Battery pack and electric equipment

Abstract

The invention discloses a battery pack and electric equipment, and relates to the technical field of energy equipment. The battery pack comprises a box frame which is hollow inside and is provided with two opposite open ends; the battery core assembly is accommodated in the box frame; the top cover plate is connected with the box frame and seals one of the open ends; the first cold plate is positioned between the battery cell assembly and the top cover plate; the bottom protection plate is connected with the box frame and seals the other open end; the second cold plate is positioned between the battery cell assembly and the bottom protection plate; and the buffer assembly is provided with a part positioned between the top cover plate and the battery core assembly and a part positioned between the battery core assembly and the bottom protection plate. According to the battery pack and the electric equipment disclosed by the invention, the bottom and the top of the battery pack have relatively good impact resistance, so that the safety of the battery pack is improved.

Description

Technical Field

[0001] This application relates to the technical field of energy equipment, and particularly relates to a battery pack and an electrical device. Background Art

[0002] The battery systems of most new energy vehicles are usually arranged in the middle of the vehicle chassis or under the floor, very close to the ground. Since the vehicle is actually driving on the road, the bottom and top of the battery pack may be impacted, such as being hit by speed bumps, stones or other obstacles. Therefore, relatively high protection requirements are imposed on the top and bottom of the battery pack.

[0003] In related technologies, the bottom and top structures of the vehicle battery pack usually adopt a thickening design, or reinforcing ribs are added to the bottom and top structures to increase the structural strength. However, this solution cannot effectively resist top and bottom ball impacts. When bottom and top ball impacts occur, the bottom and top of the battery cells may undergo a deformation of more than 15%, resulting in thermal runaway of the battery cells. Summary of the Invention

[0004] In view of this, this application provides a battery pack and an electrical device, in which both the bottom and top of the battery pack have good anti-impact capabilities, thereby improving the safety of the battery pack.

[0005] This application specifically adopts the following technical solutions:

[0006] An embodiment of this application provides a battery pack, which includes:

[0007] A box frame, which is hollow inside and has two opposite open ends;

[0008] A battery cell assembly, accommodated inside the box frame;

[0009] A top cover plate, connected to the box frame and closing one of the open ends;

[0010] A first cold plate, located between the battery cell assembly and the top cover plate;

[0011] A bottom protection plate, connected to the box frame and closing the other open end;

[0012] A second cold plate, located between the battery cell assembly and the bottom protection plate;

[0013] A buffer assembly, which has a part located between the top cover plate and the battery cell assembly, and a part located between the battery cell assembly and the bottom protection plate.

[0014] Optionally, the buffer assembly includes at least one of a first buffer layer and a second buffer layer. The first buffer layer is located between the top cover plate and the first cold plate, and the second buffer layer is located between the first cold plate and the battery cell assembly.

[0015] Wherein, the thickness of the first buffer layer is not less than the thickness of the top cover plate, and the thickness of the second buffer layer is not less than the thickness of the first buffer layer.

[0016] Optionally, the first buffer layer is a foam, and the second buffer layer is a thermally conductive adhesive layer.

[0017] Optionally, the thickness of the top cover plate is not less than 1.5 mm; and / or,

[0018] The thickness of the first buffer layer is not less than 2 mm; and / or,

[0019] The thickness of the second buffer layer is not less than 3 mm.

[0020] Optionally, the battery pack further includes an integrated busbar CCS bracket located between the first cold plate and the battery cell assembly. A plurality of convex portions protruding towards the first cold plate are spaced apart on the CCS bracket, and the CCS bracket can be in contact and cooperation with the first cold plate through the plurality of convex portions;

[0021] The battery cell assembly includes a plurality of battery cell tabs. The contact positions of the plurality of battery cell tabs with the CCS bracket are respectively located within the intervals between the plurality of convex portions, and the second buffer layer is located between the plurality of battery cell tabs and the first cold plate.

[0022] Optionally, the second buffer layer is located between the CCS bracket and the first cold plate, and at least a part of the second buffer layer is located within the intervals between the plurality of convex portions.

[0023] Optionally, a rib portion protruding towards the first buffer layer is formed on the top cover plate. On the side of the top cover plate away from the first buffer layer, the rib portion is recessed relative to the other parts of the top cover plate;

[0024] The top cover plate is in contact with the first buffer layer through the rib portion.

[0025] Optionally, the rib portion includes a plurality of first ribs and a plurality of second ribs. The plurality of first ribs are spaced apart and arranged in parallel, and each first rib extends along a first direction, and the first direction is inclined relative to the length direction and the width direction of the top cover plate; the plurality of second ribs are spaced apart and arranged in parallel, and each second rib extends along a second direction, and the second direction is inclined relative to the length direction and the width direction of the top cover plate, wherein the plurality of first ribs and the plurality of second ribs intersect.

[0026] Optionally, the buffer assembly includes at least one of a third buffer layer and a fourth buffer layer. The third buffer layer is located between the battery cell assembly and the second cold plate, and the fourth buffer layer is located between the second cold plate and the bottom protection plate.

[0027] Wherein, the thickness of the fourth buffer layer is not less than the thickness of the bottom protection plate.

[0028] Optionally, the third buffer layer is a thermally conductive adhesive layer, and the fourth buffer layer is a foam.

[0029] Optionally, the thickness of the third buffer layer is not less than 1 mm; and / or

[0030] the thickness of the fourth buffer layer is not less than 2 mm; and / or

[0031] the thickness of the bottom protection plate is not less than 1 mm.

[0032] Optionally, the first cold plate and the second cold plate are respectively welded to the box frame; and / or

[0033] At least one of the first cold plate and the second cold plate is a cold plate made of extruded profiles.

[0034] Optionally, the box frame includes a plurality of sealing beams and two expansion beams;

[0035] The plurality of sealing beams are sequentially connected along the circumference of the box frame and are hermetically connected to the top cover plate and the bottom protection plate;

[0036] The two expansion beams are respectively connected to the mutually adjacent beam walls of two sealing beams that are opposite in position among the plurality of sealing beams, and the battery cell assembly is located between the two expansion beams.

[0037] Optionally, the thickness of the expansion beam is not less than 25 mm.

[0038] On the other hand, an embodiment of the present application provides an electrical device, which includes a device body and the battery pack described in the previous aspect, and the device body is powered by the battery pack.

[0039] For the battery pack provided by the embodiment of the present application, since a buffer assembly is provided between the top cover plate and the battery cell assembly and between the bottom protection plate and the battery cell assembly, when the top or bottom of the battery pack is impacted by an external object, the buffer assembly can absorb the energy of the impact force, thereby reducing or even eliminating the impact force that the battery cell assembly needs to bear. Therefore, the probability of serious deformation of the battery cell assembly is reduced, and thus battery thermal runaway is avoided, improving safety. Description of the Drawings

[0040] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0041] Figure 1 It is a schematic external view of a battery pack provided by an embodiment of the present application;

[0042] Figure 2 is Figure 1 an exploded view of the battery pack shown;

[0043] Figure 3 It is a schematic structural view of a CCS bracket in the battery pack provided by an embodiment of the present application;

[0044] Figure 4 is Figure 3 an enlarged view of part A in

[0045] Figure 5 is Figure 1 a schematic cross-sectional structure view obtained by cutting along the A-A line in

[0046] Figure 6 is Figure 5 an enlarged view of part B in

[0047] Figure 7 It is a schematic cross-sectional structure view of the top cover plate in the battery pack provided by an embodiment of the present application;

[0048] Figure 8 It is a schematic connection view of the box frame and the first cold plate in the battery pack provided by an embodiment of the present application;

[0049] Figure 9 It is a schematic connection view of the box frame and the second cold plate in the battery pack provided by an embodiment of the present application;

[0050] Figure 10 It is a schematic structural view of the box frame in the battery pack provided by an embodiment of the present application.

[0051] Reference numerals:

[0052] 1. Box frame; 11. Open end; 12. Sealing beam; 13. Expansion beam;

[0053] 2. Cell assembly; 21. Cell tab; 22. Cell shoulder;

[0054] 3. Top cover plate; 31. First rib; 32. Second rib;

[0055] 4. First cold plate;

[0056] 5. Bottom guard plate;

[0057] 6. Second cold plate;

[0058] 7. Buffer assembly; 71. First buffer layer; 72. Second buffer layer; 73. Third buffer layer; 74. Fourth buffer layer;

[0059] 8. CCS bracket; 81. Boss part.

[0060] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and more detailed descriptions will be given later. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0061] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0062] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0063] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0064] The embodiments of the present application provide a battery pack, as Figure 1 and Figure 2 shown, the battery pack includes a box frame 1, a battery cell assembly 2, a top cover plate 3, a first cold plate 4, a second cold plate 6, a bottom guard plate 5, and a buffer assembly 7.

[0065] The box frame 1 is an annular structure with a hollow interior. The box frame 1 has two opposite open ends 11 along the axial direction. The interior of the box frame 1 communicates with the outside through these two open ends 11. The battery cell assembly 2 is accommodated inside the box frame 1. The box frame 1 is a rigid structure for providing structural support and protection to ensure that the battery cell assembly 2 will not be deformed or damaged due to collision or extrusion during use. Optionally, the box frame 1 is usually made of a high-strength material such as aluminum alloy to improve its impact resistance and durability.

[0066] The battery cell assembly 2 is the core component in the battery pack. Generally speaking, the battery cell assembly 2 includes multiple battery cells, which are used to store and release electrical energy.

[0067] The top cover plate 3 is located at the topmost layer of the battery pack. The top cover plate 3 is connected to one open end 11 of the box frame 1 to close this open end 11. The connection between the top cover plate 3 and the box frame 1 is usually a sealed connection. For example, a sealant layer can be provided between the top cover plate 3 and the box frame 1 to ensure the tightness inside the battery pack, prevent dust, moisture, and air from entering, and extend the service life of the battery. At the same time, the top cover plate 3 can also play a role in resisting mechanical impact, protecting the battery cell assembly 2 and making it not easily deformed.

[0068] The bottom protection plate 5 is located at the bottommost layer of the battery pack. The bottom protection plate 5 is connected to the other open end 11 of the box frame 1 to close this open end 11. The connection between the bottom protection plate 5 and the box frame 1 is also a sealed connection. For example, a sealant layer can be provided between the bottom protection plate 5 and the box frame 1 to ensure the tightness inside the battery pack, prevent dust, moisture, and air from entering, and extend the service life of the battery. The bottom protection plate 5 is used to protect the battery pack from damage caused by bottom impact. The bottom protection plate 5 is usually made of a high-strength material and may be equipped with a pressure relief cavity or a protective layer to absorb impact energy and disperse pressure, thereby protecting the battery cell assembly 2 from direct impact.

[0069] The first cold plate 4 and the second cold plate 6, where the first cold plate 4 is located between the battery cell assembly 2 and the top cover plate 3, and the second cold plate 6 is located between the battery cell assembly 2 and the bottom protection plate 5. The cold plates are used for heat dissipation. They can be made of heat-conducting materials or be arranged with a liquid cooling system to effectively transfer and dissipate the heat generated by the battery cell assembly 2. For example, the liquid cooling plate pumps coolant through internal channels to achieve an efficient heat dissipation effect and help the battery cell assembly 2 maintain an appropriate working temperature. In addition, the cold plates can also serve as structural support members to provide mechanical protection for the battery cell assembly 2. In some embodiments, at least one of the first cold plate 4 and the second cold plate 6 is a cold plate made of extruded profiles. The extruded profile cold plate usually has high strength, high dimensional accuracy, and stable quality.

[0070] The buffer component 7 is used to buffer when the battery pack is impacted, absorb the impact energy, and protect the battery cell component 2 from deformation. Among them, the buffer component 7 includes a plurality of parts that are connected to each other or independent of each other. One part of the buffer component 7 can be arranged between the top cover plate 3 and the battery cell component 2. For example, it can be located between the top cover plate 3 and the first cold plate 4, and / or between the first cold plate 4 and the battery cell component 2; Another part of the buffer component 7 can be arranged between the battery cell component 2 and the bottom protection plate 5. For example, it is located between the battery cell component 2 and the second cold plate 6, and / or between the second cold plate 6 and the bottom protection plate 5.

[0071] In the battery pack provided by the embodiment of the present application, since the buffer component 7 is arranged between the top cover plate 3 and the battery cell component 2, and between the bottom protection plate 5 and the battery cell component 2, when the top or bottom of the battery pack is impacted by an external object, the buffer component 7 can absorb the energy of the impact force, thereby reducing or even eliminating the impact force that the battery cell component 2 needs to bear. Therefore, the probability of serious deformation of the battery cell component 2 is reduced, and thus battery thermal runaway is avoided, and safety is improved.

[0072] The top cover plate 3 of the battery pack provided by the embodiment of the present application is usually made of aluminum alloy material or steel, considering factors such as lightweight, strength, thermal conductivity, corrosion resistance, and cost. Among them, the top cover plate 3 made of aluminum alloy material can meet the lightweight requirement and has the advantages of moderate strength, good thermal conductivity, and corrosion resistance. For scenarios that require impact resistance or have a load-bearing requirement, such as applications in commercial vehicles, the top cover plate 3 of the battery pack can be made of steel, so that the top cover plate 3 has high strength. Of course, the top cover plate 3 can also be made of other materials, such as composite materials, magnesium alloys, etc. Those skilled in the art can select the material of the top cover plate 3 according to actual needs.

[0073] Optionally, the thickness of the top cover plate 3 is not less than 1.5 mm. For example, the thickness of the top cover plate 3 can be 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc. It should be understood that the thicker the thickness of the top cover plate 3, the better its strength, but the greater the weight and the higher the overall height of the battery pack. Considering comprehensively, the thickness range of the top cover plate 3 can be set at 1.5 - 3 mm.

[0074] In some embodiments, reinforcing ribs can be arranged on the top cover plate 3 to meet the requirements of improving the impact resistance and bearing strength of the top cover plate 3. As Figure 7 shown, a ribbed portion 30 protruding towards the buffer component 7 is formed on the top cover plate 3. Optionally, the ribbed portion 30 and other parts on the top cover plate 3 are of an integrally formed structure, so as to ensure that the top cover plate 3 has high structural strength and is easy to process.

[0075] It should be understood that the rib portion 30 "protrudes towards the buffer assembly 7 (such as the first buffer layer 71)" means that when viewed from the side of the top cover plate 3 away from the first buffer layer 71, the rib portion 30 is recessed relative to other parts of the top cover plate 3; when viewed from the side of the top cover plate 3 close to the first buffer layer 71, the rib portion 30 protrudes relative to other parts of the top cover plate 3.

[0076] The top cover plate 3 contacts the first buffer layer 71 through the rib portion 30, reducing the contact area between the top cover plate 3 and the first buffer layer 71. When the top of the battery pack is impacted, such as in the top ball drop test, the rib portion 30 can quickly guide and disperse the impact load at the ball drop point, avoiding local stress concentration at the ball drop point; moreover, the rib portion 30 also forms a buffer space between the ball drop point on the top cover plate 3 and the first buffer layer 71, enabling the rib portion 30 to dissipate the impact energy through its own small deformations (such as bending, shearing, etc.), reducing the impact resistance burden of the first buffer layer 71. That is to say, the rib portion 30 not only plays a role in increasing the structural strength of the top cover plate 3, but also forms a buffer space between the rest of the top cover plate 3 and the first buffer layer 71 that is convenient for absorbing and dissipating impact energy, improving the impact resistance ability of the top cover plate 3, and thus being able to further reduce the damage to the battery pack caused by the top impact.

[0077] As Figure 7 shown, the rib portion 30 may include a plurality of first ribs 31 and a plurality of second ribs 32. The plurality of first ribs 31 are spaced and arranged in parallel, and each first rib 31 extends along a first direction, where the first direction is inclined relative to the length direction of the top cover plate 3 and also inclined relative to the width direction of the top cover plate 3. The plurality of second ribs 32 are spaced and arranged in parallel, and each first rib 31 extends along a second direction, the second direction being inclined relative to the length direction of the top cover plate 3 and also inclined relative to the width direction of the top cover plate 3. Among them, the plurality of first ribs 31 and the plurality of second ribs 32 have intersecting parts.

[0078] Optionally, the angle between the first direction and the width direction of the top cover plate 3 is 20° - 60°, and the angle between the second direction and the width direction of the top cover plate 3 is 120° - 160°.

[0079] By arranging the first ribs 31 and the second ribs 32 in an inclined manner, additional supporting forces can be provided in multiple directions, thereby improving the overall structural strength and bending resistance of the top cover plate 3, facilitating the more uniform distribution of stress in the structure, and thus better coping with complex load distributions, thereby avoiding the stress concentration problem that may occur when arranged parallel to the length direction and width direction of the top cover plate 3.

[0080] In some embodiments of the present application, as Figure 2As shown, the buffer assembly 7 may include at least one of a first buffer layer 71 and a second buffer layer 72.

[0081] The first buffer layer 71 is located between the top cover plate 3 and the first cold plate 4, and the thickness of the first buffer layer 71 is not less than the thickness of the top cover plate 3.

[0082] Optionally, when the top cover plate 3 is made of a steel plate with a thickness of not less than 1.5 mm, the thickness of the first buffer layer 71 is not less than 2 mm, such as 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc.

[0083] By providing the first buffer layer 71, the distance between the top cover plate 3 and the first cold plate 4 is greater than or equal to 2 mm. Therefore, when the top impact energy is transmitted downward through the top cover plate 3, the first buffer layer 71 can absorb and dissipate this energy, thereby further protecting the battery cell assembly 2 and reducing the probability of its damage.

[0084] Optionally, the first buffer layer 71 may be foam. Foam has the advantages of good buffer and shock absorption performance, low density, light weight, good friction resistance, and low cost.

[0085] The second buffer layer 72 is located between the first cold plate 4 and the battery cell assembly 2, and the thickness of the second buffer layer 72 is not less than the thickness of the first buffer layer 71.

[0086] Optionally, when the thickness of the first buffer layer 71 is not less than 2 mm, the thickness of the second buffer layer 72 is not less than 3 mm, such as 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0087] By providing the second buffer layer 72, the distance between the first cold plate 4 and the battery cell assembly 2 is greater than or equal to 3 mm. Therefore, when the top impact energy is transmitted downward through the first cold plate 4, the second buffer layer 72 can absorb and dissipate this part of the energy, thereby further protecting the battery cell assembly 2 and reducing the probability of its damage.

[0088] Optionally, a thermal conductive adhesive may be filled between the first cold plate 4 and the battery cell assembly 2 to form a thermal conductive adhesive layer. This thermal conductive adhesive layer can serve as the second buffer layer 72. Since the first cold plate 4 needs to dissipate heat and cool the battery cell assembly 2, in order to ensure the heat dissipation effect, the thermal conductive adhesive can be filled between the first cold plate 4 and the battery cell assembly 2, so that the thermal conductive adhesive layer can simultaneously play the roles of heat conduction and dissipation and buffer and shock absorption.

[0089] In some embodiments of the present application, such as Figure 2As shown, the battery pack further includes an integrated busbar (CCS, Cells Contact System) bracket located between the first cold plate 4 and the battery cell assembly 2. The CCS bracket 8 is mainly used for the integrated series connection and fixation between battery cells (battery cells). As Figure 3 and Figure 4 shown, a plurality of boss portions 81 protruding toward the first cold plate 4 are provided at intervals on the CCS bracket 8. Refer to Figure 5 and Figure 6 , the CCS bracket 8 can be in contact and cooperation with the first cold plate 4 through a plurality of boss portions 81.

[0090] Continue to refer to Figure 6 , the battery cell assembly 2 includes a plurality of battery cell tabs 21. The battery cell tabs 21 are usually made of copper or aluminum, and are connected to the battery cell poles by welding or crimping, and are electrically connected to an external circuit (such as a battery management system BMS) at the same time, so as to converge and conduct the current of a single battery cell to the external circuit.

[0091] In the embodiment of the present application, as Figure 6 shown, a plurality of battery cell tabs 21 are respectively in contact with the CCS bracket 8, and the contact positions are respectively within the intervals between a plurality of boss portions 81.

[0092] In this way, when the top of the battery pack is impacted, the impact force is sequentially transmitted from the top cover plate 3, the first buffer layer 71, and the first cold plate 4 to the boss portion 81 of the CCS bracket 8, and continues to be transmitted downward by the boss portion 81. Since a plurality of battery cell tabs 21 are located within the intervals between a plurality of boss portions 81, the impact force basically does not or only acts on the battery cell tabs 21 in a small amount, thereby avoiding the loosening, breakage of the connection points and the misalignment and short circuit of the positive and negative electrodes caused by the impact of the battery cell tabs 21.

[0093] In some embodiments, the second buffer layer 72 can be located between a plurality of battery cell tabs 21 and the first cold plate 4, and is used for further protecting the battery cell tabs 21 and minimizing the impact received by the battery cell tabs 21 as much as possible.

[0094] As Figure 6 shown, in one example, the second buffer layer 72 can be provided between the CCS bracket 8 and the first cold plate 4, and at least part of the second buffer layer 72 is filled in the intervals between a plurality of boss portions 81, so that each battery cell tab 21 has a part of the second buffer layer 72 on the side close to the first cold plate 4, thus realizing the shock absorption protection for each battery cell tab 21.

[0095] It should be noted that "at least part of the second buffer layer 72 is filled in the intervals between the plurality of boss parts 81" may include the case where the second buffer layer 72 is entirely located within the intervals between adjacent boss parts 81, so that the top surfaces of the plurality of boss parts 81 are in direct contact with the first cold plate 4; it may also include the case where a part of the second buffer layer 72 is located within the intervals between adjacent boss parts 81 and another part of the second buffer layer 72 covers the top surfaces of the boss parts 81, so that at least some of the boss parts 81 are indirectly in contact with the first cold plate 4 through the second buffer layer 72. Herein, the top surface of the boss part 81 refers to the surface close to the first cold plate 41.

[0096] In some embodiments of the present application, the plurality of boss parts 81 may be in contact and cooperation with the cell shoulders 22 of the plurality of cells in the cell assembly 2, so as to transmit the received impact force to the cell shoulders 22.

[0097] As Figure 6 shown, the plurality of boss parts 81 have a first orthographic projection on the plate surface of the first cold plate 4, the cell shoulders 22 of the plurality of cells in the cell assembly 2 have a second orthographic projection on the plate surface of the first cold plate 4, and the pole posts (not marked in the figure) and explosion-proof valves (not marked in the figure) of the plurality of cells in the cell assembly 2 have a third orthographic projection on the plate surface of the first cold plate 4. Among them, the first orthographic projection is located within the second orthographic projection or coincides with the second orthographic projection; the first orthographic projection is located outside the third orthographic projection.

[0098] This means that along the height direction of the battery (i.e., the direction in which the top cover plate 3 and the bottom protection plate 5 are oppositely arranged), the plurality of boss parts 81 of the CCS bracket 8 correspond to the cell shoulders 22 of the plurality of cells, and avoid the pole posts and explosion-proof valves of the cells. In this way, when the top impact force is transmitted downward through the boss parts 81, it will act on the cell shoulders 22 and will not act on the pole posts and explosion-proof valves of the cells. Since the strength of the cell shoulders 22 is usually relatively high, it can withstand and resist the impact force, avoiding thermal runaway and explosion caused by the impact on the pole posts and explosion-proof valves of the cells.

[0099] To improve the bottom impact resistance of the battery pack, the bottom protection plate 5 of the battery pack can be designed in a similar manner to the top cover plate 3. For example, the bottom protection plate 5 is made of a material with greater strength, or the thickness of the bottom protection plate 5 is increased, or reinforcing ribs are provided on the bottom protection plate 5, etc.

[0100] In some embodiments, considering factors such as lightweight, strength, thermal conductivity, corrosion resistance, and cost, the bottom protection plate 5 can be made of aluminum alloy material or steel. The advantages and applicable scenarios of the aluminum alloy material and the steel have been mentioned above and will not be elaborated here.

[0101] Optionally, the thickness of the bottom guard plate 5 is not less than 1 mm. For example, the thickness of the bottom guard plate 5 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc. It should be understood that the thicker the bottom guard plate 5, the better its strength, but the greater its weight and the higher the overall height of the battery pack. Considering comprehensively, the thickness range of the bottom guard plate 5 can be set between 1 - 3 mm.

[0102] In some embodiments of the present application, the thickness of the bottom guard plate 5 is less than the thickness of the top cover plate 3 because, in addition to mechanical impacts, the top cover plate 3 may face higher temperature changes and thermal shock risks during use.

[0103] In some embodiments, reinforcing ribs can be provided on the bottom guard plate 5 to meet the requirements of improving the impact resistance and pressure-bearing strength of the bottom guard plate 5. Exemplarily, the arrangement and style of the reinforcing ribs on the bottom guard plate 5 can be the same as or similar to the arrangement and style of the first convex rib 31 and the second convex rib 32 on the top cover plate 3.

[0104] In some embodiments of the present application, as Figure 2 shown, the buffer assembly 7 further includes at least one of a third buffer layer 73 and a fourth buffer layer 74.

[0105] The fourth buffer layer 74 is located between the second cold plate 6 and the bottom guard plate 5, and the thickness of the fourth buffer layer 74 is not less than the thickness of the bottom guard plate 5.

[0106] Optionally, when the bottom guard plate 5 is made of a steel plate with a thickness not less than 1 mm, the thickness of the fourth buffer layer 74 is not less than 2 mm, such as 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc.

[0107] By providing the fourth buffer layer 74, the distance between the bottom guard plate 5 and the second cold plate 6 is greater than or equal to 1 mm. Therefore, when the impact energy at the bottom of the battery pack is transmitted upward through the bottom guard plate 5, the fourth buffer layer 74 can absorb and dissipate this energy, thereby further protecting the cell assembly 2 and reducing the probability of its damage.

[0108] Optionally, the fourth buffer layer 74 can be foam. Foam has the advantages of good buffer and shock absorption performance, low density, light weight, good friction resistance, and low cost.

[0109] The third buffer layer 73 is located between the cell assembly 2 and the second cold plate 6. Optionally, the thickness of the third buffer layer 73 is not less than 1 mm, such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0110] By providing the third buffer layer 73, the distance between the battery cell assembly 2 and the second cold plate 6 is made greater than or equal to 1 mm. In this way, when the impact energy at the second cold plate 6 is transmitted upward, the third buffer layer 73 can absorb and dissipate this energy, thereby further protecting the battery cell assembly 2 and reducing the probability of its damage.

[0111] Optionally, the third buffer layer 73 is a thermally conductive adhesive layer. Since the second cold plate 6 needs to dissipate heat and cool the battery cell assembly 2, in order to ensure the heat dissipation effect, thermally conductive adhesive can be used to fill the space between the second cold plate 6 and the battery cell assembly 2, so that the thermally conductive adhesive layer can simultaneously play the roles of heat conduction and dissipation, as well as buffering and shock absorption.

[0112] In some embodiments of the present application, as Figure 8 and Figure 9 shown, the first cold plate 4 and the second cold plate 6 are respectively welded to the box frame 1. In this way, when the impact force at the top of the battery pack is transmitted to the first cold plate 4, or the impact force at the bottom is transmitted to the second cold plate 6, part of the impact force can act on the high-strength box frame 1 through the first cold plate 4 or the second cold plate 6, thereby reducing the probability of impact damage to the battery cell assembly 2.

[0113] In some embodiments of the present application, as Figure 10 shown, the box frame 1 includes a plurality of sealing beams 12. The plurality of sealing beams 12 are sequentially connected along the circumference of the box frame 1 and are hermetically connected to the top cover plate 3 and the bottom guard plate 5. The box frame 1 of the battery pack is hermetically connected to the bottom guard plate 5 of the top cover plate 3 respectively through the sealing beams 12 in the circumferential direction, ensuring the sealing performance inside the battery pack, and thus ensuring the safety, performance and lifespan of the battery cell assembly 2.

[0114] In some embodiments, a sealing adhesive (not shown in the figure) is used for sealing between the sealing beam 12 and the top cover plate 3, and / or a sealing adhesive (not shown in the figure) is used for sealing between the sealing beam 12 and the bottom guard plate 5.

[0115] Using a sealing adhesive to achieve sealing has a simple process, and the formed high-strength sealing layer can effectively prevent liquid leakage and the intrusion of external dust and impurities. In addition, the sealing adhesive has good adhesiveness and chemical resistance, can provide a firm bond in complex shapes and special-shaped structures, and can withstand mechanical stress at the same time.

[0116] Optionally, an annular groove can be provided at the top of the plurality of sealing beams 12 of the box frame 1, and the annular groove is filled with a sealing adhesive; an annular protrusion can be formed on one side of the top cover plate 3 close to the box frame 1, and the annular protrusion is embedded and adhesively bonded to the groove wall of the annular groove through the sealing adhesive, so as to ensure good sealing performance at the connection between the box frame 1 and the top cover plate 3.

[0117] In the embodiments of the present application, as Figure 10As shown, the box frame 1 further includes two expansion beams 13, and the two expansion beams 13 are respectively connected to the beam walls of two sealing beams 12 with opposite positions among the multiple sealing beams 12 that are close to each other.

[0118] As Figure 2 shown, the battery cell assembly 2 is located between the two expansion beams 13. The battery cell assembly 2 will expand during the charge and discharge process. The expansion beams 13 are used to resist the expansion and deformation of the battery cell assembly 2. By dispersing the expansion force generated by the battery cell assembly 2, the direct impact on the box frame 1 can be reduced, and the risk of deformation of the box frame 1 can be lowered, thereby protecting the stability and safety of the internal structure of the battery pack.

[0119] In addition, the design of the expansion beams 13 can enhance the overall structural strength and stability of the battery pack, avoid loosening or falling off of the connectors caused by the expansion of the battery cells, and further improve the safety of the battery pack.

[0120] Optionally, the thickness of the expansion beam 13 is not less than 25 mm. Exemplarily, the thickness range of the expansion beam 13 is 25 - 40 mm, such as 25 mm, 30 mm, 35 mm, 40 mm, etc. The expansion beam 13 within this thickness range can meet the requirements of structural strength and lightweight.

[0121] In some embodiments of the present application, the battery pack adopts a top cover plate 3 with a thickness greater than 1.5 mm, and a CCS bracket 8 having a boss portion 81 and capable of transmitting impact energy to the shoulder 22 of the battery cell, and the distance between the top cover plate 3 and the first cold plate 4 is greater than 2 mm and filled with a first buffer layer 71, and the distance between the battery cell tab 21 and the first cold plate 4 is greater than 3 mm and filled with a second buffer layer 72. At the same time, the first cold plate 4 adopts a high-strength extruded profile cold plate, so that the battery pack can withstand a top drop ball test with an impact energy of not less than 120 J.

[0122] In some embodiments of the present application, the battery pack adopts a bottom guard plate 5 with a thickness greater than 1 mm, and the distance between the bottom guard plate 5 and the second cold plate 6 is greater than 2 mm and filled with a fourth buffer layer 74. The distance between the battery cell assembly 2 and the second cold plate 6 is greater than 1 mm and filled with a third buffer layer 73. At the same time, the second cold plate 6 adopts a high-strength extruded profile cold plate and is welded to the box frame 1, enabling the battery pack to withstand a bottom ball impact test with an impact energy of not less than 120 J. In summary, for the battery pack provided by the embodiments of the present application, since a first buffer layer 71 is provided between the top cover plate 3 and the first cold plate 4, a second buffer layer 72 is provided between the first cold plate 4 and the battery cell assembly 2, a fourth buffer layer 74 is provided between the bottom guard plate 5 and the second cold plate 6, a third buffer layer 73 is provided between the battery cell assembly 2 and the second cold plate 6, a boss portion 81 is provided on the CCS bracket 8 to contact the first cold plate 4, and the boss portion 81 corresponds to the battery shoulder, so that the telecom bus bar, pole column, and explosion-proof valve of the battery cell avoid the boss portion 81. Therefore, when the top or bottom of the battery pack is impacted by an external object, the impact force will be dissipated and absorbed by each buffer layer, or transmitted and dissipated through the box frame 1. Even if some impact energy remains, the remaining impact energy will not directly act on the battery cell bus bar 21, pole column, and explosion-proof valve, but will act on the relatively strong battery cell shoulder 22, thereby reducing the probability of serious deformation of the battery cell assembly 2, further avoiding battery thermal runaway, and improving safety.

[0123] The embodiments of the present application further provide an electrical device, which includes a device body and the battery pack described in the above embodiments, and the device body is powered by the battery pack described in the above embodiments.

[0124] Exemplarily, the electrical device may be an energy storage device (such as a home or outdoor energy storage power supply), an electronic product, a power tool, an industrial electrical device, a new energy vehicle, an electric bicycle / scooter, a special vehicle and equipment, etc.

[0125] Taking the electrical device as a new energy vehicle (such as a pure electric vehicle or a hybrid vehicle) as an example, since the battery pack is usually installed in the middle of the vehicle chassis or under the floor, the bottom and top of the battery pack are easily impacted by external objects during vehicle driving, resulting in deformation and damage of the battery cells. In the embodiments of the present application, by improving the anti-impact ability of the bottom and top of the battery pack, the probability of deformation and damage of the battery cells in the battery pack is reduced, further avoiding battery thermal runaway, significantly improving the safety performance of the battery pack, and further improving the safety and service life of the electrical device using the battery pack.

[0126] Other embodiments of the present application will be readily apparent to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include known common general knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and examples are only illustrative.

[0127] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A battery pack, characterized in that: The battery pack comprises: A box frame (1), the box frame (1) is hollow inside and has two opposite open ends (11); A battery cell assembly (2) is accommodated inside the box frame (1); A top cover plate (3) connected to the box frame (1) and closing one of the open ends (11); A first cold plate (4) located between the battery cell assembly (2) and the top cover plate (3); A bottom guard plate (5) connected to the box frame (1) and closing the other open end (11); A second cold plate (6) is located between the battery cell assembly (2) and the bottom protective plate (5); A buffer assembly (7), wherein the buffer assembly (7) comprises a portion located between the top cover plate (3) and the battery cell assembly (2), and a portion located between the battery cell assembly (2) and the bottom guard plate (5).

2. The battery pack according to claim 1, characterized in that: The buffer assembly (7) comprises at least one of a first buffer layer (71) and a second buffer layer (72), wherein the first buffer layer (71) is located between the top cover plate (3) and the first cold plate (4), and the second buffer layer (72) is located between the first cold plate (4) and the battery cell assembly (2); Wherein, the thickness of the first buffer layer (71) is not less than the thickness of the top cover plate (3), and the thickness of the second buffer layer (72) is not less than the thickness of the first buffer layer (71).

3. The battery pack according to claim 2, characterized in that: The first buffer layer (71) is foam, and the second buffer layer (72) is a heat-conducting adhesive layer.

4. The battery pack according to claim 2, characterized in that: The thickness of the top cover plate (3) is not less than 1.5 mm; and / or, The thickness of the first buffer layer (71) is not less than 2 mm; and / or, The thickness of the second buffer layer (72) is not less than 3 mm.

5. The battery pack according to any one of claims 2 to 4, characterized in that: The battery pack further comprises an integrated busbar CCS bracket (8) located between the first cold plate (4) and the battery cell assembly (2), wherein the CCS bracket (8) is provided with a plurality of bosses (81) protruding toward the first cold plate (4) at intervals, and the CCS bracket (8) can be in contact with and cooperate with the first cold plate (4) through the plurality of bosses (81); The battery cell assembly (2) comprises a plurality of battery cell tabs (21), wherein contact positions of the plurality of battery cell tabs (21) with the CCS bracket (8) are respectively located within the intervals between the plurality of boss portions (81), wherein the second buffer layer (72) is located between the plurality of battery cell tabs (21) and the first cold plate (4).

6. The battery pack according to claim 5, characterized in that: The second buffer layer (72) is located between the CCS bracket (8) and the first cold plate (4), and at least a portion of the second buffer layer (72) is located in the intervals between the plurality of boss portions (81).

7. The battery pack according to claim 2, characterized in that: A convex rib portion (30) is formed on the top cover plate (3) and protrudes toward the first buffer layer (71); on a side of the top cover plate (3) away from the first buffer layer (71), the convex rib portion (30) is recessed relative to other parts of the top cover plate (3); The top cover plate (3) is in contact with the first buffer layer (71) via the convex rib portion (30).

8. The battery pack according to claim 7, characterized in that: The convex rib portion (30) comprises a plurality of first convex ribs (31) and a plurality of second convex ribs (32). The plurality of first convex ribs (31) are arranged in parallel and at intervals, each of the first convex ribs (31) extends along a first direction, and the first direction is inclined relative to the length direction and the width direction of the top cover plate (3); The plurality of second convex ribs (32) are arranged in parallel and at intervals, each of the second convex ribs (32) extends along a second direction, and the second direction is inclined relative to the length direction and the width direction of the top cover plate (3); Wherein, the plurality of first convex ribs (31) and the plurality of second convex ribs (32) intersect.

9. The battery pack according to claim 1, characterized in that: The buffer assembly (7) comprises at least one of a third buffer layer (73) and a fourth buffer layer (74), the third buffer layer (73) being located between the battery cell assembly (2) and the second cold plate (6), and the fourth buffer layer (74) being located between the second cold plate (6) and the bottom guard plate (5); Wherein, the thickness of the fourth buffer layer (74) is not less than the thickness of the bottom guard plate (5).

10. The battery pack according to claim 9, characterized in that: The third buffer layer (73) is a heat-conducting adhesive layer, and the fourth buffer layer (74) is foam.

11. The battery pack according to claim 9 or 10, characterized in that: The thickness of the third buffer layer (73) is not less than 1 mm; and / or, The thickness of the fourth buffer layer (74) is not less than 2 mm; and / or, The thickness of the bottom guard plate (5) is not less than 1 mm.

12. The battery pack according to claim 1, characterized in that: The first cold plate (4) and the second cold plate (6) are respectively connected to the box frame (1) by welding; and / or, At least one of the first cold plate (4) and the second cold plate (6) is a cold plate made of extruded profile.

13. The battery pack according to claim 1, characterized in that: The box frame (1) comprises a plurality of sealing beams (12) and two expansion beams (13); The plurality of sealing beams (12) are sequentially connected along the circumference of the box frame (1), and are sealedly connected to the top cover plate (3) and the bottom guard plate (5); The two expansion beams (13) are respectively connected to the beam walls of two sealing beams (12) located opposite to each other among the plurality of sealing beams (12), and the battery cell assembly (2) is located between the two expansion beams (13).

14. The battery pack according to claim 13, characterized in that: The thickness of the expansion beam (13) is not less than 25 mm.

15. An electrical equipment, characterized in that: The electrical device comprises a device body and a battery pack as described in any one of claims 1 to 14, and the device body is powered by the battery pack.

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