collector 311 is provided in the manner of the first folded portion 3113, which can realize the operation of connecting and fixing the jelly-roll 30 with the pole 22 first and then covering the top cover 23, thereby facilitating to reduce the connection difficulty between the jelly-roll 30 and the pole 22 and improve the connection stability and efficiency between the jelly-roll 30 and the pole 22.

[0116] In the case that the first current collector 311 is directly electrically connected with the pole 22 through the first main body portion 3112, after the jelly-roll 30 is loaded into the shell, the top cover 23 with the pole 22 is covered on the bottom shell 21. In the case that the connection position of the top cover 23 and the bottom shell 21 is 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 electrically connected 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 portion 3112, resulting in that the pole 22 and the first main body portion 3112 are in a non-electrically connected state. In the case that the first current collector 311 is directly electrically connected with the pole 22 through the first main body portion 3112, the connection position precision requirement of the top cover 23 and the bottom shell 21 is relatively high.

[0117] The first current collector 311 is provided in the manner of the first folded portion 3113, the position of the first folded portion 3113 can be flexibly adjusted, and the first folded portion 3113 is connected with the pole 22 first and then the top cover 23 and the bottom shell 21 are connected, 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 problem and reduce the precision requirement 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 can be in contact with the surface of the first main body portion 3112 facing the pole 22, so as to reduce the space occupied by the jelly-roll 30 in the stacking direction X of the jelly-roll 30 and improve the structural compactness of the jelly-roll 30.

[0119] In some examples, the first fold portion 3113 is welded with the pole piece 22. The first current collector 311 can be connected with the pole piece 22 through the first fold portion 3113, so that the welding operation of the first fold portion 3113 and the pole piece 22 can be facilitated. The first fold portion 3113 located outside the bottom shell 21 can be fixed with the pole piece 22 in a relative position, and then the first fold portion 3113 and the pole piece 22 are welded on one side of the first fold portion 3113, so as to reduce the connection difficulty of the first fold portion 3113 and the pole piece 22. The first fold portion 3113 and the pole piece 22 are connected by welding, which is conducive to improving the connection strength and stability between the first fold portion 3113 and the pole piece 22, and reducing the possibility of disconnection between the first fold portion 3113 and the pole piece 22 during use of the button cell 10.

[0120] Exemplarily, the first fold portion 3113 and the pole piece 22 can be welded by using a laser welding process. The thickness of the pole piece 22 is greater than the thickness of the first fold portion 3113. The laser cannot melt and weld the first fold portion 3113 and the pole piece 22 from one side of the pole piece 22. The first current collector 311 can be connected with the pole piece 22 through the first fold portion 3113, so that the first fold portion 3113 and the pole piece 22 can be welded on one side of the first fold portion 3113 by using a laser, thereby reducing the connection difficulty of the first fold portion 3113 and the pole piece 22.

[0121] In some examples, the first fold portion 3113 is bonded with the pole piece 22. The first current collector 311 can be connected with the pole piece 22 through the first fold portion 3113, which is conducive to reducing the connection difficulty between the first fold portion 3113 and the pole piece 22, facilitating observation and detection of the bonding state of the first fold portion 3113 and the pole piece 22, and eliminating the problems of overwelding and virtual welding caused by welding, and eliminating the welding marks left by welding. In the case where the bonding state of the first fold portion 3113 and the pole piece 22 meets the requirements, the top cover 23 with the pole piece 22 is sealed and connected with the bottom shell 21.

[0122] Exemplarily, the first fold portion 3113 and the pole piece 22 can be bonded by using a first bonding member 40. Exemplarily, the first bonding member 40 can be formed by an adhesive, for example, the first bonding member 40 can be adhesive. Exemplarily, the first bonding member 40 can cover the surface of the first fold portion 3113 facing the pole piece 22.

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

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

[0125] In some examples, the first folded portion 3113 has an area greater than or equal to that of the first main body portion 3112. The first folded portion 3113 can cover the entire first main body portion 3112. In the case of swelling of the jelly-roll battery 30, when the first main body portion 3112 is in contact with the first folded portion 3113, the first folded portion 3113 can support the entire first main body portion 3112 and apply a reaction force to the entire first main body portion 3112, which can be conducive to uniform stress distribution of the entire first main body portion 3112, reducing the possibility of stress concentration in the first main body portion 3112 and causing the first active material layer 312 to peel off or fall off from the first main body portion 3112 in the stress concentration area.

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

[0127] Exemplarily, the surface area of the pole column 22 facing the jelly-roll battery 30 can be greater than or equal to the area of the first folded portion 3113. The pole column 22 can cover the entire first folded portion 3113. In the case of swelling of the jelly-roll battery 30, the pole column 22 and the first folded portion 3113 can simultaneously support the entire first main body portion 3112 and apply a reaction force to the entire first main body portion 3112, which can be conducive to uniform stress distribution of the entire first main body portion 3112, reducing the possibility of stress concentration in the first main body portion 3112 and causing the first active material layer 312 to peel off or fall off from the first main body portion 3112 in the stress concentration area.

[0128] In some implementable manners, the bottom shell 21 has a bottom wall 211. The button cell 10 includes a second adhesive 50. The second adhesive 50 adheres the second current collector 321 to the bottom wall 211, which is conducive to reducing the connection difficulty between the second current collector 321 and the bottom wall 211. The second adhesive 50 connects the bottom wall 211 and the second current collector 321. The position of the jelly-roll battery 30 in the shell 20 can be fixed by the second adhesive 50, reducing the possibility of the jelly-roll battery 30 shaking in the shell 20 and causing the bottom wall 211 and the second current collector 321 to be disconnected.

[0129] Exemplarily, the second adhesive 50 can be formed by an adhesive, for example, the second adhesive 50 can be adhesive glue.

[0130] Exemplarily, the second adhesive 50 can be an insulating adhesive. The second adhesive 50 itself does not have the electrically conductive capability. For example, the second adhesive 50 can be an adhesive glue with insulating performance.

[0131] Exemplarily, the second adhesive 50 can be a pressure sensitive adhesive. The second adhesive 50 can not need to be processed by heating, solvent activation or a complex curing process, and only needs to apply a relatively small pressure on the second adhesive 50 by the second current collector 321 and the bottom wall 211 to achieve adhesion, thereby reducing the connection difficulty.

[0132] Exemplarily, the second adhesive 50 can be an electrically conductive adhesive. The second adhesive 50 itself has the electrically conductive capability, so that the bottom shell 21 and the second current collector 321 can also be electrically connected through the second adhesive 50. For example, the second adhesive 50 can be an electrically conductive glue.

[0133] In some implementable manners, referring to Figure 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 faces the jelly-roll 30. The second protrusion 202 is protrudingly arranged on the second wall surface 21a. The second protrusion 202 abuts against a surface of the second current collector 321 facing the bottom wall 211 to achieve the electrical connection between the bottom shell 21 and the second current collector 321. Along the stacking direction X of the jelly-roll 30, the second wall surface 21a and the second current collector 321 have a second spacing L2. The abutting of the second protrusion 202 against the second current collector 321 means that the second protrusion 202 and the second current collector 321 are directly in contact and have a compressive stress therebetween. By directly abutting the second protrusion 202 against the second current collector 321, on the one hand, it is beneficial to reduce the connection difficulty of achieving the electrical connection between the bottom shell 21 and the second current collector 321, and on the other hand, it is beneficial to ensure that the bottom shell 21 and the second current collector 321 maintain a stable electrical connection state in the completed button cell 10, thereby reducing the possibility of poor contact problems such as virtual connection between the bottom shell 21 and the second current collector 321.

[0134] In some examples, the second spacing L2 has a value in a range greater than 0 micrometers (μm) and less than or equal to 50 micrometers.

[0135] Exemplarily, the second adhesive 50 is arranged between the bottom wall 211 and the second current collector 321. The second adhesive 50 has a second avoiding passage 110. The bottom wall 211 is provided with a second protrusion 202. The second protrusion 202 passes through the second avoiding passage 110 and abuts against the second current collector 321. The second avoiding passage 110 is used for avoiding the second protrusion 202, reducing the possibility that the second adhesive 50 is located between the second protrusion 202 and the second current collector 321 and affects the electrical connection state of the second protrusion 202 and the second current collector 321. The shell 20 of the button cell 10 can be filled with electrolyte. The periphery of the second protrusion 202 can be surrounded by the second adhesive 50, so that the second adhesive 50 can block the electrolyte from infiltrating the connection region between the second protrusion 202 and the second current collector 321, reducing the possibility that the second protrusion 202 and the second current collector 321 are corroded in the connection region and cause the electrical connection state of the second protrusion 202 and the second current collector 321 to be unstable.

[0136] Exemplarily, the second protrusion 202 can be a shape with a top smaller than a bottom, such as a conical shape, a semicircular shape, etc., which is more convenient for the second protrusion 202 to pass through the second adhesive 50.

[0137] In some implementable manners, referring to Figure 15 , the bottom wall 211 has a second wall surface 21a and a second recess 21b. The second wall surface 21a faces the laminated cell 30. The second recess 21b includes an opening on the second wall surface 21a. The 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 adhesively connects the second current collector 321 and the pole 22.

[0138] The second wall surface 21a directly contacts the surface of the second current collector 321 facing the bottom wall 211. The spacing between the second wall surface 21a and the second current collector 321 is zero. The above structure design is beneficial to reducing the overall size of the button cell 10 in the stacking direction X of the laminated cell 30, reducing the overall volume of the button cell 10, and thus being beneficial to improving the energy density of the button cell 10.

[0139] In some examples, the number of the second recesses 21b can be multiple. The second adhesive 50 is arranged in each of the second recesses 21b.

[0140] In some implementable manners, referring to Figure 6 and Figure 7 , the second current collector 321 includes a second tab 3211 and a second main body 3212 connected to each other. The second tab 3211 and the second main body 3212 are integrally formed. The second active material layer 322 is arranged on the second main body 3212. The surface of the second main body 3212 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 the bottom wall 211. The surface of the second main body 3212 facing the bottom wall 211 can be directly electrically connected to the bottom wall 211. The second active material layer 322 is not provided on the second tab 3211. In the laminated cell 30, the second single-sided electrode 32 can be electrically connected to other electrodes of the same polarity through the second tab 3211. The second single-sided electrode 32 is located on the outermost side of the entire laminated cell 30.

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

[0143] See in some examples Figure 4 and Figure 7 As shown, the button battery 10 includes a second adhesive member 50. The second adhesive member 50 is disposed between the bottom wall 211 and the second main body portion 3212. The second adhesive member 50 bonds the second main body portion 3212 to the bottom wall 211. The second main body portion 3212 itself has a relatively large area. The method of bonding the second main body portion 3212 and the bottom wall 211 using the second adhesive member 50 helps to reduce the connection difficulty between the second adhesive member 50 and the second current collector 321, and also helps to increase the connection area between the second current collector 321 and the bottom wall 211, thereby improving the connection stability between the second current collector 321 and the bottom wall 211.

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

[0146] See in some examples Figure 12 and Figure 16As shown, the second current collector 321 includes the second tab 3211, the second body portion 3212 and the second folding portion 3213 connected together. The second tab 3211, the second body portion 3212 and the second folding portion 3213 are integrally formed. The second active material layer 322 is disposed on the second body portion 3212. The second folding portion 3213 is folded relative to the second body portion 3212. The second folding portion 3213 is located between the second body portion 3212 and the bottom shell 21. The surface of the second folding portion 3213 facing away from the pole 22 is directly electrically connected to the bottom shell 21.

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

[0148] Before the jelly-roll 30 is assembled into the bottom shell 21, the second folding portion 3213 can be connected to the bottom shell 21, and then the other parts of the jelly-roll 30 are assembled into the bottom shell 21, and then the pole 22 and the top cover 23 are covered on the bottom shell 21. During the process of assembling the other parts of the jelly-roll 30 into the bottom shell 21, the second folding portion 3213 is folded relative to the second body portion 3212. After the jelly-roll 30 is assembled into the bottom shell 21, the second folding portion 3213 is located between the bottom shell 21 and the second body portion 3212.

[0149] The second current collector 321 is provided with the second folding portion 3213, which can realize the operation of first connecting the jelly-roll 30 to the bottom wall 211 and then assembling the jelly-roll 30 into the bottom shell 21, thereby facilitating to reduce the connection difficulty between the jelly-roll 30 and the bottom shell 21 and improve the connection stability and connection efficiency between the jelly-roll 30 and the bottom shell 21.

[0150] In some examples, the surface of the second folding portion 3213 facing away from the bottom wall 211 can be in contact with the surface of the second body portion 3212 facing the bottom wall 211, so as to reduce the space occupied by the jelly-roll 30 in the stacking direction X of the jelly-roll 30 and improve the structural compactness of the jelly-roll 30.

[0151] In some examples, the bottom shell 21 has a bottom wall 211. The second fold portion 3213 is welded with the bottom wall 211. The second current collector 321 is connected with the bottom wall 211 through the second fold portion 3213, so that the welding operation of the second fold portion 3213 and the bottom wall 211 can be facilitated. The second fold portion 3213 located in the bottom shell 21 is first fixed with the bottom wall 211 in a relative position, and then the second fold portion 3213 and the bottom wall 211 are welded on one side of the second fold portion 3213, so as to reduce the connection difficulty of the second fold portion 3213 and the bottom wall 211. The second fold portion 3213 and the bottom wall 211 are connected by welding, which is conducive to improving the connection strength and stability between the second fold portion 3213 and the bottom wall 211, and reducing the possibility of disconnection between the second fold portion 3213 and the bottom wall 211 during use of the button cell 10.

[0152] Exemplarily, the second fold portion 3213 and the bottom wall 211 can be welded by using a laser welding process. The thickness of the bottom shell 21 is greater than the thickness of the second fold portion 3213. Laser cannot be used to melt and weld the second fold portion 3213 and the bottom wall 211 from the outside of the bottom shell 21. The second current collector 321 is connected with the bottom wall 211 through the second fold portion 3213, so that laser can be used to weld the second fold portion 3213 and the bottom wall 211 on one side of the second fold portion 3213, thereby reducing the connection difficulty of the second fold portion 3213 and the bottom wall 211.

[0153] In some examples, the second fold portion 3213 is bonded with the bottom wall 211. The second current collector 321 is bonded with the bottom wall 211 through the second fold portion 3213, which is conducive to reducing the connection difficulty between the second fold portion 3213 and the bottom wall 211, facilitating observation and detection of the bonding state of the second fold portion 3213 and the bottom wall 211, and eliminating the problems of overwelding and virtual welding caused by welding, as well as the welding marks left by welding. In the case that the bonding state of the second fold portion 3213 and the bottom wall 211 meets the requirements, other parts of the stacked cell 30 are then loaded into the bottom shell 21, and then the top cover 23 is covered on the bottom shell 21 and the connection operation of the top cover 23 and the bottom shell 21 is performed.

[0154] Exemplarily, the second fold portion 3213 and the bottom wall 211 can be bonded by using a second bonding member 50. Exemplarily, the second bonding member 50 can be formed by an adhesive, for example, the second bonding member 50 can be adhesive. Exemplarily, the second bonding member 50 can cover the surface of the second fold 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 the surface of the second fold portion 3213 facing the bottom wall 211 to realize the 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 21a. The second wall surface 21a abuts 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 portion 3212. The second folded portion 3213 can cover the entire second main body portion 3212. In the case of swelling of the stacked electrode cell 30, when the second main body portion 3212 is in contact with the second folded portion 3213, the second folded portion 3213 can provide support to the second main body portion 3212 and apply a reaction force to the entire second main body portion 3212, which can be beneficial to uniform stress distribution of the second main body portion 3212, reducing the possibility of stress concentration area on the second main body portion 3212 and causing the second active material layer 322 to peel off and fall off from the second main body portion 3212.

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

[0159] In some realizable ways, referring to Figure 7 , Figure 17 and Figure 18 , the stacked electrode cell 30 includes first double-sided tabs 33 and second double-sided tabs 34. The first double-sided tabs 33 and the second double-sided tabs 34 are alternately stacked between the first single-sided tabs 31 and the second single-sided tabs 32. The first single-sided tabs 31 and the first double-sided tabs 33 have the same polarity. The first single-sided tabs 31 and each first double-sided tab 33 are electrically connected. The second single-sided tabs 32 and the second double-sided tabs 34 have the same polarity. The second single-sided tabs 32 and each second double-sided tab 34 are electrically connected.

[0160] In the embodiments of the present application, the first double-sided tab 33 refers to that the active material layer is arranged on both surfaces opposite to the current collector. The second double-sided tab 34 refers to that the active material layer is arranged on both surfaces opposite to the current collector.

[0161] The first single-sided tabs 31, the second double-sided tabs 34, the first double-sided tabs 33, and the second single-sided tabs 32 are stacked along the stacking direction X. The tab adjacent to the first single-sided tab 31 is the second double-sided tab 34. A separator 35 can be arranged between the first single-sided tab 31 and the second double-sided tab 34. The tab adjacent to the second single-sided tab 32 is the first double-sided tab 33. A separator 35 can be arranged between the second single-sided tab 32 and the first double-sided tab 33. A separator 35 can be arranged between the first double-sided tab 33 and the second double-sided tab 34.

[0162] See in some examples Figure 2 , Figure 3 and Figure 4 As shown, the first tab 3111 and the third tab 331 converge towards the bottom wall 211 and then fold back towards the top cover 23, forming a two-section structure. Welded sections are formed on the folded areas of the first tab 3111 and the third tab 331 towards the top cover 23. This structural design results in the first tab 3111 and the third tab 331 occupying a relatively large space.

[0163] See Figure 7 , Figure 17 and Figure 19 As shown, the first single-sided electrode 31 includes a first tab 3111. The first double-sided electrode 33 includes a third tab 331. The first tab 3111 and each of the third tabs 331 are brought together along the stacking direction X of the stacked cells 30. They can be brought together towards the bottom wall 211 of the bottom shell 21 or towards the top cover 23 and welded together to form a first gathered portion 60. The first gathered portion 60 is a one-piece structure. That is, the first tab 3111 and the third tab 331 are brought together and welded towards the bottom wall 211 or the top cover 23. The first tab 3111 and the third tab 331 do not need to be brought together towards the bottom wall 211 or the top cover 23 and then folded in the opposite direction. This helps to reduce the space occupied by the first tab 3111 and the third tab 331, and helps to reduce the overall size of the button cell 10, thereby reducing the overall volume of the button cell 10 and thus helping to improve the energy density of the button cell 10. The first tab 3111 and the third tab 331, when folded together and then folded over once, can be called a two-segment structure. Folding them over once more creates a three-segment structure.

[0164] The bottom shell 21 includes a side wall 212. The bottom wall 211 is connected to the side wall 212 to form a connection. A first folding portion 60 is located near the connection between the bottom wall 211 and the side wall 212.

[0165] See in some examples Figure 18 , Figure 20 and ​As shown, the second tab 3211 and the fourth tab 341 are folded towards the bottom wall 211 and then reversely folded towards the top cover 23 to form a two-segment structure. The welding part is welded on the region of the second tab 3211 and the fourth tab 341 folded towards the top cover 23. The second tab 3211 and the fourth tab 341 adopt the structure design, so that the second tab 3211 and the fourth tab 341 occupy relatively large space. In the application, the uppermost single-sided tab is connected with the pole 22 and the lowermost single-sided tab is connected with the bottom shell 21, so that the adapter is not needed. In the prior art, the folded welding part needs to be connected with the adapter again, so the size of the welding part needs to be increased, while in the application, the folded welding part can be directly cut, so that the welding part can be close to the bottom wall 211 or the top cover 23, without being folded again, which greatly improves the space occupancy rate of the battery cell.

[0166] As shown in ​ 、 ​ and ​ , the second single-sided tab 32 includes a second tab 3211. The second double-sided tab 34 includes a fourth tab 341. The second tab 3211 and each fourth tab 341 can be folded towards the bottom wall 211 and welded, or folded towards the top cover 23 and welded to form a second folded part 70. The second folded part 70 is a one-segment structure. The second tab 3211 and the fourth tab 341 are folded towards the top cover 23 or the bottom wall 211 and welded, and the second tab 3211 and the fourth tab 341 do not need to be folded towards the bottom wall 211 or the top cover 23 and then reversely folded towards the other direction, thereby facilitating the reduction of the space occupied by the second tab 3211 and the fourth tab 341, and facilitating the reduction of the overall size of the button cell 10, so as to reduce the overall volume of the button cell 10, thereby facilitating the improvement of the energy density of the button cell 10. The second tab 3211 and the fourth tab 341 are folded once after being folded can be referred to as a two-segment structure, and folded once again on this basis is a three-segment structure.

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

[0168] In some implementable manners, the first single-sided tab 31 is a cathode tab. The material of the pole 22 can include aluminum or aluminum alloy. The second single-sided tab 32 is an anode tab. The material of the bottom shell 21 can include stainless steel. The material of the top cover 23 can include stainless steel. The outer edge of the top cover 23 and the top end of the bottom shell 21 are welded and sealed. As shown in ​ or ​As shown, after the first tab 3111 and each third tab 331 are crimped and welded, an insulating tape 80 can be pasted on the outside of the first tab 3111 and the third tab 331. The insulating tape 80 can insulate and separate the first tab 3111 and the third tab 331 from the bottom shell 21, respectively, to reduce the possibility of electrical connection between the first tab 3111 and the third 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, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; 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 be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A coin cell battery characterized by, The button cell comprises a shell, a laminated cell and a first adhesive. The shell comprises a bottom shell, a pole and a top cover, the top cover is in sealing connection with the bottom shell, the pole is connected with the top cover, the bottom shell and the pole lead out different polarities; The laminated cell is arranged in the shell, and along the stacking direction of the laminated cell, the laminated cell comprises first and second single-face poles located at the outermost sides, the first and second single-face poles are opposite in polarity, the first single-face pole comprises a first current collector and a first active material layer, along the stacking direction of the laminated cell, the surface of the first current collector facing the pole is directly electrically connected with the pole, and the first active material layer is arranged on the surface of the first current collector away from the pole; the second single-face pole comprises a second current collector and a second active material layer, and the surface of the second current collector away from the pole is directly electrically connected with the bottom shell, and the second active material layer is arranged on the surface of the second current collector facing the pole; The button cell comprises a first adhesive, and the first adhesive bonds the first current collector and the pole; The pole comprises a first wall surface and a first protrusion, the first wall surface is arranged to face the laminated cell, the first protrusion protrudes from the first wall surface, and the first protrusion abuts against the surface of the first current collector facing the pole, The first adhesive has a first avoiding channel, the first protrusion passes through the first avoiding channel and abuts against the first current collector.

2. The button cell of claim 1, wherein, Along the stacking direction of the laminated cell, the first wall surface and the first current collector have a first spacing.

3. The button cell of claim 2, wherein, The first spacing ranges from greater than 0 microns to less than or equal to 50 microns.

4. The button cell of claim 2, wherein, The first adhesive is arranged between the pole and the first current collector.

5. The button cell of claim 1, wherein, The first adhesive is conductive glue and / or pressure-sensitive glue.

6. The button cell of claim 1, wherein, The first current collector comprises a first tab and a first main body portion connected with each other, the first tab and the first main body portion are integrally formed, the first active material layer is arranged on the first main body portion, and the surface of the first main body portion facing the pole is directly electrically connected with the pole.

7. The button cell of claim 6, wherein, The first adhesive bonds the pole and the first main body portion.

8. The button cell of claim 1, wherein, The first current collector comprises a first tab, a first main body portion and a first folded portion connected with each other, the first tab, the first main body portion and the first folded portion are integrally formed, the first active material layer is arranged on the first main body portion, the first folded portion is folded relative to the first main body portion, the first folded portion is located between the first main body portion and the pole, and the surface of the first folded portion facing the pole is directly electrically connected with the pole.

9. The button cell of claim 8, wherein, The first adhesive bonds the first folded portion and the pole.

10. The button cell battery of claim 8, wherein, The area of the first folded portion is greater than or equal to the area of the first main body portion.

11. The button cell battery of claim 6 or 10, wherein, The surface area of the pole facing the laminated cell is greater than or equal to the area of the first main body portion.

12. The button cell battery of any one of claims 1 to 10, wherein, The bottom shell has a bottom wall, and the button cell comprises a second adhesive, and the second adhesive bonds the second current collector and the bottom wall.

13. The button cell battery of claim 12, wherein, The bottom wall has a second wall surface, the bottom shell comprises a second protrusion, the second wall surface is arranged to face the jelly-roll, and the second protrusion is arranged to protrude from the second wall surface. The second protrusion is in abutment with a surface of the second current collector facing the bottom wall. A second spacing is provided between the second wall surface and the second current collector in the stacking direction of the jelly-roll.

14. The button cell battery of claim 13, wherein, The second spacing is greater than 0 micrometers and less than or equal to 50 micrometers.

15. The button cell battery of claim 13, wherein, The second adhesive is arranged between the bottom wall and the second current collector. The second adhesive has a second avoiding passage. The second protrusion passes through the second avoiding passage and is in abutment with the second current collector.

16. The button cell of claim 12, wherein, The bottom wall has a second wall surface and a second recess. The second wall surface is arranged to face the jelly-roll. The second recess comprises an opening in the second wall surface. The second adhesive is arranged in the second recess. The second wall surface is in abutment with a surface of the second current collector facing the bottom wall. The second adhesive bonds the second current collector and the pole.

17. The button cell of claim 16, wherein, The second adhesive is conductive glue or pressure-sensitive adhesive.

18. The button cell battery of any one of claims 1 to 10, wherein, The second current collector comprises a second tab and a second main body. The second tab and the second main body are integrally formed. The second active material layer is arranged on the second main body. A surface of the second main body facing away from the pole is directly electrically connected to the bottom shell.

19. The button cell battery of claim 18, wherein, The bottom shell has a bottom wall. The button cell comprises a second adhesive. The second adhesive bonds the second main body and the bottom wall.

20. The button cell battery of any one of claims 1 to 10, wherein, The second current collector comprises a second tab, a second main body and a second folded portion. The second tab, 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. A surface of the second folded portion facing away from the pole is directly electrically connected to the bottom shell.

21. The button cell of claim 20, wherein, The bottom shell has a bottom wall. The second folded portion is welded to the bottom wall. Alternatively, the button cell comprises a second adhesive. The second adhesive bonds the second folded portion and the bottom wall.

22. The button cell of claim 20, wherein, An area of the second folded portion is greater than or equal to an area of the second main body.

23. The button cell battery of any one of claims 1 to 10, wherein, The jelly-roll comprises a first double-sided tab and a second double-sided tab. The first single-sided tab and the second single-sided tab are arranged with the first double-sided tab and the second double-sided tab alternately stacked therebetween. The first single-sided tab and the first double-sided tab have the same polarity. The first single-sided tab and each of the first double-sided tabs are electrically connected. The second single-sided tab and the second double-sided tab have the same polarity. The second single-sided tab and each of the second double-sided tabs are electrically connected.

24. The button cell of claim 23, wherein, The first single-sided tab comprises a first tab. The first double-sided tab comprises a third tab. The first tab and each of the third tabs are gathered and welded to form a first gathered portion in the stacking direction of the jelly-roll. The first gathered portion has a one-segment structure.

25. The button cell of claim 23, wherein, The second single-face pole piece comprises a second tab, the second double-face pole piece comprises a fourth tab, the second tab and each fourth tab are gathered and welded along a stacking direction of the jelly-roll to form a second gathered portion, and the second gathered portion has a one-segment structure.

26. The button cell battery of any one of claims 1 to 10, wherein, The first single-face pole piece is a cathode pole piece, and the second single-face pole piece is an anode pole piece.

27. The button cell battery of any one of claims 1 to 10, wherein, The top cover is directly electrically connected with the bottom shell, the shell comprises an insulating member, the insulating member connects the pole and the top cover, and the pole and the top cover are insulated and separated by the insulating member.

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