Battery pack and battery pack production method

Abstract

The invention belongs to the technical field of batteries, and discloses a battery pack and a battery pack production method. The battery pack comprises a box body and a battery module, wherein a plurality of accommodating cavities are formed in the box body; the battery module is arranged in the accommodating cavity, the battery module comprises a supporting frame, at least one connecting bracket and a plurality of single cells, the supporting frame is fixed on the inner wall of the box body, the plurality of single cells are arranged along a first direction to form a cell group, and a plurality of cell groups arranged along a second direction are arranged in the supporting frame; a connecting bracket is clamped between two adjacent battery cell groups, and the connecting bracket is fixed on at least one battery cell group; wherein the support frame is filled with polystyrene foam, and the polystyrene foam is used for bonding the support frame, the at least one connecting bracket and the plurality of single battery cells into a whole. According to the battery pack, the mechanical strength of the battery modules in the battery pack can be improved, the use safety and reliability of the battery pack are improved, meanwhile, the structure is simple, and the production efficiency can be improved while the production cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery pack and a battery pack production method. Background Art

[0002] In the prior art, a cylindrical battery pack generally includes a box body and a battery module disposed in the box body, wherein the box body includes a ring frame and a bottom guard plate disposed at the bottom of the ring frame; the battery module includes a battery bracket disposed at the bottom of the box body, a single cell disposed on the battery bracket, and a CCS assembly disposed on the single cell. The CCS assembly is welded to the single cell.

[0003] In the traditional assembly process, the battery holder is first assembled into the box, and then the single cells are arranged on the battery holder to form the battery module body, and finally the CCS assembly is welded on the battery module body to form the battery module. This battery module grouping method is not only complex in structure, but also cumbersome, time-consuming and labor-intensive in the assembly process, and the rigidity of the whole package is also weak.

[0004] Another method is to use a plastic bracket to fix the battery cell to form a module, and bolts are also needed to fix the formed battery module inside the battery box. Although this design is simple in structure, due to the poor strength of the plastic bracket itself, the battery module is difficult to meet the requirements of vibration, impact, and extrusion in the battery pack, which can easily cause damage to the cylindrical battery in the battery module.

[0005] Therefore, there is an urgent need to provide a new type of battery pack and a battery pack production method to solve the above-mentioned technical problems in the prior art. Summary of the invention

[0006] The object of the present invention is to provide a battery pack that can improve the mechanical strength of the battery module in the battery pack, improve the safety and reliability of the battery pack, and at the same time has a simple structure, which can reduce production costs while improving production efficiency.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The battery pack comprises a box body and a battery module, wherein the box body is provided with a plurality of accommodating cavities; the battery module is arranged in the accommodating cavities, the battery module comprises a supporting frame, at least one connecting bracket and a plurality of single cells, the supporting frame is fixed to the inner wall of the box body, a plurality of single cells are arranged along a first direction to form a cell group, a plurality of cell groups arranged along a second direction are arranged in the supporting frame, a connecting bracket is sandwiched between two adjacent cell groups, the connecting bracket is fixed to at least one cell group, and the second direction is perpendicular to the first direction; wherein the supporting frame is filled with foam glue, and the foam glue is used to bond the supporting frame, at least one connecting bracket and a plurality of single cells into one.

[0009] Optionally, the box body includes a bottom guard plate at the bottom, the top wall of the bottom guard plate carries the battery module, and the support frame is fixed to the bottom guard plate.

[0010] Optionally, a fixing portion is provided at the bottom of the support frame in a direction away from the single battery cell and extending outward, and the fixing portion is detachably connected to the bottom guard plate.

[0011] Optionally, the top wall of the bottom guard plate is provided with a thermally conductive structural adhesive, the bottom wall of the foam adhesive is higher than the bottom wall of the single battery cell, and the bottom of the single battery cell is fixed to the thermally conductive structural adhesive.

[0012] Optionally, a glue overflow groove for the thermal conductive structural glue to overflow is provided between the fixing portion and the bottom guard plate.

[0013] Optionally, a liquid cooling plate is provided on the bottom wall of the bottom guard plate.

[0014] Optionally, the height of the connecting bracket is 20% to 50% of the height of the single battery cell.

[0015] Optionally, it is characterized in that the height difference between the top of the connecting bracket and the top of the single battery is 5mm to 10mm, and the height difference between the bottom of the connecting bracket and the bottom of the single battery is 30mm to 50mm.

[0016] Optionally, the top port of the support frame and the top wall of the foamed adhesive are not higher than the top wall of the single battery cell.

[0017] Optionally, the single cell is a cylindrical cell, the side wall of the connecting bracket is wavy, and the single cell is matched with the side wall of the connecting bracket.

[0018] Optionally, a filling gap is formed between the two battery cell groups, and a size of at least one of the filling gaps along the second direction is larger than a size of the other filling gaps along the second direction.

[0019] Another object of the present invention is to provide a battery pack production method, which is used to produce a battery pack as described in any of the above schemes, including the following steps: S1, assembling a cell group: arranging a plurality of the above-mentioned single cells along a first direction, and then fixing a connecting bracket to the circumferential side wall of the above-mentioned single cells to form the above-mentioned cell group; S2, placing the plurality of the above-mentioned cell groups in step S1 on a lower mold along a second direction, and then surrounding the outer periphery of the plurality of the above-mentioned cell groups with a supporting frame; S3, placing an upper mold on the top of the above-mentioned supporting frame, the above-mentioned upper mold, the above-mentioned supporting frame and the above-mentioned lower mold forming a closed space, and the above-mentioned upper mold is provided with a glue injection hole; S4, injecting the above-mentioned foam glue into the above-mentioned closed space from the above-mentioned glue injection hole, and removing the above-mentioned upper mold and the above-mentioned lower mold after the above-mentioned foam glue solidifies to obtain the above-mentioned battery module; S5, placing the above-mentioned battery module in the accommodating cavity of the above-mentioned box body, and fixing the above-mentioned support frame to the above-mentioned box body.

[0020] Optionally, a plurality of battery cell positioning holes are provided on the top wall of the lower mold, and the bottoms of the single battery cells are inserted into the battery cell positioning holes one by one.

[0021] Optionally, a top wall of the lower mold is provided with a positioning boss that cooperates with the support frame, and the positioning boss is provided with the battery cell positioning hole.

[0022] Optionally, a plurality of battery cell avoidance holes are provided on the bottom wall of the upper mold, and the tops of the single battery cells are inserted into the battery cell avoidance holes one by one.

[0023] Optionally, step S1 further includes step S11, spraying a mold release agent: spraying a mold release agent on the top wall of the lower mold and the bottom wall of the upper mold.

[0024] Beneficial effects:

[0025] The battery pack in the present invention uses a housing cavity of a box to accommodate a battery module. The battery module includes a support frame, a connecting bracket and a single cell. After the single cell is arranged into a cell group along a first direction, it is fixed on the connecting bracket. Then, a plurality of cell groups are placed into the support frame along a second direction. The support frame is filled with foam glue, so that the cell group, the connecting bracket and the support frame are fixed to form a whole. Finally, the battery module is fixedly connected to the box by fixing the supporting frame in the box. The battery pack can improve the mechanical strength of the battery module in the battery pack by filling with foam glue, prevent the connecting bracket from falling off from the single cell due to looseness, and improve the safety and reliability of the battery pack. At the same time, its structure is simple, and no additional bracket is needed to fix the single cell, which simplifies the production process, can reduce production costs and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an axonometric diagram of a battery pack provided by a specific embodiment of the present invention with the cover plate hidden;

[0027] Figure 2 is an exploded view of a battery module provided by a specific embodiment of the present invention;

[0028] Figure 3 is a cross-sectional view of a battery pack provided by a specific embodiment of the present invention with some components hidden;

[0029] Figure 4 yes Figure 3 A partial enlarged view of the middle A;

[0030] Figure 5 is an axonometric diagram of a partial structure of a battery module provided in a specific embodiment of the present invention;

[0031] Figure 6 It is an axonometric view of a battery module installed according to a specific embodiment of the present invention;

[0032] Figure 7 It is an axonometric view of the upper mold provided by a specific embodiment of the present invention.

[0033] In the figure:

[0034] 10. Lower mold; 11. Positioning boss; 12. Battery cell positioning hole; 20. Upper mold; 21. Glue filling hole; 22. Exhaust hole; 23. Battery cell avoidance hole;

[0035] 100, box body; 101, accommodating cavity; 110, bottom guard plate; 111, liquid cooling plate; 112, overflow glue groove;

[0036] 200, battery module; 210, support frame; 211, fixing part; 220, connecting bracket; 230, battery cell group; 231, single battery cell; 232, filling gap; 240, foam glue; 250, thermal conductive structural glue. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0041] The first direction described in this embodiment is Figure 2 The X direction shown in is the length direction of the battery module 200; the second direction is Figure 2 The Y direction shown in , that is, the width direction of the battery module 200 , the first direction and the second direction are perpendicular to each other.

[0042] Please refer to Figure 1 to Figure 2In this embodiment, the battery pack includes a box body 100 and a battery module 200. The box body 100 is provided with a plurality of accommodating cavities 101. The battery module 200 is arranged in the accommodating cavity 101. The battery module 200 includes a support frame 210, at least one connecting bracket 220 and a plurality of single cells 231. The support frame 210 is fixed to the inner wall of the box body 100. The plurality of single cells 231 are arranged along a first direction to form a cell group 230. The support frame 210 is provided with a plurality of the battery cell groups 230 arranged along the second direction, the connecting bracket 220 is sandwiched between two adjacent battery cell groups 230, the connecting bracket 220 is fixed to at least one of the battery cell groups 230, and the second direction is perpendicular to the first direction; wherein, the support frame 210 is filled with foam glue 240, and the foam glue 240 is used to bond the support frame 210, at least one connecting bracket 220 and a plurality of single battery cells 231 into one body.

[0043] The battery pack in this embodiment uses the accommodating cavity 101 of the box body 100 to accommodate the battery module 200. The battery module 200 includes a support frame 210, a connecting bracket 220 and a single battery cell 231. The single battery cell 231 is arranged into a battery cell group 230 along a first direction and then fixed on the connecting bracket 220. Subsequently, a plurality of battery cell groups 230 in groups are placed into the support frame 210 along a second direction. The support frame 210 is filled with foam glue 240 to fix the battery cell group 230, the connecting bracket 220 and the support frame 210 to form a whole. Finally, the battery module 200 is fixedly connected to the box body 100 by fixing the support frame 210 in the box body 100. The battery pack can improve the mechanical strength of the battery module 200 in the battery pack by filling with foam glue 240, prevent the connecting bracket 220 from falling off the single battery cell 231 due to looseness, and improve the safety and reliability of the battery pack. At the same time, its structure is simple and there is no need to use additional brackets to fix the single battery cell 231, which simplifies the production process and can reduce production costs while improving production efficiency.

[0044] In this embodiment, the box body 100 is provided with a accommodating cavity 101, that is, it only corresponds to accommodating one battery module 200. The box body 100 is also provided with other cavities for accommodating electrical components such as a battery management unit and a thermal management unit, which will not be repeated here.

[0045] Please continue to refer to Figure 3 and Figure 4The box body 100 includes a bottom guard plate 110 at the bottom, the top wall of the bottom guard plate 110 carries the battery module 200, and the support frame 210 is fixed to the bottom guard plate 110. Specifically, the bottom guard plate 110 is used to carry the battery module 200, has high mechanical strength, can prevent the bottom of the battery module 200 from being damaged by foreign objects, and is the main load-bearing unit of the entire box body 100.

[0046] Optionally, a fixing portion 211 is provided at the bottom of the support frame 210 in a direction away from the single battery cell 231 and extending outward, and the fixing portion 211 is detachably connected to the bottom guard plate 110. It should be noted that the fixing portion 211 is also a flange extending outward from the bottom of the support frame 210, and the fixing portion 211 is detachably connected to the bottom guard plate 110 by bolts, thereby realizing a reliable connection between the battery module 200 and the box body 100, thereby preventing the battery module 200 from loosening when the battery pack is in a vibrating environment, and further improving the reliability of the battery pack.

[0047] In this embodiment, the top wall of the bottom guard plate 110 is provided with a heat-conducting structural adhesive 250, the bottom wall of the foaming adhesive 240 is higher than the bottom wall of the single battery cell 231, and the bottom of the single battery cell 231 is fixed to the heat-conducting structural adhesive 250. When the battery module 200 generates heat during discharge or charging, the heat-conducting structural adhesive 250 can conduct the generated heat outward from the bottom of the single battery cell 231 to avoid the accumulation of heat inside the battery pack. At the same time, the heat-conducting structural adhesive 250 can also provide sufficient bonding strength to firmly fix the battery module 200 inside the box 100, further improving the reliability and safety of the battery pack.

[0048] Specifically, an overflowing glue groove 112 is provided between the fixing portion 211 and the bottom guard plate 110 for the thermally conductive structural adhesive 250 to overflow. After the bottom guard plate 110 is fully coated with the thermally conductive structural adhesive 250, the battery module 200 is placed on the thermally conductive structural adhesive 250, and then the thermally conductive structural adhesive 250 overflows from the overflowing glue groove 112. After being installed in place, the support frame 210 can be fixed on the bottom guard plate 110. The setting of the overflowing glue groove 112 can discharge the excess thermally conductive structural adhesive 250, avoiding the battery module 200 and the bottom guard plate 110 from being improperly installed due to excessive thermally conductive structural adhesive 250, thereby improving the structural reliability of the battery pack.

[0049] Furthermore, a liquid cooling plate 111 is provided on the bottom wall of the bottom guard plate 110. A liquid cooling channel is formed between the liquid cooling plate 111 and the bottom guard plate 110, and the heat is conducted away from the bottom of the single battery cell 231 through the flow of the coolant, so as to realize the reliable and safe operation of the battery pack.

[0050] Optionally, the top port of the support frame 210 and the top wall of the foam glue 240 are not higher than the top wall of the single cell 231. This arrangement can expose the poles at the top of the single cell 231, facilitate welding of electrical connection components such as busbars, and improve assembly efficiency.

[0051] like Figure 5 As shown, the single cell 231 is a cylindrical cell, the side wall of the connecting bracket 220 is wavy, and the single cell 231 is matched with the side wall of the connecting bracket 220. In this embodiment, the connecting bracket 220 is bonded and fixed to the cell group 230. The connecting bracket 220 configured in this way can increase the contact area with the single cell 231, improve the reliability of the bonding and fixing of the single cell 231 and the connecting bracket 220, and at the same time can reduce the size of the battery module 200 along the second direction, thereby improving the energy density of the battery pack.

[0052] In this embodiment, the connecting bracket 220 is made of plastic, plastic or rubber and has a certain elasticity, which can prevent collision between the connected single cells 231 after the battery pack is squeezed, play a buffering role, and improve the safety of the battery pack.

[0053] Furthermore, the height of the connecting bracket 220 is 20% to 50% of the height of the single cell 231. If the proportion of the height of the connecting bracket 220 to the height of the single cell 231 is too small, it cannot play a supporting role, and if the proportion is too large, it will produce greater redundancy, increase the weight of the battery module 200 and reduce the mass energy density. In this embodiment, the height of the connecting bracket 220 is 28.6% of the height of the single cell 231, that is, the height of the single cell 231 is 70 mm, and the height of the connecting bracket 220 is 20 mm.

[0054] Optionally, it is characterized in that the height difference between the top of the connecting bracket 220 and the top of the single battery 231 is 5mm to 10mm, and the height difference between the bottom of the connecting bracket 230 and the bottom of the single battery 231 is 30mm to 50mm. Such a setting can make the connecting bracket 231 located in the middle and upper part of the single battery 231, avoid interference with the fixing structure at the bottom of the single battery 231, such as the thermal conductive structural glue 250, etc., and circumferentially position and fix the single battery 231 from the upper and lower ends, so that the stability of the battery module 200 is higher.

[0055] In this embodiment, a filling gap 232 is formed between the two battery cell groups 230, and the size of at least one of the filling gaps 232 along the second direction is greater than the size of the other filling gaps 232 along the second direction. Specifically, the filling gap 232 between two connected battery cell groups 230 is the thickness of a connecting bracket 220, and every four battery cell groups 230 form a whole, wherein three connecting brackets 220 are arranged between the four battery cell groups 230, and a thickened connecting bracket 220 is arranged every four battery cell groups 230, so that the width of the filling gap 232 here is greater than the width of other filling gaps 232, so that when the foam glue 240 is filled, it is convenient for the foam glue 240 to flow and fill every corner, so as to achieve complete filling of the foam glue 240, and further improve the reliability of the battery pack.

[0056] Please continue to refer to Figures 1 to 4 The present embodiment also provides a battery pack production method, which is used to produce a battery pack as described in any of the above schemes, including the following steps: S1, assembling a cell group 230: arranging a plurality of the above-mentioned single cells 231 along a first direction, and then fixing a connecting bracket 220 to a circumferential side wall of the above-mentioned single cells 231 to form the above-mentioned cell group 230; S2, placing the plurality of the above-mentioned cell groups 230 in step S1 on a lower mold 10 along a second direction, and then surrounding the support frame 210 around the outer periphery of the plurality of the above-mentioned cell groups 230; S3, placing an upper mold 20 is placed on the top of the above-mentioned support frame 210, and the above-mentioned upper mold 20, the above-mentioned support frame 210 and the above-mentioned lower mold 10 form a closed space, and the above-mentioned upper mold 20 is provided with a glue injection hole 21; S4, the above-mentioned foam glue 240 is injected into the above-mentioned closed space from the above-mentioned glue injection hole 21, and the above-mentioned upper mold 20 and the above-mentioned lower mold 10 are removed after the above-mentioned foam glue 240 solidifies, so as to obtain the above-mentioned battery module 200; S5, the above-mentioned battery module 200 is placed in the accommodating cavity 101 of the above-mentioned box body 100, and the above-mentioned support frame 210 is fixed to the above-mentioned box body 100.

[0057] The battery pack production method in this embodiment first arranges the single cells 231 into a cell group 230 along a first direction, and then fixes them on the connecting bracket 220, and then puts a plurality of cell groups 230 into the support frame 210 along a second direction, and fills the support frame 210 with foam glue 240, so that the cell group 230, the connecting bracket 220 and the support frame 210 are fixed to form a whole, and finally the battery module 200 is fixedly connected to the box body 100 by fixing the supporting frame 210 in the box body 100. The battery pack production method can improve the mechanical strength of the battery module 200 in the battery pack by filling the foam glue 240, prevent the connecting bracket 220 from falling off the single cell 231 due to looseness, and improve the safety and reliability of the battery pack. At the same time, its structure is simple, and no additional bracket is needed to fix the single cell 231, which simplifies the production process, can reduce production costs and improve production efficiency.

[0058] Optionally, after step S1, step S11 is further included, spraying a release agent: spraying a release agent on the top wall of the lower mold 10 and the bottom wall of the upper mold 20. The provision of the release agent can prevent the foam glue 240 from adhering to the surfaces of the upper mold 20 and the lower mold 10 after solidification, facilitates the removal of the upper mold 20 and the lower mold 10, improves production efficiency, and can prevent damage to the foam glue 240 that has been formed.

[0059] like Figure 6 and Figure 7 As shown, in this embodiment, the top wall of the lower mold 10 is provided with a plurality of cell positioning holes 12, and the bottoms of the single cells 231 are inserted into the cell positioning holes 12 one by one. The provision of the cell positioning holes 12 can facilitate the arrangement of the single cells 231 into the cell group 230 along the first direction, thereby improving production efficiency.

[0060] Optionally, the top wall of the lower mold 10 is provided with a positioning boss 11 that cooperates with the support frame 210, and the positioning boss 11 is provided with the battery cell positioning hole 12. The positioning boss 11 is provided so that a cavity is formed between the bottom of the single battery cell 231 and the inner wall of the support frame 210 when the foam glue 240 is poured, so that when the battery module 200 is subsequently placed in the box 100, it is convenient to set the heat conductive structural glue 250 in the cavity to achieve cooling and heat dissipation of the single battery cell 231.

[0061] Furthermore, the bottom wall of the upper mold 20 is provided with a plurality of cell avoidance holes 23, and the tops of the single cells 231 are inserted into the cell avoidance holes 23 one by one. The provision of the cell avoidance holes 23 can prevent the foam glue 240 from contaminating the poles on the tops of the single cells 231, and can make the heights of the top walls of the single cells 231 at the same level, which is convenient for subsequent welding of the busbar.

[0062] It should be noted that the upper mold 20 is not only provided with a number of glue injection holes 21, specifically 4, but also provided with a plurality of exhaust holes 22, which can make the foam glue 240 more smoothly poured into the enclosed space formed by the upper mold 20, the support frame 210 and the lower mold 10, and at the same time discharge the excess foam glue 240, which will not be repeated here.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery pack, characterized in that: include: A box body (100), wherein a plurality of accommodating cavities (101) are arranged inside the box body (100); A battery module (200), the battery module (200) being arranged in the accommodating cavity (101), the battery module (200) comprising a support frame (210), at least one connecting bracket (220) and a plurality of single cells (231), the support frame (210) being fixed to the inner wall of the box body (100), a plurality of single cells (231) being arranged along a first direction to form a cell group (230), a plurality of cell groups (230) being arranged along a second direction being arranged in the support frame (210), a connecting bracket (220) being sandwiched between two adjacent cell groups (230), the connecting bracket (220) being fixed to at least one cell group (230), and the second direction being perpendicular to the first direction; wherein, The support frame (210) is filled with foam glue (240), and the foam glue (240) is used to bond the support frame (210), at least one connecting bracket (220) and a plurality of single battery cells (231) into one body.

2. The battery pack according to claim 1, characterized in that: The box body (100) comprises a bottom guard plate (110), the top wall of the bottom guard plate (110) carries the battery module (200), and the support frame (210) is fixed to the bottom guard plate (110).

3. The battery pack according to claim 2, characterized in that: A fixing portion (211) is provided at the bottom of the support frame (210) in a direction away from the single battery cell (231) and extending outwards, and the fixing portion (211) is detachably connected to the bottom guard plate (110).

4. The battery pack according to claim 3, characterized in that: The top wall of the bottom guard plate (110) is provided with a heat-conducting structural adhesive (250), the bottom wall of the foam adhesive (240) is higher than the bottom wall of the single battery cell (231), and the bottom of the single battery cell (231) is fixed to the heat-conducting structural adhesive (250).

5. The battery pack according to claim 4, characterized in that: An overflow glue groove (112) for the heat-conducting structural glue (250) to overflow is provided between the fixing portion (211) and the bottom guard plate (110).

6. The battery pack according to claim 4, characterized in that: The bottom wall of the bottom guard plate (110) is provided with a liquid cooling plate (111).

7. The battery pack according to claim 1, characterized in that: The height of the connecting bracket (220) is 20% to 50% of the height of the single battery cell (231).

8. The battery pack according to claim 7, characterized in that: The height difference between the top end of the connection bracket (220) and the top end of the single battery (231) is 5 mm to 10 mm, and the height difference between the bottom end of the connection bracket (220) and the bottom end of the single battery (231) is 30 mm to 50 mm.

9. The battery pack according to any one of claims 1 to 8, characterized in that: The top port of the support frame (210) and the top wall of the foam glue (240) are not higher than the top wall of the single battery cell (231).

10. The battery pack according to any one of claims 1 to 8, characterized in that: The single cell (231) is a cylindrical cell, the side wall of the connecting bracket (220) is wavy, and the single cell (231) is compatible with the side wall of the connecting bracket (220).

11. The battery pack according to any one of claims 1 to 8, characterized in that: A filling gap (232) is formed between the two battery cell groups (220), and the size of at least one of the filling gaps (232) along the second direction is larger than the size of the other filling gaps (232) along the second direction.

12. A battery pack production method, characterized in that: For producing a battery pack as claimed in any one of claims 1 to 11, comprising the steps of: S1, assembling a cell group (230): arranging a plurality of the single cell cells (231) along a first direction, and then fixing a connecting bracket (220) to a circumferential side wall of the single cell cell (231) to form the cell group (230); S2, placing the plurality of battery cell groups (230) in step S1 on the lower mold (10) along the second direction, and then surrounding the plurality of battery cell groups (230) with a support frame (210); S3, placing the upper mold (20) on the top of the support frame (210), the upper mold (20), the support frame (210) and the lower mold (10) form a closed space, and the upper mold (20) is provided with a glue injection hole (21); S4, pouring the foam glue (240) into the enclosed space from the glue pouring hole (21), and removing the upper mold (20) and the lower mold (10) after the foam glue (240) solidifies, thereby obtaining the battery module (200); S5. Place the battery module (200) in the accommodating cavity (101) of the box (100), and fix the supporting frame (210) to the box (100).

13. The battery pack production method according to claim 12, characterized in that: The top wall of the lower mold (10) is provided with a plurality of battery cell positioning holes (12), and the bottoms of the single battery cells (231) are inserted into the battery cell positioning holes (12) in a one-to-one correspondence.

14. The battery pack production method according to claim 13, characterized in that: The top wall of the lower mold (10) is provided with a positioning boss (11) that cooperates with the support frame (210), and the positioning boss (11) is provided with the battery cell positioning hole (12).

15. The battery pack production method according to claim 12, characterized in that: The bottom wall of the upper mold (20) is provided with a plurality of battery cell avoidance holes (23), and the tops of the single battery cells (231) are inserted into the battery cell avoidance holes (23) in a one-to-one correspondence.

16. The battery pack production method according to claim 12, characterized in that: After step S1, the method further comprises step S11, spraying a mold release agent: spraying a mold release agent on the top wall of the lower mold (10) and the bottom wall of the upper mold (20).

Images