Battery pack, battery pack assembling method and electric device

Abstract

The invention belongs to the technical field of batteries, and discloses a battery pack, a battery pack assembling method and a power utilization device.The battery pack comprises a battery box, a battery cell assembly and a BMS, the battery box is provided with a first containing cavity and a second containing cavity which are not communicated with each other, the battery cell assembly is arranged in the first containing cavity and comprises a battery cell, the BMS is arranged in the second containing cavity, and the battery cell is arranged in the second containing cavity. And when the battery cell is in thermal runaway and sprays out high-temperature and high-pressure gas and particulate matters, the high-temperature and high-pressure gas and particulate matters cannot enter the second accommodating cavity and cannot be splashed to the BMS, so that a guarantee is provided for normal work of the BMS when the battery cell is in thermal runaway.

Description

Technical Field

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

[0002] Compared with traditional power vehicles, electric vehicles have good energy-saving and environmental protection effects and have been favored by more and more people. As the core component of electric vehicles, battery packs usually include battery boxes, battery modules and battery monitoring and management systems (BMS), among which the battery modules and BMS are both installed in the battery box.

[0003] When the battery cell of the battery module experiences thermal runaway, the explosion-proof valve of the battery cell opens and sprays out high-temperature and high-pressure gas and particulate matter. If the high-temperature and high-pressure gas or particulate matter splashes onto the BMS, it will damage the BMS, and then the BMS will not be able to provide thermal runaway fault signals to passengers, posing a serious safety hazard to battery vehicles.

[0004] Therefore, it is urgent to propose a battery pack, a battery pack assembly method and an electrical device to solve the above technical problems. Summary of the invention

[0005] The first object of the present invention is to provide a battery pack, in which the high-temperature and high-pressure gas and particulate matter ejected when the battery cell thermally runs away will not splash onto the BMS.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] Battery pack, including:

[0008] A battery box, wherein the battery box is provided with a first accommodating chamber and a second accommodating chamber, and the first accommodating chamber and the second accommodating chamber are not connected to each other;

[0009] A battery cell assembly, the battery cell assembly is arranged in the first accommodating cavity, and the battery cell assembly includes a battery cell;

[0010] BMS, the BMS is arranged in the second accommodating chamber.

[0011] Optionally, the battery pack further includes a CCS, the CCS includes a frame plate, and the frame plate is sealed and isolated in the battery box to form a first accommodating cavity and a second accommodating cavity in the battery box.

[0012] Optionally, the battery box includes a box cover and a box body, the box cover is snap-fitted to the box body, a frame plate is arranged in the box body, a seal is provided at the edge of the frame plate, the seal extends along the circumference of the frame plate and is connected end to end, the frame plate is sealed to the inner wall of the box body through the seal, the first accommodating cavity is located between the frame plate and the box body, and the second accommodating cavity is located between the frame plate and the box cover.

[0013] Optionally, a first protrusion is provided on a side of the box cover facing the box body, the first protrusion extends along the circumference of the box cover and is connected end to end, and the first protrusion is inserted into the sealing member.

[0014] Optionally, a baffle is provided in the box body, and battery cells are provided on both sides of the baffle.

[0015] Optionally, at least one battery cell located on one side of the baffle is provided with a first explosion-proof valve facing the baffle.

[0016] Optionally, a first gap is left between the first explosion-proof valve and the baffle, a second gap is left between each battery cell and the inner wall of the box, both sides of the baffle are spaced apart from the inner wall of the box so that the first gap is connected to the second gap to form an exhaust channel, and a fifth explosion-proof valve is provided on the box, and the exhaust channel is connected to the fifth explosion-proof valve.

[0017] Optionally, the axes of the battery cells located on both sides of the baffle are not parallel.

[0018] A second object of the present invention is to provide a battery pack assembly method, which is relatively simple and has the effect of reducing assembly difficulty and improving assembly efficiency.

[0019] To achieve this object, the present invention adopts the following technical solutions:

[0020] A battery pack assembly method is used to assemble the above-mentioned battery pack, and the battery pack assembly method comprises:

[0021] S1. Provide a frame, wherein the frame has a first area and a second area distributed along a first direction; along the second direction, fix the first battery cell and the second battery cell in the first area so that the axes of the first battery cell and the second battery cell are parallel to the first direction, and the first direction is perpendicular to the second direction;

[0022] S2, welding the electrode of the first battery cell facing the second region to the first connecting piece, and welding the electrode of the second battery cell facing the second region to the first connecting piece;

[0023] S3, fixing the fourth battery cell in the second area so that the axis of the fourth battery cell is parallel to the second direction and the fourth battery cell faces the first connecting sheet;

[0024] S4, installing the frame into the box body so that the first area and the second area are respectively located on both sides of the baffle.

[0025] A third object of the present invention is to provide an electrical device having a battery pack that is safer to use.

[0026] To achieve this object, the present invention adopts the following technical solutions:

[0027] An electrical device includes the above-mentioned battery pack.

[0028] Beneficial effects of the present invention:

[0029] The battery pack provided by the present invention divides the internal space of the battery box into a first accommodating chamber and a second accommodating chamber which are not connected to each other, arranges the battery cell assembly in the first accommodating chamber, and arranges the BMS in the second accommodating chamber. When the battery cell thermally runs away and sprays out high-temperature and high-pressure gas and particulate matter, the high-temperature and high-pressure gas and particulate matter will not enter the second accommodating chamber, and will not splash onto the BMS, thereby providing a guarantee for the normal operation of the BMS when the battery cell thermally runs away. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the explosion structure of the battery pack provided by the present invention;

[0031] Figure 2 is a schematic structural diagram of a battery pack provided by the present invention;

[0032] Figure 3 yes Figure 2 Schematic diagram of the FF cross-section structure;

[0033] Figure 4 yes Figure 3 A partial enlarged schematic diagram in the middle;

[0034] Figure 5 It is a first structural schematic diagram of the box body and the battery core assembly provided by the present invention;

[0035] Figure 6 It is a second structural schematic diagram of the box body and the battery core assembly provided by the present invention;

[0036] Figure 7 It is a first structural schematic diagram of a frame plate and a battery cell assembly provided by the present invention;

[0037] Figure 8 It is a structural schematic diagram of the frame plate provided by the present invention;

[0038] Fig. 9 It is a second structural schematic diagram of the frame plate and the battery cell assembly provided by the present invention.

[0039] In the figure:

[0040] 100, battery box; 110, first accommodating chamber; 120, second accommodating chamber; 130, box cover; 131, first protrusion; 132, first through hole; 133, second through hole; 140, box body; 141, baffle; 142, fifth explosion-proof valve; 200, battery cell assembly; 210, first battery cell; 220, second battery cell; 230, third battery cell; 240, fourth battery cell; 251, first explosion-proof valve; 252, second explosion-proof valve; 253, third explosion-proof valve; 254, fourth explosion-proof valve; 300, B MS; 400, CCS; 410, shelf; 411, first region; 412, second region; 413, second protrusion; 500, seal; 610, first gap; 620, second gap; 710, first connecting piece; 720, second connecting piece; 730, third connecting piece; 740, fourth connecting piece; 750, fifth connecting piece; 810, first conductive piece; 820, second conductive piece; 830, first sealing cover; 840, second sealing cover; D1, first direction; D2, second direction. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The present embodiment provides a battery pack, in which high-temperature and high-pressure gas and particulate matter ejected when a battery cell thermally runs away will not splash onto a BMS.

[0046] Specifically, Figures 1 to 3 As shown, the battery pack includes a battery box 100, a battery cell assembly 200 and a BMS 300, wherein the battery box 100 is provided with a first accommodating chamber 110 and a second accommodating chamber 120, the first accommodating chamber 110 and the second accommodating chamber 120 are not connected to each other, the battery cell assembly 200 is arranged in the first accommodating chamber 110, the battery cell assembly 200 includes battery cells, and the BMS 300 is arranged in the second accommodating chamber 120.

[0047] The battery pack divides the internal space of the battery box 100 into a first accommodating chamber 110 and a second accommodating chamber 120 which are not connected to each other, arranges the battery cell assembly 200 in the first accommodating chamber 110, and arranges the BMS300 in the second accommodating chamber 120. When the battery cell thermally runs away and sprays out high-temperature and high-pressure gas and particulate matter (hereinafter referred to as high-temperature medium), the high-temperature medium will not enter the second accommodating chamber 120, and will not splash onto the BMS300, thereby providing a guarantee for the normal operation of the BMS300 when the battery cell thermally runs away.

[0048] Optionally, the battery pack also includes a wiring harness plate integration (Cells Contact System, CCS), CCS400 includes a frame plate 410, and the frame plate 410 is sealed and blocked in the battery box 100 to form a first accommodating cavity 110 and a second accommodating cavity 120 in the battery box 100. This structural design utilizes the frame plate 410 of CCS400 to form a first accommodating cavity 110 and a second accommodating cavity 120 that are not connected to each other in the battery box 100, without adding other partitions or other blocking parts, thereby making full use of the internal space of the battery box 100, which is beneficial to improving the energy density of the battery pack.

[0049] Furthermore, the battery box 100 includes a box cover 130 and a box body 140, the box cover 130 is snap-fitted to the box body 140, the frame plate 410 is arranged in the box body 140, and a seal 500 is provided at the edge of the frame plate 410, the seal 500 extends along the circumference of the frame plate 410 and is connected end to end, and the frame plate 410 is sealed to the inner wall of the box body 140 through the seal 500, thereby achieving sealing between the frame plate 410 and the box body 140, preventing the high-temperature medium sprayed from the battery cell in the first accommodating chamber 110 from entering the second accommodating chamber 120 to affect the BMS300, so as to achieve isolation of the battery cell assembly 200 and the BMS300.

[0050] Furthermore, if Figure 3 and Figure 4 As shown, a second protrusion 413 is provided on one side edge of the frame plate 410 facing the box cover 130. The second protrusion 413 extends along the circumference of the frame plate 410 and is connected end to end. The seal 500 is filled between the second protrusion 413 and the inner wall of the box body 140 to improve the reliability of the seal between the frame plate 410 and the box body 140.

[0051] Optionally, the BMS 300 is fixed to a side of the box cover 130 facing the frame plate 410 to improve the integration of the battery pack, thereby facilitating improving the energy density of the battery pack.

[0052] In this embodiment, the seal 500 is a sealant, which can achieve sealing between the shelf 410 and the box 140, and can also make the shelf 410 and the box 140 become a whole through bonding. Of course, in other embodiments, the seal 500 can also be a sealing ring. In addition, in other embodiments, the seal 500 can also be sandwiched between the side wall of the shelf 410 and the inner wall of the box 140.

[0053] Optionally, a first protrusion 131 is provided on the side of the box cover 130 facing the box body 140, and the first protrusion 131 extends along the circumference of the box cover 130 and is connected end to end. The first protrusion 131 is inserted into the seal 500 to achieve the sealing between the frame plate 410 and the box cover 130. While the frame plate 410 and the box body 140 are sealed, a sealing structure between the frame plate 410 and the box cover 130 is added, which is beneficial to improve the sealing between the first accommodating cavity 110 and the second accommodating cavity 120, and can further prevent the high-temperature medium sprayed from the battery cell in the first accommodating cavity 110 from entering the second accommodating cavity 120 and affecting the BMS300. Moreover, in the present embodiment, the sealing member 500 is a sealant, and the first protrusion 131 of the box cover 130 is inserted into the sealant, so that the frame plate 410 and the box cover 130 are bonded into a whole, that is, the box body 140, the box cover 130 and the frame plate 410 are together formed into a whole, thereby improving the consistency and structural strength of the overall structure of the battery pack.

[0054] Alternatively, if Figure 5 and Figure 6 As shown, a baffle 141 is provided in the box body 140, and battery cells are provided on both sides of the baffle 141. When the battery cell on one side of the baffle 141 thermally runs away, the baffle 141 can play a certain heat insulation effect and reduce the probability of heat spread problems.

[0055] Optionally, the axes of the cells on both sides of the baffle 141 are not parallel. This structural design can be applied to the case where the internal space of the box 140 is small or other components are arranged in the box 140 and need to be avoided. In this embodiment, the axes of the cells on both sides of the baffle 141 are perpendicular to each other, so that the overall structure of the cell assembly 200 is more regular, which is conducive to improving the utilization rate of the internal space of the box 140. Of course, in other embodiments, the axes of the cells on both sides of the baffle 141 can also be arranged at an angle.

[0056] Furthermore, a first explosion-proof valve 251 is provided at a position of the battery cell on one side of the baffle 141 facing the baffle 141. When the first explosion-proof valve 251 opens and sprays out the high-temperature medium, the baffle 141 can play a good barrier effect to prevent the high-temperature medium from splashing onto the battery cell on the other side of the baffle 141, further reducing the probability of heat spread problems.

[0057] It should be pointed out that in other embodiments, when the axes of the battery cells on both sides of the baffle 141 are parallel, the battery cells on both sides of the baffle 141 may be provided with a first explosion-proof valve 251 facing the baffle 141 .

[0058] Optionally, a first gap 610 is left between the first explosion-proof valve 251 and the baffle 141, a second gap 620 is left between each battery cell and the inner wall of the box body 140, and both sides of the baffle 141 are spaced from the inner wall of the box body 140 so that the first gap 610 is connected to the second gap 620 to form an exhaust channel. A fifth explosion-proof valve 142 is provided on the box body 140, and the exhaust channel is connected to the fifth explosion-proof valve 142. When one or several battery cells thermally run away and spray out high-temperature medium, the high-temperature medium can flow in the exhaust channel to the fifth explosion-proof valve 142 and be discharged from the first accommodating cavity 110 from the fifth explosion-proof valve 142, so as to reduce the probability of explosion of the battery pack and achieve the effect of improving the safety of the battery pack.

[0059] Furthermore, explosion-proof valves are provided at both ends of each battery cell to achieve a quick exhaust effect.

[0060] In this embodiment, three battery cells are provided on one side of the baffle 141, and one battery cell is provided on the other side of the baffle 141. For ease of understanding, the three battery cells on one side of the baffle 141 are referred to as the first battery cell 210, the second battery cell 220, and the third battery cell 230, respectively, and the battery cell on the other side of the baffle 141 is referred to as the fourth battery cell 240, wherein the first battery cell 210, the second battery cell 220, and the fourth battery cell 240 are all arranged opposite to the baffle 141, the third battery cell 230 is staggered with the baffle 141, and the first battery cell 210 and the second battery cell 220 are provided with a first explosion-proof valve 210 on one side of the baffle 141. 51, a first gap 610 is left between the first explosion-proof valve 251 and the baffle 141, a second explosion-proof valve 252 is provided on the side of the first battery cell 210 and the second battery cell 220 away from the baffle 141, a third explosion-proof valve 253 is provided on both sides of the third battery cell 230, and a fourth explosion-proof valve 254 is provided on both sides of the fourth battery cell 240. A second gap 620 is left between the second explosion-proof valve 252 and the inner wall of the box body 140, between the third explosion-proof valve 253 and the inner wall of the box body 140, and between the fourth explosion-proof valve 254 and the inner wall of the box body 140, thereby forming an exhaust channel inside the box body 140 (i.e., inside the first accommodating chamber 110).

[0061] This embodiment also provides a battery pack assembly method, which is used to assemble the above-mentioned battery pack and has the effect of reducing assembly difficulty and improving assembly efficiency.

[0062] Specifically, Figures 7 to 9 As shown, the battery pack assembly method includes:

[0063] S1. Provide a frame 410, wherein the frame 410 has a first area 411 and a second area 412 distributed along a first direction D1; fix the first battery cell 210 and the second battery cell 220 in the first area 411 along the second direction D2, so that the axes of the first battery cell 210 and the second battery cell 220 are parallel to the first direction D1, and the first direction D1 is perpendicular to the second direction D2;

[0064] S2, welding the electrode of the first battery cell 210 facing the second area 412 to the first connecting sheet 710, and welding the electrode of the second battery cell 220 facing the second area 412 to the first connecting sheet 710;

[0065] S3, fixing the fourth battery cell 240 in the second area 412 so that the axis of the fourth battery cell 240 is parallel to the second direction D2, and the fourth battery cell 240 faces the first connecting sheet 710;

[0066] S4. Install the shelf 410 into the box body 140 so that the first area 411 and the second area 412 are respectively located on both sides of the baffle 141 , and a first accommodating chamber 110 is formed between the shelf 410 and the box body 140 .

[0067] In the battery pack assembly method, before fixing the fourth battery cell 240 to the frame plate 410, the first connecting piece 710 and the electrode of the first battery cell 210 facing the second area 412 are first welded, and the first connecting piece 710 and the electrode of the second battery cell 220 facing the second area 412 are welded. Compared with fixing the fourth battery cell 240 to the frame plate 410 before welding the first connecting piece 710, the assembly method provided in this embodiment reduces the difficulty of welding the first connecting piece 710 to the first battery cell 210 and the second battery cell 220, which is beneficial to improving the assembly efficiency of the battery pack.

[0068] Optionally, step S1 further includes: fixing the third battery cell 230 in the first area 411 so that the third battery cell 230 is located on a side of the second battery cell 220 away from the first battery cell 210 , and an axis of the third battery cell 230 is parallel to the first direction D1 ;

[0069] Step S2 further includes: welding the electrode of the third battery cell 230 facing the second area 412 to the second connecting piece 720, where the second connecting piece 720 is an L-shaped connecting piece;

[0070] Step S3 further includes: welding the electrode of the fourth battery cell 240 facing the second connecting sheet 720 to the second connecting sheet 720 .

[0071] After welding the third connecting piece 730 and the electrode of the third battery cell 230 facing the second area 412, the fourth battery cell 240 is fixed to the frame plate 410, and finally the electrode of the fourth battery cell 240 facing the second connecting piece 720 is welded to the second connecting piece 720. This method design is conducive to quickly finding the fixed position of the fourth battery cell 240 on the frame plate 410, which has the effect of further improving the assembly efficiency. In addition, compared with first fixing the fourth battery cell 240 to the frame plate 410 and then welding the second connecting piece 720, this design can reduce the problem of reduced welding strength between the second connecting piece 720 and the third battery cell 230 and the fourth battery cell 240 due to excessive position deviation between the third battery cell 230 and the fourth battery cell 240.

[0072] Optionally, step S2 further includes: welding the electrode of the second battery cell 220 away from the second area 412 to the third connecting piece 730, and welding the electrode of the third battery cell 230 away from the second area 412 to the third connecting piece 730; penetrating a fourth connecting piece 740 on a side of the first area 411 away from the second area 412, and welding the electrode of the first battery cell 210 away from the second area 412 to the fourth connecting piece 740; in the second area 412, passing the fifth connecting piece 750 through the frame plate 410, and setting the fifth connecting piece 750 and the second connecting piece 720 opposite to each other;

[0073] Step S3 further includes: fixing the fourth battery cell 240 between the second connecting sheet 720 and the fifth connecting sheet 750, and welding the electrode of the fourth battery cell 240 facing the fifth connecting sheet 750 to the fifth connecting sheet 750. That is, after all the battery cells and connecting sheets are connected to the frame plate 410, the fourth battery cell 240 is fixed to the frame plate 410.

[0074] Optionally, step S4 also includes: before installing the frame 410 into the box body 140, applying fixing glue on the bottom of the box body 140, and then installing the frame 410 into the box body 140, so that the first battery cell 210, the second battery cell 220, the third battery cell 230 and the fourth battery cell 240 are all bonded and fixed to the bottom of the box body 140 by the fixing glue, and the first battery cell 210, the second battery cell 220 and the third battery cell 230 are all located on the same side of the baffle 141, and the fourth battery cell 240 is located on the other side of the baffle 141.

[0075] The battery pack assembly method further includes: S5, filling a sealant between the second protrusion 413 and the inner wall of the box body 140 to achieve sealing between the frame plate 410 and the box body 140.

[0076] The battery pack assembly method also includes: S6, buckling the box cover 130 fixed with the BMS300 on the box body 140, inserting the first protrusion 131 into the sealant, achieving sealing between the frame plate 410 and the box cover 130, and forming a second accommodating cavity 120 between the frame plate 410 and the box cover 130.

[0077] like Figure 1 As shown, the battery pack assembly method further includes: S7, allowing the first conductive member 810 to sequentially penetrate the first through hole 132 and the BMS 300 and to be fixedly connected to the fourth connecting piece 740, so that the fourth connecting piece 740 is conductively connected to the BMS 300 through the first conductive member 810. Allowing the second conductive member 820 to sequentially penetrate the second through hole 133 and the BMS 300 and to be fixedly connected to the fifth connecting piece 750, so that the fifth connecting piece 750 is conductively connected to the BMS 300 through the second conductive member 820.

[0078] The battery pack assembly method further includes: S8, bonding and sealing the first sealing cover 830 at the first through hole 132, and bonding and sealing the second sealing cover 840 at the second through hole 133, so as to achieve sealing of the second accommodating cavity 120.

[0079] The present embodiment also provides an electrical device, which includes the above-mentioned battery pack. When the battery cells in the battery pack thermally run away and spray high-temperature medium, the probability of BMS300 being damaged is low, and then BMS300 can send a thermal runaway fault signal to the user, so that the electrical device has higher safety in use.

[0080] It should be noted that the electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like.

[0081] 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 battery box (100), the battery box (100) being provided with a first accommodating chamber (110) and a second accommodating chamber (120), the first accommodating chamber (110) and the second accommodating chamber (120) being not connected to each other; A battery cell assembly (200), the battery cell assembly (200) being arranged in the first accommodating cavity (110), the battery cell assembly (200) comprising a battery cell; A BMS (300), wherein the BMS (300) is disposed in the second accommodation chamber (120).

2. The battery pack according to claim 1, characterized in that: The battery pack further comprises a CCS (400), wherein the CCS (400) comprises a frame plate (410), wherein the frame plate (410) is sealed and isolated within the battery box (100) to form the first accommodating cavity (110) and the second accommodating cavity (120) within the battery box (100).

3. The battery pack according to claim 2, characterized in that: The battery box (100) comprises a box cover (130) and a box body (140), wherein the box cover (130) is snap-fittedly connected to the box body (140), the frame plate (410) is arranged in the box body (140), a sealing member (500) is arranged on the edge of the frame plate (410), the sealing member (500) extends along the circumference of the frame plate (410) and is connected end to end, the frame plate (410) is sealedly connected to the inner wall of the box body (140) via the sealing member (500), the first accommodating cavity (110) is located between the frame plate (410) and the box body (140), and the second accommodating cavity (120) is located between the frame plate (410) and the box cover (130).

4. The battery pack according to claim 3, characterized in that: A first protrusion (131) is provided on one side of the box cover (130) facing the box body (140); the first protrusion (131) extends along the circumference of the box cover (130) and is connected end to end; and the first protrusion (131) is inserted into the sealing member (500).

5. The battery pack according to claim 3, characterized in that: A baffle (141) is provided in the box body (140), and the battery core is provided on both sides of the baffle (141).

6. The battery pack according to claim 5, characterized in that: At least one of the cells located on one side of the baffle (141) is provided with a first explosion-proof valve (251) facing the baffle (141).

7. The battery pack according to claim 6, characterized in that: A first gap (610) is left between the first explosion-proof valve (251) and the baffle (141), a second gap (620) is left between each of the battery cells and the inner wall of the box (140), both sides of the baffle (141) are spaced from the inner wall of the box (140) so that the first gap (610) and the second gap (620) are connected to form an exhaust channel, and a fifth explosion-proof valve (142) is provided on the box (140), and the exhaust channel is connected to the fifth explosion-proof valve (142).

8. The battery pack according to claim 5, characterized in that: The axes of the battery cells located on both sides of the baffle (141) are not parallel.

9. A battery pack assembly method for assembling the battery pack according to claim 8, characterized in that: The battery pack assembly method comprises: S1. Provide the frame (410), wherein the frame (410) has a first area (411) and a second area (412) distributed along a first direction (D1); fix a first battery cell (210) and a second battery cell (220) in the first area (411) along a second direction (D2), so that the axes of the first battery cell (210) and the second battery cell (220) are parallel to the first direction (D1), and the first direction (D1) is perpendicular to the second direction (D2); S2, welding the electrode of the first battery cell (210) facing the second region (412) to the first connecting piece (710), and welding the electrode of the second battery cell (220) facing the second region (412) to the first connecting piece (710); S3, fixing the fourth battery cell (240) in the second area (412), so that the axis of the fourth battery cell (240) is parallel to the second direction (D2), and the fourth battery cell (240) faces the first connecting sheet (710); S4. Install the frame plate (410) into the box body (140) so that the first area (411) and the second area (412) are respectively located on two sides of the baffle (141).

10. An electrical device, characterized in that: A battery pack comprising any one of claims 1 to 8.

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