Battery module assembly, battery pack and vehicle

Abstract

The utility model relates to a battery module assembly, a battery pack and a vehicle. The battery module assembly comprises a battery module, a bar and a first phase change material piece. The battery module comprises a plurality of battery cells arranged along a first direction to form a battery cell row; the number of the bars is multiple, each bar is connected to the pole columns of two adjacent battery cells to form a busbar, and the first phase change material piece is connected with the busbar. The first phase-change material piece is connected with the busbar, so that heat generated on the pole can be directly dissipated in time through the first phase-change material piece, and the risk that the heat is accumulated near the pole is prevented. The battery module assembly disclosed by the utility model has the advantages of improving the heat dissipation capability at the pole, the fast charging capability of the battery module and the use safety.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicles, and in particular to a battery module assembly, a battery pack and a vehicle having the battery module assembly. Background Art

[0002] The battery module is composed of several to hundreds of battery cells connected in parallel and in series. The connection between the modules is achieved by welding the electrode ears in parallel and fixing them on the bus to achieve battery series and parallel connection. A large amount of heat will be generated in the battery pack during the charging process, especially for high-power fast-charging power batteries, where the heat dissipation problem is particularly serious, because the heat generation problem at the connection between the pole and the pole ear is more serious than other positions, and the heat there is often directly transferred to the inside of the battery cell body, causing heat to accumulate inside the battery cell. In the related art, the heat dissipation of the battery pack is mainly at the bottom or top of the battery, and is generally cooled by direct cooling or liquid cooling plates. This type of cooler is connected to the shoulder of the battery cell by heat conduction, thereby cooling the battery cell, but this method has limited heat dissipation effect of the pole, and there is a problem of affecting the fast charging ability and life of the battery pack. Utility Model Content

[0003] The utility model aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the embodiment of the utility model proposes a battery module assembly. The battery module assembly has the advantages of improving the heat dissipation capacity at the pole, the fast charging capacity of the battery module and the safety of use.

[0004] An embodiment of the present invention further provides a battery pack.

[0005] An embodiment of the utility model further provides a vehicle.

[0006] The battery module assembly of the embodiment of the utility model includes a battery module, a bar and a first phase change material piece.

[0007] The battery module includes a plurality of battery cells arranged along a first direction to form a battery cell row; there are a plurality of busbars, each of which is connected to the poles of two adjacent battery cells to form a busbar; the first phase change material piece includes a first phase change material piece and a phase change material filled in the first phase change material piece, and the first phase change material piece is connected to the busbar.

[0008] The battery module assembly of the embodiment of the utility model is connected to the bus through the first phase change material part, which can directly dissipate the heat generated on the pole through the first phase change material part in a timely and rapid manner, thereby improving the overall cooling capacity of the battery module by the first phase change material part, preventing heat from accumulating near the pole and causing the risk of thermal runaway of the battery cell due to local excessive temperature. The reduction in temperature near the pole is conducive to achieving fast charging of the battery and the safety of the charging and discharging process.

[0009] Therefore, the battery module assembly of the embodiment of the utility model has the advantages of improving the heat dissipation capacity at the pole, the fast charging capability of the battery module and the safety of use.

[0010] In some embodiments, the bar includes a connected overlapping section and a heat-conducting section, the overlapping section is overlapped on two poles of two adjacent battery cells in the same battery cell row, the first phase change material piece has a first heat dissipation surface and a second heat dissipation surface arranged opposite to each other in a second direction, the second direction is perpendicular to the first direction, the first heat dissipation surface is arranged on the shoulder of the battery cell, and the heat-conducting section is attached to the second heat dissipation surface.

[0011] In some embodiments, the battery module has a plurality of battery cell rows arranged along a third direction, the shoulders of the battery cells of two adjacent battery cell rows are provided with the same first phase change material piece, each of the heat conductive segments of the bus is attached to the second heat dissipation surface, and the third direction is perpendicular to either the first direction or the second direction.

[0012] In some embodiments, a convex portion is provided on a side of the second heat dissipation surface away from the battery cell, the convex portion is located in an area near the middle of the second heat dissipation surface, a first overlap area and a second overlap area are formed on both sides of the convex portion, and there are multiple busbars, and the multiple busbars are arranged one-to-one on the poles of multiple rows of battery cell rows, and two adjacent rows of the busbars are respectively arranged on the first overlap area and the second overlap area.

[0013] In some embodiments, the battery module assembly also includes a second phase change material piece, which is L-shaped and includes a first side portion and a second side portion connected to each other, the first side portion is attached between the shoulder of the battery cell in the outermost row of the battery cell row and the corresponding bar piece, and the second side portion is arranged on the side of the battery cell in the outermost row of the battery cell row.

[0014] In some embodiments, the overlapping section includes a first conductive body, a stress release portion, and a second conductive body that are sequentially connected along the first direction, the stress release portion having a curved portion that is bent toward the battery cell group, the first conductive body is electrically connected to a pole of one of the battery cells, and the second conductive body is electrically connected to a pole of another battery cell adjacent to the battery cell.

[0015] In some embodiments, the heat conducting section includes a heat dissipation fin portion and a heat conducting portion connected to each other, and the heat dissipation fin portion connects the heat conducting portion and the first conductive body.

[0016] In some embodiments, the battery module assembly further includes a thermally conductive structural adhesive layer, and the first phase change material piece is bonded to the battery core via the thermally conductive structural adhesive layer.

[0017] In some embodiments, the first phase change material piece includes a heat dissipation shell and a phase change material filled in the heat dissipation shell, and the heat dissipation shell is an insulating shell.

[0018] In some embodiments, the battery module assembly further includes a collection sheet connected to the bar sheet and the first phase change material piece.

[0019] The battery pack of the embodiment of the utility model may include a shell and a battery module assembly according to any one of the above, wherein the battery module assembly is arranged in the shell.

[0020] Therefore, the battery pack of the embodiment of the utility model has the advantages of improving the heat dissipation capacity at the pole, the fast charging capability of the battery module and the safety of use.

[0021] The vehicle according to the embodiment of the present invention may include a battery pack according to any one of the above.

[0022] Therefore, the vehicle of the embodiment of the utility model has the advantages of improving the heat dissipation capacity at the pole, the fast charging capability of the battery module and the safety of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional diagram of a battery module assembly according to an embodiment of the present utility model.

[0024] Figure 2 It is an exploded view of the battery module assembly of the embodiment of the present utility model.

[0025] Figure 3 It is a top view of the battery module assembly of an embodiment of the utility model.

[0026] Figure 4 It is a three-dimensional diagram of the bus bar, the first phase change material piece and the second phase change material piece in the embodiment of the utility model.

[0027] Figure 5 yes Figure 4 A partial view of the .

[0028] Figure 6 It is a side view of a battery module assembly according to an embodiment of the present utility model.

[0029] Figure 7 yes Figure 6 A partial view of one embodiment at A.

[0030] Figure 8 yes Figure 6 A partial view of another embodiment.

[0031] Fig. 9 yes Figure 6 Partial view at B.

[0032] Reference numerals:

[0033] Battery module assembly 100;

[0034] Battery module 1; battery cell 11; pole 111; shoulder 112, first shoulder 112a, second shoulder 112b;

[0035] Bar 2; lap section 21; first conductive body 211; stress release portion 212; second conductive body 213;

[0036] Heat conducting section 22; heat dissipating fin portion 221; heat conducting portion 222;

[0037] First phase change material member 3; first heat dissipation surface 31; second heat dissipation surface 32; convex portion 321; first overlapping area 322; second overlapping area 323;

[0038] A second phase change material member 4, a first side portion 41, and a second side portion 42;

[0039] Collection piece 5. DETAILED DESCRIPTION

[0040] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

[0041] Reference below Figure 1-Figure 9 A battery module assembly 100, a battery pack and a vehicle according to an embodiment of the present invention are described.

[0042] The battery module assembly 100 of the embodiment of the present invention includes a battery module 1 , a bar sheet 2 and a first phase change material piece 3 .

[0043] The battery module 1 includes a first direction (eg, Figure 1 A plurality of battery cells 11 are arranged in the front-to-back direction (as shown in the figure) to form a battery cell row; there are a plurality of bar sheets 2, each of which is connected to the poles 111 of two adjacent battery cells 11 to form a bus, and the first phase change material piece 3 is connected to the bus.

[0044] The battery module assembly 100 of the embodiment of the utility model is connected to the bus through the first phase change material component 3, and the heat generated on the pole 111 can be directly dissipated through the first phase change material component 3 in a timely and rapid manner, thereby improving the overall cooling capacity of the battery module 1 by the first phase change material component 3, preventing heat from accumulating near the pole 111 and causing the battery cell 11 to have a risk of thermal runaway due to local excessive temperature. The reduction in temperature near the pole 111 is conducive to achieving battery fast charging and the safety of the charging and discharging process.

[0045] In addition, the first phase change material part 3 as a cooling part does not need to be provided with connectors and pipes relative to the liquid cooling plate, and has the advantage of high installation convenience. The first phase change material part 3 provided at the same time can not only absorb the heat of the bus, but also continuously transfer the absorbed heat to the battery cell 11 when the temperature of the battery cell 11 decreases. At the same time, when the battery cell 11 has thermal runaway, the first phase change material part 3 can quickly absorb a large amount of heat, so that the temperature of the surrounding battery cells 11 will not rise rapidly and cause heat spread.

[0046] Therefore, the battery module assembly 100 of the embodiment of the utility model has the advantages of improving the heat dissipation capacity at the pole 111, the fast charging capability of the battery module 1 and the safety of use.

[0047] Specifically, the first phase change material part 3 includes a first heat dissipation shell and a phase change material filled in the first heat dissipation shell. When the battery is charged and discharged at high power, a large current passes through the bus and quickly generates heat. When the temperature is higher than the set temperature of the phase change material, the phase change material begins to absorb the heat of the bus to prevent the bus temperature from being too high; when the temperature of the battery cell 11 is lower than the set temperature of the phase change material, the phase change material can continuously output the absorbed heat to the battery cell 11 for heating the battery cell 11. And when the battery cell 11 has thermal runaway, the first phase change material part 3 will quickly absorb a large amount of heat, which is conducive to controlling the temperature of the surrounding battery cells 11 from rising rapidly and causing the problem of thermal runaway spreading. Therefore, it also has the effect of preventing thermal runaway.

[0048] like Figure 1 and Figure 5 As shown, the bar 2 includes a connected overlap section 21 and a heat conducting section 22, the overlap section 21 overlaps two poles 111 of two adjacent battery cells 11, and the first phase change material piece 3 is in the second direction (for example, Figure 1 The first heat dissipation surface 31 and the second heat dissipation surface 32 are arranged opposite to each other in the up and down direction shown in the figure. The second direction is perpendicular to the first direction. The first heat dissipation surface 31 is arranged on the shoulder 112 of the battery core 11, and the heat conductive section 22 is attached to the second heat dissipation surface 32.

[0049] The battery module assembly 100 of the embodiment of the utility model is configured by setting both surfaces (the first heat dissipation surface 31 and the second heat dissipation surface 32) of the first phase change material member 3 as heat dissipation surfaces, and setting the first heat dissipation surface 31 on the shoulder 112 of the battery cell 11, and the bar 2 is attached to the second heat dissipation surface 32. Therefore, not only can the shoulder 112 of the battery cell 11 be dissipated by the first phase change material member 3, but also most of the heat generated on the pole 111 can be transferred to the first phase change material member 3 through the bar 2, and the heat at the shoulder 112 and the pole 111 of the battery cell 11 group can be dissipated in time by relying on the first phase change material member 3, which not only helps to reduce or even eliminate the temperature difference at the shoulder 112 and the pole 111 of the battery cell 11 (the bar 2 has the function of even heat distribution), but also improves the overall cooling capacity of the first phase change material member 3 on the battery cell 11. This is conducive to improving the life of the battery cell 11 and the safety of use.

[0050] Optionally, each battery cell 11 of the battery module 1 has a shoulder 112. When the positive electrode column and the negative electrode column of the battery cell 11 are both arranged on the top surface of the battery cell 11, and the positive electrode column and the negative electrode column are arranged near the middle of the battery cell 11, the shoulder 112 can be formed in the length direction of the battery cell 11 (for example, Figure 1 on both sides of the left and right direction shown in FIG.

[0051] like Figures 1 to 4 As shown, the battery module 1 has a third direction (eg, Figure 1 A plurality of battery cell rows are arranged in the left and right directions (as shown in the figure), the shoulders 112 of the battery cells 11 of two adjacent battery cell rows are provided with the same first phase change material piece 3, each heat conductive segment 22 of the bus bar is attached to the second heat dissipation surface 32, and the third direction is arranged perpendicular to each of the first direction and the second direction.

[0052] The battery module assembly 100 of the embodiment of the present invention can reduce the number of first phase change material members 3 by setting the same first phase change material member 3 on the shoulders 112 of two adjacent battery cell rows, thereby reducing the difficulty of assembling the battery module assembly 100.

[0053] Specifically, see Figure 7 and Figure 8 In one embodiment, one battery cell 11 has a first shoulder 112a, and the battery cell 11 adjacent to the battery cell 11 has a second shoulder 112b. The first shoulder 112a and the second shoulder 112b are arranged adjacent to each other, and the same first phase change material piece 3 is placed on the shoulders 112 on adjacent sides of two adjacent battery cell rows. In other words, the same first phase change material piece 3 is arranged on the adjacent first shoulders 112a and the second shoulder 112b.

[0054] like Figures 1 to 4 and Figure 8 As shown, the second heat dissipation surface 32 is away from the side of the battery cell 11 (for example, Figure 1 A convex portion 321 is provided on the upper side (shown in the figure), the convex portion 321 is located in the area near the middle of the second heat dissipation surface 32, a first overlapping area 322 and a second overlapping area 323 are formed on both sides of the convex portion 321, there are a plurality of busbars, and two adjacent rows of busbars are respectively arranged on the first overlapping area 322 and the second overlapping area 323. Specifically, a portion of one of the busbars is arranged on the first overlapping area 322, and a portion of the other busbar is arranged on the second overlapping area 323.

[0055] The battery module assembly 100 of the embodiment of the utility model has a convex portion 321 protruding from the second heat dissipation surface 32 relative to the rest of the first heat dissipation surface 31. The convex portion 321 can provide a certain degree of electrical insulation between adjacent bus bars, thereby providing more effective electrical insulation protection. In addition, the structural setting of the convex portion 321 can also improve the overall rigidity of the first phase change material member 3, and has the advantage of good structural stability.

[0056] like Figure 6 and Fig. 9 As shown, the battery module assembly 100 of the embodiment of the utility model also includes a second phase change material piece 4, which is L-shaped and includes a first side portion 41 and a second side portion 42 connected to each other, the first side portion 41 is attached between the shoulder 112 of the battery cell 11 of the outermost row of battery cells and the corresponding bar piece 2, and the second side portion 42 is arranged on the side of the battery cell 11 of the outermost row of battery cells.

[0057] The battery module assembly 100 of the utility model embodiment, by providing an L-shaped second phase change material component 4, can not only dissipate the heat of the battery cells 1 in the outermost row of battery cells through the second phase change material component 4, but also dissipate the heat at the pole 111 in time through the bar 2 on the corresponding battery cell 1, thereby reducing or even eliminating the temperature difference between the shoulder 112 of the battery cell 11 in the outermost row of battery cells and the pole 111, thereby improving the cooling effect on the battery module 1, and the L-shaped second phase change material component 4 has a larger contact area with the battery cell 11, thereby further improving the cooling effect on the battery module 1, and further improving the life of the battery cell 11 and the safety of use.

[0058] like Figures 5 to 7 As shown, the overlapping section 21 includes a first conductive body 211, a stress release portion 212 and a second conductive body 213 which are sequentially connected along a first direction, the stress release portion 212 has a curved portion bent toward a group of battery cells 11, the first conductive body 211 is electrically connected to a pole 111 of one of the battery cells 11, and the second conductive body 213 is electrically connected to a pole 111 of another battery cell 11 adjacent to the battery cell 11.

[0059] The battery module assembly 100 of the embodiment of the utility model divides the overlapping portion into a first conductive body 211, a stress release portion 212, and a second conductive body 213 which are sequentially connected and arranged along a first direction. The stress release portion 212 can improve the applicability of the battery cell 11 model through deformation. At the same time, the stress release portion 212 can also increase the surface area of ​​the overlapping portion, thereby further improving the heat dissipation effect of the battery module assembly 100. In addition, the stress release portion 212 can absorb the assembly tolerance, so that the busbar will not be broken due to excessive internal stress.

[0060] Optionally, the plurality of bar pieces 2 in the busbar may be copper alloy bar pieces 2 or aluminum alloy bar pieces 2. Furthermore, the bar pieces 2 may be formed by stamping, machining or casting.

[0061] like Figures 5 to 7 As shown, the heat conducting section 22 includes a heat dissipation fin portion 221 and a heat conducting portion 222 which are connected to each other. The heat dissipation fin portion 221 connects the heat conducting portion 222 and the first conductive body 211 .

[0062] The battery module assembly 100 of the embodiment of the utility model divides the heat-conducting section 22 into a connected heat-dissipating fin section 221 and a heat-conducting section 222. Thus, the heat-dissipating fin section 221 can improve the heat-dissipating effect of the heat-conducting section 22.

[0063] The battery module assembly 100 of the embodiment of the utility model further includes a heat-conducting structural adhesive layer (not shown), and the first phase change material piece 3 is bonded to the battery core 11 via the heat-conducting structural adhesive layer.

[0064] Furthermore, the second phase change material member 4 is bonded to the battery core 11 and the bar sheet 2 respectively through a thermally conductive structural adhesive layer.

[0065] In the battery module assembly 100 of the embodiment of the utility model, the first phase change material part 3 is bonded to the battery cell 11 by means of a heat conductive structural adhesive layer, and the second phase change material part 4 is bonded to the battery cell 11 and the bar sheet 2 respectively by means of a heat conductive structural adhesive layer, which not only has the advantages of good structural stability and high processing convenience, but also further improves the heat conduction effect of the bonding point. Therefore, the battery module assembly 100 not only improves the heat dissipation effect, but also improves the structural stability and processing convenience of the battery module assembly 100.

[0066] The first phase change material component 3 includes a first heat dissipation shell and a phase change material filled in the first heat dissipation shell, and the first heat dissipation shell is an insulating shell. The second phase change material component 4 includes a second heat dissipation shell and a phase change material filled in the second heat dissipation shell, and the second heat dissipation shell is an insulating shell. Therefore, the insulating shell provided can isolate the electrical exchange between different battery cells 11 and heat dissipation fins, thereby improving the safety of the battery module assembly 100. Furthermore, the first phase change material component 3 has a certain structural strength, and can connect different battery cells 11 into a whole to improve the rigidity of the battery module 1; at the same time, fixing adjacent batteries together can avoid the problem of relative displacement of adjacent battery cells 11 caused by thermal expansion of the battery cells 11.

[0067] For example, the first phase change material part 3 includes a first heat dissipation shell and a phase change material filled in the first heat dissipation shell, and the second phase change material part 4 includes a second heat dissipation shell and a phase change material filled in the second heat dissipation shell. Phase change material (PCM) refers to a substance that changes the state of matter and can provide latent heat when the temperature remains unchanged. The process of changing physical properties is called a phase change process. At this time, the phase change material will absorb or release a large amount of heat energy. For example, the set temperature of the phase change material corresponds to the comfortable temperature range of the battery cell 11, such as 15 to 25°C, and the corresponding value needs to be selected according to the characteristics of different battery cells 11. If the phase change temperature is set to 20°C, it will start to absorb heat when the external temperature is greater than 20°C, and it will start to release heat when the external temperature is less than 20°C.

[0068] The battery module assembly 100 of the embodiment of the utility model further includes a collection sheet 5, which is arranged on the bar sheet 2. Thus, voltage and temperature collection can be realized, and real-time monitoring of the temperature of the battery cell 11 can be realized. Therefore, the battery module assembly 100 helps to improve the safety of the battery pack.

[0069] Optionally, the collection sheet 5 may be a temperature collector. Further, there are multiple temperature collectors, and the multiple temperature collectors are connected to the sheets 2 on the multiple battery cells 11 in a one-to-one correspondence.

[0070] The battery pack of the embodiment of the present invention may include a housing and a battery module assembly 100 according to any one of the above items, and the battery module assembly 100 is disposed in the housing.

[0071] The battery pack of the embodiment of the utility model has the advantages of improving the heat dissipation capacity at the pole 111, the fast charging capability of the battery module 1 and the safety of use.

[0072] The vehicle of the embodiment of the utility model includes the battery pack according to the above.

[0073] The vehicle of the embodiment of the utility model has the advantages of improving the heat dissipation capacity at the pole 111, the fast charging capacity of the battery module 1 and the safety of use.

[0074] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0075] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0076] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0078] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0079] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A battery module assembly, characterized in that: include: A battery module, the battery module comprising a plurality of battery cells arranged along a first direction to form a battery cell row; A busbar, wherein the busbar is provided in plurality, and each of the busbars is connected to the poles of two adjacent battery cells to form a busbar; A first phase-change material element is connected to the bus bar.

2. The battery module assembly according to claim 1, characterized in that: The bar includes a connected overlapping section and a heat-conducting section, the overlapping section is overlapped on two poles of two adjacent battery cells in the same battery cell row, the first phase change material piece has a first heat dissipation surface and a second heat dissipation surface arranged opposite to each other in a second direction, the second direction is perpendicular to the first direction, the first heat dissipation surface is arranged on the shoulder of the battery cell, and the heat-conducting section is attached to the second heat dissipation surface.

3. The battery module assembly according to claim 2, characterized in that: The battery module has a plurality of battery cell rows arranged along a third direction, the shoulders of the battery cells of two adjacent battery cell rows are provided with the same first phase change material piece, each of the heat conductive segments of the bus bar is attached to the second heat dissipation surface, and the third direction is perpendicular to either the first direction or the second direction.

4. The battery module assembly according to claim 3, characterized in that: A convex portion is provided on the side of the second heat dissipation surface away from the battery cell, and the convex portion is located in the area near the middle of the second heat dissipation surface. A first overlapping area and a second overlapping area are formed on both sides of the convex portion. There are multiple busbars, and the multiple busbars are arranged one by one on the poles of multiple rows of battery cell rows, and two adjacent rows of the busbars are respectively arranged on the first overlapping area and the second overlapping area.

5. The battery module assembly according to claim 3, characterized in that: It also includes a second phase change material piece, which is L-shaped and includes a first side portion and a second side portion connected to each other, the first side portion is attached between the shoulder of the battery cell in the outermost row of the battery cell row and the corresponding bar piece, and the second side portion is arranged on the side of the battery cell in the outermost row of the battery cell row.

6. The battery module assembly according to claim 2, characterized in that: The overlapping section includes a first conductive body, a stress release portion, and a second conductive body that are sequentially connected along the first direction, the stress release portion having a curved portion bent toward the battery cell group, the first conductive body being electrically connected to a pole of one of the battery cells, and the second conductive body being electrically connected to a pole of another battery cell adjacent to the battery cell.

7. The battery module assembly according to claim 6, characterized in that: The heat-conducting section includes a heat-dissipating fin portion and a heat-conducting portion connected to each other, and the heat-dissipating fin portion connects the heat-conducting portion and the first conductive body.

8. The battery module assembly according to claim 1, characterized in that: It also includes a heat-conducting structural adhesive layer, and the first phase change material piece is bonded to the battery core through the heat-conducting structural adhesive layer; And / or, the first phase change material piece includes a heat dissipation shell and a phase change material filled in the heat dissipation shell, and the heat dissipation shell is an insulating shell; And / or, it also includes a collection sheet, which is connected to the bar sheet and the first phase change material piece.

9. A battery pack, characterized in that: It comprises a shell and a battery module assembly according to any one of claims 1 to 8, wherein the battery module assembly is arranged in the shell.

10. A vehicle, characterized in that: Comprising a battery pack according to claim 9.

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