Battery and electric device

Abstract

The present application discloses a battery and an electric device. The battery comprises a case, an electrode assembly and a sealing member. The case comprises a side wall and a bottom wall; the bottom wall, the electrode assembly and the side wall are arranged in a first direction; and the electrode assembly is formed by stacking and then winding a first electrode sheet, a separator and a second electrode sheet. The sealing member is sealingly connected to the outer surface of the bottom wall. The battery also satisfies either of a and b: a, the first electrode sheet is connected to the bottom wall by welding and a first welding line is formed, and when viewed in the first direction, the sealing member covers the first welding line; and b, the battery further comprises a current collecting disc, the bottom wall, the current collecting disc and the electrode assembly are arranged in the first direction, the current collecting disc is connected to the first electrode sheet by welding, the current collecting disc is connected to the bottom wall by welding and a second welding line is formed, and when viewed in the first direction, the sealing member covers the second welding line.

Description

Batteries and electrical devices Technical Field

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

[0002] In cylindrical batteries, the battery casing serves as the output terminal, which is welded to the internal electrode or current collector. Conventional welding processes typically involve resistance welding, ultrasonic welding, or laser penetration welding. However, both resistance and ultrasonic welding can lead to problems such as cold welds, slag, and dust, while laser penetration welding is prone to cracks or flash points, which not only affect battery yield but also reduce assembly efficiency.

[0003] Summary of the Invention

[0004] In view of the above situation, it is necessary to provide a battery that simplifies the assembly process and improves assembly efficiency and battery yield.

[0005] An embodiment of the present application provides a battery, comprising a shell, an electrode assembly and a seal. The shell comprises a side wall and a bottom wall connected to each other, the bottom wall and the side wall are arranged along a first direction, and the side wall and the bottom wall enclose a storage space. The electrode assembly is arranged in the storage space, and the electrode assembly is formed by stacking and winding a first electrode sheet, a diaphragm and a second electrode sheet. At least part of the seal is located outside the shell and is sealed to the outer surface of the bottom wall. The battery also satisfies any one of a and b: a. The first electrode sheet and the bottom wall are welded and connected to form a first weld line, and when viewed in the first direction, the seal covers the first weld line; b. The battery also comprises a current collecting plate, the bottom wall, the current collecting plate and the electrode assembly are arranged along the first direction, the current collecting plate and the first electrode sheet are welded and connected, and the current collecting plate and the bottom wall are welded and connected to form a second weld line, and when viewed in the first direction, the seal covers the second weld line.

[0006] In the above-mentioned battery, the bottom wall of the shell is welded to the first electrode sheet to form a first welding line, or is welded to the current collecting plate to form a second welding line. The outer surface of the bottom wall is connected to the seal by a sealant to cover the first welding line or the second welding line. This is beneficial to reduce the welding requirements for the first welding line / second welding line, simplify the welding process, and improve the assembly efficiency and yield of the battery.

[0007] In some embodiments of the present application, the seal and the outer surface of the bottom wall are welded together, which helps to improve the connection stability between the seal and the bottom wall and reduce the risk of sealing failure between the seal and the bottom wall.

[0008] In some embodiments of the present application, the seal is bonded to the outer surface of the bottom wall, which helps to simplify the connection process between the seal and the bottom wall and improve the assembly efficiency of the battery.

[0009] In some embodiments of the present application, the bottom wall is provided with interconnected recesses and connecting portions, the recesses being recessed along a first direction, and the recesses and connecting portions being arranged in an aligned manner along the first direction. The provision of the recesses helps reduce the weight of the bottom wall and reduces the impact of the weight of the housing on the battery.

[0010] In some embodiments of the present application, the first pole piece, the connecting portion, and the recessed portion are connected by welding to form a first welding line.

[0011] In some embodiments of the present application, the current collecting plate, the connecting portion, and the recessed portion are connected by welding to form a second welding line.

[0012] In some embodiments of the present application, when viewed along the first direction, the seal is located in the recess, which is beneficial for utilizing the space in the recess to accommodate the seal and reducing the impact of the seal on the outer dimensions of the battery.

[0013] In some embodiments of the present application, the seal covers the recess, which helps to improve the sealing effect of the seal and reduce the risk of electrolyte leakage in the battery.

[0014] In some embodiments of the present application, the connection portion is provided with an injection hole, and the sealing member covers the injection hole when viewed along the first direction. Providing the injection hole in the connection portion and the sealing member sealing both the injection hole and the welding wire simultaneously helps reduce the number of battery components and improves space utilization of the housing.

[0015] In some embodiments of the present application, the inner diameter of the recess is defined as d2, the inner diameter of the injection hole is defined as d3, and d2-d3≥2mm, so that the connecting part has sufficient space for welding, and is beneficial to increase the welding area, and improve the flow performance and connection strength between the first pole piece and the connecting part.

[0016] In some embodiments of the present application, d3 ≥ 1 mm, which facilitates liquid injection.

[0017] In some embodiments of the present application, the diameter of the bottom wall is defined as d1, the inner diameter of the recess is defined as d2, and d2 / d1≤80%, which is beneficial to ensure the structural strength and rigidity of the bottom wall, reduce the risk of deformation or damage of the bottom wall, and improve the safety performance of the battery.

[0018] In some embodiments of the present application, 10%≤d2 / d1≤50%, which is beneficial for taking into account both the structural strength of the bottom wall and ensuring that the connecting portion has a sufficient welding area.

[0019] In some embodiments of the present application, the thickness of the bottom wall is defined as t1, the thickness of the connecting portion is defined as t2, and t2 / t1 ≥ 20%, which is beneficial to ensure the structural strength and rigidity of the connecting portion, reduce the risk of deformation or breakage of the connecting portion, improve the safety performance of the battery, and also help to make the recess have sufficient depth to accommodate the seal.

[0020] In some embodiments of the present application, 30%≤t2 / t1≤60%, which is beneficial for balancing the structural strength of the connecting portion and ensuring that the recess has a sufficient depth to accommodate the sealing member.

[0021] In some embodiments of the present application, the outer surface of the bottom wall further comprises a first groove, which is recessed along a first direction and spaced apart from the recessed portion. The first groove can form a weak area in the bottom wall. When the pressure within the housing exceeds a predetermined range, the first groove area can be damaged to release pressure, thereby reducing the risk of battery failure and improving battery safety.

[0022] In some embodiments of the present application, the area of ​​the first welding line is S1, S1 ≥ 2mm 2 , which is beneficial to improving the flow performance and connection strength between the first pole piece and the bottom wall.

[0023] In some embodiments of the present application, the area of ​​the second welding line is S2, S2 ≥ 2mm 2 , which is beneficial to improving the flow performance and connection strength between the collecting plate and the bottom wall.

[0024] In some embodiments of the present application, the first welding line is formed by laser welding, resistance welding, or ultrasonic welding.

[0025] In some embodiments of the present application, the second welding line is formed by laser welding, resistance welding, or ultrasonic welding.

[0026] An embodiment of the present application further provides an electrical device comprising the battery of any one of the aforementioned embodiments.

[0027] In the above-mentioned electrical equipment, the bottom wall of the battery casing is welded to the first electrode sheet to form a first welding line, or is welded to the current collecting plate to form a second welding line. The outer surface of the bottom wall is connected to the seal by a sealant to perform sealing, and the first welding line or the second welding line is covered and sealed, which is beneficial to reduce the welding requirements for the first welding line / second welding line, simplify the welding process, improve the assembly efficiency and yield of the battery, and reduce the impact of the assembly efficiency and yield of the battery on the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a schematic structural diagram of a battery in one embodiment of the present application.

[0029] FIG2 is a cross-sectional view of a battery according to an embodiment of the present application.

[0030] FIG3 is a partial enlarged view of area III in FIG2 .

[0031] FIG4 is a cross-sectional view of a battery according to an embodiment of the present application.

[0032] FIG5 is a partial enlarged view of the V region in FIG4 .

[0033] FIG6 is a schematic structural diagram of an electrode assembly in one embodiment of the present application.

[0034] FIG7 is a partial structural cross-sectional view of a housing in one embodiment of the present application.

[0035] FIG8 is a view of a battery along a first direction in one embodiment of the present application.

[0036] FIG. 9 is a view of a housing and a sealing member in an unconnected state according to an embodiment of the present application.

[0037] FIG10 is an exploded view of a portion of the battery structure in one embodiment of the present application.

[0038] FIG11 is a schematic structural diagram of an electrical device in an embodiment of the present application.

[0039] Description of the main components: Battery 100 Housing 10 Side wall 11 Bottom wall 12 Recess 121 Connecting portion 122 Liquid injection hole 1221 First groove 123 Accommodating space 13 First welding wire 14 Second welding wire 15 Third welding wire 16 Electrode assembly 20 First pole piece 21 First flattened portion 211 Second pole piece 22 Second flattened portion 221 Diaphragm 23 Seal 30 End cap 40 Explosion-proof disk 50 Second groove 51 Orifice plate 60 Through hole 61 Structural member 70 Insulator80 Current collecting plate 90 First direction X Electrical equipment 200

[0040] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be 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, rather than all the embodiments.

[0042] It should be noted that when an element is considered to be “connected” to another element, it may be directly connected to the other element or there may be a centrally disposed element. When an element is considered to be “disposed on” another element, it may be directly disposed on the other element or there may be a centrally disposed element.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0044] An embodiment of the present application provides a battery, comprising a shell, an electrode assembly and a seal. The shell comprises a side wall and a bottom wall connected to each other, the bottom wall and the side wall are arranged along a first direction, and the side wall and the bottom wall enclose a storage space. The electrode assembly is arranged in the storage space, and the electrode assembly is formed by stacking and winding a first electrode sheet, a diaphragm and a second electrode sheet. At least part of the seal is located outside the shell and is sealed to the outer surface of the bottom wall. The battery also satisfies any one of a and b: a. The first electrode sheet and the bottom wall are welded and connected to form a first weld line, and when viewed in the first direction, the seal covers the first weld line; b. The battery also comprises a current collecting plate, the bottom wall, the current collecting plate and the electrode assembly are arranged along the first direction, the current collecting plate and the first electrode sheet are welded and connected, and the current collecting plate and the bottom wall are welded and connected to form a second weld line, and when viewed in the first direction, the seal covers the second weld line.

[0045] In the above-mentioned battery, the bottom wall of the shell is welded to the first electrode sheet to form a first welding line, or is welded to the current collecting plate to form a second welding line. The outer surface of the bottom wall is connected to the seal by a sealant to cover the first welding line or the second welding line. This is beneficial to reduce the welding requirements for the first welding line / second welding line, simplify the welding process, and improve the assembly efficiency and yield of the battery.

[0046] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0047] As shown in FIG. 1 to FIG. 5 , an embodiment of the present application provides a battery 100 , including a housing 10 , an electrode assembly 20 , and a seal 30 .

[0048] The housing 10 includes a side wall 11 and a bottom wall 12 connected to each other. The bottom wall 12 and the side wall 11 are arranged along a first direction X. The side wall 11 and the bottom wall 12 enclose an accommodating space 13 .

[0049] The electrode assembly 20 is disposed in the accommodating space 13 . The bottom wall 12 and the electrode assembly 20 are arranged along the first direction X. The electrode assembly 20 is formed by stacking and winding a first electrode sheet 21 , a separator 23 , and a second electrode sheet 22 .

[0050] At least a portion of the sealing member 30 is located outside the housing 10 and is sealed to the outer surface of the bottom wall 12 .

[0051] Battery 100 also satisfies either a or b:

[0052] a. The first pole piece 21 and the bottom wall 12 are welded together to form a first welding line 14. When viewed along the first direction X, the sealing member 30 covers the first welding line 14.

[0053] b. The battery 100 also includes a current collecting plate 90. The bottom wall 12, the current collecting plate 90, and the electrode assembly 20 are arranged along the first direction X. The current collecting plate 90 and the first electrode sheet 21 are welded together. The current collecting plate 90 and the bottom wall 12 are welded together to form a second welding line 15. When viewed along the first direction X, the seal 30 covers the second welding line 15.

[0054] In the above-mentioned battery 100, the bottom wall 12 of the shell 10 is welded to the first electrode 21 to form a first welding line 14, or is welded to the collecting plate 90 to form a second welding line 15, so that the bottom wall 12 and the first electrode 21 are electrically connected. The welding can appropriately reduce the requirements and allow welding through. The first welding line 14 or the second welding line 15 is covered and sealed by the sealing member 30 to achieve a sealing effect, which is beneficial to reduce the welding requirements for the first welding line 14 / second welding line 15, simplify the welding process, and improve the assembly efficiency and yield of the battery 100.

[0055] In one embodiment, the battery 100 is a cylindrical battery, and the first direction X is the axial direction of the battery 100. Taking Figure 2 as an example, the first direction X is the vertically upward direction along the axial direction. In one embodiment, the battery 100 is a prismatic battery (not shown), and the first direction X is the normal direction of the bottom wall 12.

[0056] In one embodiment, the outer surface of the bottom wall 12 refers to the surface of the bottom wall 12 facing away from the electrode assembly 20 .

[0057] In one embodiment, a welding line refers to a connection area (or trace) formed when two or more items are melted and solidified during the welding process.

[0058] In one embodiment, the bottom wall 12 is provided with a recessed portion 121 and a connecting portion 122 that are connected to each other. The recessed portion 121 is recessed along the first direction X, and the recessed portion 121 and the connecting portion 122 are arranged along the first direction X. The provision of the recessed portion 121 helps to reduce the weight of the bottom wall 12 and reduce the impact of the weight of the housing 10 on the battery 100.

[0059] In one embodiment, the bottom wall 12 is a flat plate structure (not shown), which is beneficial for simplifying the processing and manufacturing process of the housing 10 , improving the manufacturing efficiency of the housing 10 , and reducing the cost of the housing 10 .

[0060] As an example, the bottom wall 12 is provided with a recessed portion 121 and a connecting portion 122 as an example for further explanation.

[0061] As shown in FIG2 , FIG3 and FIG6 , in one embodiment, along a direction opposite to the first direction X, a portion of the first electrode sheet 21 (a blank current collector without coating) extends beyond the separator 23 and is flattened to form a first flattened portion 211 .

[0062] In one embodiment, the first flattened portion 211 and the connecting portion 122 are welded together to form a first welding line 14. The flattened first flattened portion 211 connected to the connecting portion 122 facilitates welding, improves the connection strength between the first flattened portion 211 and the bottom wall 12, and improves the flow performance between the first flattened portion 211 and the bottom wall 12. It also helps to reduce the axial length of the battery 100 and improve its energy density.

[0063] In one embodiment, the first welding line 14 is formed by any one of laser welding, resistance welding and ultrasonic welding.

[0064] In another embodiment, the first welding line 14 is formed by laser welding.

[0065] In one embodiment, the area of ​​the first welding line 14 is S1, S1 ≥ 2 mm 2 This is beneficial to improving the flow performance between the first flattened portion 211 and the bottom wall 12, improving the electrochemical performance of the battery 100, and also beneficial to improving the connection strength between the first flattened portion 211 and the bottom wall 12, reducing the risk of poor contact.

[0066] As shown in Figures 4 to 6, in one embodiment, the first flattened portion 211 is welded to the current collecting plate 90, which is then welded to the connecting portion 122 of the bottom wall 12. The connection of the first electrode 21 to the bottom wall 12 via the current collecting plate 90 facilitates welding, improves welding quality, and enhances the shock resistance and electrochemical performance of the battery 100.

[0067] In one embodiment, the current collecting plate 90 and the first flattened portion 211 are welded together, which is beneficial to improving the connection strength between the first flattened portion 211 and the current collecting plate 90 and improving the flow performance between the first flattened portion 211 and the current collecting plate 90 .

[0068] In one embodiment, the current collecting plate 90 and the connecting portion 122 are connected by welding to form a second welding line 15 .

[0069] In one embodiment, the second welding line 15 is formed by any one of laser welding, resistance welding and ultrasonic welding.

[0070] In one embodiment, the second welding line 15 is formed by laser welding.

[0071] In one embodiment, the area of ​​the second welding line 15 is S2, S2 ≥ 2 mm 2 , which is beneficial to improving the flow performance between the collecting plate 90 and the bottom wall 12, improving the electrochemical performance of the battery 100, and also beneficial to improving the connection strength between the collecting plate 90 and the bottom wall 12, reducing the risk of poor contact.

[0072] As an example, the following further describes the example of the first pole piece 21 being connected to the bottom wall 12 via the current collecting plate 90 .

[0073] In one embodiment, the area S2 of the second welding line 15 is calculated as follows: along the radial direction of the recess 121, the outer radius R and the inner radius r of the ring where the second welding line 15 is located are measured, S2 = π*(R 2 -r 2 In one embodiment, the width Rr of the second weld line 15 is 0.1 mm to 2 mm. In another embodiment, the area S2 of the second weld line 15 can also be calculated using the following method: along the radial direction of the recess 121, measure the diameter D at the center line of the circular ring where the second weld line 15 is located, and the width w of the second weld line 15, then S2 = π * D * w. The area S1 of the first weld line 14 can also be calculated using any of the above methods.

[0074] In some embodiments, along the radial direction of the recess 121, the first welding line 14 and / or the second welding line 15 are arranged in the middle of the recess 121, which is beneficial to improve the connection strength between the first flattened portion 211 or the collecting plate 90 and the bottom wall 12 and reduce the risk of poor contact.

[0075] In one embodiment, the seal 30 is bonded to the outer surface of the bottom wall 12 (not shown), which simplifies the process of connecting the seal 30 and the bottom wall 12 and improves the assembly efficiency of the battery 100. In one embodiment, the seal 30 is a sealing tape. In one embodiment, the seal 30 covers the recess 121, which improves the sealing effect of the seal 30 and reduces the risk of electrolyte leakage within the battery 100.

[0076] In one embodiment, the seal 30 is made of metal and is welded to the outer surface of the bottom wall 12, which helps to improve the connection stability between the seal 30 and the bottom wall 12 and reduce the risk of sealing failure between the seal 30 and the bottom wall 12. In one embodiment, the seal 30 is a sealing nail.

[0077] As shown in Figures 5, 7 and 8, in one embodiment, the seal 30 and the bottom wall 12 are welded to form a third welding line 16. When observed along the first direction X, the third welding line 16 is a closed circular ring, which is conducive to sealing, reducing the risk of leakage of electrode liquid from the gap between the seal 30 and the bottom wall 12, and also conducive to improving the connection stability between the seal 30 and the bottom wall 12.

[0078] In one embodiment, the sealing member 30 is located in the recess 121 , which helps to utilize the space in the recess 121 to accommodate the sealing member 30 and reduce the impact of the sealing member 30 on the outer dimensions of the battery 100 .

[0079] In one embodiment, along a direction opposite to the first direction X, the sealing member 30 does not extend beyond the bottom wall 12 , which helps to reduce the impact of the sealing member 30 on the outer dimensions of the battery 100 .

[0080] In one embodiment, a region to be welded is formed between the end of the seal 30 and the end of the recess 121 along a direction opposite to the first direction X. The welding equipment performs a welding operation in the region to be welded to form a third weld line 16, which helps to reduce the impact of the third weld line 16 on the outer contour of the battery 100.

[0081] In one embodiment, the recess 121 is formed by a milling process, which is beneficial to improving the overall strength and rigidity of the bottom wall 12 , reducing the risk of deformation or damage of the bottom wall 12 , and improving the safety performance of the battery 100 .

[0082] In one embodiment, the bottom wall 12 is formed into a recess 121 by a stamping process (as shown in FIG9 ), and the thickness consistency of the bottom wall 12 is high, which is beneficial to reducing the thickness of the bottom wall 12 , reducing the weight of the shell 10 , and reducing the impact of the weight of the shell 10 on the battery 100 .

[0083] As an example, the concave portion 121 is processed by a milling process as an example for further explanation.

[0084] In one embodiment, the diameter of the bottom wall 12 is defined as d1, the inner diameter of the recess 121 is defined as d2, and d2 / d1≤80%. This is beneficial for ensuring the structural strength and rigidity of the bottom wall 12, reducing the risk of deformation or damage of the bottom wall 12, and improving the safety performance of the battery 100.

[0085] In one embodiment, 10%≤d2 / d1≤50%, which is beneficial for balancing the structural strength of the bottom wall 12 and ensuring that the connecting portion 122 has a sufficient welding area.

[0086] In one embodiment, d2 / d1 is any one of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% and 80%, which is beneficial to ensure the structural strength and rigidity of the bottom wall 12, reduce the risk of deformation or damage of the bottom wall 12, and improve the safety performance of the battery 100.

[0087] In one embodiment, d2 ≥ 3 mm, which is beneficial for ensuring that the connection portion 122 has a sufficient welding area, thereby improving the welding strength and flow performance between the connection portion 122 and the current collecting plate 90 .

[0088] In one embodiment, the thickness of the bottom wall 12 is defined as t1, and the thickness of the connecting portion 122 is defined as t2. t2 / t1 ≥ 20%. This helps ensure the structural strength and rigidity of the connecting portion 122, reduces the risk of deformation or damage to the connecting portion 122, and improves the safety performance of the battery 100. It also helps ensure that the recess 121 has a certain depth to accommodate the sealing member 30. The thickness t1 refers to the maximum thickness of the bottom wall 12.

[0089] In one embodiment, 30%≤t2 / t1≤60%, which is beneficial for balancing the structural strength of the connecting portion 122 and ensuring that the recess 121 has a sufficient depth to accommodate the sealing member 30.

[0090] In one embodiment, t2 / t1 is any one of 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% and 90%, which is beneficial to ensure the structural strength and rigidity of the connecting portion 122, reduce the risk of deformation or breakage of the connecting portion 122, improve the safety performance of the battery 100, and also help the recess 121 have a certain depth to accommodate the seal 30.

[0091] In one embodiment, t2 ≥ 0.2 mm, which is beneficial for ensuring that the connecting portion 122 has sufficient thickness to ensure its structural strength and rigidity, reduce the risk of deformation or breakage of the connecting portion 122 , and improve the safety performance of the battery 100 .

[0092] In one embodiment, the connection portion 122 is provided with a liquid injection hole 1221, and the sealing member 30 covers the liquid injection hole 1221 when viewed along the first direction X. Providing the liquid injection hole 1221 on the connection portion 122 allows the sealing member 30 to simultaneously seal the liquid injection hole 1221 and the welding wire, thereby reducing the number of sealing components of the battery 100, improving the space utilization of the housing 10, and reducing the impact of providing the liquid injection hole 1221 in other locations on the battery 100.

[0093] In one embodiment, when viewed along the first direction X, the injection hole 1221 is located at the center of the recess 121 , and the recess 121 is located at the center of the bottom wall 12 , which is beneficial to the processing and manufacturing of the bottom wall 12 , and is also beneficial to positioning during the assembly process, facilitating injection and improving injection efficiency.

[0094] In one embodiment, a through hole (not shown) is provided at a position of the collecting plate 90 corresponding to the injection hole 1221 to facilitate smooth injection of the electrode liquid into the housing 10 .

[0095] In one embodiment, the first welding wire 14 is arranged around the injection hole 1221, which is beneficial to improving the connection strength between the first electrode piece 21 and the connecting portion 122, increasing the area of ​​the first welding wire 14, and improving the flow performance between the first electrode piece 21 and the bottom wall 12.

[0096] In one embodiment, the second weld line 15 is disposed around the liquid injection hole 1221, which helps to improve the connection strength between the current collecting plate 90 and the connecting portion 122, increase the area of ​​the second weld line 15, and improve the flow performance between the current collecting plate 90 and the bottom wall 12. In one embodiment, along the radial direction of the recess 121, the second weld line 15 is located in the middle area between the liquid injection hole 1221 and the side wall of the recess 121.

[0097] In one embodiment, the inner diameter of the injection hole 1221 is defined as d3, d2-d3≥2mm, so that the connection portion 122 has sufficient space for welding, which is beneficial to increasing the area of ​​the second welding line 15 and improving the flow performance and connection strength between the collecting plate 90 and the connection portion 122.

[0098] In one embodiment, d3 ≥ 1 mm, which facilitates liquid injection and improves liquid injection efficiency.

[0099] In one embodiment, the outer surface of the bottom wall 12 further defines a first groove 123, which is recessed along the first direction X and spaced apart from the recess 121. The area where the first groove 123 is located can serve as a weak area of ​​the bottom wall 12. When the pressure within the housing 10 is excessive, the gas within the housing 10 can break through the area of ​​the first groove 123 to relieve pressure, thereby reducing the risk of explosion of the battery 100 and improving the safety of the battery 100.

[0100] As shown in Figures 4, 6 and 10, in one embodiment, one of the first electrode 21 and the second electrode 22 is a positive electrode and the other is a negative electrode. Alternatively, the first electrode 21 is a negative electrode and the second electrode 22 is a positive electrode.

[0101] In one embodiment, the first electrode 21 is electrically connected to the housing 10 via the connecting bottom wall 12 , and the housing 10 serves as an output terminal of the battery 100 .

[0102] In one embodiment, along the first direction X, a portion of the second electrode piece 22 extends beyond the diaphragm 23 to form a second flattened portion 221 .

[0103] The battery 100 further includes a structural member 70, an orifice plate 60, an explosion-proof disc 50, and an end cap 40. The electrode assembly 20, the structural member 70, the orifice plate 60, the explosion-proof disc 50, and the end cap 40 are arranged along the first direction X. The structural member 70 connects the second flattened portion 221 and the orifice plate 60, and the explosion-proof disc 50 connects the orifice plate 60 and the end cap 40, thereby electrically connecting the second electrode sheet 22 and the end cap 40. The end cap 40 serves as an output terminal of the battery 100. In one embodiment, the end cap 40 can serve as the positive terminal of the battery 100, and the housing 10 can serve as the negative terminal of the battery 100.

[0104] In one embodiment, the battery 100 further includes an insulating member 80, which connects the side wall 11 and the explosion-proof disk 50. The insulating member 80 provides insulation and reduces the risk of short circuiting in the battery 100. In one embodiment, the insulating member 80 connects the side wall 11 and the orifice plate 60, which further reduces the risk of short circuiting in the battery 100.

[0105] In one embodiment, the insulating member 80 is made of plastic material, which is beneficial to ensuring its insulation effect and reducing its own weight, thereby reducing the impact of its weight on the battery 100.

[0106] In one embodiment, the insulating member 80 is formed by melting plastic and then solidifying it using an injection molding machine, which helps to simplify the manufacturing process of the insulating member 80, improve the manufacturing efficiency of the insulating member 80, and reduce costs.

[0107] In one embodiment, the material of the insulating member 80 includes but is not limited to any one of silicone, rubber, polypropylene (PP), and polyethylene terephthalate (PET).

[0108] In one embodiment, the explosion-proof disk 50 is provided with a second groove 51, which is recessed in a direction opposite to the first direction X. The second groove 51 constitutes a weak area of ​​the explosion-proof disk 50. The orifice plate 60 is provided with a through hole 61, which allows electrolyte or gas to pass through.

[0109] In one embodiment, when the gas pressure in the battery 100 increases, the gas can act on the explosion-proof disk 50 through the through hole 61. When the gas pressure increases to the pressure resistance threshold of the weak area of ​​the explosion-proof disk 50, the gas in the shell 10 can break through the explosion-proof disk 50 to achieve the purpose of pressure relief, reduce the risk of explosion of the battery 100, and improve the safety performance of the battery 100.

[0110] In order to verify the safety and electrochemical performance of the battery 100 of the present application, a flatness test of the bottom wall 12, a welding tensile test between the bottom wall 12 and the current collecting plate 90, and a temperature rise test of the battery 100 were performed.

[0111] The flatness of bottom wall 12 is tested using a Keyence VR3000 visual testing device. A circular ring extending from the outer edge of recess 121 to the outer edge of bottom wall 12 is selected and tested for flatness. A greater flatness of bottom wall 12 indicates greater deformation and greater vulnerability to deformation, indicating lower rigidity.

[0112] Among them, the method of welding tensile test is: cut off the welded bottom wall 12 and the collecting plate 90 as a whole, use a multi-functional tensile testing machine, clamp the bottom wall 12 at one end and clamp the collecting plate 90 at the other end (a special clamp is required for clamping, which is not described in detail in this application), select a tensile speed of 50 mm / min, and perform the test. When the sample is broken, its breaking tensile value F is obtained.

[0113] The temperature rise test method is as follows: placing the battery 100 in a constant temperature environment of 25° C., attaching a temperature-sensitive wire to the center of the outer surface of the side wall 11 of the battery 100 , and recording the temperature rise data under 2C discharge.

[0114] Example 1:

[0115] The diameter d1 of the bottom wall 12 is 30 mm, the diameter d2 of the recess 121 is 10 mm, the diameter d3 of the injection hole 1221 is 2 mm, the thickness t1 of the bottom wall 12 is 1 mm, the thickness t2 of the connecting portion 122 is 0.5 mm, the thickness of the sealing member 30 is 0.4 mm, the depth of the recess 121 is 0.5 mm, the value of d2 / d1 is 33.3%, the value of t2 / t1 is 50%, the value of d2-d3 is 8 mm, and the area S2 of the second welding line 15 is 3.7 mm 2 .

[0116] Example 2:

[0117] The only difference from Example 1 is that the diameter d2 of the recess 121 is 15 mm, and the value of d2 / d1 is 50%.

[0118] Example 3:

[0119] The only difference from Example 1 is that the diameter d2 of the recess 121 is 20 mm, and the value of d2 / d1 is 66.7%.

[0120] Example 4:

[0121] The only difference from Example 1 is that the diameter d2 of the recess 121 is 24 mm, and the value of d2 / d1 is 80%.

[0122] Example 5:

[0123] The only difference from Example 1 is that the diameter d2 of the recess 121 is 3 mm, and the value of d2 / d1 is 10%.

[0124] Comparative Example 1:

[0125] The only difference from Example 1 is that the diameter d2 of the recess 121 is 25 mm, and the value of d2 / d1 is 83.3%.

[0126] Example 6:

[0127] The only difference from Example 1 is that the thickness t2 of the connecting portion 122 is 0.2 mm, the depth of the recess 121 is 0.8 mm, and the value of t2 / t1 is 20%.

[0128] Example 7:

[0129] The only difference from Example 6 is that the thickness t2 of the connecting portion 122 is 0.3 mm, the depth of the recess 121 is 0.7 mm, and the value of t2 / t1 is 30%.

[0130] Example 8:

[0131] The only difference from Example 6 is that the thickness t2 of the connecting portion 122 is 0.9 mm, the depth of the recess 121 is 0.1 mm, and the value of t2 / t1 is 90%.

[0132] Example 9:

[0133] The only difference from Example 6 is that the thickness t2 of the connecting portion 122 is 0.6 mm, the depth of the recess 121 is 0.4 mm, and the value of t2 / t1 is 60%.

[0134] Comparative Example 2:

[0135] The only difference from Example 6 is that the thickness t2 of the connecting portion 122 is 0.1 mm, the depth of the recess 121 is 0.9 mm, and the value of t2 / t1 is 10%.

[0136] Comparative Example 3:

[0137] The only difference from Example 1 is that the diameter d2 of the recess 121 is 3 mm, the value of d2-d3 is 1 mm, and the area S2 of the second welding line 15 is 1.5 mm. 2 .

[0138] Example 10:

[0139] The only difference from Example 9 is that the diameter d2 of the recess 121 is 5 mm, the value of d2-d3 is 3 mm, and the area S2 of the second welding line 15 is 2.1 mm. 2 .

[0140] Example 11:

[0141] The only difference from Example 9 is that the diameter d2 of the recess 121 is 8 mm, the value of d2-d3 is 6 mm, and the area S2 of the second welding line 15 is 3.1 mm. 2 .

[0142] Example 12:

[0143] The only difference from Example 9 is that the diameter d2 of the recess 121 is 12 mm, the value of d2-d3 is 10 mm, and the area S2 of the second welding line 15 is 4.4 mm. 2 .

[0144] The flatness test, welding tensile test and temperature rise test of the bottom wall 12 were respectively carried out on the above-mentioned multiple groups of embodiments and comparative examples, and the test results were statistically analyzed to obtain the following Table 1:

[0145] Table 1

[0146] As shown in Table 1 above, it can be concluded from Comparative Example 1 and Examples 1-5 that reducing the ratio between the diameter d2 of the recess 121 and the diameter d1 of the bottom wall 12 helps reduce the flatness of the bottom wall 12 and reduces the risk of deformation of the bottom wall 12. It can be concluded from Comparative Example 2 and Examples 1, 6-9 that increasing the ratio between the thickness t2 of the connection portion 122 and the thickness t1 of the bottom wall 12 helps reduce the flatness of the bottom wall 12 and reduces the risk of deformation of the bottom wall 12. It can be concluded from Comparative Example 3 and Examples 1, 10-12 that increasing the difference between the diameter d2 of the recess 121 and the diameter d3 of the injection hole 1221, as well as increasing the area of ​​the second weld line 15, helps improve the connection strength between the bottom wall 12 and the current collecting plate 90 (i.e., improves the reliability of the weld) and reduces the temperature rise of the battery 100.

[0147] To summarize, in the battery 100 of the present application, the bottom wall 12 of the shell 10 is welded to the first electrode 21 to form a first welding line 14, or is welded to the current collecting plate 90 to form a second welding line 15. The outer surface of the bottom wall 12 is connected by the seal 30 to cover and seal the first welding line 14 or the second welding line 15, which is beneficial to reduce the welding requirements for the first welding line 14 / second welding line 15, simplify the welding process, and improve the assembly efficiency and yield of the battery 100.

[0148] As shown in FIG11 , an embodiment of the present application further provides an electric device 200 , comprising the battery 100 according to any one of the aforementioned embodiments.

[0149] In the above-mentioned electrical equipment 200, the bottom wall 12 of the battery 100 shell 10 is welded to the first electrode 21 to form a first welding line 14, or is welded to the collecting plate 90 to form a second welding line 15. The outer surface of the bottom wall 12 is connected by the seal 30 to cover and seal the first welding line 14 or the second welding line 15, which is beneficial to reduce the welding requirements for the first welding line 14 / second welding line 15, simplify the welding process, improve the assembly efficiency and yield of the battery 100, and reduce the impact of the assembly efficiency and yield of the battery 100 on the electrical equipment 200.

[0150] In one embodiment, the electric device 200 includes but is not limited to any one of an electric vehicle, an electric two-wheeled vehicle, a drone, a home appliance, an electronic product, and a robot.

[0151] In addition, those skilled in the art may also make other changes within the spirit of this application. Of course, these changes made according to the spirit of this application should be included in the scope disclosed in this application.

Claims

1. A battery, characterized in that: include: A housing, the housing comprising a side wall and a bottom wall connected to each other, the bottom wall and the side wall are arranged along a first direction, and the side wall and the bottom wall enclose a receiving space; An electrode assembly, the electrode assembly being disposed in the accommodation space, the electrode assembly being formed by stacking a first electrode sheet, a diaphragm, and a second electrode sheet and then winding them; a sealing member, at least a portion of which is located outside the housing and is sealingly connected to an outer surface of the bottom wall; The battery also satisfies any one of a and b: a. The first pole piece and the bottom wall are welded to form a first welding line, and when viewed along the first direction, the sealing member covers the first welding line; b. The battery further includes a current collecting plate, the bottom wall, the current collecting plate and the electrode assembly are arranged along the first direction, the current collecting plate and the first electrode sheet are welded and connected, the current collecting plate and the bottom wall are welded and connected to form a second welding line, and when viewed along the first direction, the sealing member covers the second welding line.

2. The battery according to claim 1, characterized in that The sealing member is connected to the outer surface of the bottom wall by welding, or the sealing member is bonded to the outer surface of the bottom wall.

3. The battery according to claim 1, characterized in that The bottom wall is provided with a recessed portion and a connecting portion connected to each other, the recessed portion is sunken along the first direction, and the recessed portion and the connecting portion are arranged in an array along the first direction; The first pole piece, the connecting portion and the recess are connected by welding to form the first welding line, or the current collecting plate, the connecting portion and the recess are connected by welding to form the second welding line; Viewed along the first direction, the sealing member is located in the recess, or the sealing member covers the recess.

4. The battery according to claim 3, characterized in that The connecting portion is provided with a liquid injection hole; When viewed along the first direction, the sealing member covers the liquid injection hole.

5. The battery according to claim 4, characterized in that The inner diameter of the recess is defined as d2, the inner diameter of the injection hole is defined as d3, and d2-d3≥2mm.

6. The battery according to claim 5, characterized in that d3≥1mm.

7. The battery according to claim 3, characterized in that The diameter of the bottom wall is defined as d1, the inner diameter of the recess is defined as d2, and d2 / d1≤80%.

8. The battery according to claim 7, characterized in that 10%≤d2 / d1≤50%.

9. The battery according to claim 3, characterized in that The thickness of the bottom wall is defined as t1, the thickness of the connecting portion is defined as t2, and t2 / t1≥20%.

10. The battery according to claim 9, characterized in that 30%≤t2 / t1≤60%.

11. The battery according to claim 3, characterized in that The outer surface of the bottom wall is further provided with a first groove, which is recessed along the first direction and spaced apart from the recess.

12. The battery according to claim 1, characterized in that The area of ​​the first welding line is S1, or the area of ​​the second welding line is S2, S1 or S2 ≥ 2mm 2 .

13. The battery according to claim 1, characterized in that The first welding line or the second welding line is formed by laser welding, resistance welding or ultrasonic welding.

14. An electrical device, characterized in that: Comprising a battery as claimed in any one of claims 1 to 13.

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