Battery cell, battery, method for manufacturing battery cell and battery, and electric device

Abstract

A battery cell (12), a battery (100), a method for manufacturing a battery cell (12) and a battery (100), and an electric device. The battery cell (12) comprises a housing (121), an electrode terminal (123), and an electrode assembly (122), wherein the electrode terminal (123) is arranged on the housing (121) and has a first end exposed inside the housing (121), the electrode assembly (122) is arranged in the housing (121) and comprises a power lead-out portion (1220), and the power lead-out portion (1220) is welded to the first end of the electrode terminal (123) to form a first welded portion (126). The first end of the electrode terminal (123) is provided with a first groove (1231), and the first groove (1231) is adjacent to the first welded portion (126), and / or, the power lead-out portion (1220) is provided with a second groove (125), and the second groove (125) is adjacent to the first welded portion (126). The battery cell (12) has a low risk of missed detection during inspection.

Description

Battery cell, battery, manufacturing method of battery cell and battery, and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery cell, a battery, a manufacturing method of the battery cell and the battery, and an electric device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] How to reduce the risk of missed killing of battery cell products is a problem to be solved in battery technology.

[0004] SUMMARY

[0005] In view of the above problems, the present application provides a battery cell, a battery, a manufacturing method of the battery cell and the battery, and an electric device, which can reduce the risk of missed killing of battery cell products.

[0006] In a first aspect, the present application provides a battery cell, the battery cell comprising a shell, an electrode terminal and an electrode assembly, the electrode terminal being arranged in the shell, the electrode terminal having a first end exposed in the shell, the electrode assembly being arranged in the shell, the electrode assembly comprising an electric energy leading part, the electric energy leading part being welded with the first end of the electrode terminal to form a first welding part. Wherein the first end of the electrode terminal is provided with a first groove, the first groove being adjacent to the first welding part, and / or the electric energy leading part is provided with a second groove, the second groove being adjacent to the first welding part.

[0007] In the technical scheme of the present application, whether the battery cell is a good product is determined by judging whether the first welding part exceeds the groove bottom surface of the first groove, or whether the battery cell is a good product is determined by judging whether the first welding part exceeds the groove bottom surface of the second groove, which is beneficial to reduce the risk of missed killing of battery cell products. When the first end of the electrode terminal is provided with the first groove and the electric energy leading part is provided with the second groove, the battery cell product can always have a lower risk of missed killing under the working condition of welding in different directions.

[0008] In one or more embodiments of the first aspect, at least part of the first welding part exceeds the groove bottom surface of the first groove in the direction of the electrode assembly pointing to the electrode terminal, and / or at least part of the first welding part exceeds the groove bottom surface of the second groove in the direction of the electrode terminal pointing to the electrode assembly.

[0009] In the above scheme, when the electrode terminal and the power lead-out portion of the electrode assembly are welded, a part of the groove bottom surface of the first groove is melted, the unmelted part of the groove bottom surface of the first groove is connected with the first welding portion; and / or, a part of the groove bottom surface of the second groove is melted, the unmelted part of the groove bottom surface of the second groove is connected with the first welding portion, so that the penetration depth of the first welding portion is sufficient, thereby making the battery cell have higher reliability.

[0010] In one or more embodiments of the first aspect, the first end of the electrode terminal has a first surface facing the electrode assembly, and the first groove is arranged on the first surface; and / or the power lead-out portion has a second surface facing the electrode terminal, and the second groove is arranged on the second surface.

[0011] In the above scheme, the first groove is arranged on the first surface, and / or the second groove is arranged on the second surface, so that the machining difficulty is lower.

[0012] In one or more embodiments of the first aspect, at least one end of the first groove extends to the edge of the first surface; and / or at least one end of the second groove extends to the edge of the second surface.

[0013] In the above scheme, since at least one end of the first groove extends to the edge of the first surface, and / or at least one end of the second groove extends to the edge of the second surface. Therefore, during the detection of the battery cell, the detection position can be more flexible, and the risk of missing detection due to the absence of the groove at the detection position is reduced.

[0014] In one or more embodiments of the first aspect, a plurality of first grooves are arranged, and the plurality of first grooves are arranged at intervals; and / or a plurality of second grooves are arranged, and the plurality of second grooves are arranged at intervals.

[0015] In the above scheme, a plurality of first grooves and / or a plurality of second grooves are arranged, which can further reduce the risk of missing detection due to the absence of the groove at the detection position.

[0016] In one or more embodiments of the first aspect, the plurality of first grooves are parallel to each other, the distance between two adjacent first grooves is L1, and 0.05mm≤L1≤20mm is satisfied; and / or the plurality of second grooves are parallel to each other, the distance between two adjacent second grooves is L2, and 0.05mm≤L2≤20mm is satisfied.

[0017] In the scheme, when L1 is greater than or equal to 0.05 mm, the distance between the two adjacent first grooves is relatively wide, and the risk of stress concentration of the electrode terminal is reduced; when L1 is less than or equal to 20 mm, the risk of battery cell product missing caused by the first welding part at the detection position being located between the two first grooves due to the distance between the two first grooves being too wide is reduced. Therefore, when 0.05 mm≤L1≤20 mm, the risk of battery cell product missing is reduced, and the reliability of the battery cell is improved.

[0018] When L2 is greater than or equal to 0.05 mm, the distance between the two adjacent second grooves is relatively wide, and the risk of stress concentration of the electric energy leading part is reduced; when L2 is less than or equal to 20 mm, the risk of battery cell product missing caused by the first welding part at the detection position being located between the two second grooves due to the distance between the two second grooves being too wide is reduced. Therefore, when 0.05 mm≤L2≤20 mm, the risk of battery cell product missing is reduced, and the reliability of the battery cell is improved.

[0019] In one or more embodiments of the first aspect, the extension trajectory of the first groove is a curve or a polyline; and / or, the extension trajectory of the second groove is a curve or a polyline.

[0020] In the scheme, since the extension trajectory of the first groove is a curve or a polyline, and / or the extension trajectory of the second groove is a curve or a polyline, when the battery cell is detected after the electrode terminal and the electric energy leading part are welded, the first groove at the detection position is more likely to be adjacent to the first welding part. Therefore, whether the battery cell is a good product can be determined by judging whether the first welding part exceeds the groove bottom surface of the first groove, so as to reduce the risk of battery cell product missing. Or, the second groove at the detection position is more likely to be adjacent to the second welding part. Therefore, whether the battery cell is a good product can be determined by judging whether the second welding part exceeds the groove bottom surface of the second groove, so as to reduce the risk of battery cell product missing.

[0021] In one or more embodiments of the first aspect, the depth of the first groove is D1, and 50 μm≤D1≤1000 μm is satisfied; and / or, the depth of the second groove is D2, and 50 μm≤D2≤1000 μm is satisfied.

[0022] In the scheme, since the first welding part of the good product of the battery cell exceeds the groove bottom surface of the first groove, when D1 is greater than or equal to 50 μm, the first welding part of the good product of the battery cell has a relatively large depth, and the electrode terminal and the electric energy leading part have a relatively high connection strength; when D1 is less than or equal to 1000 μm, the risk of excessive welding deformation during welding caused by the excessive penetration of the first welding part is reduced. Therefore, when 50 μm≤D1≤1000 μm, the risk of excessive welding deformation during welding is reduced while the electrode terminal and the electric energy leading part have a relatively high connection strength.

[0023] When D2 is greater than or equal to 50 microns, the first welding portion of the good battery cell has a greater depth, and the electrode terminal and the power lead-out portion have a higher connection strength. When D2 is less than or equal to 1000 microns, the risk of excessive welding deformation during welding can be reduced. Therefore, when 50 microns ≤ D2 ≤ 1000 microns, the risk of excessive welding deformation during welding can be reduced while the electrode terminal and the power lead-out portion have a higher connection strength.

[0024] In one or more embodiments of the first aspect, the first groove has a width H1 that satisfies 0.05 mm ≤ H1 ≤ 20 mm; and / or, the second groove has a width H2 that satisfies 0.05 mm ≤ H2 ≤ 20 mm.

[0025] When H1 is greater than or equal to 0.05 mm, the first groove has a greater width, and the first welding portion is more likely to be adjacent to the first groove at a detection position when the battery cell is detected after the electrode terminal is welded to the power lead-out portion, and the risk of product leakage of the battery cell is lower. When H1 is less than or equal to 20 mm, the structural strength of the electrode terminal is higher. Therefore, when 0.05 mm ≤ H1 ≤ 20 mm, the risk of product leakage of the battery cell can be reduced while the battery cell has a higher reliability.

[0026] When H2 is greater than or equal to 0.05 mm, the second groove has a greater width, and the first welding portion is more likely to be adjacent to the second groove at a detection position when the battery cell is detected after the electrode terminal is welded to the power lead-out portion, and the risk of product leakage of the battery cell is lower. When H2 is less than or equal to 20 mm, the structural strength of the electrode terminal is higher. Therefore, when 0.05 mm ≤ H2 ≤ 20 mm, the risk of product leakage of the battery cell can be reduced while the battery cell has a higher reliability.

[0027] In one or more embodiments of the first aspect, the first end of the electrode terminal is provided with the first groove, the electrode assembly includes a tab, and the power lead-out portion is the tab.

[0028] In the above scheme, the power inside the battery cell can be led out by welding the tab to the electrode terminal. After welding, whether the battery cell is a good product can be determined by determining whether the first welding portion exceeds the groove bottom surface of the first groove, which helps to reduce the risk of product leakage of the battery cell.

[0029] In one or more embodiments of the first aspect, the first end of the electrode terminal is provided with the first groove, the electrode assembly includes a tab and a transition piece, the tab is welded to the transition piece, and the power lead-out portion is the transition piece.

[0030] In the above scheme, the electrical energy inside the battery monomer can be led out by welding the tab, the adapter piece and the electrode terminal. After welding, whether the battery monomer is a good product can be determined by judging whether the first welding part exceeds the groove bottom surface of the first groove, which is conducive to reducing the risk of missed killing of the battery monomer product.

[0031] In one or more embodiments of the first aspect, the electrode assembly includes a tab, and the electrical energy leading-out part is the tab, and the tab is provided with a second groove.

[0032] In the above scheme, the electrical energy inside the battery monomer can be led out by welding the tab and the electrode terminal. After welding, whether the battery monomer is a good product can be determined by judging whether the first welding part exceeds the groove bottom surface of the second groove, which is conducive to reducing the risk of missed killing of the battery monomer product.

[0033] In one or more embodiments of the first aspect, the electrode assembly includes a tab and an adapter piece, the tab is welded with the adapter piece, and the electrical energy leading-out part is the adapter piece, and the adapter piece is provided with a second groove.

[0034] In the above scheme, the electrical energy inside the battery monomer can be led out by welding the tab, the adapter piece and the electrode terminal. After welding, whether the battery monomer is a good product can be determined by judging whether the first welding part exceeds the groove bottom surface of the second groove, which is conducive to reducing the risk of missed killing of the battery monomer product.

[0035] In the second aspect, the application provides a manufacturing method of a battery monomer, the manufacturing method comprising: providing an electrode terminal and an electrode assembly, the electrode assembly including an adapter piece, the electrode terminal having a first end for connecting with the adapter piece, and the first end of the electrode terminal being provided with a first groove; and welding the adapter piece and the electrode terminal from a side of the adapter piece away from the electrode terminal to form a first welding part, so that at least part of the first welding part exceeds a groove bottom surface of the first groove.

[0036] In the above scheme, in the scheme of manufacturing the battery monomer by welding the adapter piece and the electrode terminal from the side of the adapter piece away from the electrode terminal, since part of the groove bottom surface of the first groove is melted, the unmelted part of the groove bottom surface of the first groove is connected with the first welding part, so that the penetration depth of the first welding part is sufficient, and the battery monomer has higher reliability.

[0037] In the third aspect, the application provides a manufacturing method of a battery monomer, the manufacturing method comprising: providing an electrode terminal and an electrode assembly, the electrode assembly including a tab, the electrode terminal having a first end for connecting with the tab, and the first end of the electrode terminal being provided with a first groove; and welding the tab and the electrode terminal from a side of the tab away from the electrode terminal to form a first welding part, so that at least part of the first welding part exceeds a groove bottom surface of the first groove.

[0038] In the above scheme, in the scheme of manufacturing the battery cell by welding the tab and the electrode terminal from the side of the electrode terminal away from the tab, since a part of the groove bottom surface of the first groove is melted, the unmelted part of the groove bottom surface of the first groove is connected with the first welding part, so that the penetration depth of the first welding part is sufficient, and the battery cell has higher reliability.

[0039] In the fourth aspect, the application provides a manufacturing method of a battery cell, the manufacturing method comprising: providing an electrode terminal and an electrode assembly, the electrode assembly comprising a tab, the electrode terminal having a first end for connecting with the tab, the tab being provided with a second groove; and welding the tab and the first end of the electrode terminal from the side of the electrode terminal away from the tab to form a first welding part, so that at least part of the first welding part is beyond the groove bottom surface of the second groove.

[0040] In the above scheme, in the scheme of manufacturing the battery cell by welding the tab and the electrode terminal from the side of the electrode terminal away from the tab, since a part of the groove bottom surface of the first groove is melted, the unmelted part of the groove bottom surface of the first groove is connected with the first welding part, so that the penetration depth of the first welding part is sufficient, and the battery cell has higher reliability.

[0041] In the fifth aspect, the application provides a manufacturing method of a battery cell, the manufacturing method comprising: providing an electrode terminal and an electrode assembly, the electrode assembly comprising a tab, the electrode terminal having a first end for connecting with the tab, the tab being provided with a second groove; and welding the tab and the first end of the electrode terminal from the side of the electrode terminal away from the tab to form a first welding part, so that at least part of the first welding part is beyond the groove bottom surface of the second groove.

[0042] In the above scheme, in the scheme of manufacturing the battery cell by welding the tab and the electrode terminal from the side of the electrode terminal away from the tab, since a part of the groove bottom surface of the first groove is melted, the unmelted part of the groove bottom surface of the first groove is connected with the first welding part, so that the penetration depth of the first welding part is sufficient, and the battery cell has higher reliability.

[0043] In the sixth aspect, the application provides a battery, the battery comprising at least two battery cells and a busbar, each of the battery cells comprising a shell and an electrode terminal, each of the electrode terminals having a second end extending out of the shell. The busbar is welded with at least one of the electrode terminals, and the busbar is welded with the second end of the electrode terminal to form a second welding part. The second end of the electrode terminal is provided with a third groove, the third groove being adjacent to the second welding part; and / or, the busbar is provided with a fourth groove, the fourth groove being adjacent to the second welding part.

[0044] In the above scheme, since the second end of the electrode terminal is provided with the third groove adjacent to the second welding portion, whether the battery is a good product can be determined by determining whether the second welding portion exceeds the groove bottom surface of the third groove, which is conducive to reducing the risk of missed detection of the battery product. Or, since the current-carrying member is provided with the fourth groove adjacent to the second welding portion, whether the battery is a good product can be determined by determining whether the second welding portion exceeds the groove bottom surface of the fourth groove.

[0045] In the seventh aspect, the application provides a manufacturing method of a battery, the manufacturing method comprising: providing a battery monomer and a current-carrying member, the battery monomer comprising an electrode terminal, the electrode terminal having a second end for connecting with the current-carrying member, the second end of the electrode terminal being provided with a third groove; and welding the current-carrying member and the electrode terminal from a side of the current-carrying member away from the electrode terminal to form a second welding portion, so that at least part of the second welding portion exceeds a groove bottom surface of the third groove.

[0046] In the above scheme, in the scheme of manufacturing the battery by welding the current-carrying member and the electrode terminal from a side of the current-carrying member away from the electrode terminal, since part of the groove bottom surface of the third groove is melted, the unmelted part of the groove bottom surface of the third groove is connected with the second welding portion, so that the penetration depth of the second welding portion is sufficient, and the battery has higher reliability.

[0047] In the eighth aspect, the application provides a manufacturing method of a battery, the manufacturing method comprising: providing a battery monomer and a current-carrying member, the battery monomer comprising an electrode terminal, the electrode terminal having a second end for connecting with the current-carrying member, the current-carrying member being provided with a fourth groove; and welding the current-carrying member and the electrode terminal from a side of the electrode terminal away from the current-carrying member to form a second welding portion, so that at least part of the second welding portion exceeds a groove bottom surface of the fourth groove.

[0048] In the above scheme, in the scheme of manufacturing the battery by welding the current-carrying member and the electrode terminal from a side of the electrode terminal away from the current-carrying member, since part of the groove bottom surface of the fourth groove is melted, the unmelted part of the groove bottom surface of the fourth groove is connected with the second welding portion, so that the penetration depth of the second welding portion is sufficient, and the battery has higher reliability.

[0049] In the ninth aspect, the application provides a power utilization device comprising the battery or the battery monomer in one or more of the above embodiments, and the battery or the battery monomer is used to provide electric energy.

[0050] In the above scheme, since the power utilization device comprises the battery or the battery monomer in one or more of the above embodiments, the risk of missed detection of the battery product or the battery monomer product in one or more of the above embodiments is relatively low, and therefore the risk of missed detection of the power utilization device comprising the battery or the battery monomer in one or more of the above embodiments is also relatively low.

[0051] The above description is only a summary of the technical solutions of the present application. In order to enable one skilled in the art to better understand the technical means of the present application and implement the same according to the contents of the description, and in order to enable other purposes, features and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0052] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Furthermore, the same reference numerals in all the drawings refer to the same or similar components. In the drawings:

[0053] FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application;

[0054] FIG. 2 is an exploded view of a battery according to some embodiments of the present application;

[0055] FIG. 3 is an exploded view of a battery cell according to some embodiments of the present application;

[0056] FIG. 4 is a sectional view of a partial structure of a battery cell according to some embodiments of the present application;

[0057] FIG. 5 is a structural schematic diagram of a partial structure of a battery cell according to further embodiments of the present application;

[0058] FIG. 6 is a structural schematic diagram of a partial structure of a battery cell according to some embodiments of the present application;

[0059] FIG. 7 is a structural schematic diagram of a partial structure of a battery cell according to some other embodiments of the present application;

[0060] FIG. 8 is a structural schematic diagram of a partial structure of a battery cell according to some further embodiments of the present application;

[0061] FIG. 9 is a sectional view of a partial structure of a battery cell according to some other embodiments of the present application;

[0062] FIG. 10 is a sectional view of a partial structure of a battery cell according to some other embodiments of the present application;

[0063] FIG. 11 is a sectional view of a partial structure of a battery cell according to some other embodiments of the present application;

[0064] FIG. 12 is a sectional view of a partial structure of a battery cell according to some further embodiments of the present application;

[0065] FIG. 13 is a structural schematic diagram of a partial structure of a battery cell according to some other embodiments of the present application;

[0066] FIG. 14 is a flow chart of a manufacturing method of a battery cell according to some embodiments of the present application;

[0067] Fig. 15 is a flow chart of a method of manufacturing a battery cell according to some embodiments of the present application;

[0068] Fig. 16 is a flow chart of a method of manufacturing a battery cell according to some embodiments of the present application;

[0069] Fig. 17 is a flow chart of a method of manufacturing a battery cell according to some embodiments of the present application;

[0070] Fig. 18 is a cross-sectional view of a partial structure of a battery according to some embodiments of the present application;

[0071] Fig. 19 is a cross-sectional view of a partial structure of a battery according to some embodiments of the present application;

[0072] Fig. 20 is a flow chart of a method of manufacturing a battery according to some embodiments of the present application;

[0073] Fig. 21 is a flow chart of a method of manufacturing a battery according to some embodiments of the present application.

[0074] The reference signs in the detailed description of the embodiments are as follows: 1000 - vehicle; 200 - controller; 300 - motor; 100 - battery; 11 - case body; 111 - first case body; 112 - second case body; 12 - battery cell; 121 - housing; 1211 - end cover; 1212 - shell; 122 - electrode assembly; 1221 - tab; 1222 - main body; 1220 - electric energy leading-out portion; 12201 - second surface; 123 - electrode terminal; 1231 - first recess; 1232 - first surface; 124 - adapter; 125 - second recess; 126 - first welding portion; 127 - second welding portion; 129 - third recess; 130 - fourth recess; 131 - busbar. DETAILED DESCRIPTION

[0075] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "include" and "have" and any variations thereof used in the specification and claims of the present application and the above description of the drawings are intended to cover the non-exclusive inclusion.

[0077] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0078] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The occurrence of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0079] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0080] In the present application, the battery monomer can include, but is not limited to, a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, etc. The shape of the battery monomer can include, but is not limited to, a cylinder, a flat body, a cuboid, or other shapes, etc. The battery monomer can include, but is not limited to, a cylindrical battery monomer, a square battery monomer, a soft pack battery monomer, and a blade battery monomer according to the packaging mode.

[0081] In some high-power applications such as electric vehicles, the application of the battery includes three levels: battery monomer, battery module, and battery. The battery module is to protect the battery monomer from external impact, heat, vibration, etc. A certain number of battery monomers are electrically connected together and placed in a frame. The battery refers to the final state of the battery system loaded into the electric vehicle. The battery referred to in the embodiments of the present application refers to a single physical module including one or more battery monomers to provide higher voltage and capacity. The battery generally includes a box for packaging one or more battery monomers. The box can reduce the risk of liquid or other foreign matter affecting the charging or discharging of the battery monomer.

[0082] Hereinafter, it will mainly be developed around the cuboid battery monomer. It should be understood that the embodiments described hereinafter are also applicable to cylindrical battery monomers or soft pack battery monomers or blade battery monomers in some aspects.

[0083] In a general battery monomer structure, the battery monomer includes a shell, an electrode assembly, and an electrolyte. The shell includes an end cover and a shell body, and the end cover closes the opening of the shell body to define a containing space for containing the electrode assembly.

[0084] The electrode assembly is accommodated in the accommodation space, and in some embodiments, the electrode assembly includes a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode tab and the negative electrode tab to work. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer coated on the surface of the positive electrode current collector, and the positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer serves as a positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer coated on the surface of the negative electrode current collector, and the negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer serves as a negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to pass a large current without fusing, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. In addition, the forming method of the electrode assembly can include but is not limited to a winding type or a stacking type, etc. In some embodiments, the electrode tab leads out the electrical energy of the electrode assembly by electrically connecting with a conductive piece, which can be referred to as an electrical energy leading-out part of the electrode assembly. In other embodiments, the electrode tab leads out the electrical energy of the electrode assembly by directly electrically connecting with an electrode terminal, and the electrode tab can be referred to as an electrical energy leading-out part of the electrode assembly.

[0085] The electrode terminal generally includes a positive electrode terminal and a negative electrode terminal. For a cuboid battery cell, the electrode terminal is generally arranged at the end cover part. In some other cases, the electrode terminal can also be arranged at the shell part. A plurality of battery cells are connected in series and / or in parallel together via the electrode terminal to be applied to various application occasions.

[0086] The development of battery technology needs to consider various design factors, such as performance parameters such as reliability, cycle life, discharge capacity, charge-discharge rate, energy density, etc., and in addition, whether there is a risk of missed killing in the product detection process of the battery cell needs to be considered.

[0087] The detection of the welding position of the general battery cell is realized by the way of spectral detection, but due to the influence of factors such as stains and materials, the light radiation may change, making it more difficult to detect defects such as false welding or burst points, resulting in that the substandard battery cell is not detected and is considered as a good battery cell, and the phenomenon of missed killing occurs.

[0088] In view of this, the battery cell provided in the application comprises a shell, an electrode terminal and an electrode assembly, the electrode terminal is arranged in the shell, the electrode terminal has a first end exposed in the shell, the electrode assembly is arranged in the shell, the electrode assembly comprises an electric energy lead-out part, and the electric energy lead-out part is welded with the first end of the electrode terminal to form a first welding part. The first end of the electrode terminal is provided with a first groove, the first groove is adjacent to the first welding part, and / or the electric energy lead-out part is provided with a second groove, the second groove is adjacent to the first welding part. Whether the battery cell is a good product is determined by judging whether the first welding part exceeds the groove bottom surface of the first groove, or whether the battery cell is a good product is determined by judging whether the first welding part exceeds the groove bottom surface of the second groove, which is beneficial to reduce the risk of missed killing of the battery cell product. When the first end of the electrode terminal is provided with the first groove and the electric energy lead-out part is provided with the second groove, the battery cell product can always have a lower risk of missed killing under the working condition of welding in different directions.

[0089] The technical solutions described in the embodiments of the application are suitable for battery cells, batteries and electric devices using batteries.

[0090] The electric device includes but is not limited to: electric vehicles, electric vehicles, ships and spacecraft, etc., for example, spacecraft includes airplanes, rockets, space shuttles and spaceships, etc.

[0091] The following embodiments are described for the convenience of illustration, taking a vehicle 1000 as an example for the convenience of illustration.

[0092] For example, FIG. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the application. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc. The vehicle 1000 can be provided with a motor 300, a controller 200 and a battery 100 inside. The controller 200 is used to control the power supply of the battery 100 to the motor 300. For example, the battery 100 can be arranged at the bottom, the front or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power source of the vehicle 1000, which is used for the circuit system of the vehicle 1000, for example, for the working power demand of the vehicle 1000 during starting, navigation and running. In another embodiment of the application, the battery 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0093] To meet different power demands, the battery 100 can include a plurality of battery cells 12, which can be connected in series, in parallel, or in a hybrid manner. The battery 100 can also be referred to as a battery pack. Alternatively, the plurality of battery cells 12 can be connected in series, in parallel, or in a hybrid manner to form a battery module, and a plurality of battery modules can be connected in series, in parallel, or in a hybrid manner to form the battery 100. That is, the plurality of battery cells 12 can be directly connected to form the battery 100, or the plurality of battery cells 12 can be connected to form a battery module, and the battery module can be connected to form the battery 100.

[0094] For example, referring to FIG. 2, which is an exploded view of the battery 100 according to some embodiments of the present application, the battery 100 can include a plurality of battery cells 12. The battery 100 can also include a box 11, which has a hollow structure, and the plurality of battery cells 12 can be accommodated in the box 11. As shown, the first box body 111 and the second box body 112 are coupled together. The shapes of the first box body 111 and the second box body 112 can be determined according to the shape of the plurality of battery cells 12, and the first box body 111 and the second box body 112 can each have an open face. For example, the first box body 111 and the second box body 112 can each be a hollow cuboid and have only one face as an open face. The open face of the first box body 111 and the open face of the second box body 112 are arranged opposite to each other, and the first box body 111 and the second box body 112 are coupled to each other to form the box 11 having a closed cavity. The plurality of battery cells 12 can be arranged in parallel, in series, or in a hybrid manner in the box 11 formed by the coupling of the first box body 111 and the second box body 112.

[0095] Alternatively, the battery 100 can also include other structures, which will not be described here. For example, the battery 100 can also include a busbar 131 for electrically connecting the plurality of battery cells 12, for example, in parallel, in series, or in a hybrid manner. Specifically, the busbar 131 can electrically connect the plurality of battery cells 12 by connecting the electrode terminals 123 of the battery cells 12. Further, the busbar 131 can be fixed to the electrode terminals 123 of the battery cells 12 by welding. The electric energy of the plurality of battery cells 12 can be further led out through the box 11 by a conductive mechanism.

[0096] The number of battery cells 12 can be set to any value according to different power requirements. The plurality of battery cells 12 can be connected in series, in parallel, or in a mixed manner to achieve a larger capacity or power. Since the number of battery cells 12 included in each battery 100 can be large, in order to facilitate installation, the battery cells 12 can be arranged in groups, and each group of battery cells 12 forms a battery module. The number of battery cells 12 included in the battery module is not limited and can be set according to requirements. The battery 100 can include a plurality of battery modules, and the plurality of battery modules can be connected in series, in parallel, or in a mixed manner.

[0097] Referring to FIG. 3, which is an exploded view of the battery cell 12 according to some embodiments of the present application, the battery cell 12 includes one or more electrode assemblies 122 and a housing 121. The housing 121 can include a shell 1212, and a plurality of walls of the shell 1212, i.e., a plurality of walls of the housing 121, enclose a cavity that can be used to accommodate the electrode assembly 122. The shell 1212 is shaped according to the shape of the one or more electrode assemblies 122 combined, for example, the shell 1212 can be a hollow cuboid or a square or a regular polyhedron, and one of the faces of the shell 1212 has an opening so that the one or more electrode assemblies 122 can be placed in the shell 1212. The shell 1212 is filled with an electrolyte, such as an electrolyte solution.

[0098] The battery cell 12 can also include two electrode terminals 123, which can be disposed on an end cap 1211. The end cap 1211 is generally flat, and the two electrode terminals 123 are fixed to the flat face of the end cap 1211, and the two electrode terminals 123 are respectively a positive electrode terminal and a negative electrode terminal. Each electrode terminal 123 is respectively provided with an adapter 124, which is located between the end cap 1211 and the electrode assembly 122, for leading out the electrical energy of the electrode assembly 122. In the battery cell 12, the electrode assembly 122 can be arranged as a single electrode assembly or a plurality of electrode assemblies according to actual use requirements, and the battery cell 12 is provided with a plurality of independent electrode assemblies 122.

[0099] According to some embodiments of the present application, referring to FIGS. 3-8, the present application provides a battery cell 12, the battery cell 12 comprising a housing 121, an electrode terminal 123 disposed in the housing 121, the electrode terminal 123 having a first end exposed in the housing 121, and an electrode assembly 122 disposed in the housing 121, the electrode assembly 122 comprising an electricity lead-out portion 1220, the electricity lead-out portion 1220 being welded with the first end of the electrode terminal 123 to form a first welding portion 126. Wherein the first end of the electrode terminal 123 is provided with a first groove 1231, the first groove 1231 being adjacent to the first welding portion 126, and / or the electricity lead-out portion 1220 is provided with a second groove 125, the second groove 125 being adjacent to the first welding portion 126.

[0100] The electrode terminal 123 has a first end exposed in the housing 121, meaning that the first end of the electrode terminal 123 can be used to connect with the electrode assembly 122 located in the housing 121.

[0101] In some embodiments, the electricity lead-out portion 1220 is a tab 1221.

[0102] In some embodiments, the electricity lead-out portion 1220 is an adapter 124.

[0103] The welding manner includes but is not limited to laser welding, laser penetration welding, vacuum electron beam welding, carbon dioxide gas shielded welding, etc. Of course, in some cases, welding can also be carried out in a vacuum environment to improve the welding quality of the first welding portion 126.

[0104] The shape of the battery cell 12 includes but is not limited to square cell, blade cell, cylindrical cell, and soft package cell, etc.

[0105] The shape of the first groove 1231 can include but is not limited to straight line, broken line, arc, ring, etc.

[0106] The shape of the second groove 125 can include but is not limited to straight line, broken line, arc, ring, etc.

[0107] The first groove 1231 can be formed by laser etching, ultrasonic etching, grinding machine, manual etching, computer numerical control precision machining, etc. Laser etching the first groove 1231 can process the first groove 1231 with high precision and complex shape. Ultrasonic etching can process the first groove 1231 on thin materials with high precision. Grinding machine is suitable for processing the first groove 1231 on materials with high hardness. Manual etching has lower cost for processing the first groove 1231. Computer numerical control precision machining has high automation and high processing efficiency for processing the first groove 1231.

[0108] The second groove 125 can be formed by laser etching, ultrasonic etching, a grinding machine, manual etching, computer numerical control precision machining, etc. The second groove 125 can be machined to a higher precision and a complex shape by laser etching. The second groove 125 can be machined on a thin material with high precision by ultrasonic etching. The second groove 125 can be machined on a material with high hardness by a grinding machine. The second groove 125 can be machined at a low cost by manual etching. The second groove 125 can be machined with high automation and high efficiency by computer numerical control precision machining.

[0109] In some cases, the first weld 126 can be sampled and observed by metallographic testing and scanning electron microscopy to observe the positional relationship between the first weld 126 and the first groove 1231 or to observe the relationship between the first weld 126 and the second groove 125.

[0110] If the first weld 126 is detected by industrial CT detection (tomographic slice image scanning detection), the arrangement of the first groove 1231 or the second groove 125 can cause differences in density, thickness, or structure between the welding area and other areas. These differences can form a clear contrast on the CT scan image, making the area around the first groove 1231 more prominent on the image or making the area around the second groove 125 more prominent on the image, and more easily distinguishing whether the first weld 126 has defects such as virtual welding or explosion points. During welding, the depth of the groove (the first groove 1231 or the second groove 125) can correspond to the preset depth of the first weld 126. If the first weld 126 exceeds the bottom surface of the first groove 1231 or the second groove 125 after welding, it can be basically judged that the welding part does not have a virtual welding defect, as shown in FIGS. 4 and 5. If the first weld 126 does not exceed the bottom surface of the groove after welding, it can be basically judged that the welding part has a virtual welding defect, which can also be referred to as the penetration of the first weld 126 not reaching the standard value. At this time, the CT scan image can clearly show that there is a "gap" or "gap" between the first weld 126 and the bottom wall of the groove, and a clear contrast is formed with the area of the first weld 126, which helps the detection personnel quickly identify the welding defects. When selecting the slice position, different positions can be selected to further reduce the risk of missing defects. The dashed lines in FIGS. 6 and 7 show the slice positions, and of course a certain distance can be preset to slice every interval, and if the image of multiple slices shows that the first weld 126 has defects, it means that the battery monomer 12 is a defective product.

[0111] In the technical solution of the embodiment of the application, whether the first welding portion 126 exceeds the groove bottom surface of the first groove 1231 is judged to determine whether the battery monomer 12 is a good product, or whether the first welding portion 126 exceeds the groove bottom surface of the second groove 125 is judged to determine whether the battery monomer 12 is a good product, which is beneficial to reduce the risk of missed killing of the battery monomer 12 product. When the first end of the electrode terminal 123 is provided with the first groove 1231 and the electric energy leading-out portion 1220 is provided with the second groove 125, the battery monomer 12 product can always have a lower risk of missed killing under the working condition of welding in different directions.

[0112] According to some embodiments of the application, please refer to FIGS. 3-8, at least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231 in the direction of the electrode assembly 122 pointing to the electrode terminal 123, and / or at least part of the first welding portion 126 exceeds the groove bottom surface of the second groove 125 in the direction of the electrode terminal 123 pointing to the electrode assembly 122.

[0113] Please refer to FIG. 4, the direction of the electrode assembly 122 pointing to the electrode terminal 123 is the direction from bottom to top in FIG. 4.

[0114] Please refer to FIG. 5, the direction of the electrode terminal 123 pointing to the electrode assembly 122 is the direction from top to bottom in FIG. 5.

[0115] In some embodiments, the electrode terminal 123 has oppositely arranged outer end surfaces and inner end surfaces, and a circumferential surface connecting the outer end surfaces and the inner end surfaces, and the first groove 1231 is a through hole penetrating the circumferential surface. At least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231, which means that part of the first welding portion 126 extends to the side of the through hole away from the electrode assembly 122 in the direction of the electrode assembly 122 pointing to the electrode terminal 123.

[0116] In the above scheme, when the electrode terminal 123 and the electric energy leading-out portion 1220 of the electrode assembly 122 are welded, part of the groove bottom surface of the first groove 1231 is melted, and the unmelted part of the groove bottom surface of the first groove 1231 is connected with the first welding portion 126; and / or part of the groove bottom surface of the second groove 125 is melted, and the unmelted part of the groove bottom surface of the second groove 125 is connected with the first welding portion 126, so that the penetration depth of the first welding portion 126 is sufficient, thereby making the battery monomer 12 have higher reliability.

[0117] According to some embodiments of the present application, referring to FIGS. 3-8, the first end of the electrode terminal 123 has a first surface 1232 facing the electrode assembly 122, and the first groove 1231 is arranged on the first surface 1232; and / or, the power lead-out portion 1220 has a second surface 12201 facing the electrode terminal 123, and the second groove 125 is arranged on the second surface 12201.

[0118] In some embodiments, the second surface 12201 is a surface of the tab 1221 facing the electrode terminal 123.

[0119] In some embodiments, the second surface 12201 is a surface of the adapter 124 facing the electrode terminal 123.

[0120] In some embodiments, after the first welding portion 126 is formed, the first surface 1232 is connected to the second surface 12201.

[0121] In the above scheme, the first groove 1231 is arranged on the first surface 1232, and / or the second groove 125 is arranged on the second surface 12201, which has a lower processing difficulty.

[0122] According to some embodiments of the present application, referring to FIGS. 3-8, at least one end of the first groove 1231 extends to the edge of the first surface 1232; and / or, at least one end of the second groove 125 extends to the edge of the second surface 12201.

[0123] In some embodiments, both ends of the first groove 1231 extend to the edge of the first surface 1232.

[0124] In some embodiments, both ends of the second groove 125 extend to the edge of the second surface 12201.

[0125] In the above scheme, since at least one end of the first groove 1231 extends to the edge of the first surface 1232, and / or at least one end of the second groove 125 extends to the edge of the second surface 12201. Therefore, during the detection of the battery monomer 12, the detection position can be more flexible, and the risk of missing detection due to the absence of a groove at the detection position is reduced.

[0126] According to some embodiments of the present application, referring to FIGS. 3-8, the first groove 1231 is arranged in a plurality of ways, and the plurality of first grooves 1231 are arranged in a spaced manner; and / or, the second groove 125 is arranged in a plurality of ways, and the plurality of second grooves 125 are arranged in a spaced manner.

[0127] In some embodiments, the first groove 1231 is arranged in a plurality of ways, and the plurality of first grooves 1231 are arranged in a spaced manner along a direction parallel to the first surface 1232.

[0128] In some embodiments, the second grooves 125 are provided in plurality, and the plurality of second grooves 125 are spaced apart along a direction parallel to the second surface 12201.

[0129] In the above scheme, the plurality of first grooves 1231 and / or the plurality of second grooves 125 can further reduce the risk of missing detection due to the absence of grooves at the detection position.

[0130] According to some embodiments of the present application, referring to FIGS. 3-8, the plurality of first grooves 1231 are parallel to each other, and the spacing between two adjacent first grooves 1231 is L1, which satisfies: 0.05mm≤L1≤20mm; and / or the plurality of second grooves 125 are parallel to each other, and the spacing between two adjacent second grooves 125 is L2, which satisfies: 0.05mm≤L2≤20mm.

[0131] The distance between two adjacent first grooves 1231 can refer to the minimum distance between two adjacent first grooves 1231 in a direction.

[0132] The spacing between two adjacent first grooves 1231 can be any value between greater than or equal to 0.05mm and less than or equal to 20mm, for example, 0.05mm, 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, 20mm, etc.

[0133] In some embodiments, the spacing between two adjacent first grooves 1231 can be measured by a scanning electron microscope.

[0134] The distance between two adjacent second grooves 125 can refer to the minimum distance between two adjacent second grooves 125 in a direction.

[0135] The distance between the two adjacent second grooves 125 can be any value between greater than or equal to 0.05 mm and less than or equal to 20 mm, for example, 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, 20 mm, etc.

[0136] In some embodiments, the distance between the two adjacent second grooves 125 can be measured by a scanning electron microscope.

[0137] In the above scheme, when L1≥0.05 mm, the distance between the two adjacent first grooves 1231 can be wide, reducing the risk of stress concentration of the electrode terminal 123; when L1≤20 mm, the risk of battery cell 12 product missing detection due to the distance between the two first grooves 1231 being too wide and the first welding portion 126 at the detection position being located between the two first grooves 1231 can be reduced, therefore, when 0.05 mm≤L1≤20 mm, the reliability of the battery cell 12 can be improved while reducing the risk of missing detection of the battery cell 12 product.

[0138] When L2≥0.05 mm, the distance between the two adjacent second grooves 125 can be wide, reducing the risk of stress concentration of the electric energy leading portion 1220; when L2≤20 mm, the risk of battery cell 12 product missing detection due to the distance between the two second grooves 125 being too wide and the first welding portion 126 at the detection position being located between the two second grooves 125 can be reduced, therefore, when 0.05 mm≤L2≤20 mm, the reliability of the battery cell 12 can be improved while reducing the risk of missing detection of the battery cell 12 product.

[0139] According to some embodiments of the present application, referring to FIGS. 3, 8 and 13, the extension trajectory of the first groove 1231 is a curve or a polyline; and / or, the extension trajectory of the second groove 125 is a curve or a polyline.

[0140] In the above scheme, since the extension trajectory of the first groove 1231 is a curve or a polyline, and / or the extension trajectory of the second groove 125 is a curve or a polyline, when the battery cell 12 is detected after the electrode terminal 123 is welded with the electric energy leading portion 1220, the probability that the first groove 1231 at the detection position is adjacent to the first welding portion 126 is relatively high, and then whether the battery cell 12 is a good product can be determined by judging whether the first welding portion 126 exceeds the groove bottom surface of the first groove 1231, so as to reduce the risk of product missed killing of the battery cell 12. Or, the probability that the second groove 125 at the detection position is adjacent to the second welding portion 127 is relatively high, and then whether the battery cell 12 is a good product can be determined by judging whether the second welding portion 127 exceeds the groove bottom surface of the second groove 125, so as to reduce the risk of product missed killing of the battery cell 12.

[0141] According to some embodiments of the present application, please refer to FIGS. 4-5, the depth of the first groove 1231 is D1, which satisfies: 50 μm≤D1≤1000 μm; and / or the depth of the second groove 125 is D2, which satisfies: 50 μm≤D2≤1000 μm.

[0142] The depth of the first groove 1231 can refer to the maximum dimension of the first groove 1231 in the direction of the electrode assembly 122 pointing to the electrode terminal 123.

[0143] The depth of the first groove 1231 can be any value between greater than or equal to 50 pm and less than or equal to 1000 pm, for example, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 110 pm, 120 pm, 130 pm, 140 pm, 150 pm, 160 pm, 170 pm, 180 pm, 190 pm, 200 pm, 210 pm, 220 pm, 230 pm, 240 pm, 250 pm, 260 pm, 270 pm, 280 pm, 290 pm, 300 pm, 310 pm, 320 pm, 330 pm, 340 pm, 350 pm, 360 pm, 370 pm, 380 pm, 390 pm, 400 pm, 410 pm, 420 pm, 430 pm, 440 pm, 450 pm, 460 pm, 470 pm, 480 pm, 490 pm, 500 pm, 510 pm, 520 pm, 530 pm, 540 pm, 550 pm, 560 pm, 570 pm, 580 pm, 590 pm, 600 pm, 610 pm, 620 pm, 630 pm, 640 pm, 650 pm, 660 pm, 670 pm, 680 pm, 690 pm, 700 pm, 710 pm, 720 pm, 730 pm, 740 pm, 750 pm, 760 pm, 770 pm, 780 pm, 790 pm, 800 pm, 810 pm, 820 pm, 830 pm, 840 pm, 850 pm, 860 pm, 870 pm, 880 pm, 890 pm, 900 pm, 910 pm, 920 pm, 930 pm, 940 pm, 950 pm, 960 pm, 970 pm, 980 pm, 990 pm, 1000 pm, etc.

[0144] In some embodiments, the depth of the first groove 1231 can be measured by a scanning electron microscope.

[0145] The depth of the second groove 125 can refer to the largest dimension of the second groove 125 in a direction pointing from the electrode terminal 123 toward the electrode assembly 122.

[0146] The depth of the second groove 125 can be any value between greater than or equal to 50 μm and less than or equal to 1000 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, 510 μm, 520 μm, 530 μm, 540 μm, 550 μm, 560 μm, 570 μm, 580 μm, 590 μm, 600 μm, 610 μm, 620 μm, 630 μm, 640 μm, 650 μm, 660 μm, 670 μm, 680 μm, 690 μm, 700 μm, 710 μm, 720 μm, 730 μm, 740 μm, 750 μm, 760 μm, 770 μm, 780 μm, 790 μm, 800 μm, 810 μm, 820 μm, 830 μm, 840 μm, 850 μm, 860 μm, 870 μm, 880 μm, 890 μm, 900 μm, 910 μm, 920 μm, 930 μm, 940 μm, 950 μm, 960 μm, 970 μm, 980 μm, 990 μm, 1000 μm, etc.

[0147] In some embodiments, the depth of the second groove 125 can be measured by a scanning electron microscope.

[0148] In the above scheme, when D1≥50 μm, the first welding portion 126 of the good battery monomer 12 has a greater depth, and the electrode terminal 123 and the electric energy leading portion 1220 have a higher connection strength. When D1≤1000 μm, the risk of excessive welding deformation during welding can be reduced due to the excessive penetration of the first welding portion 126. Therefore, when 50 μm≤D1≤1000 μm, the electrode terminal 123 and the electric energy leading portion 1220 have a higher connection strength, and the risk of excessive welding deformation during welding can be reduced.

[0149] When D2≥50 μm, the first welding portion 126 of the good battery monomer 12 has a larger depth, and the electrode terminal 123 and the electric energy leading portion 1220 have a higher connection strength; when D2≤1000 μm, the first welding portion 126 can reduce the risk of excessive welding deformation during welding caused by excessive penetration depth. Therefore, when 50 μm≤D2≤1000 μm, the electrode terminal 123 and the electric energy leading portion 1220 have a higher connection strength, and the risk of excessive welding deformation during welding can be reduced.

[0150] According to some embodiments of the present application, referring to FIGS. 3-7, the first groove 1231 has a width H1, which satisfies 0.05 mm≤H1≤20 mm; and / or, the second groove 125 has a width H2, which satisfies 0.05 mm≤H2≤20 mm.

[0151] The width of the first groove 1231 can refer to the maximum dimension in the direction perpendicular to the extension direction of the first groove 1231 and parallel to the electrode assembly 122 pointing to the electrode terminal 123, for example, the up-down direction of FIG. 6.

[0152] The width of the first groove 1231 can be any value between greater than or equal to 0.05 mm and less than or equal to 20 mm, for example, 0.05 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, 20 mm, etc.

[0153] In some embodiments, the width of the first groove 1231 can be observed by an electron microscope.

[0154] The width of the second groove 125 can refer to the maximum dimension in the direction perpendicular to the extension direction of the first groove 1231 and parallel to the electrode assembly 122 pointing to the electrode terminal 123, for example, the up-down direction of FIG. 7.

[0155] The width of the second groove 125 can be any value between greater than or equal to 0.05 mm and less than or equal to 20 mm, for example, 0.05 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, 20 mm, etc.

[0156] In some embodiments, the width of the second groove 125 can be observed by an electron microscope.

[0157] In the above scheme, when H1≥0.05 mm, the first groove 1231 can have a larger width, and when the electrode terminal 123 is welded with the power lead-out portion 1220, the first groove 1231 at the detection position is more likely to be adjacent to the first welding portion 126, and the risk of product leakage of the battery monomer 12 is lower; when H1≤20 mm, the structural strength of the electrode terminal 123 is higher, and therefore, when 0.05 mm≤H1≤20 mm, the risk of product leakage of the battery monomer 12 is reduced, and the battery monomer 12 also has higher reliability.

[0158] When H2≥0.05 mm, the second groove 125 can have a larger width, and when the electrode terminal 123 is welded with the power lead-out portion 1220, the second groove 125 at the detection position is more likely to be adjacent to the first welding portion 126, and the risk of product leakage of the battery monomer 12 is lower; when H2≤20 mm, the structural strength of the electrode terminal 123 is higher, and therefore, when 0.05 mm≤H2≤20 mm, the risk of product leakage of the battery monomer 12 is reduced, and the battery monomer 12 also has higher reliability.

[0159] According to some embodiments of the present application, referring to FIGS. 3, 4, and 9, the first end of the electrode terminal 123 is provided with the first groove 1231, the electrode assembly 122 includes the tab 1221, and the power lead-out portion 1220 is the tab 1221.

[0160] The material of the electrode terminal 123 can include copper or aluminum, etc. Of course, in some embodiments, the electrode terminal 123 can also be a copper-aluminum composite electrode terminal 123.

[0161] The electrode assembly 122 can include a positive electrode sheet, a separator, and a negative electrode sheet, which are stacked and formed into the electrode assembly 122 by a stacking process or a winding process. The portions of the positive electrode sheet and the negative electrode sheet on which the active material layer is not coated form the tabs 1221, and the portions of the positive electrode sheet and the negative electrode sheet on which the active material layer is coated and the separator form the body 1222. In some embodiments, in which a plurality of tabs 1221 of the same polarity are connected together by welding and form a pre-weld mark, the welding can include ultrasonic welding or the like. The electrode terminal 123 can be formed with a first weld 126 at the bundle of the tabs 1221 formed by welding.

[0162] The electrode assembly 122 can be a stacked electrode assembly or a wound electrode assembly.

[0163] The material of the shell 121 can be various, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc.

[0164] In some embodiments, the shell 121 includes a shell body 1212 and an end cover 1211, the shell body 1212 includes a bottom wall and a side wall surrounding the bottom wall, one end of the side wall is connected to the bottom wall, the other end of the side wall surrounds an opening, and the end cover 1211 is used to cover the opening. The electrode terminal 123 is provided with two, the two electrode terminals 123 are opposite in polarity, and the two electrode terminals 123 are both arranged on the end cover 1211.

[0165] In some embodiments, the shell 121 includes a shell body 1212, a first end cover 1211, and a second end cover 1211, the shell body 1212 includes a first opening and a second opening arranged opposite to each other, the first end cover 1211 closes the first opening, and the second end cover 1211 closes the second opening. The electrode terminal 123 is provided with two, the two electrode terminals 123 are opposite in polarity, one of the electrode terminals 123 is arranged on the first end cover 1211, and the other electrode terminal 123 is arranged on the second end cover 1211.

[0166] In the above scheme, the welding of the tabs 1221 and the electrode terminal 123 can lead out the electric energy inside the battery monomer 12. After welding, whether the first weld 126 exceeds the bottom surface of the first groove 1231 can be used to determine whether the battery monomer 12 is a good product, which is beneficial to reduce the risk of missed killing of the battery monomer 12 product.

[0167] According to some embodiments of the present application, referring to FIGS. 3, 4, and 10, the first end of the electrode terminal 123 is provided with a first groove 1231, the electrode assembly 122 includes a tab 1221 and an adapter sheet, the tab 1221 is welded to the adapter sheet, and the electric energy leading-out part 1220 is the adapter sheet.

[0168] The material of the adapter 124 can be various, such as copper or aluminum, etc.

[0169] The shape of the cross section of the adapter 124 can be a straight line, a Z shape, a few characters, etc.

[0170] In the above scheme, the electrical energy inside the battery monomer 12 can be led out by welding the tab 1221, the adapter piece and the electrode terminal 123. After welding, whether the battery monomer 12 is a good product can be judged by judging whether the first welding part 126 exceeds the groove bottom surface of the first groove 1231, which is helpful to reduce the risk of missed killing of the battery monomer 12 product.

[0171] According to some embodiments of the present application, please refer to FIG. 3, FIG. 5 and FIG. 11, the electrode assembly 122 includes a tab 1221, the electrical energy leading-out part 1220 is the tab 1221, and the tab 1221 is provided with a second groove 125.

[0172] In some embodiments, the electrode terminal 123 can be in the form of a sheet.

[0173] In the above scheme, the electrical energy inside the battery monomer 12 can be led out by welding the tab 1221 and the electrode terminal 123. After welding, whether the battery monomer 12 is a good product can be judged by judging whether the first welding part 126 exceeds the groove bottom surface of the second groove 125, which is helpful to reduce the risk of missed killing of the battery monomer 12 product.

[0174] According to some embodiments of the present application, please refer to FIG. 3, FIG. 5 and FIG. 12, the electrode assembly 122 includes a tab 1221 and an adapter piece, the tab 1221 is welded with the adapter piece, the electrical energy leading-out part 1220 is the adapter piece, and the adapter piece is provided with a second groove 125.

[0175] In the above scheme, the electrical energy inside the battery monomer 12 can be led out by welding the tab 1221, the adapter piece and the electrode terminal 123. After welding, whether the battery monomer 12 is a good product can be judged by judging whether the first welding part 126 exceeds the groove bottom surface of the second groove 125, which is helpful to reduce the risk of missed killing of the battery monomer 12 product.

[0176] According to some embodiments of the present application, please refer to FIG. 3, FIG. 4, FIG. 10 and FIG. 14, the present application provides a manufacturing method of a battery monomer 12, the manufacturing method includes providing an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 includes an adapter piece, the electrode terminal 123 has a first end for connecting with the adapter piece, and the first end of the electrode terminal 123 is provided with a first groove 1231; from the side of the adapter piece away from the electrode terminal 123, the adapter piece and the electrode terminal 123 are welded to form a first welding part 126, and at least part of the first welding part 126 exceeds the groove bottom surface of the first groove 1231.

[0177] In some embodiments, the manufacturing method includes the following steps:

[0178] S101, provide an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 includes a tab, the electrode terminal 123 has a first end for connecting with the tab, and the first end of the electrode terminal 123 is provided with a first groove 1231.

[0179] S102, from the side of the tab away from the electrode terminal 123, weld the tab and the electrode terminal 123 to form a first welding portion 126, and at least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231.

[0180] After welding, the battery monomer 12 can be detected to determine whether the first welding portion 126 exceeds the groove bottom surface of the first groove 1231. From the side of the tab away from the electrode terminal 123, the depth of the first groove 1231 is equivalent to the preset penetration of the first welding portion 126. It can also be understood that if the penetration of the first welding portion 126 is sufficient, part of the first welding portion 126 will exceed the groove bottom surface of the first groove 1231.

[0181] In the above scheme, in the scheme of manufacturing the battery monomer 12 by welding the tab and the electrode terminal 123 from the side of the tab away from the electrode terminal 123, a part of the groove bottom surface of the first groove 1231 is melted, and the unmelted part of the groove bottom surface of the first groove 1231 is connected with the first welding portion 126, so that the penetration of the first welding portion 126 is sufficient, and the battery monomer 12 has higher reliability.

[0182] According to some embodiments of the present application, please refer to FIG. 3, FIG. 4, FIG. 9 and FIG. 15, the present application provides a manufacturing method of a battery monomer 12, the manufacturing method includes providing an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 includes a tab 1221, the electrode terminal 123 has a first end for connecting with the tab 1221, and the first end of the electrode terminal 123 is provided with a first groove 1231; from the side of the tab 1221 away from the electrode terminal 123, weld the tab 1221 and the electrode terminal 123 to form a first welding portion 126, and at least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231.

[0183] In some embodiments, the manufacturing method includes the following steps: S201, providing an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 includes a tab 1221, the electrode terminal 123 has a first end for connecting with the tab 1221, and the first end of the electrode terminal 123 is provided with a first groove 1231.

[0184] S202, from the side of the tab 1221 away from the electrode terminal 123, weld the tab 1221 and the electrode terminal 123 to form a first welding portion 126, and at least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231.

[0185] The battery cell 12 can be detected after welding to determine whether the first welding portion 126 exceeds the groove bottom surface of the first groove 1231. From the side of the tab 1221 away from the electrode terminal 123, the depth of the first groove 1231 can be equivalent to the preset penetration of the first welding portion 126. It can also be understood that if the penetration of the first welding portion 126 is sufficient, part of the first welding portion 126 will exceed the groove bottom surface of the first groove 1231.

[0186] In the above scheme, in the scheme of manufacturing the battery cell 12 by welding the tab 1221 and the electrode terminal 123 from the side of the tab 1221 away from the electrode terminal 123, since part of the groove bottom surface of the first groove 1231 is melted, the unmelted part of the groove bottom surface of the first groove 1231 is connected with the first welding portion 126, so that the penetration of the first welding portion 126 is sufficient, thereby making the battery cell 12 have higher reliability.

[0187] According to some embodiments of the present application, referring to FIGS. 3, 5, 12 and 16, the present application provides a manufacturing method of a battery cell 12, the manufacturing method comprising: providing an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 comprising a tab, the electrode terminal 123 having a first end for connecting with the tab, the tab being provided with a second groove 125; welding the tab and the first end of the electrode terminal 123 from the side of the electrode terminal 123 away from the tab to form a first welding portion 126, so that at least part of the first welding portion 126 exceeds the groove bottom surface of the second groove 125.

[0188] In some embodiments, the manufacturing method comprises the following steps: S301, providing an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 comprising a tab, the electrode terminal 123 having a first end for connecting with the tab, the tab being provided with a second groove 125.

[0189] S302, welding the tab and the first end of the electrode terminal 123 from the side of the electrode terminal 123 away from the tab to form a first welding portion 126, so that at least part of the first welding portion 126 exceeds the groove bottom surface of the second groove 125.

[0190] The battery cell 12 can be detected after welding to determine whether the first welding portion 126 exceeds the groove bottom surface of the second groove 125. From the side of the electrode terminal 123 away from the tab, the depth of the second groove 125 can be equivalent to the preset penetration of the first welding portion 126. It can also be understood that if the penetration of the first welding portion 126 is sufficient, part of the first welding portion 126 will exceed the groove bottom surface of the second groove 125.

[0191] In the above scheme, in the scheme of manufacturing the battery monomer 12 by welding the lug and the electrode terminal 123 from the side of the electrode terminal 123 away from the lug, since a part of the groove bottom surface of the second groove 125 is melted, the unmelted part of the groove bottom surface of the second groove 125 is connected with the first welding part 126, so that the penetration depth of the first welding part 126 is sufficient, and the battery monomer 12 has higher reliability.

[0192] According to some embodiments of the present application, referring to FIG. 3, FIG. 5, FIG. 11 and FIG. 17, the present application provides a manufacturing method of a battery monomer 12, the manufacturing method comprising: providing an electrode terminal 123 and an electrode assembly 122, the electrode assembly 122 comprising a tab 1221, the electrode terminal 123 having a first end for connecting with the tab 1221, the tab 1221 being provided with a second groove 125; welding the tab 1221 and the electrode terminal 123 from the side of the electrode terminal 123 away from the tab 1221 to form a first welding part 126, so that at least part of the first welding part 126 exceeds the groove bottom surface of the second groove 125.

[0193] In some embodiments, the manufacturing method comprises the following steps: S401, the electrode assembly 122 comprises a tab 1221, the electrode terminal 123 has a first end for connecting with the tab 1221, and the tab 1221 is provided with a second groove 125.

[0194] S402, welding the tab 1221 and the electrode terminal 123 from the side of the electrode terminal 123 away from the tab 1221 to form a first welding part 126, so that at least part of the first welding part 126 exceeds the groove bottom surface of the second groove 125.

[0195] After welding, the battery monomer 12 can be detected to determine whether the first welding part 126 exceeds the groove bottom surface of the second groove 125. From the side of the electrode terminal 123 away from the tab 1221, the depth of the second groove 125 is equivalent to the preset penetration depth of the first welding part 126. It can also be understood that if the penetration depth of the first welding part 126 is sufficient, part of the first welding part 126 will exceed the groove bottom surface of the second groove 125.

[0196] In the above scheme, in the scheme of manufacturing the battery monomer 12 by welding the lug and the electrode terminal 123 from the side of the electrode terminal 123 away from the lug, since a part of the groove bottom surface of the second groove 125 is melted, the unmelted part of the groove bottom surface of the second groove 125 is connected with the first welding part 126, so that the penetration depth of the first welding part 126 is sufficient, and the battery monomer 12 has higher reliability.

[0197] According to some embodiments of the present application, referring to FIG. 2, FIG. 18 and FIG. 19, the present application provides a battery 100, the battery 100 comprises at least two battery monomers 12 and a busbar 131, each battery monomer 12 comprises an outer shell 121 and an electrode terminal 123, each electrode terminal 123 has a second end extending out of the outer shell 121. The busbar 131 and at least one electrode terminal 123 are welded, and the busbar 131 is welded to the second end of the electrode terminal 123 and forms a second welding portion 127. The second end of the electrode terminal 123 is provided with a third groove 129, and the third groove 129 is adjacent to the second welding portion 127; and / or, the busbar 131 is provided with a fourth groove 130, and the fourth groove 130 is adjacent to the second welding portion 127.

[0198] In some embodiments, the busbar 131 can be a bar.

[0199] In some embodiments, the busbar 131 can be provided on the isolation member, for example, the isolation member is a wire harness isolation plate, and the busbar 131 is a bar.

[0200] In the above scheme, since the second end of the electrode terminal 123 is provided with the third groove 129 adjacent to the second welding portion 127, whether the battery 100 is a good product can be judged by judging whether the second welding portion 127 exceeds the groove bottom surface of the third groove 129, which is beneficial to reduce the risk of missed killing of the battery 100 product. Or, since the busbar 131 is provided with the fourth groove 130 adjacent to the second welding portion 127, whether the battery 100 is a good product can be judged by judging whether the second welding portion 127 exceeds the groove bottom surface of the fourth groove 130.

[0201] According to some embodiments of the present application, referring to FIG. 2, FIG. 18 and FIG. 20, the present application provides a manufacturing method of a battery 100, the manufacturing method comprises providing a battery monomer 12 and a busbar 131, the battery monomer 12 comprises an electrode terminal 123, the electrode terminal 123 has a second end for connecting with the busbar 131, and the second end of the electrode terminal 123 is provided with a third groove 129; from the side of the busbar 131 away from the electrode terminal 123, the busbar 131 and the electrode terminal 123 are welded to form a second welding portion 127, so that at least part of the second welding portion 127 exceeds the groove bottom surface of the third groove 129.

[0202] In some embodiments, the manufacturing method comprises the following steps: S501, providing the battery cell 12 and the busbar 131, the battery cell 12 comprises the electrode terminal 123, the electrode terminal 123 has a second end for connecting with the busbar 131, the second end of the electrode terminal 123 is provided with the third groove 129; from the side of the busbar 131 away from the electrode terminal 123, welding the busbar 131 and the electrode terminal 123 to form the second welding portion 127, and at least part of the second welding portion 127 exceeds the groove bottom surface of the third groove 129.

[0203] S502, from the side of the busbar 131 away from the electrode terminal 123, welding the busbar 131 and the electrode terminal 123 to form the second welding portion 127, and at least part of the second welding portion 127 exceeds the groove bottom surface of the third groove 129.

[0204] After the welding of the electrode terminal 123 of the battery cell 12 and the busbar 131, detection can be performed to determine whether the second welding portion 127 exceeds the groove bottom surface of the third groove 129. When welding from the side of the busbar 131 away from the battery cell 12, the depth of the third groove 129 can be equivalent to the preset penetration depth of the second welding portion 127.

[0205] In the above scheme, in the scheme of manufacturing the battery 100 by welding the busbar 131 and the electrode terminal 123 from the side of the busbar 131 away from the electrode terminal 123, since part of the groove bottom surface of the third groove 129 is melted, the unmelted part of the groove bottom surface of the third groove 129 is connected with the second welding portion 127, so that the penetration depth of the second welding portion 127 is sufficient, and the battery 100 has higher reliability.

[0206] According to some embodiments of the present application, referring to FIG. 2, FIG. 19 and FIG. 21, the present application provides a manufacturing method of a battery 100, the manufacturing method comprises providing a battery cell 12 and a busbar 131, the battery cell 12 comprises an electrode terminal 123, the electrode terminal 123 has a second end for connecting with the busbar 131, the busbar 131 is provided with a fourth groove 130; from the side of the electrode terminal 123 away from the busbar 131, welding the busbar 131 and the electrode terminal 123 to form a second welding portion 127, and at least part of the second welding portion 127 exceeds the groove bottom surface of the fourth groove 130.

[0207] In some embodiments, the manufacturing method comprises the following steps: S601, providing the battery cell 12 and the busbar 131, the battery cell 12 comprises the electrode terminal 123, the electrode terminal 123 has a second end for connecting with the busbar 131, the busbar 131 is provided with the fourth groove 130.

[0208] S602, from the side of the electrode terminal 123 away from the busbar 131, welding the busbar 131 and the electrode terminal 123 to form a second welding portion 127, so that at least part of the second welding portion 127 is beyond the groove bottom surface of the fourth groove 130.

[0209] After the welding of the electrode terminal 123 and the busbar 131 of the battery monomer 12, detection can be performed to determine whether the second welding portion 127 is beyond the groove bottom surface of the fourth groove 130. By welding from the side of the electrode terminal 123 away from the busbar 131, the depth of the fourth groove 130 can be equivalent to the preset penetration depth of the second welding portion 127.

[0210] In the above scheme, in the scheme of manufacturing the battery 100 by welding the busbar 131 and the electrode terminal 123 from the side of the electrode terminal 123 away from the busbar 131, since part of the groove bottom surface of the fourth groove 130 is melted, the unmelted part of the groove bottom surface of the fourth groove 130 is connected with the second welding portion 127, so that the penetration depth of the second welding portion 127 is sufficient, and the battery 100 has higher reliability.

[0211] According to some embodiments of the present application, referring to FIG. 1, the present application provides a power consuming device, which includes the battery 100 or the battery monomer 12 in one or more of the above embodiments, and the battery 100 or the battery monomer 12 is used to provide electric energy.

[0212] In the above scheme, since the power consuming device includes the battery 100 or the battery monomer 12 in one or more of the above embodiments, the risk of missed detection of the battery 100 product or the battery monomer 12 product in one or more of the above embodiments is relatively low, and therefore the risk of missed detection of the power consuming device including the battery 100 or the battery monomer 12 in one or more of the above embodiments is also relatively low.

[0213] According to some embodiments of the present application, referring to FIG. 4, FIG. 6 and FIG. 10, the present application provides a battery monomer 12, which comprises a shell 121, an electrode terminal 123 and an electrode assembly 122. The electrode terminal 123 is arranged on an end cover 1211, and the electrode terminal 123 has a first end exposed in the shell 121. The electrode assembly 122 is arranged in the shell 121, and the electrode assembly 122 comprises a tab, a tab 1221 and a main body 1222. The tab 1221 is electrically connected to the tab, and the tab is welded to the first end of the electrode terminal 123 to form a first welding portion 126. The first end of the electrode terminal 123 is provided with a first groove 1231, and the first groove 1231 is adjacent to the first welding portion 126. In the direction from the electrode assembly 122 to the electrode terminal 123, at least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231. The first end of the electrode terminal 123 has a first surface 1232 facing the electrode assembly 122, and the first groove 1231 is arranged on the first surface 1232. Both ends of the first groove 1231 extend to the edge of the first surface 1232. The first groove 1231 is provided with a plurality of first grooves 1231, and the plurality of first grooves 1231 are arranged at intervals.

[0214] After the first welding portion 126 is welded in the direction from the electrode assembly 122 to the electrode terminal 123, whether the battery monomer 12 is a good product is determined by determining whether the first welding portion 126 exceeds the groove bottom surface of the first groove 1231.

[0215] According to some embodiments of the present application, referring to FIG. 5, FIG. 7 and FIG. 12, the present application provides a battery monomer 12, which comprises a shell 121, an electrode terminal 123 and an electrode assembly 122. The electrode terminal 123 is arranged on an end cover 1211, and the electrode terminal 123 has a first end exposed in the shell 121. The electrode assembly 122 is arranged in the shell 121, and the electrode assembly 122 comprises a tab, a tab 1221 and a main body 1222. The tab 1221 is electrically connected to the tab, and the tab is welded to the first end of the electrode terminal 123 to form a first welding portion 126. The tab is provided with a second groove 125, and the second groove 125 is adjacent to the first welding portion 126. In the direction from the electrode terminal 123 to the electrode assembly 122, at least part of the first welding portion 126 exceeds the groove bottom surface of the second groove 125. The tab has a second surface 12201 facing the electrode terminal 123, and the second groove 125 is arranged on the second surface 12201. Both ends of the second groove 125 extend to the edge of the second surface 12201. The second groove 125 is provided with a plurality of second grooves 125, and the plurality of second grooves 125 are arranged at intervals.

[0216] After the first welding portion 126 is welded in the direction from the electrode terminal 123 to the electrode assembly 122, whether the battery cell 12 is a good product is determined by determining whether the first welding portion 126 exceeds the groove bottom surface of the second groove 125.

[0217] According to some embodiments of the present application, referring to FIGS. 6 and 7, the present application provides a battery cell 12, which includes a shell 121, an electrode terminal 123, and an electrode assembly 122. The electrode terminal 123 is arranged on the end cover 1211, and the electrode terminal 123 has a first end exposed in the shell 121. The electrode assembly 122 is arranged in the shell 121, and the electrode assembly 122 includes a tab, a tab 1221, and a main body 1222. The tab 1221 is electrically connected to the tab, and the tab is welded to the first end of the electrode terminal 123 to form a first welding portion 126. The first end of the electrode terminal 123 is provided with a first groove 1231, and the tab is provided with a second groove 125. The first groove 1231 is adjacent to the first welding portion 126, and the second groove 125 is adjacent to the first welding portion 126. In the direction from the electrode assembly 122 to the electrode terminal 123, at least part of the first welding portion 126 exceeds the groove bottom surface of the first groove 1231. In the direction from the electrode terminal 123 to the electrode assembly 122, at least part of the first welding portion 126 exceeds the groove bottom surface of the second groove 125. The electrode terminal 123 has a first surface 1232 facing the tab, and the tab has a second surface 12201 facing the electrode terminal 123. The first groove 1231 is arranged on the first surface 1232, and the second groove 125 is arranged on the second surface 12201. Both ends of the first groove 1231 extend to the edge of the first surface 1232, and both ends of the second groove 125 extend to the edge of the second surface 12201. The first groove 1231 is provided with a plurality of first grooves 1231, and the plurality of first grooves 1231 are arranged at intervals. The second groove 125 is provided with a plurality of second grooves 125, and the plurality of second grooves 125 are arranged at intervals.

[0218] Whether the first welding portion 126 is welded in the direction from the electrode terminal 123 to the electrode assembly 122 or in the direction from the electrode assembly 122 to the electrode terminal 123, whether the battery cell 12 is a good product can be determined by determining whether the first welding portion 126 exceeds the groove bottom surface of the first groove 1231 or the second groove 125, and the manufacturing of the battery cell 12 is more flexible.

[0219] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The electrode terminal has a first end exposed in the shell. The electrode assembly includes an electric energy lead-out part, and the electric energy lead-out part is welded with the first end of the electrode terminal to form a first welding part. The first end of the electrode terminal is provided with a first groove, and the first groove is adjacent to the first welding part. The electric energy lead-out part is provided with a second groove, and the second groove is adjacent to the first welding part. At least part of the first welding part exceeds the groove bottom surface of the first groove in the direction of the electrode assembly pointing to the electrode terminal. At least part of the first welding part exceeds the groove bottom surface of the second groove in the direction of the electrode terminal pointing to the electrode assembly.

2. The battery cell of claim 1, wherein, The first end of the electrode terminal has a first surface facing the electrode assembly, and the first groove is arranged on the first surface. The electric energy lead-out part has a second surface facing the electrode terminal, and the second groove is arranged on the second surface.

3. The battery cell according to claim 1 or 2, characterized in that, At least one end of the first groove extends to the edge of the first surface. At least one end of the second groove extends to the edge of the second surface.

4. The battery cell of claim 3, wherein, The first groove is provided with a plurality of first grooves arranged at intervals. The second groove is provided with a plurality of second grooves arranged at intervals.

5. The battery cell of any one of claims 1-4, wherein, The first grooves are parallel to each other, and the interval between two adjacent first grooves is L1, which satisfies 0.05mm≤L1≤20mm. The second grooves are parallel to each other, and the interval between two adjacent second grooves is L2, which satisfies 0.05mm≤L2≤20mm.

6. The battery cell of claim 5, wherein, The extension trajectory of the first groove is a curve or a broken line. The extension trajectory of the second groove is a curve or a broken line.

7. The battery cell of any one of claims 1-6, wherein, The depth of the first groove is D1, which satisfies 50μm≤D1≤1000μm. The depth of the second groove is D2, which satisfies 50μm≤D2≤1000μm.

8. The battery cell of any one of claims 1-7, wherein, The width of the first groove is H1, which satisfies 0.05mm≤H1≤20mm. The width of the second groove is H2, which satisfies 0.05mm≤H2≤20mm.

9. The battery cell of any one of claims 1-8, wherein, The first end of the electrode terminal is provided with the first groove, the electrode assembly includes a tab, and the electric energy lead-out part is the tab. The first end of the electrode terminal is provided with the first groove, the electrode assembly includes a tab and a conversion sheet, the tab is welded to the conversion sheet, and the electric energy lead-out part is the conversion sheet.

10. The battery cell of any one of claims 1-9, wherein, The electrode assembly includes a tab, the electric energy lead-out part is the tab, and the tab is provided with the second groove.

11. The battery cell of any one of claims 1-9, wherein, The electrode assembly includes a tab and a conversion sheet, the tab is welded to the conversion sheet, the electric energy lead-out part is the conversion sheet, and the conversion sheet is provided with the second groove.

12. The battery cell of any one of claims 1-9, wherein, The electrode terminal and the electrode assembly are provided, the electrode assembly includes a conversion sheet, the electrode terminal has a first end for connecting with the conversion sheet, and the first end of the electrode terminal is provided with a first groove.

13. The battery cell of any one of claims 1-9, wherein, ​ 14. A method of manufacturing a battery cell, characterized by, ​ ​ From a side of the adapter tab facing away from the electrode terminal, the adapter tab and the electrode terminal are welded to form a first weld portion, and at least a portion of the first weld portion is made to protrude beyond a groove bottom surface of the first groove.

15. A method of manufacturing a battery cell, characterized by, Comprising: Providing an electrode terminal and an electrode assembly including a tab, the electrode terminal having a first end for connecting with the tab, the tab being provided with a second groove; From a side of the electrode terminal facing away from the tab, the tab and the first end of the electrode terminal are welded to form a first weld portion, and at least a portion of the first weld portion is made to protrude beyond a groove bottom surface of the second groove.

16. A method of manufacturing a battery cell, characterized by, Comprising: Providing an electrode terminal and an electrode assembly including a tab, the electrode terminal having a first end for connecting with the tab, the tab being provided with a second groove; From a side of the electrode terminal facing away from the tab, the tab and the first end of the electrode terminal are welded to form a first weld portion, and at least a portion of the first weld portion is made to protrude beyond a groove bottom surface of the second groove.

17. A method of manufacturing a battery cell, characterized by, Comprising: Providing an electrode terminal and an electrode assembly including a tab, the electrode terminal having a first end for connecting with the tab, the tab being provided with a second groove; From a side of the electrode terminal facing away from the tab, the tab and the first end of the electrode terminal are welded to form a first weld portion, and at least a portion of the first weld portion is made to protrude beyond a groove bottom surface of the second groove.

18. A battery, characterized by Comprising: At least two battery cells, each of the battery cells including a housing and an electrode terminal, each of the electrode terminals having a second end protruding out of the housing; A busbar welded with at least one of the electrode terminals, and the busbar being welded to the second end of the electrode terminal to form a second weld portion; The second end of the electrode terminal is provided with a third groove, and the third groove is adjacent to the second weld portion; And / or, the busbar is provided with a fourth groove, and the fourth groove is adjacent to the second weld portion.

19. A method of manufacturing a battery, characterized by, Comprising: Providing a battery cell and a busbar, the battery cell including an electrode terminal, the electrode terminal having a second end for connecting with the busbar, and the second end of the electrode terminal being provided with a third groove; From a side of the busbar facing away from the electrode terminal, the busbar and the electrode terminal are welded to form a second weld portion, and at least a portion of the second weld portion is made to protrude beyond a groove bottom surface of the third groove.

20. A method of manufacturing a battery, characterized by Comprising: Providing a battery cell and a busbar, the battery cell including an electrode terminal, the electrode terminal having a second end for connecting with the busbar, and the busbar being provided with a fourth groove; From a side of the electrode terminal facing away from the busbar, the busbar and the electrode terminal are welded to form a second weld portion, and at least a portion of the second weld portion is made to protrude beyond a groove bottom surface of the fourth groove.

21. An electrical device, comprising: A battery cell as claimed in any one of claims 1 to 13 or a battery as claimed in claim 18, for providing electrical energy.

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