Heat sink and battery

Abstract

The present invention relates to a heat sink and a battery, wherein the heat sink comprises a sealing shell, a plurality of directional transmission blocks and a working medium; the sealing shell is a hollow shell plate, an inner cavity is formed inside the shell plate, and one side of the shell plate is a bottom plate; the directional transmission blocks are located in the inner cavity, and the array is arranged on the bottom plate and forms a gap, the working medium is filled in the gap formed by the directional transmission block array, and the volume value of the working medium is 80 to 120% of the volume value of the gap of the directional transmission block array; the directional transmission block has a special shape. The present invention improves the capillary force of the heat sink in the axial direction through the directional transmission blocks of special shapes, which can meet the heat dissipation requirements of blade batteries.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and in particular to a heat sink and a battery. Background Art

[0002] In recent years, new energy vehicles have had a huge impact on the traditional automotive industry with their advantages such as lower energy costs and intelligent driving. One of the most serious problems facing new energy vehicles at present is the rapid attenuation of driving range and the slow charging speed, and high-energy-density batteries are the key to solving this problem. The blade battery based on lithium iron phosphate technology not only achieves a high energy density comparable to that of ternary lithium batteries, but also improves the reliability and safety of the battery. The blade battery's tabs are distributed on both sides of the long end of the battery. During the charging and discharging process, the blade battery is limited by its narrow and long structure. The heat generated by the blade battery is concentrated near the tabs at both ends, resulting in an unbalanced temperature state of "high at both ends and low in the middle". When heat cannot be effectively extracted in a timely manner, the temperature difference between the two ends and the middle of the battery is too large, and the electrochemical reaction rate in the high-temperature area is greater than that in the low-temperature area, resulting in an unbalanced capacity in different areas of the battery, which not only reduces the total capacity of the battery, but also damages the battery's cycle life.

[0003] Existing batteries achieve heat dissipation by wrapping the battery with a heat sink such as a heat spreader. The heat spreader is a non-solid structure. A hollow pipe is opened inside the heat spreader along the battery axis (length direction). A wick is arranged on the inner tube wall of the hollow pipe. The wick has multiple pore structures. The working fluid is filled in the pore structure of the wick and moves under the action of capillary action. Its working principle is as follows: the internal working fluid evaporates in the high temperature zone (near the pole ear) and takes away a large amount of heat. Driven by the pressure difference, the steam diffuses toward the low temperature zone. The steam condenses into liquid in the low temperature zone (middle of the battery) and releases latent heat. At this time, the heat is absorbed by the battery casing, causing the temperature in the middle of the battery to rise, thereby reducing the temperature difference between the two ends and the middle of the battery. In addition, the condensed working fluid accumulated in the low temperature zone moves to the high temperature zone through the capillary action of the wick to replenish the burned area, and the cycle repeats like this. In order to ensure the stability of the working fluid movement, the inner cavity of the hollow tube of the heat spreader is generally at 10 -1 In a negative pressure environment of pa or below.

[0004] The heat dissipation effect of the heat sink mainly depends on the performance of the liquid wick. However, the capillary force of the liquid wick in the prior art is not strong enough, and it is not enough to adapt to the narrow and long structure of the blade battery in the axial direction (length direction). The liquid drawn back by the capillary force of the liquid wick in the prior art cannot meet the amount required for evaporation, which easily leads to the drying of the liquid wick in the high-temperature area, and the temperature of the tube wall in the high-temperature area rises sharply, resulting in the problem of "high temperature at both ends and low temperature in the middle" of the battery, and even the problem of burning the tube wall. In this regard, a heat sink that can improve the axial heat transfer capacity is needed. Summary of the invention

[0005] Based on this, the purpose of the present invention is to overcome the defects or shortcomings of the prior art and provide a heat sink and a battery that can improve the axial heat transfer capacity.

[0006] The heat sink comprises a sealing shell, a plurality of directional transmission blocks and a working medium; the sealing shell is a hollow shell plate, an inner cavity is formed inside the shell plate, and one side of the shell plate is a bottom plate; the directional transmission blocks are located in the inner cavity, and the array is arranged on the bottom plate to form a gap, and the working medium is filled in the gap formed by the directional transmission block array, and the volume value of the working medium is 80-120% of the volume value of the gap of the directional transmission block array;

[0007] The directional transmission block includes a bottom surface, a first guide surface, a second guide surface, a top surface, a first connection surface, a second connection surface, a first side surface, and a second side surface; the bottom surface is parallel to the bottom plate, the bottom surface is adjacent to the first guide surface and the second guide surface, respectively, and the first guide surface and the second guide surface are arranged oppositely; the top surface is parallel to the bottom surface; the first guide surface is adjacently connected to the top surface through the first connection surface; the second guide surface is adjacently connected to the top surface through the second connection surface, and the first side surface and the second side surface are arranged oppositely, and are adjacently connected to the bottom surface respectively;

[0008] The angle between the bottom surface and the first guide surface is α 1 , the angle between the bottom surface and the second guide surface is α 2 , α 2 >α 1 ; The height of the top edge of the first guide surface from the bottom surface is x 1 , the height of the top surface from the bottom surface is x 2 , x 2 >x 1 or x 2 <x 1 ;

[0009] Furthermore, the first guide surface and the second guide surface are curved surfaces protruding outward; and the first side surface and the second side surface are parallel to each other.

[0010] Furthermore, the second guide surface extends from the bottom along α 2 Extend outward in the direction of x 1 When the height is α, the second connecting surface is connected to the top surface and the second connecting surface faces away from α 2 extends in the direction of.

[0011] Furthermore, it also includes a first liquid absorption layer, which is arranged on the bottom plate, and the directional transmission block array is arranged on the first liquid absorption layer. The first liquid absorption layer has a plurality of pore structures, and the working medium is filled in the pore structure of the first liquid absorption layer. The volume of the working medium is 80 to 120% of the volume value of the pore structure of the first liquid absorption layer.

[0012] Furthermore, it also includes a plurality of directional connecting belts, which are connected between two directional transmission blocks in the same row. The working fluid is stored in the gap formed by the directional transmission block and the directional connecting belt array, and the volume value of the working fluid is 80 to 120% of the total volume value of the gap formed by the directional transmission block and the directional connecting belt array and the pore structure of the first liquid absorption layer.

[0013] Furthermore, the directional transport block is provided with a pore structure that provides storage space for liquid working medium; the first liquid absorption layer, the directional transport block, and the directional connecting belt have micro-nano pore structures on their surfaces.

[0014] Furthermore, α 1 , α 2 The size is in the range of 30 to 70°.

[0015] Furthermore, the first liquid-absorbing layer is one or more of a wire mesh layer, a fiber sintered layer, a powder sintered layer, and a foam layer; the oriented connecting tape is one or more of a powder or fiber, and a woven tape; the material of the first liquid-absorbing layer and the oriented connecting tape is one or more of copper, aluminum and its alloys, stainless steel, and PI.

[0016] Furthermore, a battery is provided, comprising the heat sink, battery cells, insulating end covers and pole ears; the heat sink forms a rectangular structure with openings at both ends, and the battery cells are wrapped in the rectangular structure; the insulating end covers are arranged at the openings at both ends of the rectangular structure to form a battery shell structure with the heat sink, and the pole ears are respectively led out from the positive and negative electrodes at both ends of the battery cells; the directional transmission blocks are arranged in at least one row of arrays along the axial direction of the battery, and the first guide surface of each directional transmission block faces the end of a closer pole ear.

[0017] Furthermore, the heat sink includes n sub-heat sinks, and the sub-heat sinks are arranged along the axial direction of the battery, where n≥2.

[0018] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A top view and a cross-sectional view of the blade battery of the present invention;

[0020] Figure 2 The present invention corresponds to Figure 1 An enlarged schematic diagram of the heat spreader structure in the cross-sectional direction of the BB;

[0021] Figure 3 for Figure 2 An enlarged schematic diagram of the heat sink structure corresponding to the CC section direction;

[0022] Figure 4 It is a structural schematic diagram of a directional transmission block of the present invention;

[0023] Figure 5 Schematic diagram of a heat spreader structure formed by multiple heat spreader sub-plates arranged along the axial direction.

[0024] Description of the drawings: blade battery 100, battery cell 1, insulating end cap 2, insulating film 3, pole ear 4, heat spreader 200, sealing shell 210, bottom plate 211, first liquid absorption layer 220, second liquid absorption layer 230, support column 240, directional transmission block 21, bottom surface 22, first guide surface 23, second guide surface 24, top surface 25, first connecting surface 26, second connecting surface 27, first side surface 28, directional connecting belt 31. DETAILED DESCRIPTION

[0025] Example 1

[0026] The heat sink capable of improving axial heat transfer capacity of the present invention can be applied to batteries such as blade batteries, soft-pack batteries and square batteries; the heat sink can be a heat spreader, a heat pipe or a liquid cooling plate. The following takes the application of a heat spreader in a blade battery as an example to introduce the heat sink capable of improving axial heat transfer capacity of the present invention. Figure 1 , which are a top view and a cross-sectional view of the blade battery 100 of the present invention, in which a heat sink capable of improving axial heat transfer capability is provided.

[0027] The blade battery 100 includes a heat spreader 200, a battery cell 1, an insulating end cap 2, an insulating film 3 and a tab 4. The heat spreader 200 is surrounded by a rectangular structure with openings at both ends, and the battery cell 1 is wrapped in the rectangular structure. The insulating end cap 2 is provided at the openings at both ends of the rectangular structure to form an integrated battery shell structure with the heat dissipation structure and the shell integrated with the heat spreader 200, and the insulating film 3 is wrapped and covered on the surface of the integrated battery shell; the tab 4 is respectively led out from the positive and negative electrodes at both ends of the battery cell 1, passes through the insulating end cap 2 and the insulating film 3 in turn, and is fixed by welding, mechanical connection, etc. In some embodiments, the structure of the blade battery is different from the above structure. Specifically, the blade battery 100 also includes a shell, which has a rectangular structure with openings at both ends. The shell and the insulating end cap 2 are wrapped around the outside of the battery cell 1 to form a battery shell structure, and the insulating film 3 is wrapped and covered on the surface of the battery shell. The heat spreader 200 is covered on the outside of the insulating film 3 as a heat sink.

[0028] Specifically, the heat spreader 200 is formed into a plurality of straight plate structures, or is bent into an L-shaped or U-shaped structure to fit the shape of the battery and form a rectangular structure with two ends open. Figure 1 In the AA section, in this embodiment, one U-shaped vapor chamber 200 and one straight vapor chamber 200 are spliced ​​to form a rectangular parallelepiped structure with openings at both ends, and the straight vapor chamber 200 is placed at the opening of the U-shaped vapor chamber 200. There are many ways to splice to form a rectangular parallelepiped structure with openings at both ends, and the present invention does not limit the number and shape of the vapor chambers 200 used for splicing, as long as they can be spliced ​​to form a rectangular parallelepiped structure with openings at both ends, for example, two L-shaped vapor chambers 200 can be spliced, or at least four straight vapor chambers 200 can be spliced.

[0029] See also Figure 2 , which is an enlarged schematic diagram of the heat spreader structure in this embodiment, corresponding to Figure 1 The cross-sectional direction of BB; Figure 3 for Figure 2The enlarged schematic diagram of the heat spreader structure corresponding to the CC cross-sectional direction of the heat spreader 200. The heat spreader 200 includes a sealed shell 210, a first liquid absorption layer 220, a second liquid absorption layer 230, a support column 240 and a working medium. The sealed shell 210 is a hollow metal shell plate with a smooth surface, and an inner cavity is formed inside the shell plate. Among them, the shell plate on the side close to the battery cell 1 is the bottom plate 211. The first liquid absorption layer 220 and the second liquid absorption layer 230 are located in the inner cavity and are arranged on the bottom plate 211 from bottom to top. A plurality of support columns 240 are arranged at equal intervals on the surface of the second liquid absorption layer 230, and the top surface of the support column 240 is in contact with the inner cavity surface of the top plate of the sealed shell 210. The working medium is filled in the first liquid absorption layer 220 and the second liquid absorption layer 230. The first liquid absorption layer 220, the second liquid absorption layer 230, the support column 240 and the area where the working medium is located in the inner cavity form a heat conduction area, and the gap above the second liquid absorption layer and between the support columns 240 forms a heat dissipation area for accommodating the gas working medium.

[0030] The first liquid absorbing layer 220 has a plurality of pore structures, and the working medium is stored in the pore structures of the first liquid absorbing layer 220 and moves in a plane parallel to the bottom plate 211. The working medium can be one or more low-boiling point liquids such as deionized water, acetone, freon, anhydrous ethanol, etc. The first liquid absorbing layer 220 can be one or more of a wire mesh layer, a fiber sintered layer, a powder sintered layer, and a foam layer. The wire mesh layer can be formed by a single layer or multiple layers of regularly arranged mesh-shaped metal wire meshes tightly attached to the inner cavity wall of the sealing shell 210; the powder sintering layer can be formed by sintering a certain mesh number of powders on the inner cavity wall of the sealing shell 210 to form a porous structure, forming an integral structure with the inner cavity wall; the fiber sintering layer can be formed by sintering short fibers on the inner cavity wall of the sealing shell 210 to form a three-dimensional mesh porous structure, forming an integral structure with the inner cavity wall; the foam layer can be formed by mixing special metal materials containing foam pores with materials such as copper powder and sintering on the inner cavity wall of the sealing shell 210, forming an integral structure with the inner cavity wall. It should be noted that the present invention does not limit the specific material of the first liquid absorption layer 220, and its specific material can be one or more metal materials such as copper, aluminum and its alloys, stainless steel, etc., or non-metallic materials such as PI (polyimide). In this embodiment, the first liquid absorbing layer 220 is a screen layer, the mesh number of the screen layer is 400-10 meshes, preferably 400 meshes, 330 meshes, 250 meshes, 200 meshes or 100 meshes, and the porosity of the screen layer is in the range of 65-85%.

[0031] The second liquid absorption layer 230 includes a plurality of directional transmission blocks 21. The directional transmission blocks 21 are arranged in an array on the first liquid absorption layer 220, and are arranged in at least one row along the axial direction (length direction) of the battery. In this embodiment, they are arranged in 8 rows. The spacing between the directional transmission blocks 21 on the same row is less than 2.5 mm; the row spacing between two adjacent rows of directional transmission blocks 21 is less than 1.5 mm. In some embodiments, adjacent directional transmission blocks can also be arranged closely adjacent to each other. The directional transmission blocks 21 arranged in an array form a small gap similar to a capillary structure, which can store the working fluid and guide the working fluid to flow therein.

[0032] See also Figure 4 , which is a schematic diagram of the structure of the directional transmission block 21 of this embodiment. The directional transmission block 21 is an octahedral structure, including a bottom surface 22, a first guide surface 23, a second guide surface 24, a top surface 25, a first connecting surface 26, a second connecting surface 27, a first side surface 28 and a second side surface (not shown).

[0033] The bottom surface 22 is adjacent to the first guide surface 23 and the second guide surface 24 respectively, and the first guide surface 23 is arranged opposite to the second guide surface 24; the top surface 25 is parallel to the bottom surface 22. The first guide surface 23 is adjacent to and connected to the top surface 25 via a first connecting surface 26; the second guide surface 24 is adjacent to and connected to the top surface 25 via a second connecting surface 27; the first side surface 27 is arranged opposite to the second side surface, and is adjacent to and connected to the bottom surface 22 respectively.

[0034] The bottom surface 22 is parallel to the bottom plate 211, and the angle between the bottom surface 22 and the first guide surface 23 is α 1 The angle between the bottom surface 22 and the second guide surface 24 is α 2 , there is a strong wetting effect at the angles between the bottom surface 22 and the first guide surface 23 and between the bottom surface 22 and the second guide surface 24, which can store working fluid. The height of the top edge of the first guide surface 23 from the bottom surface 22 is x 1 , the height of the top surface 25 from the bottom surface 22 is x 2 In this embodiment, α 2 >α 1 , x 2 >x 1 The first guide surface 23 and the second guide surface 24 are preferably curved surfaces protruding outwards. In this case, the angle between the curved surface and the bottom surface 22 is the angle between the curved surface tangent corresponding to the boundary line between the curved surface and the bottom surface 22 and the bottom surface 22. The first guide surface 23 and the second guide surface 24 are set as curved surfaces to reduce dead angles, reduce resistance to the flow of the working fluid, and improve flow efficiency. In this embodiment, the second guide surface 24 is formed from the bottom along α 2 extends outward in the direction of x1 When the height is α, the second connecting surface 27 is connected to the top surface and the second connecting surface 27 is away from α 2 , so as to avoid the second guide surface 24 extending toward α 2 The directional extension is too long, which causes the directional transmission body 21 to be unbalanced in the length direction and fall over.

[0035] The top surface 25 is parallel to the bottom surface 22, which facilitates the fixed connection of the support column 230 to the top surface 25 to strengthen the support; in addition, the bottom surface 22 and the top surface 25 are designed to be flat, which is convenient for processing or demoulding, so that the structure will not be damaged during manufacturing. Preferably, the width of the top surface 25 is the same as that of the bottom surface 22, so that the directional transmission block 21 is evenly stressed and maintains good mechanical properties in a high vacuum environment, so as to prevent the heat spreader 200 from collapsing or breaking when the vacuum in the inner cavity is too high.

[0036] In some embodiments, the first connection surface 26 and the second connection surface 27 can be a plane or a curved surface with an undulating structure. The first side surface 27 and the second side surface are parallel to each other and are adjacent to and connected to the bottom surface 22 respectively. At this time, the second side surface 27 of each row of directional transmission blocks 21 and the first side surface 27 of the directional transmission blocks 21 in the adjacent row form a capillary structure, which can guide the working medium to flow on both sides of each directional transmission block 21.

[0037] It should be noted that the capillary force that the array of directional transmission blocks 21 can provide should be greater than or equal to the gravity of the working fluid to avoid uneven distribution of the working fluid due to the influence of gravity. Therefore, the height of the working fluid in the vapor chamber 200 is < x 1 , so that the gravity of the working medium is less than or equal to the carrying capacity corresponding to the maximum capillary force that the first and second liquid absorbing layers can provide, and accordingly, the volume value of the working medium is 80-120% of the total volume value of the gap formed by the directional transmission block and the directional connection belt array and the pore structure of the first liquid absorbing layer. In addition, according to the results of the experimental test, the direction in which the directional transmission block 21 guides the flow of the working medium depends on α 1 With α 2 The relationship between 1 With x 2 The relationship between 1 With x 2 The relationship between determines whether the directional transmission block 21 can limit the directional movement of the working medium in the axial direction. Specifically, when x 2 >x 1 or x 2 <x 1 When x 2 =x 1When α, the working fluid moves in any direction on the two-dimensional plane. 1 With α 2 The relationship between limits the specific movement direction of the working medium in the axial direction. Specifically, when α 2 >α 1 When α 1 The wetting effect at the angle is stronger. 1 At the angle α, the working fluid stored between the first guide surface 23 and the first liquid absorbing layer 220 extends to the adjacent directional transmission block 21 on the same row under the action of the wetting effect. 1 After the working medium stored at the angle moves, the α 2 At the angle, the working fluid stored between the second guide surface 24 and the first liquid absorbing layer 220 quickly moves to the α 1 The working medium moves from the second guide surface 24 of the same directional transmission block 21 to the first guide surface 23; similarly, when α 2 <α 1 When the working medium moves from the first guide surface 23 to the second guide surface 24. It should be noted that, since the liquid has a wetting effect on the solid, and fine capillaries are formed between adjacent directional transmission blocks 21 in the same row, even if only one row of directional transmission blocks 21 is provided in some embodiments, the working medium can flow on the first side surface 27 and the second side surface.

[0038] Based on the above analysis results, in this embodiment, α 2 >α 1 , x 2 >x 1 Therefore, the working medium moves from the second guide surface 24 to the first guide surface 23. In some embodiments, the directional transmission block 21 can also be configured as follows: 2 >α 1 , x 2 <x 1 , the working medium moves from the second guide surface 24 to the first guide surface 23. Or α 2 <α 1 , x 2 >x 1 , the working medium moves from the first guide surface 23 to the second guide surface 24. Or α 2 <α 1 , x 2 <x 1 , the working medium moves from the first guide surface 23 to the second guide surface 24. Since the shape of the directional transmission block 21 satisfies the above relationship, the directional transmission of the working medium can be achieved. 1 , α 2 、x 1、x 2 The specific size of α is not limited. Preferably, α 1 , α 2 The value of is in the range of 30 to 70° (including the end value). In an ultra-thin heat spreader with a thickness of less than 2 mm, preferably, x 1 <1mm,x 2 <1mm.

[0039] Since both ends of the blade battery are provided with tabs 4, the working fluid needs to be transported from the middle to both ends, so the directional transmission blocks 21 are distributed and arranged in a mirror-symmetrical manner, and the symmetry line is the perpendicular midline of the battery axis. In this embodiment, the first guide surface 23 of each directional transmission block 21 inside the heat spreader 200 is arranged toward the end of a battery tab 4 that is closer. Accordingly, since the first guide surface 23 is arranged opposite to the second guide surface 24, the second guide surface 24 is facing away from the end of the battery tab 4.

[0040] As a further optimization of the above solution, the directional transmission block 21 is provided with a pore structure, and the pore structure provides a storage space for the liquid working medium.

[0041] Furthermore, the second liquid absorption layer 230 also includes a directional connection belt 31, which is connected between two directional transmission blocks 21 in the same row. The working medium is stored in the gap formed by the directional transmission block 21 and the array of directional connection belts 31. The directional connection belt 31 further guides the working medium between adjacent directional transmission blocks 21 in the same row to extend rapidly. The directional connection belt 31 is sintered by one or more of powder or fiber, braided belt, and has multiple pore structures. The pore structure further provides storage space for liquid working medium and provides capillary force to move the working medium in the axial direction. The directional connection belt 31 is a cylindrical or rectangular structure as a whole, preferably a rectangular structure.

[0042] As a further optimization of the above scheme, the surfaces of the first liquid absorption layer 220, the directional transmission block 21, and the directional connection belt 31 have a micro-nano pore structure formed by chemical corrosion. It should be noted that the micro-nano pore structure is not the same as the pore structure. The micro-nano pore structure is a micron-scale or nano-scale pore such as a nanoflower or nanograss structure, which is hydrophilic and can increase the capillary force. It is formed by oxidation corrosion of chemical materials, and its chemical material properties are changed; while the pore size of the pore structure is much larger than that of the micro-nano pore structure, and compared with the solid structure, there is only a change in physical shape, and its chemical material properties have not changed.

[0043] The support column 240 supports the inner cavity structure to prevent the shell plate from being deformed during subsequent processing or use, thereby affecting the heat dissipation effect. In some embodiments, the first liquid absorbing layer 220 and the second liquid absorbing layer 230 are sequentially arranged on the surface of the top plate opposite to the bottom plate 211, and the support column 240 is fixed between two layers of directional transmission blocks 21 arranged oppositely. In some embodiments, the support column 240 is not arranged, and the inner cavity structure is supported directly by two layers of directional transmission blocks 21 arranged oppositely or by a layer of directional transmission blocks 21 with a higher height being attached to the top plate.

[0044] As a further optimization of the above solution, the vapor chamber 200 includes n sub-vapor chambers 201, and the sub-vapor chambers 201 are arranged along the axial direction of the battery, where n≥2. Figure 5 When n is an even number, the arrangement direction of the directional transmission blocks 21 in a single sub-vaporizing plate 201 is the same, which can realize unidirectional transportation of the working medium in the axial direction. When splicing, the sub-vaporizing plates 200 on both sides are arranged in opposite directions with the perpendicular midline of the battery axis as the symmetry line to realize the transportation of the working medium from the middle part to the two ends; when n is an odd number, only the directional transmission blocks 21 in one sub-vaporizing plate 201 in the center need to be distributed in a mirror-symmetrical manner, and the arrangement direction of the directional transmission blocks 21 in other sub-vaporizing plates 201 is the same. It is only necessary to arrange the unidirectional transmission sub-vaporizing plates 201 in opposite directions on both sides of the sub-vaporizing plate 201 in the center when splicing. In addition, the split arrangement of the vaporizing plate 200 in this way can simplify the array arrangement of the directional transmission blocks 21 and improve production efficiency.

[0045] In the present invention, the weld forms of the welding connection include butt welds and fillet welds. The insulating film 3 is specifically an insulating blue film, and the insulating blue film can also be replaced by an insulating layer formed by insulating paint or other insulating materials through spraying or the like. Furthermore, a thermally conductive interface material is provided between the battery cell 1 and the heat spreader 200, and thermally conductive silicone grease, thermally conductive double-sided tape, thermally conductive mud and other thermally conductive interface materials with fluidity that can reduce thermal resistance can be selected. Furthermore, the outer surface of the heat spreader 200 also includes temperature control devices such as liquid cooling plates and thermoelectric cooling sheets, which can control the temperature of the battery casing to control the temperature of the entire battery, keep the temperature in a suitable temperature range, and enable the battery to reach the best working state.

[0046] It should be noted that the first liquid absorption layer 220 and the second liquid absorption layer 230 form a liquid absorption core structure, and the liquid absorption core structure can also be arranged in a heat sink such as a heat pipe and a liquid cooling plate that requires directional movement of liquid working medium.

[0047] The following is an introduction to the working principle of battery heat dissipation by taking the blade battery with the heat spreader of the present invention as an example: when the battery is working, heat accumulates near the pole ears 4 at both ends of the battery to form a high-temperature zone. The working fluid in the high-temperature zone of the heat spreader quickly evaporates and moves to the heat dissipation zone, taking away a large amount of heat. Driven by the pressure difference, the steam diffuses toward the low-temperature zone in the middle of the battery, condenses into liquid and is stored again in the first liquid absorption layer 220 and the second liquid absorption layer 230 and releases latent heat. At this time, part of the heat is absorbed by the battery casing, causing the temperature in the middle of the battery to rise, thereby reducing the temperature difference between the two ends and the middle of the battery; part of the heat is dissipated to the outside of the battery to reduce the overall heat of the battery. In addition, the liquid working fluid accumulated in the low-temperature zone quickly moves to the high-temperature zone through capillary action, replenishing the liquid working fluid for the high-temperature zone, and the cycle repeats like this. Specifically, the first liquid absorption layer 220 causes the working fluid to diffuse in a two-dimensional plane; the second liquid absorption layer 230 guides the working fluid to flow from the middle of the battery to the two ends. Since the directional transmission block 21 is in α 1 The wetting effect at the angle is stronger, so 1 The working medium stored at the angle extends to the adjacent directional transmission block 21 on the same row under the action of the wetting effect. 1 After the working medium stored at the angle moves, the α 2 The working fluid stored at the angle is quickly replenished to α 1 The position of the angle, in this process, the working fluid passes through the first side 27 and the second side; further, the first liquid absorption layer 220 guides the working fluid to extend from the middle of the battery to the two ends at the bottom of the directional transmission block 21; the directional connection belt 31 further guides the working fluid between adjacent directional transmission blocks 21 in the same row to extend rapidly. In addition, a capillary-like structure is formed between each row of directional transmission blocks 21 arranged in the array, which can store more working fluid. The stored working fluid is rapidly transferred from the middle to the two ends in the axial direction through capillary action, and its transmission speed is faster than the diffusion speed of the working fluid in the two-dimensional plane; the transmission strip layer further improves the ability of axial transmission of working fluid, and the stored working fluid is rapidly transferred from the middle to the two ends in the axial direction through capillary action.

[0048] The manufacturing method of the vapor chamber 200 specifically comprises the following steps:

[0049] Design a corresponding three-dimensional drawing according to the shape of the directional transmission block 21, and print the matrix of the directional transmission block 21 by high-precision 3D printing technology;

[0050] Treating the matrix of the directional transport block 21 with a pore-forming agent to form the directional transport block 21 having a plurality of pore structures;

[0051] The first liquid absorbing layer 220 is placed in the mold, the directional transmission blocks 21 are arranged in an array, and a plurality of transmission strips are placed between two directional transmission blocks 21 in each column to form a second liquid absorbing layer 230, which are sintered at a high temperature into a whole;

[0052] A micro-nano structure is generated on the surface of the directional transmission block 21, the first liquid absorption layer 220, and the directional connection belt 31 by a chemical corrosion method using an etchant to generate a nano grass or nano flower structure, changing the material from a hydrophobic state to a super hydrophilic state to obtain a liquid absorption core.

[0053] The wick is sintered on the bottom plate of the sealing shell of the vapor chamber, and then the top plate of the sealing shell is welded with the support column at high temperature. Then, liquid working medium is injected into the wick, and the sealing shell is sealed into a negative pressure vacuum chamber to obtain the vapor chamber of the present invention.

[0054] The manufacturing method of the blade battery 100 specifically includes the following steps:

[0055] The heat spreaders are spliced ​​to form a square cylinder with openings at both ends, the battery cell 1 is wrapped in the square cylinder, the positive and negative electrodes of the battery cell 1 are led out through the pole ears 4, the pole ears 4 are welded to the two ends of the blade battery, the insulating end caps 2 are encapsulated at the openings at both ends, the electrolyte is injected, and finally the insulating film 3 is coated to obtain an integrated blade battery with a heat dissipation structure and a shell integrated.

[0056] Different from the above manufacturing method, in some embodiments, the manufacturing method of the blade battery 100 includes the following steps:

[0057] A shell is spliced ​​or bent to form a square cylinder with openings at both ends, the battery cell 1 is wrapped in the square cylinder, the positive and negative electrodes of the battery cell 1 are led out through the pole ears 4, the pole ears 4 are welded to the two ends of the blade battery, the insulating end caps 2 are encapsulated at the openings at both ends, the electrolyte is injected, the insulating film 3 is coated, and finally the heat spreader 200 is coated on the surface of the insulating film 3 to obtain a blade battery with a heat dissipation structure.

[0058] Compared with the prior art, the heat sink of the present invention improves the capillary force of the heat sink in the axial direction by designing a directional transmission block 21 of a special shape and arranging it into a second liquid absorption layer 230, promotes the movement of the working medium in the axial direction, greatly improves the heat transfer efficiency and temperature equalization ability of the heat sink to the battery, and can meet the heat transfer requirements of long distances and narrow spaces, especially for blade batteries with uneven heat generation, and can meet their heat dissipation and thermal control requirements. Specifically, the direction of the working medium transmitted by the directional transmission block 21 can be controlled by setting the angle between the first guide surface 23 and the second guide surface 24 and the bottom surface 22. Further, the capillary force of the heat sink in the axial direction is strengthened by the transmission strip layer. Further, the transmission of the working medium in a two-dimensional plane is realized by the first liquid absorption layer 220. Further, the liquid absorption core formed by the first liquid absorption layer 220 and the second liquid absorption layer 230 is arranged on the heat spreader and arranged on the blade battery, avoiding the temperature imbalance problem of the blade battery with low temperature in the middle and high temperature at both ends, avoiding the accumulation of battery heat, ensuring the safety and life of the battery, and providing support for further realizing extremely fast charging. Furthermore, a plurality of axially arranged sub-heat spreaders 200 form a heat spreader, which simplifies the structure and manufacturing cost and improves the heat dissipation effect. The liquid wick of the present application also has the advantages of simple manufacturing and convenient processing, and the integrated blade battery further reduces the volume of the blade battery.

[0059] Example 2

[0060] Embodiment 2 is substantially the same as Embodiment 1, except that the first liquid absorbing layer 220 is not provided, and the second liquid absorbing layer 230 is directly provided on the bottom plate 211 of the vapor chamber 200 to reduce the thickness of the vapor chamber.

[0061] Correspondingly, the difference in the working principle is that the directional transmission block 21 quickly transmits the stored working fluid from the middle to both ends along the axial direction through capillary action, and the working fluid mainly moves in a directional direction in the direction of the row where the directional transmission block 21 is located (the length direction of the battery), and diffuses a small amount in the non-directional direction. This embodiment can also quickly transmit the stored working fluid from the middle to both ends along the axial direction, but the working fluid transmission efficiency in the non-directional direction is lower.

[0062] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that, unless otherwise specified, "multiple" refers to two or more; the terms "first", "second", etc. are only used to distinguish, rather than to describe a specific order or sequence, and cannot be understood as indicating or implying relative importance. When the above description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0063] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A battery, characterized in that: It comprises a heat sink, a battery cell, an insulating end cover, an insulating film and a pole ear; the heat sink is formed into a rectangular parallelepiped structure with openings at both ends, and the battery cell is wrapped in the rectangular parallelepiped structure; the insulating end cover is arranged at the openings at both ends of the rectangular parallelepiped structure, the insulating film is arranged between the battery cell and the heat sink or on the surface of the heat sink, and the pole ear is respectively led out from the positive electrode and the negative electrode at both ends of the battery cell; The heat sink comprises a sealing shell, a plurality of directional transmission blocks and a working medium; the sealing shell is a hollow shell plate, an inner cavity is formed inside the shell plate, and one side of the shell plate is a bottom plate; the directional transmission blocks are located in the inner cavity, and the array is arranged on the bottom plate to form a gap, and the working medium is filled in the gap formed by the directional transmission block array, and the volume value of the working medium is 80-120% of the volume value of the gap of the directional transmission block array; and the directional transmission blocks are arranged in at least one row of arrays along the axial direction of the battery, and the first guide surface of each directional transmission block faces the end of a closer pole ear; The directional transmission block includes a bottom surface, a first guide surface, a second guide surface, a top surface, a first connection surface, a second connection surface, a first side surface, and a second side surface; the bottom surface is parallel to the bottom plate, the bottom surface is adjacent to the first guide surface and the second guide surface, and the first guide surface and the second guide surface are arranged oppositely; the top surface is parallel to the bottom surface; the first guide surface is adjacently connected to the top surface through the first connection surface; the second guide surface is adjacently connected to the top surface through the second connection surface, the first side surface and the second side surface are arranged oppositely, and are adjacently connected to the bottom surface respectively; the first guide surface and the second guide surface are curved surfaces protruding outward; the first side surface and the second side surface are parallel to each other; The angle between the bottom surface and the first guide surface is α1, and the angle between the bottom surface and the second guide surface is α2, α2>α1; the height of the top edge of the first guide surface from the bottom surface is x1, and the height of the top surface from the bottom surface is x2, x2>x1 or x2<x1.

2. The battery according to claim 1, characterized in that: The second guide surface extends outward from the bottom along the direction of α2. When it extends to the height of x1, it is connected to the top surface through the second connecting surface, and the second connecting surface extends in the direction away from α2.

3. The battery according to claim 2, characterized in that: It also includes a first liquid absorption layer, which is arranged on the bottom plate, and the directional transmission block array is arranged on the first liquid absorption layer; the first liquid absorption layer has a plurality of pore structures, and the working medium is filled in the pore structure of the first liquid absorption layer, and the volume of the working medium is 80-120% of the volume value of the pore structure of the first liquid absorption layer.

4. The battery according to claim 3, characterized in that: It also includes a plurality of directional connection belts, which are connected between two directional transmission blocks in the same row. The working medium is stored in the gap formed by the directional transmission block and the directional connection belt array, and the volume value of the working medium is 80-120% of the total volume value of the gap formed by the directional transmission block and the directional connection belt array and the pore structure of the first liquid absorption layer.

5. The battery according to claim 4, characterized in that: The surface of the directional transmission block is provided with a pore structure that provides storage space for liquid working medium; the surfaces of the first liquid absorption layer, the directional transmission block and the directional connecting belt have micro-nano pore structures.

6. The battery according to any one of claims 1 to 5, characterized in that: The sizes of α1 and α2 are in the range of 30~70°.

7. The battery according to claim 4, characterized in that: The first liquid-absorbing layer is one or more of a wire mesh layer, a fiber sintered layer, a powder sintered layer, and a foam layer; the oriented connecting tape is one or more of a powder or fiber, and a woven tape; the material of the first liquid-absorbing layer and the oriented connecting tape is one or more of copper, aluminum and its alloys, stainless steel, and PI.

8. The battery according to claim 1, characterized in that: The heat sink includes n sub-heat sinks, and the sub-heat sinks are arranged along the axial direction of the battery, where n≥2.

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