Battery

Abstract

The present application provides a battery, which solves the technical problems of the low safety and poor operation stability of the conventional lithium battery in the field of battery technology. A first conductive material is provided in a receiving cavity of the battery, and an insulating adhesive layer is provided between the first conductive material and a bottom cover, connecting the first conductive material and the bottom cover. The bottom cover is provided with a through hole covered by the first conductive material. The annular side wall is welded to the bottom cover at an edge close to the bottom cover, and a welding mark is formed around the bottom cover. A first gap is provided between the welding mark and the insulating adhesive layer, the width of which is at least three times the width of the welding mark. A first tab of the cell is electrically connected to the first conductive material, and a second tab of the cell is electrically connected to the case. The present application can improve the safety during the manufacture of the battery and the operation stability of the battery.

Description

[Technical Field]

[0001] This application relates to the field of battery technology, and more particularly to batteries. [Background technology]

[0002] Lithium batteries have the advantages of high energy density, long service life, and environmental friendliness, and are widely used in industries such as mobile phones, laptops, digital cameras, electric vehicles, power tools, and new energy vehicles.

[0003] Current lithium batteries generally include a battery cell and a packaging case. The battery cell is located within the packaging case, and the packaging case has a top and bottom cover that cover each other and are connected by welding. The battery cell is formed by winding an anode electrode and a cathode electrode, and a spacer is provided between the anode and cathode electrodes. The tab of the battery cell is electrically connected to the packaging case via an electrical connection assembly, and insulating adhesive paper is provided between the tab and the packaging case and between the battery cell and the bottom cover.

[0004] However, current lithium batteries have low safety during manufacturing and low operational stability. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION In order to solve at least one of the problems in the background art, the present application provides a battery that improves safety during the manufacturing process of the battery and the operational stability of the battery. [Means for solving the problem]

[0006] To achieve the above object, the present application provides a battery comprising a conductive case and a battery cell, the case having a top case and a bottom cover, the top case having a top cover and an annular side wall connected to the top cover, the top case being arranged to cover the bottom cover and to commonly surround a storage cavity, and the battery cell being located within the storage cavity.

[0007] A first conductive material is provided in the receiving cavity, and an insulating adhesive layer is provided between the first conductive material and the bottom cover to connect the first conductive material and the bottom cover. The bottom cover has a through hole covered by the first conductive material. The annular side wall is welded to the bottom cover at an edge closest to the bottom cover, forming a welding mark around the circumference.

[0008] There is a first gap between the weld mark and the insulating adhesive layer, the first gap having a width that is at least three times the width of the weld mark.

[0009] A first tab of the battery cell is electrically connected to the first conductive material, and a second tab of the battery cell is electrically connected to the case.

[0010] The battery provided by the present application includes a top case and a bottom cover, allowing a battery cell to be loaded into the cavity formed by the top case and the bottom cover, and facilitating the top case and the bottom cover being welded and sealed after the cell is loaded. The first conductive material allows the first tab of the cell to be electrically connected to the external electrode. The insulating adhesive layer prevents electrical contact between the first conductive material and the bottom cover. The first gap prevents contact between the welding mark and the insulating adhesive layer during welding, avoiding safety hazards and improving safety during the battery manufacturing process. Meanwhile, the high temperatures generated by welding prevent the adhesive properties of the insulating adhesive layer from being affected, thereby preventing the insulating properties of the insulating adhesive layer from being affected and improving the operational stability of the battery.

[0011] In the above battery, optionally, the annular side wall has a flange on the edge closer to the bottom cover, the flange is welded to the bottom cover, and a welding mark is formed around the circumference of the annular side wall.

[0012] In the above battery, optionally, the width of the welding mark is greater than 0 mm and less than or equal to 1 mm.

[0013] In the above battery, optionally, the ratio of the area of ​​the first conductive material covered by the bottom cover to the area of ​​the bottom cover is 0.4 to 0.99.

[0014] In the above battery, optionally, the cell has at least two pole pieces of opposite polarity, the cell has a stacked region, and at least two pole pieces located in the stacked region are stacked with each other and parallel to the surface of the bottom cover and / or the top surface of the top case. A separator is provided between the two pole pieces of opposite polarity.

[0015] In the above battery, optionally, the first conductive material includes a first connecting plate and a first bent plate connected to each other, the first connecting plate is attached to the bottom cover, the first bent plate is located between the cell and the annular side wall, and the first tab is welded to the first bent plate.

[0016] In the above battery, optionally, the first connecting plate has a protrusion on a side away from the receiving cavity, and the protrusion is provided through the through-hole.

[0017] In the battery, optionally, a first gap is formed between the outer periphery of the protrusion and the wall of the through-hole. The width of the first gap is within a range of 0.1 to 2 mm. The insulating adhesive layer has an overflow portion located within the first gap.

[0018] In the above battery, optionally, a sealing insulating material is filled in the first gap.

[0019] In the above battery, optionally, there is a second gap between the first folded plate and the annular side wall, the second gap being in the range of 0.2 to 3 mm.

[0020] In the above battery, optionally, a first insulating layer is provided between the first folded plate and the cell, and / or a second insulating layer is provided between the first folded plate and the annular side wall.

[0021] In the above battery, optionally, the second tab is welded to the annular side wall.

[0022] In the above battery, optionally, the distance between the first tab and the annular side wall is greater than the distance between the second tab and the annular side wall.

[0023] In the above battery, optionally, a second conductive material is provided within the accommodating cavity, and at least a portion of the second conductive material is positioned between the second tab and the case and electrically connects the second tab and the case.

[0024] The second conductive material and the first conductive material are insulated from each other.

[0025] In the above battery, optionally, the second conductive material includes a second connecting plate and a second folded plate connected to each other, the second connecting plate is attached to the bottom cover, the second folded plate is located between the cell and the annular side wall, and the second tab is welded to the second folded plate.

[0026] In the above battery, optionally, the difference in height between the first connecting plate and the second connecting plate is less than 0.3 mm.

[0027] A second gap is present between the first connecting plate and the second connecting plate.

[0028] The width of the second gap is in the range of 0.5 to 5 mm, and / or a porous insulating material is filled in the second gap.

[0029] In the above battery, optionally, the first tab and the second tab are located at the same end of the cell, and the first folding plate and the second folding plate are located at the same end of the cell.

[0030] In the above battery, optionally, the first tab is located on a side of the first folded plate that faces away from the cell, and / or the second tab is located on a side of the second folded plate that faces away from the cell.

[0031] The battery described above may optionally further comprise a third insulating layer positioned between the cell and the first conductive material and between the cell and the second conductive material.

[0032] In the above battery, optionally, there is a third gap between the end of the first tab and the end of the second tab, the third gap being equal to or greater than 0 mm and equal to or less than 1 mm.

[0033] In the above battery, optionally, the area of ​​the first connection plate is larger than the area of ​​the second connection plate, and the area ratio of the first connection plate to the second connection plate is in the range of 1 to 9.9.

[0034] In the battery, optionally, a reinforcing piece and a liquid inlet are provided on the annular side wall at a distance from each other, the reinforcing piece and the second tab are located on opposite sides of the annular side wall, and the liquid inlet communicates with the outside of the case and the accommodating cavity. The top cover has a pressure relief groove provided adjacent to the first tab or the second tab.

[0035] The liquid inlet is provided with a sealing piece that seals the liquid inlet.

[0036] And / or the cell further comprises a finishing adhesive located on a side of the cell adjacent to the top cover. [Brief explanation of the drawings]

[0037] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. [Figure 1] 1 is a structural schematic diagram of a battery provided according to an embodiment of the present application at a first viewing angle. FIG. [Figure 2] FIG. 2 is a structural schematic diagram of a battery provided according to an embodiment of the present application at a second viewing angle. [Figure 3]FIG. 2 is a side view of the case of a battery provided in accordance with an embodiment of the present application. [Figure 4] FIG. 2 is a plan view of a case of a battery provided in accordance with an embodiment of the present application. [Figure 5] 1 is a structural schematic diagram of the conductive material, bottom cover, and cell of a battery provided by an embodiment of the present application. [Figure 6] FIG. 1 is an exploded view of a battery provided in accordance with an embodiment of the present application. [Figure 7] 1 is a structural schematic diagram of the bottom cover and conductive material of the battery provided by the embodiment of the present application. [Figure 8] 1 is an exploded view of a bottom cover and a conductive material of a battery provided by an embodiment of the present application at a first viewing angle. FIG. [Figure 9] FIG. 2 is an exploded view of the bottom cover and conductive material of the battery provided by an embodiment of the present application at a second viewing angle. [Figure 10] 1 is a schematic diagram of a local structure of a battery provided by an embodiment of the present application; [Figure 11] FIG. 2 is an exploded view of another battery provided in accordance with an embodiment of the present application. [Figure 12] FIG. 2 is a schematic diagram of a local structure of another battery provided by an embodiment of the present application. [Figure 13] 1 is a structural schematic diagram of a cell end of a battery provided by an embodiment of the present application. FIG. [Figure 14] FIG. 2 is a structural schematic diagram of the cell tail of the battery provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0038] As described in the Background Art, in the related art, lithium battery packaging cases are formed by welding a top case and a bottom cover, with an insulating adhesive paper disposed between the cells and the bottom cover. During the packaging case welding process, the welding marks are close to the cells and the insulating adhesive paper, so the welding marks are likely to come into contact with the cells or the insulating adhesive paper, creating a safety hazard. Meanwhile, the high temperatures during welding are likely to affect the adhesive performance of the insulating adhesive paper, causing poor adhesion and poor insulation in the areas of the insulating adhesive paper close to the welding marks, thereby affecting the operational stability of the lithium battery.

[0039] The battery provided by the present application includes a top case and a bottom cover, allowing cells to be loaded into the cavity formed by the top case and the bottom cover, and facilitating the top case and the bottom cover being welded and sealed after the cells are loaded. The first conductive material allows the first tab of the cell to be electrically connected to the external electrode. The insulating adhesive layer prevents electrical contact between the first conductive material and the bottom cover. The first gap prevents contact between the welding mark and the insulating adhesive layer during welding, avoiding safety hazards and improving safety during battery manufacturing. It also prevents high temperatures generated by welding from affecting the adhesive properties of the insulating adhesive layer, thereby preventing the insulating properties of the insulating adhesive layer from being affected and improving the operational stability of the battery.

[0040] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be described in more detail below with reference to the drawings of preferred embodiments of the present application. In the drawings, the same or similar symbols throughout represent the same or similar components or components having the same or similar functions. The described embodiments are only a portion of the embodiments of the present application, and are not all of the embodiments. The embodiments described below with reference to the drawings are for the purpose of explaining the present application and should not be understood as limiting the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative work fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0041] FIG. 1 is a structural schematic diagram of a battery provided by an embodiment of the present application, viewed from a first angle. FIG. 2 is a structural schematic diagram of a battery provided by an embodiment of the present application, viewed from a second angle. FIG. 3 is a side view of a case of a battery provided by an embodiment of the present application. FIG. 4 is a plan view of a case of a battery provided by an embodiment of the present application. FIG. 5 is a structural schematic diagram of a conductive material, bottom cover, and cell of a battery provided by an embodiment of the present application. FIG. 6 is an exploded view of a battery provided by an embodiment of the present application. FIG. 7 is a structural schematic diagram of a bottom cover and conductive material of a battery provided by an embodiment of the present application. FIG. 8 is an exploded view of the bottom cover and conductive material of a battery provided by an embodiment of the present application, viewed from a first angle. FIG. 9 is an exploded view of the bottom cover and conductive material of a battery provided by an embodiment of the present application, viewed from a second angle. FIG. 10 is a structural schematic diagram of a portion of a battery provided by an embodiment of the present application. FIG. 11 is an exploded view of another battery provided by an embodiment of the present application. FIG. 12 is a structural schematic diagram of a portion of another battery provided by an embodiment of the present application. 13 and 14 are schematic diagrams of the structure of the cell end and tail of the battery provided by the embodiment of the present application, respectively.

[0042] As shown in FIGS. 1 to 14 , an embodiment of the present application provides a battery. The battery 100 includes a conductive case 10 and a cell 60. The case 10 includes a top case 11 and a bottom cover 12. The top case 11 includes a top cover 112 and an annular sidewall 111 connected to the top cover 112. The top case 11 is disposed over the bottom cover 12 and commonly surrounds a receiving cavity 20. The cell 60 is located within the receiving cavity 20. A first conductive material 31 is disposed within the receiving cavity 20. An insulating adhesive layer 40 is disposed between the first conductive material 31 and the bottom cover 12, connecting the first conductive material 31 and the bottom cover 12. The insulating adhesive layer 40 can prevent electrical contact between the first conductive material 31 and the bottom cover 12. For example, the insulating adhesive layer 40 may be an insulating adhesive or an injection-molded insulating material, in which an adhesive is disposed on the injection-molded insulating material. A first tab 61 of the cell 60 is electrically connected to the first conductive material 31, and a second tab 62 of the cell 60 is electrically connected to the case 10. The bottom cover 12 is provided with a through-hole 13 covered by the first conductive material 31, so that the first conductive material 31 can be partially exposed to the outside of the accommodating cavity 20 to facilitate electrical connection with an external electrode.

[0043] 10 , the annular side wall 111 is welded to the bottom cover 12 at its edge closest to the bottom cover 12, and a welding mark 18 is formed around the circumference. A first distance L1, whose width is at least three times the width of the welding mark 18, is formed between the welding mark 18 and the insulating adhesive layer 40. In this way, the welding mark 18 and the insulating adhesive layer 40 do not come into contact with each other during welding, which avoids safety hazards and improves safety during the manufacture of the battery 100. At the same time, the high temperatures generated by welding do not affect the adhesive properties of the insulating adhesive layer 40, which in turn affects the insulating properties of the insulating adhesive layer 40 and improves the operational stability of the battery 100.

[0044] 10 , the annular side wall 111 has a flange 113 on the edge closer to the bottom cover 12, and the flange 113 is welded to the bottom cover 12 and has a welding mark 18 formed around the circumference of the annular side wall 111. The provision of the flange 113 increases the bonding area between the top case 11 and the bottom cover 12, making it easier to weld the top case 11 and the bottom cover 12 and improving the connection stability between the top case 11 and the bottom cover 12.

[0045] In one possible embodiment, the width of welding mark 18 is greater than 0 mm and less than or equal to 1 mm, where the width of welding mark 18 can be 0.3 mm, 0.5 mm, 0.8 mm, or 1 mm. By setting the width of welding mark 18 within the above range, top case 11 and bottom cover 12 can be firmly welded and sealed together, while the amount of welding work can be reduced, thereby reducing manufacturing costs.

[0046] In one possible embodiment, the ratio of the area of ​​the first conductive material 31 covered by the bottom cover 12 to the area of ​​the bottom cover 12 is 0.4 to 0.99, where the ratio can be 0.4, 0.6, 0.8, or 0.99. When the ratio is within the above range, the contact area between the first conductive material 31 and the bottom cover 12 is within a reasonable range, thereby improving the connection stability between the first conductive material 31 and the bottom cover 12, preventing the first conductive material 31 from sliding relative to the bottom cover 12, and improving the stability of the battery 100.

[0047] The cell 60 has at least two pole pieces (not shown) of opposite polarity, and the cell 60 has a stacked region, and at least two pole pieces located in the stacked region are stacked on top of each other, and the pole pieces located in the stacked region are parallel to the surface of the bottom cover 12 and the top surface of the top case 11. In this way, the space occupied by the cell 60 in the height direction within the accommodating cavity 20 can be maximized, and the energy density of the battery 100 can be increased. A separator is provided between the two pole pieces of opposite polarity to maintain insulation between the positive and negative pole pieces.

[0048] In the present embodiment, it can be seen that the flat cell 60 has two arcuate side edges, and the region between the two arcuate side edges is the stacked region.

[0049] 7, the first conductive member 31 includes a first connecting plate 311 and a first bent plate 312 connected to each other, the first connecting plate 311 is attached to the bottom cover 12, the first bent plate 312 is located between the cell 60 and the annular side wall 111, and the first tab 61 is welded to the first bent plate 312. The first connecting plate 311 and the first bent plate 312 have plate surfaces perpendicular to each other, allowing the first bent plate 312 to stand upright between the end of the cell 60 and the annular side wall 111, minimizing the space occupied by the first bent plate 312 and allowing the first bent plate 312 to be parallel to the tab, facilitating electrical connection therebetween.

[0050] 9, the first connecting plate 311 has a protrusion 3111 formed on the side away from the receiving cavity 20, the protrusion 3111 penetrating the through-hole 13. In this way, the first conductive material 31 can be electrically connected to the external electrode via the protrusion 3111.

[0051] Specifically, there is a first gap between the outer periphery of the protrusion 3111 and the wall of the through hole 13. The width of the first gap is within a range of 0.1 to 2 mm, and specifically, the width of the first gap can be 0.1 mm, 0.5 mm, 1.5 mm, or 2 mm. If the gap is less than 0.1 mm, the distance between the protrusion 3111 and the bottom cover 12 is too close, which can easily cause the first conductive material 31 to shift or an error in assembly, resulting in contact between the protrusion 3111 and the bottom cover 12 and a short circuit. If the gap is greater than 2 mm, the gap between the protrusion 3111 and the bottom cover 12 is too large, which can easily affect the sealing performance of the case 10.

[0052] In addition, the insulating adhesive layer 40 has an overflow portion located within the first gap, which prevents the insulating adhesive layer 40 from sliding on the bottom cover 12, while partially adhering the protrusion 3111 so that the protrusion 3111 slides, thereby preventing electrical contact between the protrusion 3111 and the bottom cover 12.

[0053] In addition, a sealing insulating material can be filled into the first gap. In this way, the sealing insulating material insulates the protrusion 3111 from the bottom cover 12, making the battery 100 less likely to short-circuit and improving the stability of the battery 100 in use.

[0054] As shown in FIG. 10 , there is a second gap L2 between the first folded plate 312 and the annular side wall 111, the second gap L2 being in the range of 0.2 to 3 mm. The second gap L2 can be 0.2 mm, 0.8 mm, 1.3 mm, 2 mm, 2.5 mm, or 3 mm. If the second gap L2 is less than 0.2 mm, it becomes more difficult to assemble the first conductive member 31 and the cell 60. If the gap L2 is greater than 3 mm, the overall size of the battery 100 becomes larger, which is detrimental to miniaturizing the battery 100.

[0055] In one possible embodiment, a first insulating layer (not shown) is provided between the first folded plate 312 and the cell 60, and a second insulating layer 50 is provided between the first folded plate 312 and the annular side wall 111. In this way, insulation is maintained between the first folded plate 312 and the top case 11 and between the first folded plate 312 and the cell 60, and a short circuit of the first conductive material 31 can be avoided.

[0056] 7 , a second conductive material 32 is provided in the accommodating cavity 20, and at least a portion of the second conductive material 32 is located between the second tab 62 and the case 10 and electrically connects the second tab 62 and the case 10. The second conductive material 32 and the first conductive material 31 are insulated from each other. In this manner, the second conductive material 32 is partially located between the second tab 62 and the annular side wall 111 and electrically connects the second tab 62 and the annular side wall 111.

[0057] In the embodiment of the present application, the first conductive material 31 and the second conductive material 32 can be collectively referred to as conductive material 30, and the main role of conductive material 30 is to electrically connect the tab of cell 60 to the case 10 or the external electrode.

[0058] Specifically, the second conductive material 32 comprises a second connecting plate 321 and a second bent plate 322 connected to each other, the second connecting plate 321 is attached to the bottom cover 12, the second bent plate 322 is located between the cell 60 and the annular side wall 111, and the second tab 62 is welded to the second bent plate 322.

[0059] In particular, during assembly, the first tab 61 is welded to the first bent plate 312, and the second tab 62 is welded to the second bent plate 322. This allows welding to be performed before assembling the case 10, which is advantageous in reducing the difficulty of processing the battery 100. Furthermore, compared to welding the second tab 62 to the annular side wall 111 via the second bent plate 322, i.e., indirectly fixing the second tab 62 to the annular side wall 111 and directly welding the second tab 62 to the annular side wall 111, welding using this fixing method makes it more difficult to weld through the tabs.

[0060] Furthermore, the shapes of the first connecting plate 311 and the second connecting plate 321 may be the same or different, and the specific shapes may be regular or irregular, and the embodiments of the present application are not limited thereto.

[0061] In one possible embodiment, the height difference between the first connecting plate 311 and the second connecting plate 321 is less than 0.3 mm, and thus the first connecting plate 311 and the second connecting plate 321 can be positioned on the same plane as much as possible, thereby maximizing the energy density of the cell 60 as much as possible.

[0062] 7, the first connecting plate 311 and the second connecting plate 321 have a second gap in the horizontal direction. The width L of the second gap is 0.5 to 5 mm, and specifically, the width L can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm. If the width L is less than 0.5 mm, the distance between the first conductive member 31 and the second conductive member 32 is too close, which may cause misalignment of the conductive member 30 or an assembly error, resulting in contact between the first conductive member 31 and the second conductive member 32 and a short circuit. If the width L is greater than 5 mm, the width L between the first conductive member 31 and the second conductive member 32 is too large, which may cause the contact area between the conductive member 30 and the bottom cover 12 to be too small, thereby affecting the assembly stability of the conductive member 30.

[0063] In one possible embodiment, a porous insulating material (not shown) can be filled in the second gap, which can insulate the first conductive material 31 and the second conductive material 32 while storing the electrolyte. Specifically, the porous insulating material can be foam cotton.

[0064] In this embodiment, the first tab 61 and the second tab 62 are located at the same end of the cell 60. The first folding plate 312 and the second folding plate 322 are located at the same end of the cell 60. The first tab 61 is located on the side of the first folding plate 312 that faces away from the cell 60, and the second tab 62 is located on the side of the second folding plate 322 that faces away from the cell 60. This is advantageous for welding and assembling the battery 100.

[0065] In the embodiment of the present application, the first tab 61 is a positive electrode tab, the second tab 62 is a negative electrode tab, the case 10 is electrically connected to the second conductive material 32, the entire case 10 becomes a negative electrode, and the first conductive material 31 becomes a positive electrode. It can be understood that if the electrical connection method between the tabs of the cell 60 and the first conductive material 31 and the second conductive material 32 is reversed, the entire case 10 becomes a positive electrode, and the first conductive material 31 becomes a negative electrode.

[0066] In one possible embodiment, as shown in Figures 10, 13, and 14, a third insulating layer 70 is further provided between the cell 60 and the first conductive material 31 and between the cell 60 and the second conductive material 32. In this way, the conductive material 30 and the cell 60 are prevented from coming into electrical contact with each other, thereby avoiding short circuits. The third insulating layer 70 may have three parts: a first part located between the tab and the end of the cell 60, a second part located between the cell 60 and the connection plate, and a third part located at the tail of the cell 60.

[0067] In one possible embodiment, there is a third gap of 0 mm or more and less than 1 mm between the end of the first tab 61 and the end of the second tab 62. In this way, the end of the first tab 61 and the end of the second tab 62 can be made as flush as possible, thereby reducing the difficulty of assembling the first tab 61 and the second tab 62. Note that the end of the first tab 61 refers to the end of the first tab 61 that is closest to the annular side wall 111, and the end of the second tab 62 refers to the end of the second tab 62 that is closest to the annular side wall 111.

[0068] In one possible embodiment, the area of ​​the first connecting plate 311 is larger than the area of ​​the second connecting plate 321, and the area ratio between the first connecting plate 311 and the second connecting plate 321 is in the range of 1 to 9.9. Specifically, the area of ​​the first connecting plate 311 may be 1 time, 3 times, 7 times, or 9.9 times the area of ​​the second connecting plate 321. In this way, the arrangement manner of the first conductive material 31 and the second conductive material 32 can be diversified, making it possible to easily arrange the conductive material 30.

[0069] In one possible embodiment, the annular side wall 111 is provided with a reinforcing piece 14 and a liquid inlet 15 spaced apart from each other, and the liquid inlet 15 connects the outside of the case 10 to the accommodating cavity 20. In this manner, welding to an external electrode is possible via the reinforcing piece 14, thereby preventing damage to the case 10. The liquid inlet 15 facilitates the injection of electrolyte. The liquid inlet 15 is provided with a sealing piece 16, which can be welded to the liquid inlet 15 after the electrolyte is injected, thereby preventing liquid leakage from the battery 100. The top cover 112 can further include a pressure relief groove 17 adjacent to the first tab 61 or the second tab 62, thereby facilitating pressure relief for the battery 100 and preventing the battery 100 from exploding. The pressure relief groove 17 may be formed by thinning the top cover 112, and the shape of the pressure relief groove 17 may be an "L" shape, an "O" shape, or other shapes.

[0070] Specifically, the cell 60 is further provided with a finishing adhesive (not shown) located on a pole piece plane close to the top cover 112 and in contact with the inner wall surface of the top cover 112, thus making the assembly of the cell 60 easier and making the cell 60 less likely to cause adhesion failure in the finishing adhesive.

[0071] Furthermore, since the case 10 is a negative electrode, the position of the reinforcing piece 14 can be adjusted according to the position of the external negative electrode, and it can be understood that welding is easier when the reinforcing piece 14 is positioned close to the external negative electrode, and welding is easier when the reinforcing piece 14 and the second tab 62 are positioned on opposite sides of the annular side wall 111, and welding can be avoided by penetrating the annular side wall 111 and the second tab 62 during welding.

[0072] As shown in Figures 11 and 12, an embodiment of the present application provides another battery, in which the second tab 62 of the battery 100 is welded to the annular side wall 111, and a support plate 19 can be provided in the area of ​​the bottom cover 12 where the first conductive material 31 is not provided, and the upper surface of the support plate 19 is at the same height as the upper surface of the connection plate of the first conductive material 31, so that the lower surface of the cell 60 has a complete support surface and can ensure that the cell 60 is maintained in a stable state.

[0073] In addition, since the second tab 62 is directly fixed to the annular side wall 111 by welding, it is possible to effectively prevent the cell 60 from sliding within the accommodating cavity 20 and improve the stability of the battery 100. In addition, the distance between the first tab 61 and the annular side wall 111 is greater than the distance between the second tab 62 and the annular side wall 111, so that the first tab 61 and the annular side wall 111 do not come into contact with each other, thereby preventing the battery 100 from being short-circuited.

[0074] Other technical features of the battery 100 are the same as those of the first type battery, so they will not be described again here.

[0075] In the description of the embodiments of the present application, unless otherwise specified, the terms "attach," "couple," and "connect" should be understood in a broad sense, and may refer to, for example, a fixed connection, an indirect connection through an intermediate medium, or an internal communication or an interactive relationship between two components. Those skilled in the art will understand the specific meaning of the above terms in the present application depending on the specific circumstances. The orientations or positional relationships indicated by terms such as "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are based on the orientations or positional relationships shown in the drawings and are intended solely to facilitate the explanation and simplification of the present application. They do not explicitly or imply that the depicted devices or elements must have a specific orientation, be configured, or operate in a specific orientation, and therefore should not be understood as limiting the present application. In the description of the present application, "plurality" means two or more, unless otherwise specified.

[0076] The terms "first," "second," "third," "fourth," etc. (when present) in the specification and claims of this application, and in the drawings described above, are intended to distinguish between similar objects and are not necessarily intended to describe a particular order or sequence. It should be understood that the data used in this manner can be interchanged as appropriate, such that the embodiments of this application described herein can be performed, for example, in orders other than those shown or described herein. Also, the terms "comprise" and "have," and all variations thereof, are intended to cover non-exclusive inclusions; for example, a process, method, system, product, or device comprising a series of steps or units need not be limited to the explicitly listed steps or units, but may include other steps or units that are not explicitly listed or that are inherent to those processes, methods, products, or devices.

[0077] Finally, it should be noted that the above embodiments are for illustrating the technical solutions of the present application, but are not limiting thereof. The present application will be described in detail with reference to the above embodiments, but those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some or all of the technical features thereof, and these modifications or substitutions will not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0078] This application claims priority to a Chinese patent application entitled "Battery" filed with the China Patent Office on July 29, 2021, bearing application number 202110867172.9, the entire contents of which are incorporated herein by reference.

Claims

1. a conductive case and a battery cell, the case having a top case and a bottom cover, the top case having the top cover and an annular side wall connected to the top cover, the top case and the bottom cover being disposed to cover each other and to commonly surround an accommodating cavity, the battery cell being located within the accommodating cavity; a first conductive material is provided in the accommodating cavity, an insulating adhesive layer is provided between the first conductive material and the bottom cover to connect the first conductive material and the bottom cover, a through hole covered by the first conductive material is provided in the bottom cover, the annular side wall is welded to the bottom cover at an edge on a side closer to the bottom cover, and a welding mark is formed around the annular side wall; a first gap between the weld mark and the insulating adhesive layer, the first gap having a width greater than or equal to three times the width of the weld mark; a first tab of the battery cell electrically connected to the first conductive material, and a second tab of the battery cell electrically connected to the case; The cell has at least two pole pieces of opposite polarity, the cell has a stacking region, the at least two pole pieces located in the stacking region are stacked with each other, and the pole pieces located in the stacking region are parallel to a surface of the bottom cover and / or a top surface of the top case, and a separator is provided between the two pole pieces of opposite polarity, the annular side wall has a flange on an edge closer to the bottom cover, the flange is welded to the bottom cover, and the welding mark is formed around the circumference of the annular side wall, and the welding mark is provided around the outer periphery of the annular side wall; The width of the weld mark is greater than 0 mm and less than or equal to 1 mm; A battery, wherein a ratio of an area of ​​the first conductive material covered by the bottom cover to an area of ​​the bottom cover is 0.4 to 0.

99.

2. 2. The battery of claim 1, wherein the first conductive material comprises a first connecting plate and a first bent plate connected to each other, the first connecting plate being attached to the bottom cover, the first bent plate being located between the cell and the annular side wall, and the first tab being welded to the first bent plate.

3. a protrusion penetrating the through hole on a side of the first connecting plate away from the accommodating cavity; a first gap having a width in a range of 0.1 to 2 mm is formed between an outer peripheral edge of the protrusion and a hole wall of the through hole, and the insulating adhesive layer has an overflow portion located within the first gap; The battery of claim 2 , wherein a sealing insulating material is disposed within the first gap.

4. a second spacing between the first folded plate and the annular side wall in the range of 0.2 to 3 mm; or 3. The battery of claim 2, wherein a first insulating layer is provided between the first folded plate and the cell, and / or a second insulating layer is provided between the first folded plate and the annular side wall.

5. the second tab is welded to the annular side wall; 10. The battery of claim 1, wherein the distance between the first tab and the annular sidewall is greater than the distance between the second tab and the annular sidewall.

6. a second conductive material is provided in the accommodating cavity, the second conductive material being at least partially located between the second tab and the case and electrically connecting the second tab and the case, the second conductive material and the first conductive material being insulated from each other; 3. The battery of claim 2, wherein the second conductive material comprises a second connecting plate and a second bent plate connected to each other, the second connecting plate being attached to the bottom cover, the second bent plate being located between the cell and the annular side wall, and the second tab being welded to the second bent plate.

7. The difference in height between the first connecting plate and the second connecting plate is less than 0.3 mm, there is a second gap between the first connecting plate and the second connecting plate, the width of the second gap is in the range of 0.5 to 5 mm, and / or a porous insulating material is filled in the second gap, or 7. The battery according to claim 6, wherein the area of ​​the first connection plate is larger than the area of ​​the second connection plate, and the area ratio of the first connection plate to the second connection plate is in the range of 1 to 9.

9.

8. the first tab and the second tab are located at the same end of the cell, and the first bent plate and the second bent plate are located at the same end of the cell; the first tab is located on a side of the first folded plate that is away from the cell, and / or the second tab is located on a side of the second folded plate that is away from the cell; a third insulating layer located between the cell and the first conductive material and between the cell and the second conductive material; or 7. The battery of claim 6, wherein there is a third gap between the end of the first tab and the end of the second tab, the third gap being equal to or greater than 0 mm and equal to or less than 1 mm.

9. a reinforcing piece and a liquid inlet are provided on the annular side wall with a gap therebetween, the reinforcing piece and the second tab are located on opposite sides of the annular side wall, the liquid inlet communicates with the outside of the case and the accommodating cavity, and the top cover is provided with a pressure relief groove provided adjacent to the first tab or the second tab, the liquid inlet is provided with a sealing piece that seals the liquid inlet, and / or the cell further comprises a finishing adhesive located on a side of the cell proximal to the top cover.

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