Battery pack

Abstract

The utility model relates to the technical field of batteries, in particular to a battery pack which comprises a battery box body, cylindrical batteries and a fixing plate, the cylindrical battery is arranged in the battery box body, two end surfaces of the cylindrical battery are respectively a first surface and a second surface, the cylindrical surface of the cylindrical battery is a third surface, the first surface and the second surface are arranged at an interval in a first direction and are respectively vertical to the first direction, the first direction is the axial direction of the cylindrical battery, and the third surface is connected between the first surface and the second surface; the connecting area of the third surface and the first surface is provided with a first welding mark, the third surface is provided with a first insulating layer, and the first insulating layer does not cover the first welding mark; the fixing plate is arranged on the third surface of the cylindrical battery and is made of a metal material; the fixing plate and the third surface are oppositely arranged and are fixedly connected; wherein the first welding mark and the fixing plate are arranged at an interval, and in the first direction, the minimum distance between the first face and the adjacent edge of the fixing plate ranges from 1.5 mm to 30 mm.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery pack. Background Art

[0002] In the existing design of battery packs, some battery packs adopt the design of setting a metal fixing plate on the third side of the cylindrical battery. However, after the end face of the cylindrical battery is connected to the third side by welding, a weld mark will be formed at the connection between the third side and the end face. The weld mark area has a higher short circuit risk than other areas on the third side, and is easy to short-circuit with the metal fixing plate, affecting the safety of the battery pack. Utility Model Content

[0003] A main purpose of the present invention is to overcome at least one defect of the above-mentioned prior art and provide a battery pack with better safety.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] According to one aspect of the utility model, a battery pack is provided, which includes a battery case, a cylindrical battery and a fixing plate; the cylindrical battery is arranged in the battery case, the two circular end surfaces of the cylindrical battery are respectively the first surface and the second surface, the cylindrical surface of the cylindrical battery is the third surface, the first surface and the second surface are arranged at intervals in a first direction and are respectively perpendicular to the first direction, the first direction is the axial direction of the cylindrical battery, the third surface is connected between the first surface and the second surface, the connection area between the third surface and the first surface has a first welding mark, the third surface is provided with a first insulating layer, and the first insulating layer does not cover the first welding mark; the fixing plate is arranged on the third surface of the cylindrical battery and is made of metal, the fixing plate is arranged opposite to the third surface and fixedly connected; wherein, the first welding mark is spaced apart from the fixing plate, and along the first direction, the minimum spacing between the first surface and the adjacent edge of the fixing plate is greater than or equal to 1.5 mm to 30 mm.

[0006] It can be seen from the above technical solutions that the advantages and positive effects of the battery pack proposed by the utility model are:

[0007] The battery pack proposed by the utility model includes a cylindrical battery and a fixing plate; the connection area between the third surface of the cylindrical battery and the first surface has a first weld mark, the third surface is provided with a first insulating layer, and the first insulating layer does not cover the first weld mark. The fixing plate is made of metal, and the fixing plate is arranged on the third surface of the cylindrical battery; the first weld mark is spaced apart from the fixing plate, and along the axial direction of the cylindrical battery, the minimum spacing between the first surface and the adjacent edge of the fixing plate is 1.5mm to 30mm. Through the above structural design, the utility model can use the fixing plate made of metal to provide strong structural support and thermal conductivity. On this basis, the utility model separates the fixing plate from the first weld mark by a certain distance, which can effectively avoid electrical connection between the fixing plate and the relevant area of ​​the cylindrical battery, reduce the risk of short circuit, and improve the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The various objects, features and advantages of the present invention will become more apparent by considering the following detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are only exemplary illustrations of the present invention and are not necessarily drawn to scale. In the accompanying drawings, the same reference numerals always represent the same or similar parts. Among them:

[0009] Figure 1 is a schematic diagram of a three-dimensional structure of a battery pack according to an exemplary embodiment;

[0010] Figure 2 yes Figure 1 A partial enlarged schematic diagram of a battery pack is shown;

[0011] Figure 3 yes Figure 2 A schematic plan view of a portion of the structure shown;

[0012] Figure 4 yes Figure 1 A schematic diagram of a three-dimensional structure of a partial structure of a battery pack is shown;

[0013] Figure 5 yes Figure 4 Schematic diagram of three-dimensional decomposition.

[0014] The following are the descriptions of the reference numerals:

[0015] 100. Battery box;

[0016] 110. Bottom plate;

[0017] 1101. Module base plate;

[0018] 200. Cylindrical battery;

[0019] 201. Battery pack;

[0020] 202. Battery column;

[0021] 210. Page 1;

[0022] 220. Second side;

[0023] 230. Third side;

[0024] 231. First weld mark;

[0025] 232. Second weld mark;

[0026] 240. A first insulating layer;

[0027] 300. Fixed plate;

[0028] 400. Heat exchange plate;

[0029] 410. Page 4;

[0030] 500. Conductive bar;

[0031] 510. Connecting part;

[0032] 520. Crossover;

[0033] 600. Insulation panels;

[0034] 610. Hollow part;

[0035] D1. Minimum spacing;

[0036] D2. Minimum spacing;

[0037] L1. Length;

[0038] L2. Length;

[0039] X. First direction;

[0040] Y. Second direction;

[0041] Z. Third direction. DETAILED DESCRIPTION

[0042] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and drawings therein are essentially for illustrative purposes rather than for limiting the present invention.

[0043] In the following description of different exemplary embodiments of the utility model, reference is made to the accompanying drawings, which form a part of the utility model and in which different exemplary structures, systems and steps that can implement multiple aspects of the utility model are shown by way of example. It should be understood that other specific schemes of components, structures, exemplary devices, systems and steps can be used, and structural and functional modifications can be made without departing from the scope of the utility model. Moreover, although the terms "above", "between", "within", etc. can be used in this specification to describe different exemplary features and elements of the utility model, these terms are used herein only for convenience, such as according to the direction of the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of the utility model.

[0044] See also Figure 1 , which representatively shows a three-dimensional structural schematic diagram of the battery pack proposed by the utility model. In this exemplary embodiment, the battery pack proposed by the utility model is described by taking a vehicle-mounted battery as an example. It is easy for those skilled in the art to understand that in order to apply the relevant design of the utility model to other types of battery devices, various modifications, additions, substitutions, deletions or other changes are made to the specific embodiments described below, and these changes are still within the scope of the principle of the battery pack proposed by the utility model.

[0045] like Figure 1 As shown, in one embodiment of the present invention, the battery pack provided by the present invention includes a battery box 100, a cylindrical battery 200 and a fixing plate 300. Figures 2 to 5 , Figure 2 , a partial enlarged schematic diagram of a battery pack is representatively shown, in which structures such as the conductive bar 500 and the insulating plate 600 are hidden; Figure 3 A representative example is shown in Figure 2 A schematic plan view of a partial structure is shown, in which the planar structure of the cylindrical battery 200 and the fixing plate 300 is specifically shown; Figure 4 , a three-dimensional schematic diagram of a partial structure of a battery pack is representatively shown, wherein a combined structure of a partial cylindrical battery 200, a heat exchange plate 400, a conductive bar 500 and an insulating plate 600 is specifically shown; Figure 5 A representative example is shown in Figure 4 The following will be combined with the above-mentioned drawings to explain in detail the structure, connection method and functional relationship of the main components of the battery pack proposed by the utility model.

[0046] like Figures 1 to 3As shown, in one embodiment of the present utility model, a cylindrical battery 200 is disposed in a battery box 100, and the cylindrical battery 200 is substantially cylindrical, and its two circular end faces are respectively the first face 210 and the second face 220, and the cylindrical surface of the cylindrical battery 200 is the third face 230. The first face 210 and the second face 220 are arranged at intervals in the first direction X and are respectively perpendicular to the first direction X, and the first direction X is the axial direction of the cylindrical battery 200, and the third face 230 is connected between the first face 210 and the second face 220. Among them, the third face 230 and the first face 210 are welded, so the connection area between the third face 230 and the first face 210 has a first weld mark 231. In addition, the third face 230 is provided with a first insulating layer 240, such as but not limited to an insulating coating, and the first insulating layer does not cover the first weld mark 231. The fixing plate 300 is arranged on the third surface 230 of the cylindrical battery 200 and is made of metal. The fixing plate 300 is arranged opposite to the third surface 230 and is fixedly connected. On this basis, the first welding mark 231 is spaced apart from the fixing plate 300, and along the first direction X, the minimum spacing D1 between the first surface and the adjacent edge of the fixing plate 300 is 1.5mm to 30mm, such as 1.5mm, 5mm, 10mm, 20mm, 30mm, etc. Through the above structural design, the utility model can use the fixing plate 300 made of metal to provide strong structural support and thermal conductivity. On this basis, the utility model separates the fixing plate 300 from the first welding mark 231 by a distance, which can effectively avoid electrical connection between the fixing plate 300 and the relevant area of ​​the cylindrical battery 200, reduce the risk of short circuit, and improve the safety of the battery pack.

[0047] It should be noted that, in actual applications, affected by different welding processes, the first weld mark 231 formed by welding the first surface 210 and the third surface 230 of the cylindrical battery 200 may be difficult to accurately locate at the junction of the first surface 210 and the third surface 230. For example, the first weld mark 231 may be located at a position of the third surface 230 adjacent to the first surface 210, such as the end area of ​​the third surface 230 in the first direction X, or the first weld mark 231 may also be located at a position of the first surface 210 adjacent to the third surface 230, such as the peripheral area of ​​the first surface 210. Accordingly, the connection area between the first surface 210 and the third surface 230 can be understood as including a partial area of ​​the third surface 230, a partial area of ​​the first surface 210, or the junction of the two. In addition, since the weld mark may not be a standard annular path, the minimum spacing D1 between the first surface 210 and the fixing plate 300 is used in this specification to represent the minimum spacing between the first weld mark and the fixing plate 300. Similarly, the following description of the second weld mark 232 can also be understood with reference to the above description.

[0048] like Figure 3As shown, in one embodiment of the present invention, the third surface 230 of the cylindrical battery 200 is welded to the second surface 220, so the connection area between the third surface 230 and the second surface 220 has a second weld mark 232. On this basis, the second weld mark 232 can also be spaced apart from the fixing plate 300, and along the first direction X, the minimum spacing D2 between the adjacent edges of the second surface 220 and the fixing plate 300 is 1.5mm to 30mm, such as 1.5mm, 5mm, 10mm, 20mm, 30mm, etc. Through the above structural design, the present invention can further reduce the risk of short circuit and further improve the safety of the battery pack.

[0049] In one embodiment of the present invention, the third surface 230 and the second surface 220 can be integrally formed. On this basis, along the first direction X, the minimum spacing D2 between the second surface 220 and the adjacent edge of the fixing plate 300 is greater than or equal to 1.5 mm to 2.8 mm, such as 1.5 mm, 1.7 mm, 2 mm, 2.5 mm, 2.8 mm, etc. Through the above structural design, the present invention is conducive to the lightweight design of the fixing plate 300, and at the same time can facilitate the assembly of the fixing plate 300, better absorb the assembly tolerance, and avoid friction and scratches between the fixing plate 300 and the heat exchange plate 400 attached to the second surface 220 under the vibration condition of the battery pack.

[0050] like Figure 3 As shown, in one embodiment of the present invention, along the first direction X, the length L1 of the fixing plate 300 may account for 5% to 95% of the length L2 of the third surface 230, such as 5%, 15%, 25%, 30%, 50%, 80%, 95%, etc. Through the above structural design, the present invention can avoid the fixing plate 300 covering too little of the cylindrical battery 200, which makes the heat conduction and structural reinforcement of the fixing plate 300 not obvious enough, and can also avoid the fixing plate 300 covering too much of the cylindrical battery 200, which makes the minimum distance between the fixing plate 300 and the above welding mark too small to affect the insulation effect, and can also reduce the weight of the fixing plate 300.

[0051] like Figure 4 and Figure 5As shown, in one embodiment of the present invention, at least two cylindrical batteries 200 are arranged into a battery column 202 along a second direction Y, and the second direction Y is perpendicular to the first direction X (for example, parallel to the fourth surface 410 of the heat exchange plate 400 and parallel to the bottom plate 110). On this basis, the fixing plate 300 can be arranged on the third surface 230 of each cylindrical battery 200 belonging to a battery column 202, and the fixing plate 300 is wavy. Through the above structural design, the present invention can make full use of the internal space of the battery box 100 to arrange the cylindrical batteries 200, which is conducive to improving the energy density of the battery pack, and on this basis, a fixing plate 300 is used to simultaneously arrange the corresponding at least two cylindrical batteries 200 contained in a battery column 202, which is conducive to reducing the number of parts and simplifying the complexity of the structure. In some embodiments, for each cylindrical battery 200 belonging to a battery column 202, at least two fixing plates 300 can also be arranged for reinforcement and heat conduction, and each fixing plate 300 corresponds to at least one cylindrical battery 200, which is not limited to this embodiment.

[0052] like Figure 4 and Figure 5 As shown, based on the structural design that the fixing plate 300 simultaneously corresponds to the arrangement of each cylindrical battery 200 of the same battery column 202, in one embodiment of the present utility model, at least two battery columns 202 are arranged into a battery group 201 along the third direction Z, and the third direction Z is perpendicular to the first direction X and perpendicular to the second direction Y (for example, perpendicular to the bottom plate 110 and parallel to the fourth surface 410 of the heat exchange plate 400). On this basis, a fixing plate 300 can be arranged between two adjacent battery columns 202 belonging to a battery group 201. Through the above structural design, the present utility model can further improve the energy density of the battery pack by using the design of forming a battery group 201 with multiple layers of battery columns 202, and on this basis, the fixing plate 300 is used to simultaneously provide heat conduction and structural reinforcement for two adjacent layers of battery columns 202 in the third direction Z, which is conducive to reducing the number of parts and simplifying the complexity of the structure. In some embodiments, for each layer of battery columns 202 belonging to a battery group 201, the present utility model can also be provided with a fixing plate 300 respectively, which is not limited to this embodiment.

[0053] like Figure 4 and Figure 5As shown, in one embodiment of the present invention, the battery pack proposed by the present invention further includes a heat exchange plate 400, and the battery box 100 includes a bottom plate 110. On this basis, the cylindrical battery 200 can be arranged in a "lying" manner, and the so-called "lying" is relative to the bottom plate 110, that is, the axial direction (first direction X) of the cylindrical battery 200 is parallel to the bottom plate 110. In addition, the heat exchange plate 400 can be arranged vertically relative to the bottom plate 110, that is, the heat exchange plate 400 is arranged in a "standing" manner relative to the bottom plate 110, and the heat exchange plate 400 is in contact with the cylindrical battery 200 for heat exchange (it can be direct contact or indirect contact through other structures). Among them, the heat exchange plate 400 has a fourth surface 410 facing the second surface 220, and the first surface 210 is facing away from the heat exchange plate 400.

[0054] like Figure 4 and Figure 5 As shown, in one embodiment of the present invention, battery columns 202 may be respectively arranged on both sides of the heat exchange plate 400 in the first direction X. In other words, for two battery columns 202 adjacent to each other in the first direction X, the cylindrical batteries 200 of the two are arranged with their respective second faces 220 facing each other (that is, arranged with their respective first faces 210 facing each other), and the second faces 220 of the cylindrical batteries 200 of the two are respectively facing the two fourth faces 410 on both sides of the heat exchange plate 400. Through the above structural design, the present invention can use the heat exchange plate 400 to achieve heat exchange with the two battery columns 202 arranged in the first direction X, which is conducive to reducing the number of components and simplifying the complexity of the structure.

[0055] Different from Figure 5 In the illustrated embodiment, a structural design is adopted in which the fixing plate 300 and the heat exchange plate 400 are spaced apart (i.e., the fixing plate 300 does not cover the second welding mark 232). In one embodiment of the present invention, the fixing plate 300 can also be connected to the heat exchange plate 400. Through the above structural design, the present invention can utilize the fixing plate 300 to enhance the heat transfer between the third surface 230 of the cylindrical battery 200 and the heat exchange plate 400, and further improve the heat exchange effect.

[0056] In addition, when the third surface 230 has the second welding mark 232 and the fixing plate 300 is connected to the heat exchange plate 400 , insulation treatment may be performed between the fixing plate 300 and the second welding mark 232 region of the third surface 230 , such as providing an additional insulation structure.

[0057] In one embodiment of the present invention, the elastic modulus of the fixing plate 300 may be greater than or equal to 10 GPa. For example, the material of the fixing plate 300 may be metal, such as an aluminum plate, a steel plate, etc. Through the above design, the present invention can avoid insufficient reinforcement effect caused by insufficient elastic modulus of the fixing plate 300. In some embodiments, the fixing plate 300 may also be an aluminum alloy plate, a steel-aluminum composite plate, a copper plate, a copper alloy plate, etc.

[0058] In one embodiment of the present invention, the fixing plate 300 and the third surface 230 of the cylindrical battery 200 can be bonded via quick-adhesive adhesive. Through the above design, the present invention can use quick-adhesive adhesive to achieve convenient and fast assembly, thereby improving assembly efficiency.

[0059] like Figure 4 As shown, in one embodiment of the present invention, the battery pack further includes a conductive bar 500, which is disposed on one side of the cylindrical battery 200 on the first surface 210, and the conductive bar 500 is suitable for realizing electrical connection between two adjacent cylindrical batteries 200, for example, the conductive bar 500 can be connected to the electrode lead-out terminal disposed on the first surface 210 of the cylindrical battery 200. Specifically, the conductive bar 500 includes two connecting parts 510 and a bridging part 520, the two connecting parts 510 are respectively connected to two adjacent batteries, and the bridging part 520 is connected between the two connecting parts 510. On this basis, the battery pack proposed by the present invention may further include an insulating plate 600, the insulating plate 600 is partially located between the bridging part 520 and the first surface 210, which is equivalent to the insulating plate 600 being partially located between the conductive bar 500 and the fixing plate 300. Through the above structural design, the present invention can optimize the insulation effect between the conductive bar 500 and the fixing plate 300 by using the insulating plate 600, further reduce the risk of short circuit, and further improve the safety of the battery pack.

[0060] like Figure 4 As shown, based on the structural design that the battery pack includes a conductive bar 500 and an insulating plate 600, in one embodiment of the present invention, the insulating plate 600 may be provided with a hollow portion 610, and the hollow portion 610 is arranged corresponding to the position of the connecting portion 510, and the hollow portion 610 can expose a partial area of ​​the first surface 210, and the connecting portion 510 is connected to the partial area of ​​the first surface 210 exposed in the hollow portion 610, that is, the electrode lead end of the first surface 210 is exposed in the hollow portion 610. Through the above structural design, the present invention can facilitate the connection between the conductive bar 500 and the battery on the basis of ensuring the insulation effect between the conductive bar 500 and the fixing plate 300.

[0061] In one embodiment of the present invention, the first insulating layer 240 may be an insulating coating. Further, the first insulating layer 240 may be coated on the third surface 230 of the cylindrical battery 200 by spraying. In some embodiments, when the first insulating layer 240 is an insulating coating, the first insulating layer 240 may also be coated by other coating processes, such as spin coating, etc., and is not limited to this embodiment.

[0062] In one embodiment of the utility model, a second insulating layer may be provided on the surface of the fixed plate 300, and the second insulating layer may be, for example, an insulating spray layer. Through the above-mentioned structural design, the utility model can further reduce the risk of short circuit and further improve the safety of the battery pack. In addition, when the fixed plate 300 is connected to the heat exchange plate 400 and the third surface 230 has a second weld mark 232, the fixed plate 300 and the second weld mark 232 can at least be insulated through the second insulating layer. Of course, even if the second weld mark 232 is exposed outside the fixed plate 300 (for example, when the fixed plate 300 is not connected to the heat exchange plate 400), a second insulating layer may also be provided on the surface of the fixed plate 300, which is not limited to the above-mentioned embodiments.

[0063] Based on the structural design that the second insulating layer is provided on the surface of the fixing plate 300, in one embodiment of the present invention, the second insulating layer may be an insulating coating. Further, the second insulating layer may be coated on the surface of the fixing plate 300 by spraying. In some embodiments, when the second insulating layer is an insulating coating, the second insulating layer may also be coated by other coating processes, such as spin coating, etc., and is not limited to this embodiment.

[0064] like Figure 3 As shown, in one embodiment of the present invention, the third surface 230 of the cylindrical battery 200 may be provided with a first insulating layer 240. For ease of observation and understanding, Figure 3 The dot-shaped filling pattern is used to represent the first insulating layer 240 disposed on the third surface 230. On this basis, along the first direction X, the fixing plate 300 can all fall within the range of the first insulating layer 240, that is, the edges of both sides of the fixing plate 300 in the first direction X do not exceed the edges of the first insulating layer 240. Through the above structural design, the utility model can further reduce the risk of short circuit and further improve the safety of the battery pack.

[0065] In one embodiment of the present invention, the thickness of the fixing plate 300 can be 0.5 mm to 10 mm, such as 0.5 mm, 1 mm, 2 mm, 5 mm, 10 mm, etc. Through the above structural design, the present invention can avoid the fixing plate 300 being too thick and causing excessive space occupation, and can also avoid the fixing plate 300 being too thin and causing insufficient rigidity to affect the strengthening effect.

[0066] It should be noted that Figure 1 Taking the illustrated embodiment as an example, when cylindrical batteries 200 are provided on both sides of the heat exchange plate 400 in the first direction X, the heat exchange plate 400 and the cylindrical batteries 200 on both sides and other related structures can together constitute a battery module, and the battery module can be arranged on the module bottom plate 1101, and arranged on the bottom plate 110 of the battery box through the module bottom plate 1101. At this time, the relative arrangement relationship between each structure and the bottom plate 110 in this specification can be correspondingly understood as the relative arrangement relationship between each structure and the module bottom plate 1101. Through the above-mentioned structural design, the utility model can improve the integration of the battery module, which is conducive to improving the assembly efficiency. It should be understood that in some embodiments, the battery pack may not be provided with a module bottom plate 1101, and the battery module may also be directly arranged on the bottom plate 110 of the battery box 100.

[0067] It should be noted that the battery packs shown in the drawings and described in this specification are only a few examples of many types of battery packs that can adopt the principles of the present invention. It should be clearly understood that the principles of the present invention are by no means limited to any details of the battery packs shown in the drawings or described in this specification or any components of the battery packs.

[0068] In summary, the battery pack proposed by the utility model includes a cylindrical battery 200 and a fixing plate 300; the connection area between the third surface 230 of the cylindrical battery 200 and the first surface 210 has a first welding mark 231, and the third surface 230 is provided with a first insulating layer 240, and the first insulating layer 240 does not cover the first welding mark 231. The fixing plate 300 is made of metal and is arranged on the third surface 230 of the cylindrical battery 200; the first welding mark 231 is arranged at intervals from the fixing plate 300, and along the axial direction of the cylindrical battery 200, the minimum spacing between the adjacent edges of the first surface 210 and the fixing plate 300 is 1.5mm to 30mm. Through the above-mentioned structural design, the utility model can utilize the metal fixing plate 300 to provide strong structural support and thermal conductivity. On this basis, the utility model separates the fixing plate 300 from the first welding mark 231 by a certain distance, which can effectively avoid electrical connection between the fixing plate 300 and the relevant area of ​​the cylindrical battery 200, reduce the risk of short circuit, and improve the safety of the battery pack.

[0069] The exemplary embodiments of the battery pack proposed by the utility model are described and / or illustrated in detail above. However, the embodiments of the utility model are not limited to the specific embodiments described here. On the contrary, the components and / or steps of each embodiment can be used independently and separately from other components and / or steps described here. Each component and / or each step of an embodiment can also be used in combination with other components and / or steps of other embodiments. When introducing the elements / components / etc. described and / or illustrated here, the terms "one", "one" and "above" are used to indicate the presence of one or more elements / components / etc. The terms "comprising", "including" and "having" are used to express the meaning of open inclusion and mean that in addition to the listed elements / components / etc., there may be additional elements / components / etc. In addition, the terms "first" and "second" in the claims and the specification are used only as marks and are not numerical restrictions on their objects.

[0070] Although the battery pack of the present invention has been described according to different specific embodiments, those skilled in the art will recognize that the implementation of the present invention can be modified within the spirit and scope of the claims.

Claims

1. A battery pack, characterized in that: include: Battery box; A cylindrical battery is arranged in the battery box, wherein the two end surfaces of the cylindrical battery are respectively the first surface and the second surface, the cylindrical surface of the cylindrical battery is the third surface, the first surface and the second surface are arranged at intervals in a first direction and are respectively perpendicular to the first direction, the first direction is the axial direction of the cylindrical battery, the third surface is connected between the first surface and the second surface, the connection area between the third surface and the first surface has a first welding mark, the third surface is provided with a first insulating layer, and the first insulating layer does not cover the first welding mark; as well as A fixing plate, which is disposed on the third surface of the cylindrical battery and is made of metal, and the fixing plate is disposed opposite to the third surface and is fixedly connected; The first welding mark is spaced apart from the fixing plate, and along the first direction, the minimum spacing between the first surface and the adjacent edge of the fixing plate is 1.5 mm to 30 mm.

2. The battery pack according to claim 1, characterized in that: The connection area between the third surface and the second surface has a second welding mark, and the second welding mark is spaced apart from the fixing plate. Along the first direction, the minimum spacing between the second surface and the adjacent edge of the fixing plate is greater than or equal to 1.5 mm to 30 mm.

3. The battery pack according to claim 1, characterized in that: The third surface is integrally formed with the second surface, and along the first direction, a minimum spacing between the second surface and an adjacent edge of the fixing plate is 1.5 mm to 2.8 mm.

4. The battery pack according to claim 1, characterized in that: Along the first direction, the length of the fixing plate accounts for 5% to 95% of the length of the third surface.

5. The battery pack according to claim 1, characterized in that: At least two of the cylindrical batteries are arranged into a battery column along a second direction, which is perpendicular to the first direction, and at least two of the battery columns are arranged into a battery group along a third direction, which is perpendicular to the first direction and perpendicular to the second direction; wherein the fixing plate is arranged between two adjacent battery columns belonging to one battery group.

6. The battery pack according to any one of claims 1 to 5, characterized in that: The elastic modulus of the fixing plate is greater than or equal to 10 GPa.

7. The battery pack according to any one of claims 1 to 5, characterized in that: The first insulating layer is an insulating coating.

8. The battery pack according to any one of claims 1 to 5, characterized in that: A second insulating layer is disposed on the surface of the fixing plate.

9. The battery pack according to claim 8, characterized in that: The second insulating layer is an insulating coating.

10. The battery pack according to any one of claims 1 to 5, characterized in that: The thickness of the fixing plate is 0.5 mm to 10 mm.

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