Vapor chamber and battery pack

Abstract

Disclosed in the present application are a vapor chamber and a battery pack. The vapor chamber comprises a first thermally conductive layer, a second thermally conductive layer and a third thermally conductive layer, wherein the first thermally conductive layer comprises a first surface and a second surface that are opposite each other in a first direction; the second thermally conductive layer comprises a third surface and a fourth surface that are opposite each other in the first direction; the third thermally conductive layer is disposed between the first thermally conductive layer and the second thermally conductive layer in the first direction; and the third thermally conductive layer comprises a fifth surface, a sixth surface, a seventh surface, and an eighth surface that are connected sequentially, the fifth surface abutting against the second surface, and the seventh surface abutting against the fourth surface.

Description

A heat spreader and battery pack

[0001] This application claims priority to Chinese Patent Application No. 202422572590.7, filed with the Chinese Patent Office on October 23, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the technical field of batteries, and in particular to a heat spreader and battery pack. Background Technology

[0003] Currently, commercially available vapor chambers employ internal vacuum microcavity structures designed along either the length or thickness direction. Vapor chambers designed for length-direction heat transfer exhibit excellent thermal conductivity in that direction, but poor conductivity in the thickness direction. Vapor chambers designed for thickness-direction heat transfer, on the other hand, offer excellent thermal conductivity in that direction but poor conductivity along the length. This type of vapor chamber structure can improve heat dissipation in a specific direction, achieving in-plane heat dissipation and thus improving the heat dissipation and heat dissipation of electronic devices. Technical issues

[0004] However, in certain applications, such as within square lithium-ion battery packs, even if the heat dissipation effect is poor in the direction perpendicular to the large surface of the square lithium-ion battery, it will still limit the heat dissipation effect of the battery cell, provided that the heat dissipation within the large surface of the square lithium-ion battery is ensured. Technical solutions

[0005] In a first aspect, this application provides a heat spreader, including a first heat-conducting layer, a second heat-conducting layer, and a third heat-conducting layer. The first heat-conducting layer includes a first surface and a second surface opposite to each other along a first direction. The second heat-conducting layer includes a third surface and a fourth surface opposite to each other along the first direction. The third heat-conducting layer is disposed between the first heat-conducting layer and the second heat-conducting layer along the first direction. The third heat-conducting layer includes a fifth surface, a sixth surface, a seventh surface, and an eighth surface connected in sequence. The fifth surface abuts against the second surface, and the seventh surface abuts against the fourth surface. When the first surface and the third surface are heated, the heat transfer direction of the first heat-conducting layer is from the first surface toward the second surface and further to the fifth surface. The heat transfer direction of the second heat-conducting layer is from the third surface toward the fourth surface and further to the seventh surface.

[0006] Secondly, this application provides a battery pack, including: a plurality of individual cells and a heat spreader plate of any of the above, wherein the heat spreader plate is disposed between the individual cells along the thickness direction of the individual cells, and the first surface and the third surface are in contact with the individual cells respectively. Beneficial effects

[0007] The beneficial effects provided by this application are: the heat dissipation plate of this application embodiment can absorb heat from both sides of the heat dissipation plate through the first heat-conducting layer and the second heat-conducting layer, and transfer heat from one end to the other end through the third heat-conducting layer. Therefore, good heat dissipation can be achieved along the thickness direction and length direction of the heat dissipation plate, thereby improving the heat dissipation effect of the heat dissipation plate. Attached Figure Description

[0008] Figure 1 is a schematic diagram of the first structure of the heat spreader provided in the embodiment of this application.

[0009] Figure 2 is a schematic diagram of the exploded structure of the heat spreader shown in Figure 1.

[0010] Figure 3 is a schematic diagram of heat transfer in the heat spreader provided in the embodiment of this application.

[0011] Figure 4 is a schematic diagram of the internal structure of the heat spreader provided in the embodiment of this application.

[0012] Figure 5 is a schematic diagram of a second structure of the heat spreader provided in an embodiment of this application.

[0013] In the picture:

[0014] 100 - Heat sink; 200 - Battery cell; 300 - Flexible component; 1000 - Battery module;

[0015] 10 - First thermally conductive layer; 20 - Second thermally conductive layer; 30 - Third thermally conductive layer; 40 - Liquid cooling plate; 50 - Second liquid cooling plate;

[0016] 101 - First surface; 102 - Second surface; 201 - Third surface; 202 - Fourth surface; 301 - Fifth surface; 302 - Sixth surface; 303 - Seventh surface; 304 - Eighth surface;

[0017] 11-First frame; 12-First liquid-absorbing core; 13-Second liquid-absorbing core; 14-First heat-conducting component; 21-Second frame; 22-Third liquid-absorbing core; 23-Fourth liquid-absorbing core; 24-Second heat-conducting component; 31-Third frame; 32-Fifth liquid-absorbing core; 33-Third heat-conducting component.

[0018] Implementation methods of this application

[0019] This application provides a heat spreader. The heat spreader can be applied to energy storage batteries, power batteries, etc., to dissipate heat from the battery, achieving uniform temperature distribution and heat dissipation.

[0020] Referring to Figures 1 to 3, Figure 1 is a schematic diagram of the first structure of the heat spreader 100 provided in the embodiment of this application, Figure 2 is an exploded structural schematic diagram of the heat spreader 100 shown in Figure 1, and Figure 3 is a schematic diagram of heat transfer of the heat spreader 100 provided in the embodiment of this application.

[0021] The heat spreader 100 includes a first heat-conducting layer 10, a second heat-conducting layer 20, and a third heat-conducting layer 30, which are stacked along a first direction. The second heat-conducting layer 20 is disposed opposite to and spaced from the first heat-conducting layer 10. The third heat-conducting layer 30 is disposed between the first heat-conducting layer 10 and the second heat-conducting layer 20.

[0022] The first thermally conductive layer 10 includes a first surface 101 and a second surface 102 that are opposite each other along a first direction. In practical applications, the first surface 101 is the side that absorbs heat, as shown by the dashed arrow on one side of the first thermally conductive layer 10 in Figure 3. The heat transfer direction of the first thermally conductive layer 10 is from the first surface 101 toward the second surface 102.

[0023] The second thermally conductive layer 20 includes a third surface 201 and a fourth surface 202 that are opposite each other along a first direction. The fourth surface 202 is opposite to and spaced apart from the second surface 102. In practical applications, the third surface 201 is the side that absorbs heat, as shown by the dashed arrow on one side of the second thermally conductive layer 20 in Figure 3. The heat transfer direction of the second thermally conductive layer 20 is from the third surface 201 toward the fourth surface 202.

[0024] A third thermally conductive layer 30 is disposed between the first thermally conductive layer 10 and the second thermally conductive layer 20. The third thermally conductive layer 30 includes a fifth surface 301, a sixth surface 302, a seventh surface 303, and an eighth surface 304 connected in sequence. The fifth surface 301 abuts against the second surface 102. The seventh surface 303 abuts against the fourth surface 202.

[0025] In practical applications, heat from the first thermally conductive layer 10 can be transferred to the third thermally conductive layer 30, that is, from the second surface 102 to the fifth surface 301, as shown by the solid arrow in Figure 3. Similarly, heat from the second thermally conductive layer 20 can be transferred to the third thermally conductive layer 30, that is, from the fourth surface 202 to the seventh surface 303, as shown by the solid arrow in Figure 3. When the sixth surface 302 or the eighth surface 304 contacts the liquid cooling plate, heat from the third thermally conductive layer 30 can be transferred from one end to the other.

[0026] The heat spreader 100 of this application embodiment can absorb heat from the first direction through the first heat-conducting layer 10 and the second heat-conducting layer 20, and transfer heat from one end to the other end along the direction perpendicular to the first direction through the third heat-conducting layer 30. Therefore, good heat dissipation can be achieved along the thickness direction and length direction of the heat spreader 100, thereby improving the heat dissipation effect of the heat spreader 100.

[0027] In some embodiments, the heat transfer direction of the first thermally conductive layer 10 is from the center of the first surface 101 toward the periphery of the second surface 102, as shown by the solid arrow in FIG3. The heat transfer direction of the second thermally conductive layer 20 is from the center of the third surface 201 toward the periphery of the fourth surface 202, as shown by the solid arrow in FIG3.

[0028] Referring to Figure 4, which is a schematic diagram of the internal structure of the heat spreader 100 provided in an embodiment of this application, the first heat-conducting layer 10 includes a first frame 11, a first liquid-absorbing core 12, a second liquid-absorbing core 13, and a plurality of first heat-conducting elements 14.

[0029] In practical applications, the interior of the first frame 11 forms a first cavity filled with a heat-conducting liquid, and the first cavity can be in a vacuum state. The material of the first frame 11 can be a metal or alloy with good thermal conductivity, such as copper or aluminum. The first surface 101 and the second surface 102 of the first heat-conducting layer 10 are located on opposite sides of the first frame 11.

[0030] A first absorbent core 12 is disposed within a first frame 11, close to a first surface 101. A second absorbent core 13 is disposed within the first frame 11, close to a second surface 102. The first absorbent core 12 can absorb heat-conducting liquid, thus its interior is entirely filled with heat-conducting liquid. The first absorbent core 12 can be made of foam, sponge, etc. The second absorbent core 13 can absorb heat-conducting liquid, thus its interior is entirely filled with heat-conducting liquid. The second absorbent core 13 can also be made of foam, sponge, etc. The heat-conducting liquid on the first absorbent core 12 absorbs heat and vaporizes, moving to the second absorbent core 13 where it releases heat and liquefies. Multiple first heat-conducting elements 14 are spaced apart between the first absorbent core 12 and the second absorbent core 13. In practical applications, the first heat-conducting elements 14 can be made of metals or alloys with good thermal conductivity, such as copper. The first heat-conducting element 14 has a columnar structure and plays a guiding role in the process of the heat-conducting liquid flowing from the second surface 102 to the first surface 101 after liquefaction.

[0031] Optionally, the first heat-conducting element 14 can be cylindrical or rectangular. Multiple nanopores are formed inside the first heat-conducting element 14 to enhance capillary action and accelerate the movement of the heat-conducting liquid on the first heat-conducting element 14.

[0032] Of course, in another case, the first heat-conducting element 14 is a plate-shaped structure, and the first heat-conducting element 14 spans the first frame 11. In this way, the first heat-conducting element 14 provides stronger support for the first frame. The first heat-conducting element 14 has multiple through holes spaced apart from each other. The heat-conducting liquid flows through the through holes in adjacent first heat-conducting elements 14 to improve the fluidity of the heat-conducting liquid.

[0033] Optionally, the distance between the first surface 101 and the third surface 201 is H1, where 0.4mm ≤ H1 ≤ 5mm, for example, 0.4mm, 1mm, 1.5mm, 2mm, 2.6mm, 3mm, 3.5mm, 4mm, 4.3mm, 4.8mm, 5mm, etc. H1 is the thickness of the heat spreader in the first direction. When the heat spreader is too thin, its compressive strength is insufficient to withstand the pressure generated by the expansion of a single cell. When the heat spreader is too thick, it occupies too much volume of the single cell, affecting the volumetric energy density of the battery pack.

[0034] Optionally, the distance between the first absorbing core 12 and the second absorbing core 13 is H2, and the space between the first absorbing core 12 and the second absorbing core 13 is configured for the flow of vaporized endothermic liquid, with a value of 0.1mm ≤ H2 ≤ 0.2mm, such as 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, etc. When the distance between the first absorbing core 12 and the second absorbing core 13 is too large, it will greatly increase the thermal resistance of the heat spreader and affect the thermal conductivity of the heat spreader; when the distance between the first absorbing core 12 and the second absorbing core 13 is too small, it will greatly reduce the movement distance of the endothermic liquid, which is not conducive to the liquefaction of vaporized endothermic liquid.

[0035] Optionally, the thickness D1 of the first absorbent core 12 is 0.1mm≤D1≤1.5mm, for example, 0.1mm, 0.3mm, 0.5mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, etc. When the first absorbent core 12 is larger than this size, the vaporized heat absorbent liquid is not easy to evaporate, and the liquefied heat absorbent liquid is not easy to flow along the first heat conduction element 14; when the first absorbent core 12 is smaller than this size, the amount of heat absorbent liquid stored in the first absorbent core 12 is insufficient for use. And / or, the thickness D2 of the second absorbent core 13 is 0.1mm≤D2≤1.5mm, for example 0.1mm, 0.3mm, 0.5mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, etc. When the second absorbent core 13 is larger than this size, the vaporized heat absorbent liquid is not easy to evaporate, and the liquefied heat absorbent liquid is not easy to flow along the first heat conduction element 14; when the second absorbent core 13 is smaller than this size, the amount of heat absorbent liquid stored in the second absorbent core 13 is insufficient for use.

[0036] Optionally, the spacing of the first heat-conducting elements 14 is L1, where 0.05mm ≤ L1 ≤ 0.5mm, such as 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc. When the spacing of the first heat-conducting elements 14 is greater than 0.5mm, the strength of the heat spreader is insufficient; when the spacing of the first heat-conducting elements 14 is less than 0.05mm, it is not conducive to the flow of the heat-absorbing liquid between the first heat-conducting elements 14.

[0037] Optionally, the first cavity includes a middle cavity and an edge cavity, which are interconnected. The edge cavity is located on the outer periphery of the middle cavity, and the ratio of the space of the edge cavity to the space of the middle cavity is α, where 1 ≤ α ≤ 2. The spacing of the first heat-conducting elements 14 in the middle cavity is L2, and the spacing of the first heat-conducting elements in the edge cavity is L1, where 1.1 ≤ L2 / L1 ≤ 5, for example, 1.1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc. In this embodiment, the density of the first heat-conducting elements 14 in the middle cavity is greater than that in the edge cavity to locally enhance the compressive strength of the heat spreader in the middle region.

[0038] The second heat-conducting layer 20 includes a second frame 21, a third liquid-absorbing core 22, a fourth liquid-absorbing core 23, and a plurality of second heat-conducting components 24.

[0039] In practical applications, a second cavity filled with a heat-conducting liquid is formed inside the second frame 21. The second cavity can be in a vacuum state, as shown in Figure 4. The material of the second frame 21 can be a metal or alloy with good thermal conductivity, such as copper or aluminum. The third surface 201 and the fourth surface 202 of the second heat-conducting layer 20 are located on opposite sides of the second frame 21.

[0040] The third absorbent core 22 is disposed within the second frame 21, near the third surface 201. The fourth absorbent core 23 is disposed within the second frame 21, near the fourth surface 202. The third absorbent core 22 is filled with a heat-conducting liquid to absorb it; the third absorbent core 22 can be made of foam, sponge, etc. The fourth absorbent core 23 is also filled with a heat-conducting liquid to absorb it; the fourth absorbent core 23 can be made of foam, sponge, etc. The heat-conducting liquid on the third absorbent core 22 absorbs heat and vaporizes, moving to the fourth absorbent core 23 where it releases heat and liquefies. Multiple second heat-conducting elements 24 are spaced apart between the third and fourth absorbent cores 22 and 23. In practical applications, the second heat-conducting elements 24 can be made of metals or alloys with good thermal conductivity, such as copper. The second heat-conducting elements 24 have a columnar structure and act as guides during the flow of the liquefied heat-conducting liquid from the third surface 201 to the fourth surface 202.

[0041] Optionally, the second heat-conducting element 24 can be cylindrical or rectangular. Multiple nanopores are formed inside the second heat-conducting element 24 to enhance capillary action and accelerate the movement of the heat-conducting fluid on the second heat-conducting element 24.

[0042] Of course, in another case, the second heat-conducting element 24 is a plate-shaped structure, and the second heat-conducting element 24 spans the second frame 21. In this way, the second heat-conducting element 24 provides stronger support for the second frame 21. The second heat-conducting element 24 has multiple through holes spaced apart from each other, and the heat-conducting liquid flows through the through holes in adjacent second heat-conducting elements 24 to improve the fluidity of the heat-conducting liquid.

[0043] Optionally, the distance between the third wick 22 and the fourth wick 23 is H2, and the space between the third wick 22 and the fourth wick 23 is configured for the flow of vaporized endothermic liquid, with a value of 0.1mm ≤ H3 ≤ 0.2mm, such as 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, etc. When the distance between the third wick 22 and the fourth wick 23 is too large, it will greatly increase the thermal resistance of the heat spreader and affect the thermal conductivity of the heat spreader; when the distance between the third wick 22 and the fourth wick 23 is too small, it will greatly reduce the movement distance of the endothermic liquid, which is not conducive to the liquefaction of vaporized endothermic liquid.

[0044] Optionally, the thickness D3 of the third absorbent core 22 is 0.1mm≤D3≤1.5mm, such as 0.1mm, 0.3mm, 0.5mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, etc. When the third absorbent core 22 is larger than this size, the vaporized heat absorbent is not easy to evaporate, and the liquefied heat absorbent is not easy to flow along the second heat conductor 24; when the third absorbent core 22 is smaller than this size, the amount of heat absorbent stored in the third absorbent core 22 is insufficient for use. And / or, the thickness D4 of the fourth absorbent core 23 is 0.1mm≤D4≤1.5mm, for example 0.1mm, 0.3mm, 0.5mm, 0.7mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, etc. When the fourth absorbent core 23 is larger than this size, the vaporized heat absorbent liquid is not easy to evaporate, and the liquefied heat absorbent liquid is not easy to flow along the second heat conductor 24; when the fourth absorbent core 23 is smaller than this size, the amount of heat absorbent liquid stored in the fourth absorbent core 23 is insufficient for use.

[0045] Optionally, the spacing of the second heat-conducting elements 24 is L3, where 0.05mm ≤ L3 ≤ 0.5mm, such as 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc. When the spacing of the second heat-conducting elements 24 is greater than 0.5mm, the strength of the heat spreader is insufficient; when the spacing of the second heat-conducting elements 24 is less than 0.05mm, it is not conducive to the flow of the heat-absorbing liquid between the second heat-conducting elements 24.

[0046] Optionally, the second cavity includes a second intermediate cavity and a second edge cavity, which are interconnected. The second edge cavity is located on the outer periphery of the second intermediate cavity, and the ratio of the space of the second edge cavity to the space of the second intermediate cavity is α, where 1 ≤ α ≤ 2. The spacing of the second heat-conducting elements 24 in the second intermediate cavity is L2, and the spacing of the second heat-conducting elements 24 in the edge cavity is L1, where 1.1 ≤ L2 / L1 ≤ 5, for example, 1.1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc. In this embodiment, the density of the second heat-conducting elements 24 in the intermediate cavity is greater than that in the edge cavity to locally enhance the compressive strength of the heat spreader in the middle region.

[0047] In some embodiments, the third thermally conductive layer 30 includes a third frame 31, a fifth liquid-absorbing core 32, and a plurality of third thermally conductive elements 33.

[0048] In practical applications, a third cavity filled with a heat-conducting liquid is formed inside the third frame 31. The third cavity can be in a vacuum state, as shown in Figure 4. The material of the third frame 31 can be a metal or alloy with good thermal conductivity, such as copper or aluminum. Among them, the fifth surface 301, the sixth surface 302, the seventh surface 303, and the eighth surface 304 of the third heat-conducting layer 30 are located in the third frame 31.

[0049] The fifth absorbent core 32 is disposed within the third frame 31. The fifth absorbent core 32 is filled with a thermally conductive liquid. The third thermally conductive element 33 has multiple nanopores formed inside. In practical applications, the third thermally conductive element 33 can be made of metals or alloys with good thermal conductivity, such as copper.

[0050] In this configuration, the fifth absorbent core 32 is located near the fifth surface 301, i.e., near the first thermally conductive layer 10; multiple third thermally conductive elements 33 are spaced apart on the side of the fifth absorbent core 32 away from the fifth surface 301, i.e., on the side of the fifth absorbent core 32 facing the second thermally conductive layer 20. Alternatively, the fifth absorbent core 32 is located near the seventh surface 303, i.e., near the second thermally conductive layer 20; multiple third thermally conductive elements 33 are spaced apart on the side of the fifth absorbent core 32 away from the seventh surface 303, i.e., on the side of the fifth absorbent core 32 facing the first thermally conductive layer 10, as shown in Figure 4.

[0051] This application also protects a battery pack, which includes: a plurality of individual cells and a heat spreader as described in any of the above embodiments. The heat spreader is disposed between the individual cells along the thickness direction of the individual cells, that is, between the largest sides of the individual cells. The first surface 101 and the third surface 201 are in contact with the individual cells to absorb heat from the individual cells.

[0052] In some embodiments, referring to FIG5, FIG5 is a schematic diagram of a second structure of the heat spreader 100 provided in the embodiments of this application.

[0053] The heat spreader 100 also includes a liquid cooling plate 40. The liquid cooling plate 40 is disposed on at least one of the sixth surface 302 and the eighth surface 304 of the third heat-conducting layer 30. The liquid cooling plate 40 in Figure 5 abuts against the eighth surface 304. Heat from the eighth surface 304 is transferred to the liquid cooling plate 40. The liquid cooling plate 40 can dissipate heat through its internal liquid. Therefore, by setting the liquid cooling plate 40 to abut against the eighth surface 304, heat from the third heat-conducting layer 30 can be quickly removed by the liquid cooling plate 40, improving the overall heat dissipation effect of the heat spreader 100.

Claims

1. An equalizing plate, comprising: a first heat-conductive layer comprising a first surface and a second surface opposite to each other along a first direction; a second heat-conductive layer comprising a third surface and a fourth surface opposite to each other along the first direction; a third heat-conductive layer arranged between the first heat-conductive layer and the second heat-conductive layer along the first direction, the third heat-conductive layer comprising a fifth surface, a sixth surface, a seventh surface and an eighth surface connected in sequence, the fifth surface abutting against the second surface, and the seventh surface abutting against the fourth surface; wherein, when the first surface and the third surface are heated, a heat transfer direction of the first heat-conductive layer is from the first surface to the second surface and further to the fifth surface, and a heat transfer direction of the second heat-conductive layer is from the third surface to the fourth surface and further to the seventh surface.

2. The vapor chamber of claim 1, wherein, the first heat-conductive layer comprises: a first frame, the first surface and the second surface being located on opposite sides of the first frame, and a first cavity filled with a heat-conductive liquid being formed inside the first frame; a first liquid-absorbing core arranged in the first frame and close to the first surface; a second liquid-absorbing core arranged in the first frame and close to the second surface; a plurality of first heat-conductive members arranged between the first liquid-absorbing core and the second liquid-absorbing core.

3. The vapor chamber of claim 2, wherein, The material of the first frame is copper or aluminum.

4. The vapor chamber of claim 2, wherein, The first liquid-absorbing core is foam or sponge, and the second liquid-absorbing core is foam or sponge.

5. The wick plate of claim 2, wherein The first heat-conductive member is in a columnar structure and provided with nanopores, or the first heat-conductive member is in a plate structure and spans the first frame, and a plurality of through holes are formed in the first heat-conductive member.

6. The vapor chamber of claim 5, wherein, The first heat-conductive member is in a cylindrical or square columnar structure.

7. The wick plate of claim 2, wherein The distance between the first surface and the third surface is H1, and 0.4mm≤H1≤5mm.

8. The wick plate of claim 2, wherein The distance between the first liquid-absorbing core and the second liquid-absorbing core is H2, and 0.1mm≤H2≤0.2mm.

9. The wick plate of claim 2, wherein The thickness of the first liquid-absorbing core is D1, and 0.1mm≤D1≤1.5mm; and / or, The thickness of the second liquid-absorbing core is D2, and 0.1mm≤D2≤1.5mm.

10. The wick plate of claim 2, wherein The distance between the first heat-conductive members is L1, and 0.05mm≤L1≤0.5mm.

11. The wick plate of claim 10, wherein The first cavity comprises an intermediate cavity and an edge cavity, the edge cavity being located on the outer periphery of the intermediate cavity, the ratio of the space of the edge cavity to the space of the intermediate cavity being α, and 1≤α≤2, the distance between the first heat-conductive members located in the intermediate cavity being L2, the distance between the first heat-conductive members located in the edge cavity being L1, and 1.1≤L2 / L1≤5.

12. The vapor chamber of any one of claims 1-11, wherein, the second heat-conductive layer comprises: a second frame, the third surface and the fourth surface being located on opposite sides of the second frame, and a second cavity filled with a heat-conductive liquid being formed inside the second frame; a third liquid-absorbing core arranged in the second frame and close to the third surface; a fourth liquid-absorbing core arranged in the second frame and close to the fourth surface; A plurality of second heat-conducting members are arranged at intervals between the third wick and the fourth wick.

13. The wick plate of claim 12, wherein, The second cavity is in a vacuum state.

14. The wick plate of claim 12, wherein, The material of the second frame is copper or aluminum.

15. The wick plate of claim 12, wherein, The third wick is a foam or a sponge, and the fourth wick is a foam or a sponge.

16. The wick plate of claim 12, wherein, The second heat-conducting member is in a cylindrical or square column shape.

17. The vapor chamber of any one of claims 1-11, wherein, The third heat-conducting layer comprises: A third frame, wherein the fifth surface, the sixth surface, the seventh surface, and the eighth surface are located in the third frame; A fifth wick arranged in the third frame and close to the fifth surface or the seventh surface; A plurality of third heat-conducting members arranged at intervals on the fifth wick; The fifth wick is close to the fifth surface, and the plurality of third heat-conducting members are arranged at intervals on a side of the fifth wick away from the fifth surface; or the fifth wick is close to the seventh surface, and the plurality of third heat-conducting members are arranged at intervals on a side of the fifth wick away from the seventh surface.

18. The wick plate of claim 17, wherein, The third cavity is in a vacuum state, and the material of the third frame is copper or aluminum.

19. A battery pack comprising: A plurality of single batteries and the heat spreading plate according to any one of claims 1 to 18, wherein the heat spreading plate is arranged between the single batteries along the thickness direction of the single batteries, and the first surface and the third surface are in contact with the single batteries, respectively.

20. The battery pack of claim 19, wherein, The heat spreading plate further comprises a liquid cooling plate in contact with at least one of the sixth surface and the eighth surface.

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