Battery monomer, battery module and electric equipment

Abstract

The utility model relates to a battery monomer, a battery module and electric equipment, the battery monomer comprises an electrode assembly and an adapter, the electrode assembly comprises a tab, the tab is connected with the adapter and is arranged on the adapter along a first direction, the tab comprises a first surface and a second surface which are adjacent to each other, the adapter comprises a first section and a second section which are connected, the second section protrudes out of the first section in the first direction, the first section is provided with a first welding surface used for being welded to the first face in an attached mode, and the area, protruding out of the first section, of the second section is provided with a second welding surface used for being welded to the second face in an attached mode. According to the battery module, the two adjacent surfaces of the tab are connected with the adapter, so that the connection area of the tab is increased, the current of the electrode assembly of the battery monomer can be transmitted to the adapter through the first surface and the second surface of the tab, the overcurrent area is increased, the internal resistance of the battery monomer is reduced, and the performance of the battery module is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a battery cell, a battery module and an electrical device. Background Art

[0002] In the battery field, the adapter is a key component used to connect the tabs of the battery cell and the external circuit, which is responsible for transmitting the current generated by the battery cell. The adapter and the tab are usually connected by welding, but the existence of the adapter in the related technology will increase the resistance, making the internal resistance of the battery cell larger and affecting the performance of the battery module. Utility Model Content

[0003] In order to overcome the problems existing in the related art, the present disclosure provides a battery cell, a battery module and an electrical device.

[0004] According to a first aspect of an embodiment of the present disclosure, a battery cell is provided, comprising an electrode assembly and a converter, wherein the electrode assembly comprises a pole lug, wherein the pole lug is connected to the converter and arranged on the converter along a first direction, wherein the pole lug comprises adjacent first and second surfaces, wherein the converter comprises a first section and a second section connected to each other, wherein the second section protrudes from the first section along the first direction, wherein the first section has a first welding surface for fitting and welding with the first surface, and an area of ​​the second section protruding from the first section has a second welding surface for fitting and welding with the second surface.

[0005] Optionally, the second section is constructed with a plurality of steps to form a plurality of the second welding surfaces, the electrode tabs have a plurality of groups stacked along the first direction, and the second surfaces of the plurality of groups of electrode tabs are welded to the plurality of the second welding surfaces in a one-to-one correspondence.

[0006] Optionally, the pole ear is arranged to extend along a second direction, the second direction intersects with the first direction, the first welding surface is configured as a surface of the first section along one side of the first direction, and the second welding surface is configured as a surface of the second section along one side of the second direction.

[0007] Optionally, the adapter is constructed as an L-shaped structure, the long side of the L-shaped structure is configured as the first section, the short side is configured as the second section, and the pole ear is arranged in a notch groove surrounded by the L-shaped structure.

[0008] Optionally, along the first direction, the ratio of the dimension H2 of the pole lug to the dimension H1 of the second segment exceeding the first segment is not less than 0.5, and / or, along the first direction, the ratio of the dimension H2 of the pole lug to the dimension H1 of the second segment exceeding the first segment is not greater than 2.

[0009] Optionally, in the first direction, the ratio of the dimension H3 of the first section to the dimension H2 of the tab is not less than 1, and / or, in the first direction, the ratio of the dimension H3 of the first section to the dimension H2 of the tab is not greater than 100.

[0010] Optionally, the angle between the laser beam f for welding between the second surface and the surface of the second section and the second welding surface is , and the ratio of the dimension H2 of the tab in the first direction to cos is not greater than 10.

[0011] Optionally, the angle between the laser beam f for welding between the second surface and the surface of the second section and the second welding surface is , and the ratio of the dimension H1 by which the second section extends beyond the first section in the first direction to cos is not greater than 10.

[0012] According to a second aspect of the embodiments of the present disclosure, there is provided a battery module including the battery cell provided by the present disclosure.

[0013] According to a third aspect of the embodiments of the present disclosure, there is provided an electrical device including the battery module provided by the present disclosure.

[0014] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects: Connecting two adjacent surfaces of the tab to the adapter increases the connection area of the tab, enabling the current of the electrode assembly of the battery cell to be transmitted to the adapter through both the first surface and the second surface of the tab, increasing the current-carrying area, avoiding the single transmission path caused by transmission from one surface, and by providing a two-section adapter, the electron transfer path can be reasonably planned and the path can be shortened. In the embodiments of the present disclosure, by transmitting current through two surfaces of the tab, the internal resistance of the battery cell is reduced and the performance of the battery module is improved.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and explanatory and should not limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure and, together with the specification, are used to explain the principles of the present disclosure.

[0017] Figure 1 is a schematic diagram of a battery cell shown according to an exemplary embodiment.

[0018] Figure 2 is a schematic diagram of the position where a tab is connected to an adapter shown according to an exemplary embodiment.

[0019] Figure 3 It is a schematic diagram showing the connection between a tab and an adapter according to another exemplary embodiment.

[0020] Figure 4 It is a schematic diagram showing the laser welding of a tab and an adapter according to an exemplary embodiment.

[0021] Figure 5 It is a schematic diagram showing the laser welding of a tab and an adapter according to another exemplary embodiment.

[0022] Figure 6 It is a schematic diagram showing the separate welding of multiple groups of tabs according to an exemplary embodiment.

[0023] Description of Reference Numerals

[0024] 10 - Electrode assembly, 11 - Tab, 111 - First surface, 112 - Second surface, 20 - Adapter, 21 - First section, 211 - First welding surface, 22 - Second section, 221 - Second welding surface. Detailed Embodiment

[0025] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0026] The embodiments described in some of the following embodiments of the present disclosure do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0027] Such as Figure 1As shown, an embodiment of the present disclosure provides a battery cell, including an electrode assembly 10 and an adapter 20. The electrode assembly 10 is formed by sequentially laminating a positive electrode sheet, a separator, and a negative electrode sheet. The electrode assembly 10 includes a tab 11. Electrode leads are formed on the positive electrode sheet and the negative electrode sheet. The tab 11 is a structure composed of multiple electrode leads, and the tab 11 is connected to the adapter 20. The adapter 20 is used to connect the tab 11 to an external circuit of the battery cell to transmit the current generated by the battery cell. However, when the adapter 20 is connected, the internal resistance between the battery cell and the external circuit will increase, and this internal resistance will affect the performance of the battery module. For example, in terms of power, a larger internal resistance will limit the output current of the battery cell and affect its power performance; in terms of discharge efficiency, when the internal resistance is large, there will be a large voltage drop during the discharge process of the battery cell, resulting in a large difference between the actual output voltage and the theoretical value and low discharge efficiency; in terms of capacity retention, the increase in internal resistance will be accompanied by the attenuation of the battery cell capacity; in terms of thermal management, a battery cell with a larger internal resistance will generate more heat during charge and discharge, causing the temperature of the battery cell to rise, affecting the performance and safety of the battery module; in terms of cycle life, the increase in internal resistance will accelerate the aging process of the battery cell and reduce the cycle life; in terms of charge and discharge rate, a larger internal resistance results in a slower charge and discharge speed of the battery cell.

[0028] Therefore, an embodiment of the present disclosure provides a battery cell with a smaller internal resistance to solve the above problems. Referring to Figure 2 , the tab 11 in the battery cell is arranged on the adapter 20 along a first direction, that is, the tab 11 is arranged on one side of the adapter 20 along the first direction. Here, the first direction can be the arrangement direction of the tab 11 and the electrode assembly 10. The tab 11 includes adjacent first surface 111 and second surface 112. Among them, the adapter 20 includes a connected first section 21 and second section 22. The first section 21 and the second section 22 can be constructed as a split structure welded together or as an integral structure to minimize the internal resistance. The second section 22 protrudes from the first section 21 along the first direction 21. The first section 21 has a first welding surface 211 for fitting and welding with the first surface 111, and the area where the second section 22 protrudes from the first section 21 has a second welding surface 221 for fitting and welding with the second surface 112. In an embodiment of the present disclosure, the tab 11 can be composed of multiple electrode sheets, and the multiple electrode sheets can be welded together by ultrasonic welding to form the tab 11. Since both the tab 11 and the adapter 20 have a certain thickness, laser welding can be used between them to penetrate and weld.

[0029] Through the above technical solution, two adjacent faces of the tab 11 are connected to the adapter 20, increasing the connection area of the tab 11, so that the current of the electrode assembly 10 of the battery cell can be transmitted to the adapter 20 through the first face 111 and the second face 112 of the tab 11, increasing the current-carrying area and avoiding the single transmission path caused by transmission from one face. By setting the two-stage adapter 20, the electron transfer path can be reasonably planned and the path can be shortened. In the embodiment of the present disclosure, by transmitting current through two faces of the tab 11, the internal resistance of the battery cell is reduced and the performance of the battery module is improved.

[0030] Specifically, the improvement of the battery module performance can be reflected in the following aspects: the lower the internal resistance of the battery cell, the less the energy loss during charging and discharging of the battery cell, thus improving the charging and discharging efficiency of the battery; the heat generated during the charging and discharging process of the battery cell is proportional to the internal resistance. The smaller the internal resistance, the less heat is generated, thus reducing the heat dissipation requirement and improving the thermal management performance; due to the improvement of the charging and discharging efficiency and the reduction of heat, the cycle life of the battery can be extended; in a low-temperature environment, the internal resistance of the battery cell will increase, and reducing the internal resistance helps to improve the performance of the battery cell under low-temperature conditions. The battery cell in the embodiment of the present disclosure has a significant positive impact on improving the overall performance of the battery module, including but not limited to aspects such as charging and discharging efficiency, power output, thermal management performance, life, and response speed.

[0031] Refer to Figures 2 to 5 , the tab 11 is arranged to extend along the second direction, and the second direction can intersect the first direction, such as being perpendicular. The first welding surface 211 is configured as the surface on one side of the first section 21 along the first direction, and the second welding surface 221 is configured as the surface on one side of the second section 22 along the second direction. By welding the first welding surface 211 to the tab 11 on one side along the first direction, the tab 11 can be fixed in the arrangement direction of the tab 11 and electron transfer can be performed on this side. Also, by welding the second welding surface 221 to the tab 11 on one side along the extension direction of the tab 11, the tab 11 can be fixed at the extended end of the tab 11, for example, it can be fixed at the extended end of the tab 11. Taking Figure 2 the drawing direction as an example for illustration, the tab 11 is arranged on the top of the first section 21. The first welding surface 211 is the upper surface of the first section 21, and this upper surface is welded to the lower surface of the tab 11. The second welding surface 221 is the right surface of the second section 22, and this right surface is welded to the left end face of the tab 11. In this way, the current passing through the tab 11 can be respectively transmitted from the lower surface of the tab 11 to the first section 21 and from the left end face of the tab 11 to the second section 22, effectively increasing the current transfer path, improving the current-carrying area and current-carrying efficiency, and reducing the internal resistance of the battery cell.

[0032] In one embodiment, the adapter 20 can be configured as an L-shaped structure. Specifically, the cross-section of the adapter 20 cut along the plane where the first direction and the second direction are located can be configured as an L-shape. When the adapter 20 needs to meet any of the foregoing requirements, compared with other special-shaped structures that meet the requirements, setting the adapter 20 as an L-shaped structure can make the structure of the adapter 20 more regular, facilitate manufacturing, and can reasonably plan the space occupied by the adapter 20 in the battery module, so that the space is reasonably utilized, ensuring the power density of the battery while occupying a certain volume. Among them, the long side of the L-shaped structure can be configured as the first section 21, and the short side can be configured as the second section 22. The tab 11 is arranged in the notch groove surrounded by the L-shaped structure. In this way, the profiles of the tab 11 and the adapter 20 can cooperate with each other, and the tab 11 effectively utilizes the space of the adapter 20 for arrangement, thereby improving the space utilization rate.

[0033] Referring to Figure 4 , in the first direction, the size of the tab 11 is H2, and the size of the second section 22 exceeding the first section 21 is H1. The ratio H2 / H1 of H2 to H1 is not less than 0.5 to ensure a more reasonable space layout and ensure the current-carrying capacity. When the size H2 of the tab 11 is certain, if this ratio is too small and less than 0.5, then the current size H1 of the second section 22 exceeding the first section 21 is too large compared with the current size of the tab 11. That is to say, in Figure 4 , the part where the second section 22 protrudes upward from the tab 11 is too large. On the one hand, the excessive protruding part cannot be utilized, resulting in waste of materials and excessive occupation of space. On the other hand, the too large size of the adapter 20 will also increase the total resistance and affect the current-carrying capacity of the adapter 20.

[0034] In one embodiment, the ratio H2 / H1 of H2 to H1 can be set to not greater than 2 to ensure the welding quality and the reliability of the tab 11. Specifically, when the size H2 of the tab 11 is certain, if this ratio is too large and greater than 2, then the current size H1 of the second section 22 exceeding the first section 21 is too small compared with the current size of the tab 11. That is to say, in Figure 4 , the tab 11 protrudes upward from the second section 22 too much, which will cause nowhere to weld the protruding tab 11, resulting in this part becoming a structurally weak area of the tab 11. During long-term use, since the lower part of the tab 11 is welded to the second section 22, this weak area will tear between the welded tab 11, resulting in the failure of the tab 11 at this place and affecting the performance of the tab 11.

[0035] Referring to Figure 4, in the first direction, the dimension of the first section 21 is H3, and the ratio H3 / H2 of the dimension H3 of the first section 21 to the dimension H2 of the tab 11 is not less than 1, that is, the dimension H3 of the first section 21 is not less than the dimension H2 of the tab 11, so as to ensure the current-carrying effect.

[0036] In one embodiment, the ratio H3 / H2 of the dimension H3 of the first section 21 to the dimension H2 of the tab 11 can be set to be not greater than 100, so as to avoid unnecessary material waste and space occupation.

[0037] Refer to Figure 4 , the included angle between the laser beam f (shown by the dashed line in Figure 4 ) for welding between the second surface 112 and the surface of the second section 22 and the second welding surface 221 is , and the ratio H2 / cos of the dimension H2 of the tab 11 in the first direction to can be set to be not greater than 10. In Figure 4 , when laser welding the tab 11 and the second section 22, the laser beam f can enter from one side of the tab 11. By limiting the ratio of H2 to cos to be not greater than 10, it is to limit the maximum travel of the laser beam in the tab 11 to be not greater than 10, so as to ensure that the laser can penetrate.

[0038] In one embodiment, when the laser beam f enters from one side of the second section 22, as shown in Figure 5 , the included angle between the laser beam f for welding between the second surface 112 and the surface of the second section 22 and the second welding surface 221 is , and the ratio H1 / cos of the dimension H1 by which the second section 22 extends beyond the first section 21 in the first direction to can be set to be not greater than 10, that is, to limit the maximum travel of the laser beam f in the second section 22 to be not greater than 10, so as to ensure that the laser can penetrate.

[0039] In the embodiments of the present disclosure, the included angle between the laser beam f and the second welding surface 221 can be not greater than 45 degrees, so as to avoid the path of the laser beam f passing through the tab 11 or the adapter 20 being too long and difficult to penetrate, which affects the welding quality.

[0040] In one embodiment, refer to Figure 3, the second section 22 can be configured with multiple steps to form multiple second welding surfaces 221. The tab 11 can be divided into multiple groups stacked along the first direction. The second surfaces 112 of the multiple groups of tabs 11 are welded to the multiple second welding surfaces 221 in a one-to-one correspondence. In this way, the second surface 112 of the tab 11 can be welded to the second section 22 section by section to ensure the welding quality. For example, in Figure 3 In the embodiment shown, the second surface 112 of the lowermost tab 11 can be welded to the corresponding second welding surface 221 first, and then a second group of tabs 11 can be arranged on this group of tabs 11 to be welded to the corresponding second welding surface 221, and so on, welding all the tabs 11 group by group. When welding in this way, since it is not necessary to weld all the tabs 11 at one time, but to divide them into multiple thinner groups of tabs 11, the laser travel through the tabs 11 can be shortened. As shown in Figure 6 , the laser travel shown by the dotted line for welding each group of tabs 11 is shorter, and there is no need to penetrate a thick area as in Figure 4 and Figure 5 . The shortening of the laser travel can ensure the welding quality, and since the laser will have a certain destructive effect on the components it passes through, the thickness of the tabs 11 or the adapter 20 through which the laser passes in this way becomes smaller, thereby reducing the damage to the tabs 11 and the adapter 20. Among them, the number of steps can be adjusted according to actual needs, and can be two, three, four or more. The present disclosure does not make specific limitations on this.

[0041] According to a second aspect of the embodiments of the present disclosure, a battery module is provided, including the above-mentioned battery cell and having all the beneficial effects of the above-mentioned battery cell, which will not be elaborated here. The battery module may include a housing, and a pole column may be provided on the housing. The adapter 20 may be connected to the pole column to transfer current.

[0042] According to an electrical device of the embodiments of the present disclosure, including the above-mentioned battery module and having all the beneficial effects of the above-mentioned battery module, which will not be elaborated here. The electrical device includes but is not limited to vehicles, mobile phones, laptop computers, electric toys, and electric tools, etc.

[0043] In the foregoing detailed description, reference has been made to the accompanying drawings, in which certain aspects of the present disclosure may be practiced by way of illustration. In this regard, directional or positional relationship terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. may be used with reference to the orientation of the described figures. Since the components of the described device may be positioned in a plurality of different orientations, the directional terms may be used for illustrative purposes and not be limiting. It should be understood that other aspects may be utilized and structural or logical changes may be made without departing from the concepts of the present disclosure. Accordingly, the following detailed description should not be taken in a limiting sense.

[0044] It should be understood that, unless otherwise specifically stated, the features of some embodiments of the various aspects of the present disclosure described herein may be combined with each other. As used herein, the term "and / or" includes any one of the related listed items and any combination of any two or more of them; similarly, "at least one of... " includes any one of the related listed items and any combination of any two or more of them.

[0045] It should be understood that, unless otherwise expressly specified and limited, the terms "engage", "attach", "mount", "connect", "couple", "fix", etc. as used in the embodiments of the present disclosure should be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integral; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise expressly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure may be understood according to specific circumstances.

[0046] In addition, the term "above" as used with respect to a component, element, or layer of material formed "above" or located "above" a surface may be used herein to mean that the component, element, or layer of material is "indirectly" positioned (e.g., placed, formed, deposited, etc.) on the surface such that one or more additional components, elements, or layers are disposed between the surface and the component, element, or layer of material. However, the term "above" as used with respect to a component, element, or layer of material formed "above" or located "above" a surface may alternatively have a specific meaning: the component, element, or layer of material is "directly" positioned (e.g., placed, formed, deposited, etc.) on the surface, e.g., in direct contact with the surface.

[0047] Although terms such as "first", "second", and "third" may be used herein to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited to these terms. Instead, these terms are only used to distinguish one component, part, region, layer, or section from another. Thus, the first component, part, region, layer, or section mentioned in the examples described herein may also be referred to as the second component, part, region, layer, or section without departing from the teachings of the examples. Additionally, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description herein, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0048] It should be understood that spatial relative terms, such as "above", "upper", "below", and "lower", are used herein to describe the relationship of one element shown in the figures to another element. In addition to the orientation depicted in the figures, such spatial relative terms are also intended to encompass different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to that other element. Thus, depending on the spatial orientation of the device, the term "above" encompasses both the above and below orientations. The device may have other orientations (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0049] Furthermore, the word "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as being advantageous compared to other aspects or designs. Instead, the use of the word exemplary is intended to present concepts in a concrete manner. As used herein, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified, or clear from the context, "X applies A or B" is intended to mean any of the natural inclusive permutations. That is, if X applies A; X applies B; or X applies both A and B, then "X applies A or B" is satisfied in any of the foregoing instances. Additionally, unless otherwise specified or clear from the context referring to the singular form, the articles "a" and "an" as used in this application and the appended claims are generally understood to mean "one or more".

[0050] Likewise, although the present disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art upon reading and understanding this specification and the drawings. The present disclosure includes all such modifications and variations and is limited only by the scope of the claims. Specifically with respect to the various functions performed by the components described above (e.g., elements, resources, etc.), unless otherwise indicated, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific function of the described component, even if not structurally equivalent to the disclosed structure. Additionally, although a particular feature of the present disclosure may have been disclosed with respect to only one of several implementations, such a feature may, as may be desired and advantageous for any given or particular application, be combined with one or more other features of other implementations. Further, to the extent that the terms "comprises," "has," "includes," "contains," or any variation thereof are used in the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprising."

[0051] Other embodiments of the present disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are pointed out by the appended claims.

[0052] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A battery cell, characterized in that: It includes an electrode assembly and a transition piece, the electrode assembly includes a pole ear, the pole ear is connected to the transition piece and arranged on the transition piece along a first direction, the pole ear includes an adjacent first surface and a second surface, wherein the transition piece includes a connected first section and a second section, the second section protrudes from the first section along the first direction, the first section has a first welding surface for fitting and welding with the first surface, and the area of ​​the second section protruding from the first section has a second welding surface for fitting and welding with the second surface.

2. The battery cell according to claim 1, characterized in that: The second section is configured with a plurality of steps to form a plurality of the second welding surfaces. The electrode tabs have a plurality of groups stacked along the first direction. The second surfaces of the plurality of groups of electrode tabs are welded to the plurality of the second welding surfaces in a one-to-one correspondence.

3. The battery cell according to claim 1, characterized in that: The pole tab is arranged to extend along a second direction intersecting the first direction, the first welding surface is configured as a surface of the first section along the first direction, and the second welding surface is configured as a surface of the second section along the second direction.

4. The battery cell according to claim 1, characterized in that: The adapter is constructed as an L-shaped structure, the long side of the L-shaped structure is configured as the first section, the short side is configured as the second section, and the pole ear is arranged in a notch groove surrounded by the L-shaped structure.

5. The battery cell according to claim 1, characterized in that: Along the first direction, the ratio of the dimension H2 of the pole lug to the dimension H1 of the second segment exceeding the first segment is not less than 0.5, and / or, along the first direction, the ratio of the dimension H2 of the pole lug to the dimension H1 of the second segment exceeding the first segment is not greater than 2.

6. The battery cell according to claim 1, characterized in that: In the first direction, a ratio of a size H3 of the first segment to a size H2 of the pole lug is not less than 1, and / or a ratio of a size H3 of the first segment to a size H2 of the pole lug is not greater than 100.

7. The battery cell according to claim 1, characterized in that: The angle between the laser beam f used for welding between the second surface and the surface of the second segment and the second welding surface is The dimension H2 of the tab along the first direction is cos The ratio is not greater than 10.

8. The battery cell according to claim 1, characterized in that: The angle between the laser beam f used for welding between the second surface and the surface of the second segment and the second welding surface is , the dimension H1 of the second segment extending beyond the first segment along the first direction is equal to cos The ratio is not greater than 10.

9. A battery module, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: Comprising the battery module according to claim 9.

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