Battery pack and electric device comprising same

Abstract

A battery pack, comprising a battery module, an upper cover portion, a lower cover portion, and a reinforcing plate. The upper cover portion and the lower cover portion define an accommodating cavity; in a first direction, at least one side of the upper cover portion is provided with a first connecting edge, and at least one side of the lower cover portion is provided with a second connecting edge; the reinforcing plate is provided with a third connecting edge, and the second connecting edge is sandwiched between the first connecting edge and the third connecting edge to form a connection mating portion; and a crushing space is provided between the battery pack and the connection mating portion.

Description

Battery packs and electrical devices that have them

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 2024221067439, filed on August 28, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and more specifically, to a battery pack and an electrical device having the same. Background Technology

[0004] In car collisions, when the battery cells in a car are deformed due to impact and compression, they may experience thermal runaway and catch fire. Thermal runaway and fire can cause secondary injuries to the occupants of the vehicle and affect the surrounding environment. Therefore, how to strengthen the protection of battery cells and make them less prone to deformation or with a smaller degree of deformation in a collision has become a major challenge.

[0005] Application content

[0006] This application aims to at least solve one of the technical problems existing in the prior art. To this end, this application proposes a battery pack that utilizes an upper cover, a lower cover, and a reinforcing plate to jointly bear the compressive force on the battery pack, thereby increasing the maximum compressive force that the battery pack can withstand. Furthermore, the battery pack is provided with a crumple zone to reduce the possibility of damage to the battery pack when deformation occurs, thus providing better protection for the battery pack and improving its safety.

[0007] This application also proposes an electrical device having the aforementioned battery pack.

[0008] A battery pack according to a first aspect of this application includes: an upper cover and a lower cover, the upper cover and the lower cover defining a receiving cavity; in a first direction, at least one side of the upper cover has a first connecting edge, and at least one side of the lower cover has a second connecting edge; a reinforcing plate disposed on the side of the lower cover facing away from the upper cover, the reinforcing plate having a third connecting edge, the second connecting edge clamping the first connecting edge and the third connecting edge to form a connecting mating portion; and a battery pack disposed within the receiving cavity and having a collapsible space between it and the connecting mating portion.

[0009] According to the embodiments of this application, the battery pack utilizes the upper cover, lower cover, and reinforcing plate to jointly bear the compressive force on the battery pack, thereby increasing the maximum compressive force that the battery pack can withstand. In addition, the battery pack also has a reserved crumple space to reduce the possibility of the battery pack being damaged when the battery pack deforms, thus providing better protection for the battery pack and improving its safety.

[0010] In addition, the battery pack according to the above embodiments of this application may also have the following additional technical features:

[0011] According to some embodiments of this application, the lower cover is provided with a flow channel for circulating a heat exchange medium, and at least a portion of the battery cells in the battery pack exchange heat with the lower cover.

[0012] According to some optional embodiments of this application, the lower cover includes a heat-equalizing plate and a flow channel plate, the flow channel plate being disposed between the heat-equalizing plate and the reinforcing plate, and the flow channel being defined between the heat-equalizing plate and the flow channel plate.

[0013] According to some embodiments of this application, the collapse space includes a first collapse sub-space, the upper cover portion further includes a first sidewall connected to the first connecting edge, and the lower cover portion further includes a second sidewall connected to the second connecting edge. The first sidewall, the second sidewall, and the battery pack define the first collapse sub-space.

[0014] According to some optional embodiments of this application, in the first direction, the first sidewall extends obliquely in a direction away from the first connecting edge and the second sidewall, and the second sidewall extends obliquely in a direction away from the second connecting edge and the first sidewall.

[0015] According to some optional embodiments of this application, the angle between the first sidewall and the first direction is X, and the angle between the second sidewall and the first direction is Y, where X > Y.

[0016] According to some optional embodiments of this application, the angle between the first sidewall and the first direction is X, and the angle between the second sidewall and the first direction is Y, 60°≤X≤80°; and / or, 20°≤Y≤40°.

[0017] According to some specific embodiments of this application, 65°≤X≤75°; and / or, 25°≤Y≤35°.

[0018] According to some optional embodiments of this application, the collapse space further includes a second collapse subspace, and the reinforcing plate further includes a third sidewall connected to the third connecting edge, wherein the second collapse subspace is defined between the third sidewall and the second sidewall.

[0019] According to some alternative embodiments of this application, the third sidewall extends obliquely in a first direction away from the third connecting edge and the second sidewall.

[0020] According to some optional embodiments of this application, the angle between the third sidewall and the first direction is Z, and the angle between the second sidewall and the first direction is Y, where Z = 2Y.

[0021] According to some optional embodiments of this application, the angle between the third sidewall and the first direction is Z, where 50°≤Z≤70°.

[0022] According to some specific embodiments of this application, 55°≤Z≤65°.

[0023] According to some embodiments of this application, each battery cell in the battery pack is provided with a terminal post facing the connection mating portion. In the first direction, the terminal post is located within the collapsible space and is spaced apart from the connection mating portion.

[0024] According to some embodiments of this application, the battery pack includes a fixed connection hole passing through the first connecting edge, the second connecting edge and the third connecting edge, and the battery pack also includes a fixed connector, which is installed in the fixed connection hole.

[0025] According to some optional embodiments of this application, in the first direction, the minimum distance between the central axis of the fixed connector and the inner edge of the connecting mating part toward the pole post is A, the minimum distance between the inner edge of the connecting mating part toward the pole post and the pole post is B, and the minimum distance between the central axis of the fixed connector and the first end of the battery cell where the pole post is located is C, wherein 1 / 3B≤A≤1 / 2C.

[0026] According to some specific embodiments of this application, 40mm≤B≤70mm, and / or 90mm≤C≤130mm.

[0027] According to some specific embodiments of this application, a bottom protective plate is also included, wherein the reinforcing plate is an annular reinforcing plate, and the bottom protective plate is disposed on the side of the reinforcing plate facing away from the lower cover and covers the middle part of the annular reinforcing plate.

[0028] In some embodiments, the reinforcing plate further includes a support portion connected to the third connecting edge, the support portion being connected to the side of the lower cover portion away from the upper cover portion, and in the first direction, the first end of the battery cell having the electrode post is located between the outer end and the inner end of the support portion.

[0029] In some examples, in the first direction, the minimum distance between the central axis of the fixed connector and the first end is C, and the maximum distance between the first end of the battery cell and the inner end of the support is D, wherein 1 / 2C ≥ D ≥ 1 / 3C.

[0030] Furthermore, 90mm≤C≤130mm.

[0031] According to a second aspect of this application, an electrical device is provided, the electrical device including a battery pack according to an embodiment of a first aspect of this application.

[0032] According to the embodiments of this application, the electrical equipment utilizes the battery pack described in the first aspect of this application. By using the upper cover, lower cover, and reinforcing plate to jointly bear the compressive force on the battery pack, the maximum compressive force that the battery pack can withstand is increased. Furthermore, the battery pack is provided with a collapse space to reduce the possibility of the battery pack being damaged when the battery pack deforms, thereby providing better protection for the battery pack and improving its safety.

[0033] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0034] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0035] Figure 1 is a schematic diagram of the structure of a battery pack according to an embodiment of this application;

[0036] Figure 2 is an exploded view of a battery pack according to an embodiment of this application;

[0037] Figure 3 is a top view of a battery pack according to an embodiment of this application;

[0038] Figure 4 is a cross-sectional view at point AA in Figure 3;

[0039] Figure 5 is a cross-sectional view according to an embodiment of this application;

[0040] Figure 6 is a cross-sectional view according to an embodiment of this application;

[0041] Figure 7 is a schematic diagram of the structure of the heat spreader, flow channel plate and reinforcing plate according to an embodiment of the present application;

[0042] Figure 8 is a structural diagram of the connecting mating part being extruded with a constant extrusion force of 100KN according to an embodiment of this application;

[0043] Figure 9 is a mathematical model of the extrusion time and the extrusion force at the fixed connector when the connecting part is extruded under a constant extrusion force of 100KN according to an embodiment of this application.

[0044] Figure 10 is a schematic diagram of the structure of the connecting and mating part according to an embodiment of the present application, which collapses after being squeezed for a preset time.

[0045] Figure 11 shows the stress distribution when the battery pack experiences its first resonance and the stress distribution when the battery pack experiences its second resonance, according to an embodiment of this application.

[0046] Figure 12 shows the stress distribution on the top cover and the heat spreader plate when the battery pack first resonates according to an embodiment of this application;

[0047] Figure 13 is a schematic diagram of a battery pack and electrical equipment according to an embodiment of this application.

[0048] Reference numerals: Electrical equipment 1000, battery pack 1, fixing connection hole 101, receiving cavity 102.

[0049] Top cover 10, first connecting edge 11, first side wall 12,

[0050] Reinforcing plate 201, bottom guard plate 202, third connecting edge 21, third side wall 22, support part 23, connecting and mating part 25.

[0051] Lower cover 3, heat spreader 30, second connecting edge 31, second sidewall 32, flow channel plate 40, flow channel 41

[0052] Collapse space 50, first collapse subspace 501, second collapse subspace 502, fixed connector 63, buffer pad 64, battery pack 70, battery cell 701, terminal post 71, adhesive layer 81, thermally conductive adhesive 82. Detailed Implementation

[0053] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0054] The battery pack 1 according to an embodiment of the present application is described below with reference to the accompanying drawings.

[0055] As shown in Figures 1-7, the battery pack 1 according to an embodiment of this application includes an upper cover 10, a lower cover 3, a reinforcing plate 201, and a battery pack 70.

[0056] The upper cover 10 and the lower cover 3 define a receiving cavity 102. A reinforcing plate 201 is provided on the side of the lower cover 3 away from the upper cover 10. In a first direction, at least one side of the upper cover 10 has a first connecting edge 11, and at least one side of the lower cover 3 has a second connecting edge 31. The reinforcing plate 201 is provided with a third connecting edge 21. The second connecting edge 31 is clamped between the first connecting edge 11 and the third connecting edge 21 to form a connecting mating part 25. The battery pack 70 is provided in the receiving cavity 102, and a collapsible space 50 is provided between the battery pack 70 and the connecting mating part 25.

[0057] The collapsible space 50 is used to reserve space for the deformation of the connecting part 25, the upper cover 10, the lower cover 3 and the reinforcing plate 201. When the connecting part 25 is squeezed, the connecting part 25 can resist the squeezing force by deforming. When the connecting part 25 is squeezed and deformed, the collapsible space 50 can prevent the connecting part 25 from directly contacting the battery pack 70, thereby reducing the possibility of deformation of the battery pack 70 and avoiding safety accidents caused by battery deformation.

[0058] Specifically, the first connecting edge 11, the second connecting edge 31, and the third connecting edge 21 are arranged together. When the connecting mating part 25 is subjected to compressive force along the first direction, the upper cover part 10, the lower cover part 3, and the reinforcing plate 201 can jointly bear the compressive force, thereby enabling the connecting mating part 25 to withstand a large compressive force without collapsing. This allows the battery pack 1 to bear a large load-bearing capacity, making it less likely for the compressive force to directly compress the battery pack 70 when the battery pack 1 is subjected to compressive force along the first direction. This reduces the probability of deformation of the battery pack 70 and improves the safety of the battery pack 1.

[0059] In the existing battery pack 1, when the battery pack 1 is subjected to compressive force, the upper cover 10 and the lower cover 3 usually bear the compressive force. However, this application provides a third connecting edge 21 on the reinforcing plate 201, so that the first connecting edge 11, the second connecting edge 31 and the third connecting edge 21 jointly define the connecting mating part 25. The upper cover 10, the lower cover 3 and the reinforcing plate 201 jointly bear the compressive force on the battery pack 1. This can increase the maximum compressive force that the battery pack 1 can withstand, thereby providing better protection for the battery pack 70, reducing the probability of deformation of the battery pack 70 and improving the safety of the battery pack 1.

[0060] According to the embodiments of this application, the battery pack 1 uses the upper cover 10, the lower cover 3 and the reinforcing plate 201 to jointly bear the compressive force on the battery pack 1, thereby increasing the maximum compressive force that the battery pack 1 can withstand. In addition, the battery pack also has a reserved collapse space 50 to reduce the possibility of the battery pack 70 being damaged when the battery pack 1 is deformed, thereby providing better protection for the battery pack 70 and improving the safety of the battery pack 1.

[0061] The battery pack 1 according to a specific embodiment of this application is described below with reference to the accompanying drawings.

[0062] In some specific embodiments of this application, as shown in Figures 1-8, the battery pack 1 includes an upper cover 10 and a lower cover 3, a reinforcing plate 201, and a battery pack 70.

[0063] In some embodiments of this application, as shown in FIG5, the lower cover 3 is provided with a flow channel 41 for circulating a heat exchange medium. At least a portion of the battery cells 701 in the battery pack 70 exchange heat with the lower cover 3. When the heat exchange medium flows in the flow channel 41, it can carry away the heat on at least a portion of the battery cells 701, thereby absorbing the heat generated by the battery cells 701.

[0064] In some embodiments, the lower cover 3 is disposed between the battery pack 70 and the reinforcing plate 201 to support the battery pack 70. This allows the battery pack 70 to better contact the lower cover 3 under the action of gravity, so that the lower cover 3 can better dissipate heat from at least a portion of the battery cells 701.

[0065] In some embodiments, a portion of the reinforcing plate 201 is attached to the bottom of the lower cover 3 so that the reinforcing plate 201 and the lower cover 3 together support the battery pack 70 and provide stable support for the battery pack 70.

[0066] In some embodiments, as shown in FIG2, an adhesive layer 81 is provided between the battery pack 70 and the upper cover 10 to fix the battery pack 70 and the upper cover 10 together and to define the position of the battery pack 70 in the receiving cavity 102.

[0067] In some other embodiments, as shown in FIG2, thermally conductive adhesive 82 is provided between the battery pack 70 and the lower cover 3 to fix the battery pack 70 and the lower cover 3 together, while enabling heat exchange through the thermally conductive adhesive 82.

[0068] In some optional embodiments of this application, as shown in Figures 2, 5 and 7, the lower cover 3 includes a heat exchange plate 30 and a flow channel plate 40. The flow channel plate 40 is disposed between the heat exchange plate 30 and the reinforcing plate 201. A flow channel 41 is defined between the heat exchange plate 30 and the flow channel plate 40. When the heat exchange medium flows in the flow channel 41, it can carry away at least a portion of the heat on the battery cell 701, thereby absorbing the heat generated by the battery cell 701.

[0069] The heat exchange medium exchanges heat with the heat exchange plate 30. The heat exchange plate 30 can achieve uniform heat exchange on the battery pack 70, thereby keeping the battery pack 70 at a suitable temperature, which is conducive to improving the working performance of the battery pack 70.

[0070] Specifically, when the heat exchange medium flows within the flow channel 41, it exchanges heat with the temperature distribution plate 30. When the ambient temperature of the battery pack 1 is too low and heating of the battery pack 70 is required, the heat exchange medium can heat the temperature distribution plate 30, which can then evenly transfer heat to the battery cells 701 in contact with it, thus providing uniform heating to the battery cells 701. When the ambient temperature of the battery pack 1 is too high and cooling of the battery pack 70 is required, the heat generated on the battery cells 701 in contact with it is evenly transferred to the temperature distribution plate 30. The flowing heat exchange medium can then carry away the heat from the temperature distribution plate 30, thus providing uniform cooling to the battery cells 701.

[0071] In some embodiments of this application, as shown in FIG5, the collapse space 50 includes a first collapse subspace 501, the upper cover 10 also includes a first sidewall 12 connected to the first connecting edge 11, and the lower cover 3 also includes a second sidewall 32 connected to the second connecting edge 31. The first collapse subspace 501 is defined between the first sidewall 12, the second sidewall 32 and the battery pack 70.

[0072] Specifically, the first sidewall 12 defines the inner wall of the first collapse subspace 501, and the second sidewall 32 defines the inner wall of the first collapse subspace 501, so that the lower cover 3 and the upper cover 10 together define the first collapse subspace 501, which can improve the structural strength of the upper cover 10 and the lower cover 3, thereby enabling the upper cover 10 and the lower cover 3 to withstand greater compressive force.

[0073] Meanwhile, the first collapsible subspace 501 provides space for the deformation of the upper cover 10, the lower cover 3 and the reinforcing plate 201. In this way, when the upper cover 10, the lower cover 3 and the reinforcing plate 201 are subjected to compressive force and deform, they can produce a certain deformation to resist the compressive force, thereby increasing the compressive force that the upper cover 10, the lower cover 3 and the reinforcing plate 201 can withstand.

[0074] In some embodiments, as shown in Figures 5 and 6, in a first direction, the first sidewall 12 extends obliquely toward the direction opposite to the first connecting edge 11 and the second sidewall 32, which facilitates the forming of the upper cover portion 10. In addition, the first sidewall 12 can support the first connecting edge 11 in an extension direction different from that of the first connecting edge 11, thereby supporting the connecting mating portion 25.

[0075] Specifically, when the connecting mating part 25 is compressed along the first direction and deforms towards the inside of the first collapsible subspace 501 along the first direction, since the first sidewall 12 and the first connecting edge 11 extend in different directions, the first sidewall 12 is not easily crushed during the process of the first connecting edge 11 being compressed and deformed along the first direction, and can also support the first connecting edge 11 when it deforms, thereby improving the support effect on the connecting mating part 25.

[0076] In some embodiments, in a first direction, the second sidewall 32 extends obliquely toward the direction opposite to the second connecting edge 31 and the first sidewall 12, which facilitates the forming of the lower cover portion 3. In addition, the second sidewall 32 can support the second connecting edge 31 in a different extension direction than the second connecting edge 31, thereby supporting the connecting mating portion 25.

[0077] Specifically, when the connecting mating part 25 is compressed along the first direction and deforms inward toward the first collapsible subspace 501 along the first direction, since the second sidewall 32 and the second connecting edge 31 extend in different directions, the second sidewall 32 is not easily crushed during the process of the second connecting edge 31 being compressed and deformed along the first direction, and can also support the second connecting edge 31 when it deforms, thereby improving the support effect on the connecting mating part 25.

[0078] In some specific embodiments, in the first direction, the first sidewall 12 extends obliquely in a direction away from the first connecting edge 11 and the second sidewall 32, and the second sidewall 32 extends obliquely in a direction away from the second connecting edge 31 and the first sidewall 12. It can be understood that the extension directions of the first sidewall 12, the second sidewall 32 and the connecting mating part 25 are all different, so that the first sidewall 12 and the second sidewall 32 can support the connecting mating part 25 from different directions. In other words, when the connecting mating part 25 is subjected to compressive force, the connecting mating part 25 can disperse the compressive force along the direction of the first sidewall 12 and the direction of the second sidewall 32, avoiding the compressive force from concentrating in one place, thereby improving the pressure bearing effect of the connecting mating part 25, enabling the connecting mating part 25 to bear greater pressure, enabling the battery pack 1 to bear greater compressive force, and improving the safety of the battery pack 1.

[0079] In some examples, as shown in Figures 5 and 6, the first direction extends in the left-right direction, the upper cover 10 is located above the lower cover 3, and the first connecting edge 11 and the second connecting edge 31 extend in the left-right direction (it should be understood that the above direction limitation is only for the convenience of describing the drawings and does not limit the actual setting position and direction of the battery pack 1). The first connecting edge 11 is located outside the first side wall 12, which extends upward from the outside to the inside. The second connecting edge 31 is located outside the second side wall 32, which extends downward from the outside to the inside. This allows the first side wall 12 and the second side wall 32 to extend in different directions. When the connecting mating part 25 is subjected to compressive force, the connecting mating part 25 can disperse the compressive force along the direction of the first side wall 12 and the direction of the second side wall 32, avoiding the compressive force from concentrating on the upper cover 10 or the lower cover 3. This improves the pressure resistance of the connecting mating part 25, enabling it to withstand greater compressive force, allowing the battery pack 1 to bear greater compressive force, and improving its safety.

[0080] It should be explained here that the above-mentioned inside and outside are relative to the central axis of the receiving cavity 102. The direction on the side of the first sidewall 12 closer to the central axis of the receiving cavity 102 is the inside, and the direction on the side of the first sidewall 12 away from the central axis of the receiving cavity 102 is the outside.

[0081] In some specific embodiments of this application, the angle between the first sidewall 12 and the first direction is X, and the angle between the second sidewall 32 and the first direction is Y, where X > Y.

[0082] The first connecting edge 11 and the third connecting edge 21 extend along the first direction, making the angle between the first sidewall 12 and the first direction larger, and the angle between the second sidewall 32 and the first direction smaller. This allows the lower cover 3 to bear greater pressure, while the upper cover 10 bears less pressure.

[0083] In some embodiments, the base material of the upper cover 10 is a metal flat plate, and a portion of the first collapsible subspace 501 is defined by pressing a portion of the base material of the upper cover 10 upward. The base material of the lower cover 3 is also a metal flat plate, and another portion of the first collapsible subspace 501 is defined by pressing a portion of the base material of the lower cover 3 downward.

[0084] The upper cover 10 has a smaller thickness to give it better deformability, allowing the base material of the upper cover 10 to be stamped to a greater extent, thus defining a larger receiving cavity 102 to accommodate more battery packs 70. The lower cover 3 has a smaller thickness to give it better thermal conductivity, thereby balancing the temperature of the multiple battery packs 70.

[0085] Therefore, X > Y, that is, the angle between the first sidewall 12 and the first connecting edge 11 is larger. When the connecting part 25 is subjected to compressive force, the compressive force transmitted to the first sidewall 12 is less, so that the thinner upper cover part 10 bears less pressure. The angle between the second sidewall 32 and the second connecting edge 31 is smaller, so when the connecting part 25 is subjected to compressive force, the compressive force transmitted to the second sidewall 32 is greater, so that the thicker lower cover part 3 can bear more pressure. This facilitates the reasonable distribution of compressive force, so that the stronger lower cover part 3 bears greater pressure and the weaker upper cover part 10 bears less pressure, thereby improving the overall compressive strength of the battery pack 1.

[0086] In some embodiments, the angle between the first sidewall 12 and the first direction is X, and the angle between the second sidewall 32 and the first direction is Y, where 60°≤X≤80°. X is placed within this range so that the upper cover 10 can define a portion of a larger receiving cavity 102, thereby facilitating the storage of more battery packs 70 within the receiving cavity 102. Simultaneously, when the connecting mating portion 25 is subjected to compressive force, a portion of the compressive force at the connecting mating portion 25 can be smoothly distributed to the upper cover 10, allowing the upper cover 10 to share the compressive force.

[0087] X can be 60°, 65°, 70°, 75° or 80°, etc.

[0088] In some examples, 65°≤X≤75°. Through experiments, it was found that when the value of X is within this range, the compressive force at the connecting mating part 25 can be distributed to the upper cover part 10, and the upper cover part 10 can withstand this part of the compressive force without being crushed, so as to achieve a better compressive resistance effect.

[0089] Specifically, X can be 65°, 67°, 69°, 70°, 72°, 74°, or 75°, etc.

[0090] In some embodiments, the angle between the first sidewall 12 and the first direction is X, and the angle between the second sidewall 32 and the first direction is Y, where 20°≤Y≤40°, so that Y is within this range so that the lower cover 3 can define another part of the first collapsible subspace 501. At the same time, when the connecting mating part 25 is subjected to compressive force, a portion of the compressive force at the connecting mating part 25 can be smoothly distributed to the lower cover 3, so that the lower cover 3 can bear the compressive force together.

[0091] Where Y can be 20°, 25°, 30°, 35° or 40°, etc.

[0092] In some examples, 25°≤Y≤35°. Through experiments, it was found that when the value of Y is within this range, the compressive force at the connecting part 25 can be distributed to the lower cover part 3. The lower cover part 3 can withstand this part of the compressive force without being crushed, thus achieving a better compressive resistance effect.

[0093] Specifically, X can be 25°, 27°, 29°, 30°, 32°, 34°, or 35°, etc.

[0094] In some optional embodiments of this application, as shown in FIG5, the collapse space 50 further includes a second collapse subspace 502, and the reinforcing plate 201 further includes a third sidewall 22 connected to the third connecting edge 21, with the second collapse subspace 502 defined between the third sidewall 22 and the second sidewall 32.

[0095] The third sidewall 22 defines the inner wall of the second collapse subspace 502, and the second sidewall 32 defines the inner wall of the second collapse subspace 502, so that the lower cover 3 and the reinforcing plate 201 together define the second collapse subspace 502, which can improve the structural strength of the lower cover 3 and the reinforcing plate 201, thereby enabling the lower cover 3 and the reinforcing plate 201 to withstand greater compressive force.

[0096] Meanwhile, the second collapsible subspace 502 provides space for the deformation of the upper cover 10, the lower cover 3 and the reinforcing plate 201. In this way, when the upper cover 10, the lower cover 3 and the reinforcing plate 201 are subjected to compressive force and deform, they can produce a certain deformation to resist the compressive force, thereby increasing the compressive force that the upper cover 10, the lower cover 3 and the reinforcing plate 201 can withstand.

[0097] In some embodiments, the third sidewall 22 extends obliquely in a first direction away from the third connecting edge 21 and the second sidewall 32, which facilitates the forming of the reinforcing plate 201. In addition, the third sidewall 22 can support the third connecting edge 21 and the connecting mating part 25 in an extension direction different from that of the third connecting edge 21.

[0098] Specifically, when the connecting mating part 25 is compressed along the first direction and deforms towards the inside of the second collapsible subspace 502 along the first direction, since the extension directions of the third sidewall 22 and the third connecting edge 21 are different, the third sidewall 22 is not easily crushed during the process of the third connecting edge 21 being compressed and deformed along the first direction, and can also support the third connecting edge 21 when it deforms, thereby improving the support effect on the connecting mating part 25.

[0099] In some optional embodiments of this application, as shown in FIG6, the angle between the third sidewall 22 and the first direction is Z, Z = 2Y, so that the third sidewall 22 of the reinforcing plate 201 and the second sidewall 32 of the lower cover 3 can define a second collapsible subspace 502 with a certain volume.

[0100] The first sidewall 12, the second sidewall 32, and the third sidewall 22 extend in different directions, and each of them has an angle with the first direction. This allows the connecting part 25 to distribute the pressure along the directions of the first sidewall 12, the second sidewall 32, and the third sidewall 22 when it is subjected to compressive force. By limiting the values ​​of X, Y, and Z, the compressive force can be appropriately distributed to the upper cover 10, the lower cover 3, and the reinforcing plate 201.

[0101] In some optional embodiments of this application, as shown in FIG6, the angle between the third sidewall 22 and the first direction is Z, 50°≤Z≤70°, so that Z is within this range to define a larger volume of the second collapsible subspace 502. At the same time, the connecting mating part 25 is subjected to compressive force, and a portion of the compressive force at the connecting mating part 25 can be smoothly dispersed to the reinforcing plate 201, so that the reinforcing plate 201 can bear the compressive force together.

[0102] In some examples, 55°≤Z≤65°. Through experiments, it was found that when the value of Z is within this range, the compressive force at the connecting mating part 25 can be distributed to the reinforcing plate 201. The reinforcing plate 201 can withstand this part of the compressive force without being crushed, thus achieving a better compressive resistance effect.

[0103] Specifically, Z can be 55°, 57°, 59°, 60°, 62°, 64°, or 65°, etc.

[0104] In some specific embodiments of this application, as shown in FIG5, the first direction extends along the left and right direction, and in the direction from top to bottom, there are, in sequence, the upper cover 10, the lower cover 3 and the reinforcing plate 201, the first sidewall 12 extends upward from the outside to the inside, and the angle between the first sidewall 12 and the first direction is X, the second sidewall 32 extends downward from the outside to the inside, and the angle between the second sidewall 32 and the first direction is Y, and the third sidewall 22 extends downward from the outside to the inside, and the angle between the third sidewall 22 and the first direction is Z.

[0105] The first sidewall 12 of the upper cover 10 extends upward from the outside to the inside, and the second sidewall 32 of the lower cover 3 extends downward from the outside to the inside, so that the upper cover 10 and the lower cover 3 define a large first collapsible subspace 501, and a portion of the multiple battery packs 70 are disposed in the first collapsible subspace 501 and supported on the lower cover 3.

[0106] The third sidewall 22 of the reinforcing plate 201 extends downward from the outside to the inside, and the second sidewall 32 of the lower cover 3 extends downward from the outside to the inside. The lower cover 3 also includes a second plate portion located inside the second sidewall 32. The reinforcing plate 201 also includes a support portion 23 located inside the third sidewall 22. The second plate portion and the support portion 23 are in contact. At least a portion of the battery pack 70 is supported by the second plate portion and the support portion 23, so that the lower cover 3 and the reinforcing plate 201 together support multiple battery packs 70.

[0107] The third sidewall 22 of the reinforcing plate 201 and the second sidewall 32 of the lower cover 3 define the second collapsible subspace 502. Since the reinforcing plate 201 is located below the lower cover 3, ∠Y is inside ∠Z, and Z > Y.

[0108] The first sidewall 12, the second sidewall 32, and the third sidewall 22 extend in different directions, and each of them has an angle with the first direction. This allows the connecting part 25 to distribute the pressure along the directions of the first sidewall 12, the second sidewall 32, and the third sidewall 22 when it is subjected to compressive force. By limiting the values ​​of X, Y, and Z, the compressive force can be appropriately distributed to the upper cover 10, the lower cover 3, and the reinforcing plate 201.

[0109] Specifically, 60°≤X≤80°, 20°≤Y≤40°, and 50°≤Z≤70° are used to properly distribute the compressive force on the connecting part 25 to the upper cover part 10, the lower cover part 3, and the reinforcing plate 201, so that it can withstand a portion of the compressive force without being easily crushed.

[0110] Where X > Z, since the thickness of the upper cover 10 is smaller and the thickness of the reinforcing plate 201 is larger, X > Z, so that when the connecting mating part 25 is subjected to compressive force, the compressive force transmitted to the first side wall 12 is less and the compressive force transmitted to the third side wall 22 is greater, so that the reinforcing plate 201 with greater strength bears greater compressive force and the upper cover 10 with less strength bears less pressure, thereby facilitating the improvement of the overall compressive strength of the battery pack 1.

[0111] In some examples, 20° ≥ XZ ≥ 10° is used to distribute more compressive force to the reinforcing plate 201, thus avoiding excessive compressive force on the reinforcing plate 201.

[0112] In some embodiments, as shown in Figures 1 and 5, the battery pack 1 includes a fixing connection hole 101 passing through the first connecting edge 11, the second connecting edge 31, and the third connecting edge 21. The fixing connection hole 101 is adapted to install a fixing connector 63 so that the first connecting edge 11, the second connecting edge 31, and the third connecting edge 21 can be connected together by the fixing connector 63 to form a connecting mating part 25, and the battery pack 1 can be fixed to a designated position from the connecting mating part 25.

[0113] In some examples, in the experiment of pressing the connecting mating part 25 with a pressing force of 100KN for a preset time, X=70°, Y=30°, Z=60°, as shown in Figures 8 and 9. Figure 8 is a structural diagram of pressing the connecting mating part 25 with a constant pressing force of 100KN, and Figure 9 is a mathematical model of the pressing time and the pressing force on the fixed connecting part 63.

[0114] Specifically, when the connecting part 25 is compressed for a preset time with a constant extrusion force of 100KN, the connecting part 25 will deform under the support of the first side wall 12, the second side wall 32 and the third side wall 22, but it will always have the ability to resist the external extrusion force and will not be crushed. That is to say, when X=70°, Y=30° and Z=60°, the battery pack 1 also has good resistance to the extrusion force of 100KN.

[0115] It should be noted that the different colors in the figure represent different stress levels in different areas, not the specific stress values ​​at those areas. The vertical axis in Figure 9 represents the compressive force at the connection joint 25; 1E+005 indicates 1×10⁻⁶. 5 =100000N, 1.5E+005 refers to 1.5 × 10 5 =150000N.

[0116] In some embodiments of this application, as shown in Figures 5 and 6, each battery cell 701 in the battery pack 70 is provided with a terminal post 71 facing the connecting mating part 25. In the first direction, the terminal post 71 is located within the collapsible space 50 and is spaced apart from the connecting mating part 25 to reserve space for deformation of the connecting mating part 25. In this way, when the connecting mating part 25 is squeezed and deformed into the collapsible space 50, the possibility of direct contact between the connecting mating part 25 and the terminal post 71 can be reduced, thereby reducing the possibility of damage to the battery cell 701 and improving the safety of the battery pack 1.

[0117] In some optional embodiments of this application, as shown in FIG1, the battery pack 1 includes a fixed connection hole 101 passing through the first connecting edge 11, the second connecting edge 31 and the third connecting edge 21. The battery pack 1 also includes a fixed connector 63, which is installed in the fixed connection hole 101 to connect the first connecting edge 11, the second connecting edge 31 and the third connecting edge 21 to form a connecting mating part 25. At the same time, the battery pack 1 can be fixed to a designated position from the connecting mating part 25.

[0118] In some embodiments, as shown in FIG1, the width direction of the first connecting edge 11, the second connecting edge 31 and the third connecting edge 21 extends along the first direction, and the length direction extends along the second direction. The second direction is perpendicular to the first direction. A plurality of fixed connectors 63 are arranged at intervals along the second direction to connect and fix the first connecting edge 11, the second connecting edge 31 and the third connecting edge 21 together at different positions.

[0119] In some optional embodiments of this application, as shown in Figures 5 and 6, in the first direction, the minimum distance between the central axis of the fixed connector 63 and the inner edge of the connecting mating part 25 facing the pole post 71 is A, the minimum distance between the inner edge of the connecting mating part 25 facing the pole post 71 and the pole post 71 is B, and the minimum distance between the central axis of the fixed connector 63 and the first end of the battery cell 701 where the pole post 71 is provided is C.

[0120] It is understandable that the collapse space 50 is located between the fixed connector 63 and the first end of the battery cell 701, with the first end of the battery cell 701 located at the edge of the collapse space 50. In other words, by setting the collapse space 50, space is reserved for the deformation of the fixed connector 63, so as to prevent the fixed connector 63 from collapsing into the receiving cavity 102 and squeezing the terminal post 71 of the battery cell 701, thus preventing the battery pack 70 from being squeezed and deformed, and preventing the battery pack 70 from thermal runaway and catching fire due to deformation.

[0121] Wherein, 1 / 3B≤A≤1 / 2C, when the battery pack 1 is compressed in the first direction, 1 / 3B≤A is made to limit the distance between the fixed connector 63 and the inner edge of the connecting mating part 25 facing the pole post 71, so as to avoid the distance between the fixed connector 63 and the inner edge of the connecting mating part 25 facing the pole post 71 being too small, so that there is a certain distance between the fixed connector 63 and the inner edge of the connecting mating part 25 facing the pole post 71 to ensure the strength and deformability of the connecting mating part 25, thereby enabling the connecting mating part 25 to withstand a certain compressive force.

[0122] A ≤ 1 / 2C is set to limit the distance between the fixed connector 63 and the inner edge of the connecting mating part 25 facing the pole post 71, so as to avoid the distance between the fixed connector 63 and the inner edge of the connecting mating part 25 facing the pole post 71 being too large. In this way, when the connecting mating part 25 is squeezed in the first direction and collapses into the collapse space 50, even if the fixed connector 63 is completely deformed into the collapse space 50, it will only occupy half of the collapse space 50 at most, so as to fully prevent the fixed connector 63 from squeezing the first end of the battery cell 701.

[0123] In some specific embodiments of this application, 40mm≤B≤70mm is used. Making 40mm≤B ensures that the inner edge of the connecting mating part 25 facing the terminal 71 remains within a safe distance from the terminal 71, preventing damage to the terminal 71 when the inner edge of the connecting mating part 25 deforms into the collapsible space 50 and comes into contact with it. Making B≤70mm avoids an excessive distance between the fixing connector 63 and the battery pack 70. Since the battery pack 70 exerts pressure on the bottom wall of the receiving cavity 102, an excessive distance between the fixing connector 63 and the battery pack 70 would result in excessive torque transmitted to the fixing connector 63.

[0124] In some embodiments, B = 40mm, 45mm, 50mm, 55mm, 60mm, 65mm or 70mm.

[0125] In some specific embodiments of this application, 90mm ≤ C ≤ 130mm is used. Setting 90mm ≤ C ensures that the inner edge of the connecting mating part 25 facing the terminal post 71 is kept within a safe distance from the first end of the battery cell 701, preventing damage to the battery cell 701 from contact with the first end when the inner edge of the connecting mating part 25 facing the terminal post 71 deforms into the collapsible space 50. Setting C ≤ 130mm avoids an excessive distance between the fixing connector 63 and the first end of the battery cell 701. Since the battery pack 70 exerts pressure on the bottom wall of the receiving cavity 102, an excessive distance between the fixing connector 63 and the battery pack 70 would result in excessive torque transmitted to the fixing connector 63.

[0126] In some specific embodiments of this application, as shown in Figures 1, 5 and 7, the battery pack also includes a bottom protective plate 202 and a reinforcing plate 201, which is an annular reinforcing plate 201. The bottom protective plate 202 is disposed on the side of the reinforcing plate 201 facing away from the lower cover 3 and covers the middle of the annular reinforcing plate 201. By separating the bottom protective plate 202 and the reinforcing plate 201, it is easier to improve the flexibility of material and size selection.

[0127] For example, the thickness of the reinforcing plate 201, which bears greater compressive force, can be set to be larger, while the thickness of the lower support plate can be set to be smaller, thereby saving materials and reducing costs.

[0128] In some embodiments, as shown in FIG7, the battery pack 1 further includes a flow channel plate 40, which is disposed above the reinforcing plate 201 and a lower support plate is disposed below the reinforcing plate 201. The inner side of the reinforcing plate 201 supports the outer periphery of the flow channel plate 40, and the lower support plate supports the interior of the flow channel plate 40.

[0129] In some examples, as shown in Figures 2 and 5, a buffer pad 64 is provided between the lower support plate and the flow channel plate 40. This reduces the vibration transmitted to the flow channel plate 40 when the battery pack 1 vibrates, thereby lowering the vibration frequency of the flow channel plate 40.

[0130] In some embodiments of this application, as shown in FIG5, the reinforcing plate 201 further includes a support portion 23 connected to the third connecting edge 21. The support portion 23 is located on the side of the lower cover portion 3 away from the upper cover portion 10. In the first direction, the first end of the battery cell 701 with the pole post 71 is located between the outer end and the inner end of the support portion 23, so as to support the multiple battery cells 701 by means of the reinforcing plate 201.

[0131] In some embodiments, as shown in FIG1, a plurality of battery cells 701 are arranged along a second direction, the length direction of the reinforcing plate 201 extends along the second direction, the width direction extends along the first direction, and a portion of the plurality of battery cells 701 is supported on the inner side of the support portion 23.

[0132] In some optional embodiments of this application, as shown in FIG6, in the first direction, the minimum distance between the central axis of the fixed connector 63 and the first end of the battery cell 701 with the pole post 71 is C, and the maximum distance between the first end of the battery cell 701 and the inner end of the support portion 23 is D, wherein 1 / 2C≥D≥1 / 3C, so that the support portion 23 supports the battery cell 701 and a part of the lower cover portion 3, thereby stably supporting the battery pack 70 and the lower cover portion 3, improving the overall structural strength of the battery pack 1, and at the same time facilitating the increase of the natural frequency of the battery pack 1 when resonance occurs, so that the stress on the upper cover portion 10 and the cold plate at both ends of the first direction is smaller when the battery pack 1 experiences its first resonance.

[0133] In some embodiments, 90mm ≤ C ≤ 130mm, where 90mm ≤ C, ensures that the inner edge of the connecting mating part 25 facing the terminal post 71 is within a safe distance from the first end of the battery cell 701. This prevents the inner edge of the connecting mating part 25 facing the terminal post 71 from contacting the first end of the battery cell 701 and damaging the terminal post 71 when it deforms into the collapsible space 50. C ≤ 130mm is used to avoid an excessive distance between the fixing connector 63 and the battery pack 70. The battery pack 70 exerts pressure on the bottom wall of the receiving cavity 102; if the distance between the fixing connector 63 and the battery pack 70 is too large, it will result in excessive torque transmitted to the fixing connector 63.

[0134] Where C can be 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, or 130mm.

[0135] In some embodiments, a vibration simulation experiment was conducted on battery pack 1, with C = 110 mm. Figure 11 shows the stress distribution when battery pack 1 experiences its first resonance and the stress distribution when battery pack 1 experiences its second resonance. When battery pack 1 experiences its first resonance, its natural frequency is 64.08 Hz, and when battery pack 1 experiences its second resonance, its natural frequency is 66.29 Hz. This larger natural frequency increases the difficulty of battery pack 1 resonating, thereby improving the safety of battery pack 1.

[0136] It needs to be explained here that when battery pack 1 resonates, it will cause excessive stress in a local area of ​​battery pack 1. At this time, the structure of battery pack 1 is very fragile and easily damaged. Therefore, by increasing the difficulty of battery pack 1 resonating, that is, by increasing the value of the natural frequency, the possibility of battery pack 1 resonating can be reduced, thereby improving the safety of battery pack 1.

[0137] It should be noted that the different colors in the figure represent different stresses in different areas, and do not represent the stress values ​​in those areas.

[0138] As shown in Figure 12, this is the stress distribution at the top cover 10 and the flow channel plate 40 when the battery pack 1 experiences its first resonance. The experiment shows that the stress on the top cover 10 and the cold plate at both ends in the first direction is relatively small. At this time, when the connecting part 25 is subjected to the extrusion force in the first direction, the top cover 10 and the cold plate are not easily crushed.

[0139] It should be noted that the different colors in the figure represent different stresses in different areas, and do not represent the stress values ​​in those areas.

[0140] As shown in Figure 10, in two experiments where the connecting mating part 25 was compressed with a pressure of 100KN for a preset time, X=70°, Y=30°, Z=60°, and C=110mm, Figure 10 is a schematic diagram of the structure of the connecting mating part 25 after being compressed for a preset time and then collapsing. At this time, the degree of deformation of the connecting mating part 25 is 11.5%, and the dimensions of the collapsing of the connecting mating part 25 are 36.1mm and 43.1mm, respectively. Compared with the dimension of C=110mm, after the connecting mating part 25 collapses, there is still a large distance between it and the first end of the battery cell 701. In other words, the experiment can prove that after the connecting mating part 25 collapses, it is difficult for it to contact the first end of the battery cell 701, that is, it will not compress the first end of the battery cell 701, thus proving that the battery pack 1 has good safety.

[0141] The following describes an electrical appliance 1000 according to an embodiment of this application. As shown in FIG13, the electrical appliance 1000 according to an embodiment of this application includes a battery pack 1 according to the above embodiment of this application.

[0142] The electrical equipment can be either the electrical equipment 1000 inside a vehicle or the electrical equipment 1000 in a household appliance; there are no further restrictions here.

[0143] When the electrical equipment 1000 is an electrical equipment inside the vehicle, the first direction extends in the left and right direction. Specifically, when a collision occurs in the left and right direction of the vehicle during driving, the battery pack 1 inside the vehicle is easily squeezed. By using the upper cover 10, the lower cover 3 and the reinforcing plate 201 to jointly bear the squeezing force of the battery pack 1 in the first direction, the battery pack 70 can be better protected to avoid deformation of the battery pack 70 or reduce the probability of deformation of the battery pack 70, thereby improving the safety of the vehicle.

[0144] According to the embodiments of this application, the electrical device 1000 utilizes the battery pack 1 according to the above embodiments of this application. By utilizing the upper cover 10, the lower cover 3, and the reinforcing plate 201 to jointly bear the compressive force on the battery pack 1, the maximum compressive force that the battery pack 1 can withstand is increased. Furthermore, the battery pack also has a reserved collapse space 50 to reduce the possibility of damage to the battery pack 70 when the battery pack 1 deforms. This provides better protection for the battery pack 70 and improves the safety of the battery pack 1.

[0145] Other configurations and operations of the electrical equipment 1000 according to the embodiments of this application are known to those skilled in the art and will not be described in detail here.

[0146] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more. In the description of this application, "above" or "below" a second feature may include direct contact between the first and second features, or it may include contact between the first and second features not being in direct contact but through another feature between them.

[0147] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0148] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0149] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0150] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery pack (1), wherein, include: The upper cover (10) and the lower cover (3) define a receiving cavity (102). In a first direction, at least one side of the upper cover (10) has a first connecting edge (11) and at least one side of the lower cover (3) has a second connecting edge (31). A reinforcing plate (201) is provided on the side of the lower cover (3) facing away from the upper cover (10). The reinforcing plate (201) is provided with a third connecting edge (21). The second connecting edge (31) is clamped between the first connecting edge (11) and the third connecting edge (21) to form a connecting mating part (25). The battery pack (70) is disposed in the receiving cavity (102) and has a collapsible space (50) between it and the connecting mating part (25).

2. The battery pack (1) according to claim 1, wherein, The lower cover (3) is provided with a flow channel (41) for circulating heat exchange medium, and at least a portion of the battery cells (701) in the battery pack (70) exchange heat with the lower cover (3).

3. The battery pack (1) according to claim 2, wherein, The lower cover (3) includes a heat equalization plate (30) and a flow channel plate (40). The flow channel plate (40) is disposed between the heat equalization plate (30) and the reinforcing plate (201). The flow channel (41) is defined between the heat equalization plate (30) and the flow channel plate (40).

4. The battery pack (1) according to any one of claims 1-3, wherein, The collapsible space (50) includes a first collapsible subspace (501), the upper cover (10) further includes a first sidewall (12) connected to the first connecting edge (11), and the lower cover (3) further includes a second sidewall (32) connected to the second connecting edge (31). The first collapsible subspace (501) is defined between the first sidewall (12), the second sidewall (32), and the battery pack (70).

5. The battery pack (1) according to claim 4, wherein, In the first direction, the first sidewall (12) extends obliquely in a direction away from the first connecting edge (11) and the second sidewall (32), and the second sidewall (32) extends obliquely in a direction away from the second connecting edge (31) and the first sidewall (12).

6. The battery pack (1) according to claim 5, wherein, The angle between the first sidewall (12) and the first direction is X, and the angle between the second sidewall (32) and the first direction is Y, where X > Y.

7. The battery pack (1) according to claim 5 or 6, wherein, The angle between the first sidewall (12) and the first direction is X, and the angle between the second sidewall (32) and the first direction is Y, 60°≤X≤80°; and / or, 20°≤Y≤40°.

8. The battery pack (1) according to claim 7, wherein, 65°≤X≤75°; and / or, 25°≤Y≤35°.

9. The battery pack (1) according to any one of claims 5-7, wherein, The collapse space (50) further includes a second collapse subspace (502), and the reinforcing plate (201) further includes a third sidewall (22) connected to the third connecting edge (21), the second collapse subspace (502) being defined between the third sidewall (22) and the second sidewall (32).

10. The battery pack (1) according to claim 9, wherein, The third sidewall (22) extends obliquely in a first direction away from the third connecting edge (21) and the second sidewall (32).

11. The battery pack (1) according to claim 10, wherein, The angle between the third sidewall (22) and the first direction is Z, and the angle between the second sidewall (32) and the first direction is Y, where Z = 2Y.

12. The battery pack (1) according to claim 10 or 11, wherein, The angle between the third sidewall (22) and the first direction is Z, where 50°≤Z≤70°.

13. The battery pack (1) according to claim 12, wherein, 55°≤Z≤65°。 14. The battery pack (1) according to any one of claims 1-13, wherein, Each battery cell (701) in the battery pack (70) is provided with a terminal post (71) facing the connection mating part (25). In the first direction, the terminal post (71) is located in the collapsible space (50) and is spaced apart from the connection mating part (25).

15. The battery pack (1) according to claim 14, wherein, The battery pack includes a fixing connection hole (101) that passes through the first connecting edge (11), the second connecting edge (31) and the third connecting edge (21). The battery pack also includes a fixing connector (63) that is installed in the fixing connection hole (101).

16. The battery pack (1) according to claim 15, wherein, In the first direction, the minimum distance between the central axis of the fixing connector (63) and the inner edge of the connecting mating part (25) facing the pole post (71) is A, the minimum distance between the inner edge of the connecting mating part (25) facing the pole post (71) and the pole post (71) is B, and the minimum distance between the central axis of the fixing connector (63) and the first end of the battery cell (701) where the pole post (71) is located is C. Among them, 1 / 3B≤A≤1 / 2C.

17. The battery pack (1) according to claim 16, wherein, 40mm≤B≤70mm, and / or, 90mm≤C≤130mm.

18. The battery pack (1) according to any one of claims 14-17, wherein, It also includes a bottom guard plate (202), the reinforcing plate (201) is an annular reinforcing plate (201), the bottom guard plate (202) is disposed on the side of the reinforcing plate (201) facing away from the lower cover (3) and covers the middle part of the annular reinforcing plate (201).

19. The battery pack (1) according to any one of claims 15-17, wherein, The reinforcing plate (201) also includes a support portion (23) connected to the third connecting edge (21). The support portion (23) is located on the side of the lower cover portion (3) away from the upper cover portion (10). In the first direction, the first end of the battery cell (701) with the pole post (71) is located between the outer end and the inner end of the support portion (23).

20. The battery pack (1) according to claim 19, wherein, In the first direction, the minimum distance between the central axis of the fixed connector (63) and the first end is C, and the maximum distance between the first end and the inner end of the support (23) is D. Among them, 1 / 2C≥D≥1 / 3C.

21. The battery pack (1) according to claim 20, wherein, 90mm≤C≤130mm.

22. An electrical appliance (1000), wherein, Includes the battery pack (1) according to any one of claims 1-21.

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