Battery

Abstract

The invention provides a battery, relates to the technical field of batteries, and is used for solving the problem that the energy density of a battery in the related technology is relatively low. The battery comprises a shell, and a stacked core, a first connecting piece and a second connecting piece which are arranged in the shell; the laminated core comprises a positive plate, a negative plate and a diaphragm which are arranged in a laminated manner, a first tab extends out of one side of a positive current collector in the positive plate, a second tab extends out of one side of a negative current collector in the negative plate, a negative active layer positioned on the negative current collector comprises a silicon-carbon composite material, and the mass ratio of silicon element is 5-50%; the problem of pole piece breakage caused by expansion of the negative pole piece is avoided while the energy density of the battery is improved; the first connecting piece and the second connecting piece are horizontally arranged on the same side of the laminated core, and the first bending part of the first connecting piece and the second bending part of the second connecting piece are respectively used for connecting the bending parts of the first tab and the second tab, so that the space occupied by the structure for leading out the positive electrode and the negative electrode of the laminated core is reduced, and the energy density is further improved.

Description

Technical Field

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

[0002] The battery of the related technology includes a shell and a battery cell arranged in the shell. The positive electrode ear of the battery cell is electrically connected to the pole through a conductive member to lead the positive electrode of the battery cell through the pole; the negative electrode ear of the battery cell is welded to the shell to make the shell negatively charged.

[0003] In the development of existing battery technology, how to improve the energy density of batteries is one of the research directions in battery technology. Summary of the Invention

[0004] In view of the above problems, an embodiment of the present application provides a battery to solve the problem of low energy density of batteries in the related art.

[0005] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions:

[0006] The embodiment of the present application provides a battery, which includes: a shell and a stacked core, a first connector and a second connector arranged in the shell; the stacked core includes a positive electrode sheet, a negative electrode sheet and a separator arranged in a stacked manner; the positive electrode sheet includes a positive electrode collector and a first electrode tab extending from one side of the positive electrode collector, the negative electrode sheet includes a negative electrode collector, a second electrode tab extending from one side of the negative electrode collector and a negative electrode active layer located on the negative electrode collector, the negative electrode active layer includes a silicon-carbon composite material, and the mass proportion of silicon element in the negative electrode active layer is 5-50%; the first electrode tab includes a first electrode tab bending portion, and the second electrode tab includes a second electrode tab Bending portion, the first connecting member has a first bending portion, the second connecting member has a second bending portion, the first bending portion and the second bending portion extend from between the first surface of the stacked core and the first inner wall surface of the shell respectively, the first pole ear bending portion is connected to the first bending portion, and the second pole ear bending portion is connected to the second bending portion; the battery also includes a sealant arranged between the first connecting member and the first inner wall surface; in the thickness direction of the stacked core, the projection of the first connecting member is located within the projection of the sealant, and a spacing is formed between the second connecting member and the sealant, and the spacing is 0.05-0.3mm.

[0007] In one embodiment of the present application, the first tab bend portion and / or the second tab bend portion are parallel to the thickness direction of the stacked core; and / or, along the thickness direction of the stacked core, the first surface of the stacked core and the first inner wall surface of the shell are opposite, and the first connecting member and / or the second connecting member are arranged between the first surface and the first inner wall surface.

[0008] In one embodiment of the present application, the battery further includes: an insulating pad; the insulating pad is arranged between the first connecting member and the first surface; in the thickness direction of the stacked core, the projection of the first connecting member and / or the projection of the second connecting member at least partially overlap with the projection of the insulating pad, and / or the diaphragm on opposite sides of the positive electrode sheet includes a protruding portion that protrudes beyond the positive electrode sheet, and the protruding portions on opposite sides of the positive electrode sheet are bonded.

[0009] In one embodiment of the present application, a pole protrusion is provided on the surface of the first connecting member close to the first inner wall surface, and a first through hole is provided on the first inner wall surface, and the pole protrusion passes through the shell from the first through hole; the pole protrusion is spaced a first distance from the hole wall of the first through hole, and the first distance is less than 0.15 mm.

[0010] In one embodiment of the present application, in the thickness direction of the stacked core, the projection of the first connecting member and the projection of the second connecting member do not overlap and are separated by a second distance, and the second distance is less than 0.15 mm.

[0011] In one embodiment of the present application, in the direction from the first connecting member to the second connecting member, the projection of the sealant between the first connecting member and the second connecting member in the thickness direction of the stacked core has a first width, and the first width is ≥0.5 mm, and / or the sealant has a first thickness h1, and the second connecting member has a second thickness h2, and the relationship between the first thickness h1 and the second thickness h2 is: h1<1 / 2h2.

[0012] In one embodiment of the present application, in the thickness direction of the stacked core, the angle formed between the projection of the center line of the first pole tab and the projection of the center line of the second pole tab is 90-180°, and / or the shell includes a bottom shell and a shell cover, the bottom shell has an opening, the shell cover is sealed to the opening to form a sealed cavity in the shell, the stacked core is arranged in the sealed cavity, and the edge of the shell cover extends radially outwardly with a positioning protrusion; and along the radial direction of the shell cover, the width of the positioning protrusion is less than 2 mm.

[0013] In one embodiment of the present application, the battery further includes: an insulating sleeve; the insulating sleeve is arranged in the shell, the insulating sleeve is sleeved on the outer periphery of the stacked core, and the first connector and the second connector are both located in the insulating sleeve; the insulating sleeve is provided with a plurality of second through holes arranged in an array.

[0014] In one embodiment of the present application, the shell includes a bottom shell and a shell cover, the bottom shell includes a circular bottom plate and side walls surrounding the circular bottom plate, the side walls have an opening, and the shell cover is sealed to the opening to form a sealed cavity in the shell, and the stacked core is arranged in the sealed cavity; the side wall includes a first cross-section and / or a second cross-section, the projection of the first cross-section on the side wall of the pole piece assembly and the projection of the first pole ear bend on the side wall of the pole piece assembly at least partially overlap, and / or the projection of the second cross-section on the side wall of the pole piece assembly and the projection of the second pole ear bend on the side wall of the pole piece assembly at least partially overlap.

[0015] In one embodiment of the present application, the first connecting member includes a corner portion connected to the first bending portion, the sealant includes an extension portion corresponding to the corner portion, and the edge of the extension portion extends beyond the corner portion and away from the edge of the first connecting member.

[0016] The battery provided in the embodiments of the present application has the following technical effects:

[0017] The positive and negative electrodes of the stacked core are respectively led out through the first connecting member and the second connecting member, wherein the first connecting member and the second connecting member are both horizontally arranged on the same side of the stacked core, and the first bending portion of the first connecting member and the second bending portion of the second connecting member are respectively used to connect the first tab bending portion and the second tab bending portion obtained by bending the two tabs of the stacked core, and the first bending portion and the second bending portion are also arranged roughly parallel to the side wall of the stacked core, reducing the space occupied by the structure for leading out the positive and negative electrodes of the stacked core, thereby further improving the energy density.

[0018] In addition, by adding silicon-carbon composite materials to the negative electrode active layer, the overall energy density of the battery can be further improved; at the same time, by arranging the entire battery cell into a stacked core, the expansion force of the negative electrode sheet including the silicon-carbon composite material will not be constrained by the stress caused by the bending or curling of the electrode sheet, so that the expansion force is fully released, thereby avoiding the risk of electrode breakage.

[0019] Furthermore, by providing a gap between the second connector and the sealant, contact between the first connector and the second connector is prevented. Moreover, a spacing of 0.05-0.3 mm is formed between the second connector and the sealant, thereby preventing the negative electrode sheet doped with silicon-carbon composite material from expanding during the charge and discharge process, thereby preventing the first connector and the second connector from moving towards each other due to the traction force of the positive and negative ears and then contacting to cause a short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 A schematic diagram of the three-dimensional structure of a battery provided in an embodiment of the present application;

[0022] Figure 2 Schematic diagram of the explosion structure of the battery provided in the embodiment of this application Figure 1 ;

[0023] Figure 3 Schematic diagram of the explosion structure of the battery provided in the embodiment of this application Figure 2 ;

[0024] Figure 4 A cross-sectional view of a battery provided in an embodiment of the present application along its axial direction;

[0025] Figure 5 The cross section of the battery provided in the embodiment of the present application in its radial direction Figure 1 ;

[0026] Figure 6 The cross section of the battery provided in the embodiment of the present application in its radial direction Figure 2 ;

[0027] Figure 7 Schematic diagram of the projection of the stacked core of the battery provided in the embodiment of the present application in its axial direction Figure 1 ;

[0028] Figure 8 Schematic diagram of the projection of the stacked core of the battery provided in the embodiment of the present application in its axial direction Figure 2 .

[0029] Reference numerals:

[0030] 100-housing;

[0031] 101- bottom shell; 102- shell cover;

[0032] 1011 - circular bottom plate; 1012 - side wall; 1013 - first section; 1014 - second section; 1021 - first through hole; 1022 - liquid injection hole; 1023 - positioning protrusion;

[0033] 200-stacked core;

[0034] 201-positive electrode sheet; 202-negative electrode sheet; 203-diaphragm; 2011-first tab bend; 2021-second tab bend;

[0035] 300-first connecting member;

[0036] 301-first bending portion; 302-pole protrusion;

[0037] 400-sealant;

[0038] 401-third through hole;

[0039] 500-insulation pad;

[0040] 600- second connecting piece;

[0041] 601- second bending portion;

[0042] 700-insulating sleeve;

[0043] 701-second through hole; 702-third section; 703-fourth section;

[0044] 800-Sealing cap. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0046] In the embodiment of the present application, the thickness direction of the pole piece and the thickness direction of the stacked core are both the z-axis shown in the figure; the radial direction of the pole piece and the radial direction of the stacked core are both the x-axis and y-axis shown in the figure.

[0047] refer to Figures 1-4 The battery provided in the embodiment of the present application includes: a shell 100 and a stacked core 200, a first connector 300 and a second connector 600 arranged in the shell 100.

[0048] The stacked core 200 includes a plurality of stacked positive electrode sheets 201 , negative electrode sheets 202 and separators 203 , with separators 203 disposed between adjacent positive electrode sheets 201 and negative electrode sheets 202 .

[0049] The positive electrode sheet 201 includes a positive electrode current collector and a first electrode tab extending from one side of the positive electrode current collector, and the negative electrode sheet 202 includes a negative electrode current collector and a second electrode tab extending from one side of the negative electrode current collector.

[0050] Each positive electrode current collector has a radial direction ( Figure 4The tabs extending outwards along the x-axis shown in FIG) are fitted together to form a first tab; the first tab is bent to obtain a first tab bent portion 2011, and the first tab bent portion 2011 is aligned with the thickness direction (x-axis) of the stacked core 200. Figure 4 parallel to the z-axis shown in ).

[0051] Similarly, each negative electrode current collector has a radial direction ( Figure 4 The tabs extending outwards along the x-axis shown in FIG) are fitted together to form a second tab; the second tab is bent to obtain a second tab bent portion 2021, which is aligned with the thickness direction (x-axis) of the stacked core 200. Figure 4 parallel to the z-axis shown in ).

[0052] The first tab bend portion 2011 and the second tab bend portion 2021 are both aligned with the thickness direction of the stacked core 200 ( Figure 4 The z-axis shown in FIG is parallel to the first tab bend portion 2011 and the second tab bend portion 2021, which can reduce the space occupied by the first tab bend portion 2011 and the second tab bend portion 2021 as much as possible, thereby improving the energy density.

[0053] Along the thickness direction of the stacked core 200 ( Figure 4 (z-axis shown in FIG), the stacked core 200 has opposing first and second surfaces, and the housing 100 has opposing first and second inner wall surfaces, with the first surface adjacent to the first inner wall surface and the second surface adjacent to the second inner wall surface. The first surface and the first inner wall surface are opposed to each other and spaced apart. The first connector 300 and the second connector 600 are both disposed between the first surface and the first inner wall surface, and are parallel to the positive electrode sheet 201 (or the negative electrode sheet 202). In other words, the first connector 300 and the second connector 600 are both disposed horizontally on the same side of the stacked core 200.

[0054] The first connecting member 300 further includes a first bending portion 301, and the second connecting member 600 includes a second bending portion 601. The first bending portion 301 and the second bending portion 601 extend from between the first surface and the first inner wall surface, respectively, and are both bent toward the second surface. The first bending portion 301 and the second bending portion 601 are aligned with the thickness direction of the stacked core 200 ( Figure 4 parallel to the z-axis shown in ).

[0055] The first bend portion 301 is connected to the first tab bend portion 2011 , and the second bend portion 601 is connected to the second tab bend portion 2021 . In other words, the positive electrode and the negative electrode of the stacked core 200 are led out through the first connector 300 and the second connector 600 , respectively.

[0056] The first electrode tab formed by laminating the electrode tabs of multiple positive electrode sheets 201 to each other is connected to the first bending portion 301 of the first connecting member 300, which can improve the connection stability between the electrode tab of each positive electrode sheet 201 and the first bending portion 301; similarly, the second electrode tab formed by laminating the electrode tabs of multiple negative electrode sheets 202 to each other is connected to the second bending portion 601 of the second connecting member 600, which can improve the connection stability between the electrode tab of each negative electrode sheet 202 and the second bending portion 601.

[0057] At the same time, the first bending portion 301 and the second bending portion 601 are also aligned with the thickness direction of the stacked core 200 ( Figure 4 The first tab bend portion 2011 and the second tab bend portion 2021 are respectively led out through the first bend portion 301 and the second bend portion 601, and the first connector 300 and the second connector 600 for connecting the first bend portion 301 and the second bend portion 601 are horizontally arranged on the same side of the stacked core 200, which can minimize the space occupied by the structure for leading out the first tab bend portion 2011 and the second tab bend portion 2021, thereby further improving the energy density.

[0058] It should be noted that the first tab is led out of the housing 100 through the first connector 300 , and the first connector 300 is positively charged, and the second tab is led to the housing 100 through the second connector 600 , so that the housing 100 is negatively charged.

[0059] Since the stacked core 200 is arranged in the shell 100 and the negative electrode ear is directly welded to the inner wall of the shell 100, welding is difficult; therefore, the present application uses the second connecting piece 600 to lead the negative electrode of the stacked core 200 to the shell 100, making the manufacturing process simpler.

[0060] In the embodiment of the present application, the negative electrode sheet 202 further includes a negative electrode active layer located on the negative electrode current collector. The negative electrode active layer includes a silicon-carbon composite material. The mass proportion of silicon in the negative electrode active layer is 5-50%.

[0061] Silicon-containing negative electrodes can store more lithium ions, and adding silicon-carbon composite materials to the negative electrode active layer can further improve the overall energy density of the battery. At the same time, by arranging the entire battery cell into a stacked core, the expansion force of the negative electrode sheet including the silicon-carbon composite material will not be constrained by the stress caused by the bending or curling of the electrode sheet, so that the expansion force can be fully released, thereby avoiding the risk of electrode breakage.

[0062] Continue to refer Figure 2 and Figure 4 In the embodiment of the present application, the battery further includes: a sealant 400.

[0063] The sealant 400 is disposed between the first connector 300 and the first inner wall surface. The sealant 400 is used to prevent the first connector 300 from contacting the negatively charged housing 100 and causing a short circuit.

[0064] The first connecting member 300 is located in the thickness direction of the stacked core 200 ( Figure 4 The projection of the sealant 400 on the z-axis (shown in FIG) is within the projection of the sealant 400 in the thickness direction of the stacked core 200. In other words, the edge of the sealant 400 extends beyond the junction of the first connector 300 and the first bent portion 301, preventing the first bent portion 301 from contacting the negatively charged housing 100 and causing a short circuit.

[0065] At the same time, a gap is formed between the second connector 600 and the sealant 400 , thereby preventing the second connector 600 from contacting the housing 100 .

[0066] The spacing between the second connector 600 and the sealant 400 is 0.05-0.3 mm, thereby preventing the negative electrode sheet 202 doped with silicon-carbon composite material from expanding during the charge and discharge process, and the first connector 300 and the second connector 600 are pulled by the positive and negative tabs to move toward each other and then contact to cause a short circuit.

[0067] In the embodiment of the present application, the melting points of the materials at the bonding interface between the sealant 400 and the first connector 300 and the bonding interface between the sealant 400 and the first inner wall surface of the housing 100 are both 60° C.-165° C.

[0068] This indicates that the sealant 400 changes from a solid state to a liquid state within this temperature range; that is, the battery can be processed at a relatively low temperature, which helps reduce damage to heat-sensitive components; while it can also maintain a stable solid state at a higher temperature.

[0069] Continue to refer Figure 2 and Figure 4 In the embodiment of the present application, the battery further includes: an insulating pad 500.

[0070] The insulating pad 500 is disposed between the first connector 300 and the first surface. The first connector 300 is disposed in the thickness direction ( Figure 4 ), and / or the projection of the second connecting member 600 in the thickness direction ( z axis shown in ) of the stacked core 200 Figure 4 The projection on the z-axis shown in FIG) is consistent with the projection of the insulating pad 500 in the thickness direction of the stacked core 200 ( Figure 4 The projections on the z-axis (shown in ) at least partially overlap.

[0071] The insulating pad 500 is used to prevent the first connector 300 from contacting the stacked core 200 and / or the second connector 600 from contacting the stacked core 200 to cause a short circuit.

[0072] Among them, the diaphragm 203 on the opposite sides of the positive electrode sheet 201 also includes a protruding portion that protrudes beyond the positive electrode sheet 201. The protruding portions on the opposite sides of the positive electrode sheet 201 are bonded together, and the protruding portions are used to isolate the edge of the positive electrode sheet 201 from the inner wall surface of the shell 100, effectively isolating the positive and negative electrodes, preventing short circuits, and enhancing battery safety.

[0073] Continue to refer Figure 2 and Figure 4 In the embodiment of the present application, a pole protrusion 302 is provided on the side wall of the first connecting member 300 close to the first inner wall surface, and a first through hole 1021 is provided on the first inner wall surface. The pole protrusion 302 passes through the shell 100 from the first through hole 1021; the positive electrode of the stacked core 200 is led out through the pole protrusion 302.

[0074] The pole protrusion 302 is spaced apart from the inner wall of the first through hole 1021 by a first distance, and the first distance is less than 0.15 mm, so as to prevent the pole protrusion 302 from contacting the housing 100 and causing a short circuit.

[0075] It should be noted that the sealant 400 is provided with a third through hole 401 , the central axis of the third through hole 401 coincides with the central axis of the first through hole 1021 , and the pole protrusion 302 passes through the third through hole 401 and the first through hole 1021 in sequence before passing through the housing 100 .

[0076] The diameter of the third through hole 401 is smaller than that of the first through hole 1021 ; or, the diameter of the third through hole 401 is equal to that of the first through hole 1021 , so as to prevent the pole protrusion 302 from contacting the housing 100 and causing a short circuit.

[0077] Continue to refer Figure 2 and Figure 4 In the embodiment of the present application, in the thickness direction of the stacked core 200 ( Figure 4 On the z-axis shown in FIG ), the projection of the second connecting member 600 does not overlap with the projection of the first connecting member 300 and is spaced apart by a second distance, where the second distance is less than 0.15 mm.

[0078] The second distance can avoid the risk of the second connector 600 contacting the first connector 300 due to the overall expansion of the stacked core 200 during the expansion of the negative electrode sheet 202; at the same time, no other insulating members need to be provided, and insulation can be achieved only by the spacing.

[0079] Continue to refer Figure 2 and Figure 4 In the embodiment of the present application, in the direction from the first connecting member 300 to the second connecting member 600 ( Figure 4 The sealant 400 between the first connector 300 and the second connector 600 is located in the thickness direction of the stacked core 200 (x-axis shown in FIG). Figure 4 ) has a first width; that is, the edge of the sealant 400 exceeds the edge of the first connector 300, so that part of the sealant 400 is located between the first connector 300 and the second connector 600, which can further prevent the second connector 600 from contacting the first connector 300, ensuring that the second connector 600 and the first connector 300 can be effectively isolated; at the same time, it prevents the electrolyte from penetrating into the sealant 400 (the electrolyte will form bubbles between the sealant 400 and the shell 100, thereby affecting the adhesion between the sealant 400 and the shell), and the extended edge can ensure the sealing of the sealant 400.

[0080] Among them, the first width is ≥0.5mm to ensure the isolation effect.

[0081] In the embodiment of the present application, the sealant 400 has a first thickness h1, and the second connecting member 600 has a second thickness h2. The relationship between the first thickness h1 and the second thickness h2 is: h1<1 / 2h2.

[0082] The sealant 400 can play the role of cushioning the first connecting member 300, so that the first connecting member 300 and the second connecting member 600 are aligned in the thickness direction of the stacked core 200 ( Figure 4 Even if the first connecting member 300 and the second connecting member 600 are brought close to each other by the expansion force, the first connecting member 300 and the second connecting member 600 can be prevented from contacting each other by the misalignment in the thickness direction.

[0083] Continue to refer Figure 2 and Figure 4 In the embodiment of the present application, the battery further includes an insulating sleeve 700 .

[0084] The insulating sleeve 700 is disposed in the housing 100 and sleeved on the outer periphery of the stacked core 200 . The insulating sleeve 700 is used to prevent the side wall of the pole piece assembly from contacting the negatively charged housing 100 and causing a short circuit.

[0085] Among them, the first connector 300, the second connector 600, the sealant 400 and the insulating pad 500 are all located in the insulating sleeve 700. At this time, the insulating sleeve 700 also has a limiting function on the above components to ensure the stability of the battery structure.

[0086] refer to Figure 3 In the embodiment of the present application, a plurality of second through holes 701 arranged in an array are provided on the insulating sleeve 700, and the diameter of the second through holes is 0.3 mm-1.0 mm.

[0087] The second through holes 701 can improve the infiltration effect of the electrolyte on the stacked core 200, thereby increasing the electrolyte retention amount.

[0088] refer to Figure 5 and Figure 6 In the embodiment of the present application, the housing 100 includes a bottom housing 101 and a housing cover 102 .

[0089] The bottom shell 101 includes a circular bottom plate 1011 and a side wall 1012 surrounding the circular bottom plate 1011. The side wall 1012 has an opening at one end away from the circular bottom plate 1011. The shell cover 102 is sealed with the opening to form a sealed cavity in the shell 100. The stacked core 200 is arranged in the sealed cavity.

[0090] The side wall 1012 includes a first section 1013 and / or a second section 1014. The projection of the first section 1013 on the side wall of the pole piece assembly (i.e., Figure 6 ) and the projection of the first tab bend 2011 on the side wall of the pole piece assembly at least partially overlap; and / or, the projection of the second section 1014 on the side wall of the pole piece assembly and the projection of the second tab bend 2021 on the side wall of the pole piece assembly at least partially overlap.

[0091] That is, the positions of the first section 1013 and the second section 1014 correspond to the positions of the first tab bend 2011 and the second tab bend 2021 , respectively.

[0092] For a battery with a cylindrical structure, providing a first section 1013 and / or a second section 1014 corresponding to the tab on the side wall 1012 can reduce the gap (redundant, unused space) in the internal space of the battery, making the battery design more compact, thereby improving the battery volume energy density.

[0093] In the embodiment of the present application, in the radial direction of the pole piece assembly ( Figure 6 ), the first section 1013 and the second section 1014 both have a second width, and the second width is 1.5 mm-4 mm.

[0094] Continue to refer Figure 5 and Figure 6 In the embodiment of the present application, the insulating sleeve 700 includes a third section 702 and a fourth section 703. The projection of the third section 702 on the side wall of the pole piece assembly (i.e., Figure 6 The projection on the x-axis shown in the figure) overlaps with the projection of the first pole ear bend 2011 on the side wall of the pole piece assembly, and the projection of the fourth section 703 on the side wall of the pole piece assembly overlaps with the projection of the second pole ear bend 2021 on the side wall of the pole piece assembly.

[0095] That is, the positions of the third section 702 and the fourth section 703 correspond to the positions of the first tab bend 2011 and the second tab bend 2021 , respectively.

[0096] Further reducing the gaps (extra, unused space) within the battery makes the battery design more compact, thereby increasing the battery volume energy density.

[0097] refer to Figure 1 In the embodiment of the present application, a positioning protrusion 1023 is extended radially outward from the edge of the shell cover 102; when the battery is installed in the device, the positioning protrusion 1023 is used to position the battery to improve installation efficiency.

[0098] In the radial direction of the housing cover 102 , the positioning protrusion 1023 has a third width, which is less than 2 mm.

[0099] In the embodiment of the present application, the angle formed between the projection of the center line of the first tab and the projection of the center line of the second tab is 90-180°.

[0100] refer to Figure 7 , in the direction perpendicular to the thickness of the core ( Figure 7 On the x-axis shown in FIG ), the first tab bend portion 2011 and the second tab bend portion 2021 are opposite to each other; that is, the first tab bend portion 2011 and the second tab bend portion 2021 are symmetrically arranged at 180 degrees.

[0101] It helps to achieve more uniform current distribution inside the battery and also helps to dissipate heat more evenly inside the battery. At the same time, the 180-degree symmetrical design can also simplify the battery positioning and welding process and improve production efficiency.

[0102] refer to Figure 8 In the thickness direction of the stacked core 200, the projection of the first tab bend 2011 and the projection of the second tab bend 2021 are perpendicular, that is, the projection of the first tab bend 2011 and the second tab bend 2021 are set at 90 degrees, which helps to better utilize space and simplify the electrical connection between batteries in some battery pack designs.

[0103] In the embodiment of the present application, the top electrode sheet and the bottom electrode sheet of the stacked core 200 are both single-sided negative electrode sheets, and the single-sided negative electrode sheet includes a negative electrode collector. An active material layer is provided on one surface of the negative electrode collector along the thickness direction of the electrode sheet (the z-axis shown in the figure), and no active material layer is provided on the other surface.

[0104] In which, the shell 100 includes a first inner wall surface and a second inner wall surface relative to each other along the thickness direction of the stacked core 200 (the z-axis shown in the figure); the circular bottom plate 1011 and the shell cover 102 are relative to each other along the thickness direction of the stacked core 200 (the z-axis shown in the figure), the first inner wall surface is the inner wall surface of the shell cover 102, and the second inner wall surface is the inner wall surface of the circular bottom plate 1011.

[0105] In the stacked core 200, the top single-sided negative electrode sheet is close to the second inner wall surface, and the bottom single-sided negative electrode sheet is close to the first inner wall surface; at the same time, the surface of the top single-sided negative electrode sheet without the active material layer is close to the second inner wall surface, and the surface of the bottom single-sided negative electrode sheet without the active material layer is close to the first inner wall surface.

[0106] That is, the surfaces of the single-sided negative electrode sheets at the top and bottom layers without active material layers are close to the inner wall of the shell 100 , and the surfaces with active material layers are opposite to the positive electrode sheets.

[0107] The top and bottom electrodes of the stacked core 200 are both designed as single-sided negative electrodes, which reduces the use of active materials, reduces production costs, reduces the overall weight of the battery and the complexity of the manufacturing process; at the same time, the heat of the battery is more easily dissipated through the second surface where the active material layer is not set, thereby achieving the purpose of improving the battery's heat dissipation performance, enhancing battery safety and performance stability.

[0108] In the embodiment of the present application, the aspect ratio of the battery is greater than 1.5.

[0109] The battery's aspect ratio is the ratio of the battery's diameter to its height. A battery's aspect ratio greater than 1.5 indicates that the battery's height is significantly greater than its diameter. A higher aspect ratio helps expand the electrode area, increase battery capacity, and thus increase energy density. At the same time, a higher aspect ratio also makes the battery structure more stable and the battery reliability higher.

[0110] In an embodiment of the present application, the first connecting member 300 includes a corner portion connected to the first bending portion 301, and the sealant 400 includes an extension portion arranged corresponding to the corner portion, and the edge of the extension portion extends beyond the corner portion and away from the edge of the first connecting member 300; so that the sealant 400 can isolate the connection between the first connecting member 300 and the first bending portion 301, preventing the connection between the first connecting member 300 and the first bending portion 301 from contacting the negatively charged shell 100 and causing a short circuit.

[0111] The corner portion may be an arc-shaped corner, and the arc-shaped design can effectively disperse stress and reduce stress concentration, thereby reducing the risk of breakage when the first connecting member 300 is connected to the first bending portion 301 .

[0112] Continue to refer Figure 1 and Figure 2In the embodiment of the present application, the battery further includes a sealing cover 800.

[0113] A liquid injection hole 1022 is provided on the first inner wall surface or the second inner wall surface, and the electrolyte enters the shell through the liquid injection hole 1022 . The sealing cover 800 is sealedly connected to the liquid injection hole 1022 to seal the shell 100 .

[0114] In the embodiment of the present application, thinning notches are further provided on the circular bottom plate 1011 and / or the shell cover 102 of the shell 100 , and the depth of the thinning notches is greater than 50% of the thickness of the circular bottom plate 1011 or the shell cover 102 .

[0115] The thinning notch serves as a pressure relief notch for the battery. When the internal pressure of the battery increases due to overcharging, short circuit or other faults, the thinning notch can provide a predetermined rupture point, allowing the gas to be safely released, which can significantly reduce the risk of battery explosion and protect user safety.

[0116] In summary, the embodiment of the present application provides a battery, which includes: a shell 100 and a stacked core 200, a first connector 300 and a second connector 600 arranged in the shell 100; the stacked core 200 includes a positive electrode sheet 201, a negative electrode sheet 202 and a separator 203 arranged in a stacked manner, the positive electrode sheet 201 includes a positive electrode collector and a first electrode ear extending from one side of the positive electrode collector, the negative electrode sheet 202 includes a negative electrode collector, a second electrode ear extending from one side of the negative electrode collector and a negative electrode active layer located on the negative electrode collector, the negative electrode active layer includes a silicon-carbon composite material, and the mass proportion of silicon element in the negative electrode active layer is 5-50%; the first electrode ear includes a first electrode ear bending portion 2011, and the second electrode ear includes a second electrode ear bending portion 2012. The second tab bend 2021, the first connector 300 has a first bend 301, the second connector 600 has a second bend 601, the first bend 301 and the second bend 601 extend from between the first surface and the first inner wall respectively, the first bend 301 is connected to the first tab bend 2011, and the second bend 601 is connected to the second tab bend 2021; the battery also includes a sealant 400 arranged between the first connector 300 and the first inner wall; in the thickness direction of the stacked core 200, the projection of the first connector 300 is located within the projection of the sealant 400, and a spacing is formed between the second connector 600 and the sealant 400, the spacing is 0.05-0.3mm.

[0117] The positive and negative electrodes of the stacked core 200 are respectively led out through the first connector 300 and the second connector 600, wherein the first connector 300 and the second connector 600 are both horizontally arranged on the same side of the stacked core, and the first bending portion 301 and the second bending portion 601 are respectively used to connect the first pole ear bending portion 2011 and the second pole ear bending portion 2021 obtained after bending the two pole ears of the stacked core. The first pole ear bending portion 2011 and the second pole ear bending portion 2021 are both parallel to the side walls of the stacked core 200, and the first bending portion 301 and the second bending portion 601 are also roughly parallel to the side walls of the stacked core 200, reducing the space occupied by the structure for leading out the first pole ear bending portion 2011 and the second pole ear bending portion 2021, thereby improving the energy density.

[0118] When the stacked core 200 is placed in the shell 100 and then the negative electrode ear of the stacked core 200 is welded to the inner wall of the shell 100, welding is difficult; therefore, the negative electrode of the stacked core 200 is led to the shell 100 through the second connecting piece 600, making the preparation process simpler.

[0119] In addition, by adding silicon-carbon composite materials to the negative electrode active layer, the overall energy density of the battery can be further improved; at the same time, by arranging the entire battery cell into a stacked core, the expansion force of the negative electrode sheet including the silicon-carbon composite material will not be constrained by the stress caused by the bending or curling of the electrode sheet, so that the expansion force is fully released, thereby avoiding the risk of electrode breakage.

[0120] Furthermore, by providing a gap between the second connector 600 and the sealant 400, contact between the first connector 300 and the second connector 600 is prevented. Moreover, a spacing of 0.05-0.3 mm is formed between the second connector 600 and the sealant 400, thereby preventing the negative electrode sheet doped with silicon-carbon composite material from expanding during the charge and discharge process, and the first connector 300 and the second connector 600 are pulled by the positive and negative ears to move closer to each other and then contact to cause a short circuit.

[0121] In this specification, each embodiment or example is described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referenced to each other.

[0122] It should be noted that references in this specification to "one embodiment," "an embodiment," "an exemplary embodiment," "some embodiments," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not necessarily every embodiment includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not.

[0123] Generally speaking, terms should be understood, at least in part, based on the context in which they are used. For example, as used herein, the term "one or more" can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense, depending at least in part on the context. Similarly, terms such as "a," "an," or "the" can also be understood to convey either singular or plural usage, depending at least in part on the context.

[0124] It should be readily understood that “on,” “above,” and “over” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something,” but also includes “on something” with intervening features or layers therebetween, and “above” or “over” includes not only the meaning of “above” or “over,” but also includes “above” or “over” with no intervening features or layers therebetween (i.e., directly on something).

[0125] Additionally, spatially relative terms, such as "below," "beneath," "beneath," "above," and the like, may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be in other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized in that: It comprises: a shell, and a stacked core, a first connecting member and a second connecting member arranged in the shell; The stacked core comprises a positive electrode sheet, a negative electrode sheet and a separator which are stacked; The positive electrode sheet includes a positive electrode current collector and a first electrode tab extending from one side of the positive electrode current collector. The negative electrode sheet includes a negative electrode current collector, a second electrode tab extending from one side of the negative electrode current collector, and a negative electrode active layer located on the negative electrode current collector. The negative electrode active layer includes a silicon-carbon composite material, and the mass percentage of silicon in the negative electrode active layer is 5-50%; The first tab includes a first tab bend portion, the second tab includes a second tab bend portion, the first connector has a first bend portion, the second connector has a second bend portion, the first bend portion and the second bend portion respectively extend from between the first surface of the stacked core and the first inner wall surface of the shell, the first tab bend portion is connected to the first bend portion, and the second tab bend portion is connected to the second bend portion; The battery further includes a sealant disposed between the first connector and the first inner wall surface; In the thickness direction of the stacked core, the projection of the first connecting member is located within the projection of the sealant, and a distance is formed between the second connecting member and the sealant, and the distance is 0.05-0.3 mm.

2. The battery according to claim 1, characterized in that The first tab bend portion and / or the second tab bend portion are parallel to the thickness direction of the stacked core; and / or, Along the thickness direction of the stacked core, the first surface of the stacked core is opposite to the first inner wall surface of the shell, and the first connecting member and / or the second connecting member is arranged between the first surface and the first inner wall surface.

3. The battery according to claim 1, characterized in that The battery further comprises: an insulating pad; The insulating pad is arranged between the first connecting member and the first surface; In the thickness direction of the stacked core, the projection of the first connector and / or the projection of the second connector at least partially overlaps with the projection of the insulating pad, and / or, The separators on two opposite sides of the positive electrode sheet include protruding portions that protrude from the positive electrode sheet, and the protruding portions on two opposite sides of the positive electrode sheet are bonded.

4. The battery according to claim 1, characterized in that A pole protrusion is provided on a surface of the first connecting member close to the first inner wall surface, a first through hole is provided on the first inner wall surface, and the pole protrusion passes through the housing through the first through hole; The pole protrusion is spaced apart from the wall of the first through hole by a first distance, and the first distance is less than 0.15 mm.

5. The battery according to claim 1, characterized in that In the thickness direction of the stacked core, the projection of the first connecting member and the projection of the second connecting member do not overlap and are separated by a second distance, and the second distance is less than 0.15 mm.

6. The battery according to claim 1, characterized in that In the direction from the first connecting member to the second connecting member, a projection of the sealant between the first connecting member and the second connecting member in the thickness direction of the laminated core has a first width, and the first width is ≥0.5 mm, and / or, The sealant has a first thickness h1, the second connecting member has a second thickness h2, and the relationship between the first thickness h1 and the second thickness h2 is: h1<1 / 2h2.

7. The battery according to claim 1, characterized in that In the thickness direction of the stacked core, the angle formed between the projection of the center line of the first pole tab and the projection of the center line of the second pole tab is 90-180°, and / or, The housing includes a bottom shell and a housing cover, the bottom shell having an opening, the housing cover being sealed and connected to the opening to form a sealed cavity in the housing, the stacked core being disposed in the sealed cavity, and a positioning protrusion extending radially outward from an edge of the housing cover; Furthermore, along the radial direction of the shell cover, the width of the positioning protrusion is less than 2 mm.

8. The battery according to claim 1, characterized in that The battery further comprises: an insulating sleeve; The insulating sleeve is disposed in the housing, the insulating sleeve is sleeved on the outer circumference of the stacked core, and the first connector and the second connector are both located in the insulating sleeve; The insulating sleeve is provided with a plurality of second through holes arranged in an array.

9. The battery according to claim 1, characterized in that The housing includes a bottom shell and a housing cover, the bottom shell includes a bottom plate and side walls surrounding the bottom plate, the side walls have an opening, the housing cover is sealedly connected to the opening to form a sealed cavity in the housing, and the stacked core is disposed in the sealed cavity; The side wall includes a first cut surface and / or a second cut surface, The projection of the first section on the side wall of the pole piece assembly and the projection of the first tab bent portion on the side wall of the pole piece assembly at least partially overlap, and / or, The projection of the second section on the side wall of the pole piece assembly and the projection of the second tab bent portion on the side wall of the pole piece assembly at least partially overlap.

10. The battery according to claim 1, characterized in that The first connecting member includes a corner portion connected to the first bending portion, the sealant includes an extension portion corresponding to the corner portion, and an edge of the extension portion extends beyond the corner portion and away from an edge of the first connecting member.

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