Heat exchange plate, battery module, battery pack and electric equipment

Abstract

The invention discloses a heat exchange plate, a battery module, a battery pack and electric equipment, and belongs to the field of batteries. The heat exchange plate comprises a refrigerant and a heat exchange flow channel, the refrigerant is arranged in the heat exchange flow channel, the heat exchange flow channel comprises an ascending flow channel and a descending flow channel which are communicated end to end, and under the condition that the temperature difference of the battery cells in the height direction is larger than a temperature threshold value, the ascending flow channel is used for passing through the refrigerant in evaporation or after evaporation, and the descending flow channel is used for passing through the descending flow channel. And the descending flow channel is used for allowing the condensed or condensed refrigerant to pass through. By arranging the ascending runner and the descending runner which are connected end to end, high-efficiency heat exchange of the upper and lower areas of the battery cell can be realized through high heat transfer capability formed by refrigeration evaporation-condensation circulation, and the overall temperature difference of the battery module is effectively reduced.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a heat exchange plate, a battery module, a battery pack and electrical equipment. Background Art

[0002] In order to improve the user experience of new energy vehicles and reduce the waiting time for charging, achieving high-rate fast charging of power batteries has become a technical problem that the new energy vehicle industry has paid more and more attention to in recent years. However, due to the large amount of heat generated by the battery cells under high-temperature and high-rate fast charging conditions, if the battery cells cannot be cooled in real time and efficiently, the battery cells are prone to the risk of overheating and excessive temperature differences, and their safety is poor.

[0003] At present, for the sake of thermal safety of the battery cells, the charging current can only be reduced, which restricts the fast charging rate of the battery cells. Currently, most battery packs are cooled by installing a liquid cooling plate or a direct cooling plate above or below the battery module. Since the coolant or refrigerant only flows through the upper or lower side of the battery cell, this cooling method will cause a large temperature difference between the upper and lower sides, and the temperature on the side away from the cooling surface is higher, which cannot achieve efficient cooling of the battery cell and needs to be improved. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a heat exchange plate, a battery module, a battery pack and an electrical device, which can effectively reduce the temperature difference of the entire battery module.

[0005] In a first aspect, the present application provides a heat exchange plate, which is arranged on the side of a battery cell, and the heat exchange plate comprises:

[0006] refrigerant;

[0007] A heat exchange flow channel, in which the refrigerant is arranged, and the heat exchange flow channel includes an ascending flow channel and a descending flow channel which are connected end to end. When the temperature difference of the battery cell along the height direction is greater than a temperature threshold, the ascending flow channel is used to pass the refrigerant in the process of evaporation or after evaporation, and the descending flow channel is used to pass the refrigerant in the process of condensation or after condensation.

[0008] According to the heat exchange plate of the present application, by setting an ascending flow channel and a descending flow channel connected end to end, when the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the lower end of the heat exchange plate exchanges heat with the lower part of the battery cell and the tray, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate. The refrigerant changes from liquid phase to gas phase at the lower end of the heat exchange plate, and the gas phase refrigerant flows to the upper end of the heat exchange plate along the ascending flow channel under the action of buoyancy; the upper end of the heat exchange plate exchanges heat with the upper part of the battery cell and the cooler, and the gas phase refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate, and the liquid phase refrigerant flows to the lower end of the heat exchange plate along the descending flow channel under the action of gravity, forming a refrigerant reflux, so that the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle can realize efficient heat exchange between the upper and lower areas of the battery cell, and effectively reduce the overall temperature difference of the battery module. Compared with the solution of setting a cooler at the upper and lower parts of the battery cell in the height direction, the cost and weight of the battery module are reduced, and the structure is simple.

[0009] According to one embodiment of the present application, the heat exchange channel is annular, and the ascending channel is formed along the first direction between the lowest point and the highest point of the inner circle contour line of the heat exchange channel, and the descending channel is formed along the first direction between the highest point and the lowest point of the inner circle contour line of the heat exchange channel, and the flow rate of the ascending channel is smaller than the flow rate of the descending channel.

[0010] According to one embodiment of the present application, the descending flow channel includes a first flow channel, a second flow channel and a third flow channel connected in sequence, and the ascending flow channel includes a fourth flow channel and a fifth flow channel connected in sequence;

[0011] The lower end of the first flow channel is connected to the upper end of the second flow channel, the lower end of the second flow channel is connected to the upper end of the third flow channel, the lower end of the third flow channel is connected to the lower end of the fourth flow channel, the upper end of the fourth flow channel is connected to the lower end of the fifth flow channel, and the upper end of the fifth flow channel is connected to the upper end of the first flow channel;

[0012] An upper end of the fifth flow channel is higher than an upper end of the second flow channel along a gravity direction.

[0013] According to one embodiment of the present application, the second flow channel and the fifth flow channel extend in the direction of gravity; and / or the flow area of ​​the fifth flow channel is larger than the flow area of ​​the second flow channel.

[0014] According to an embodiment of the present application, the following is satisfied: 0°<θ1≤25°, wherein θ1 is an inclination angle of the first flow channel with respect to the horizontal direction; and / or,

[0015] Satisfies: 0°<θ2≤45°, wherein θ2 is the inclination angle of the third flow channel with the horizontal direction; and / or,

[0016] Satisfies: 0°<θ3≤45°, wherein θ3 is an inclination angle of the fourth flow channel with respect to the horizontal direction.

[0017] According to one embodiment of the present application, the flow cross-sectional area of ​​the fourth flow channel gradually increases from the end connected to the third flow channel to the end connected to the fifth flow channel; and / or,

[0018] The flow cross-sectional area of ​​the first flow channel gradually increases from an end connected to the fifth flow channel to an end connected to the second flow channel.

[0019] According to one embodiment of the present application, the first flow channel, the second flow channel, the third flow channel and the fourth flow channel each include two groups, and the two groups of the first flow channels, the two groups of the second flow channels, the two groups of the third flow channels and the two groups of the fourth flow channels are symmetrically distributed on both sides of the fifth flow channel with the fifth flow channel as the axis of symmetry.

[0020] According to one embodiment of the present application, the heat exchange channel also includes a sixth channel, which is arranged between the third channel and the fourth channel, and extends in a horizontal direction and is close to the bottom end of the heat exchange plate along the gravity direction.

[0021] According to one embodiment of the present application, an inclination angle of the fourth flow channel with respect to the horizontal direction is greater than an inclination angle of the third flow channel with respect to the horizontal direction.

[0022] According to one embodiment of the present application, the heat exchange plate includes a first portion and a second portion, and the first portion and the second portion jointly define the heat exchange flow channel;

[0023] A first boss and a second boss are disposed on the outer side of the first part and / or the outer side of the second part. The first boss and the second boss are arranged spaced apart along the gravity direction. The first boss and the second boss are used to be connected to the battery core.

[0024] According to an embodiment of the present application, the first part and the second part are positioned and matched.

[0025] According to an embodiment of the present application, the heat exchange plate further includes a pressure relief valve, and the pressure relief valve is communicated with the heat exchange flow channel.

[0026] According to an embodiment of the present application, the heat exchange plate is further provided with a thinning area, and the thinning area is located in the heat exchange flow channel.

[0027] In a second aspect, the present application provides a battery module, comprising a battery cell and a heat exchange plate as described in any one of the above, wherein the heat exchange plate is arranged on a side of the battery cell.

[0028] The battery module provided by the embodiment of the present application is provided with a heat exchange plate in the above embodiment on the side of the battery cell, and the heat exchange plate is provided with an ascending flow channel and a descending flow channel connected end to end. When the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the lower end of the heat exchange plate exchanges heat with the lower part of the battery cell and the tray, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate. The refrigerant changes from liquid phase to gas phase at the lower end of the heat exchange plate, and the gas phase refrigerant flows to the upper end of the heat exchange plate along the ascending flow channel under the action of buoyancy; the upper end of the heat exchange plate exchanges heat with the upper part of the battery cell and the cooler, and the gas phase refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate, and the liquid phase refrigerant flows to the lower end of the heat exchange plate along the descending flow channel under the action of gravity, forming a refrigerant reflux, so that the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle can realize efficient heat exchange between the upper and lower areas of the battery cell, and effectively reduce the overall temperature difference of the battery module. Compared with the solution of providing a cooler at the upper and lower parts of the battery cell in the height direction, the cost and weight of the battery module are reduced, and the structure is simple.

[0029] According to one embodiment of the present application, it also includes a tray and a cooler, the cooler is arranged on the top of the battery cell along the direction of gravity, the battery cell and the heat exchange plate are arranged on the tray, the top end of the heat exchange plate along the direction of gravity is close to the cooler, and the bottom end of the heat exchange plate along the direction of gravity is close to the bottom of the tray.

[0030] In a third aspect, the present application provides a battery pack comprising a battery module as described in any of the above embodiments.

[0031] The battery pack provided in the embodiment of the present application is provided with the battery module in the above embodiment. The battery module is provided with the heat exchange plate in the above embodiment on the side of the battery cell. The heat exchange plate is provided with an ascending flow channel and a descending flow channel connected end to end. When the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the lower end of the heat exchange plate exchanges heat with the lower part of the battery cell and the tray, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate. The refrigerant changes from liquid phase to gas phase at the lower end of the heat exchange plate. The gas-phase refrigerant flows along the ascending flow channel to the upper end of the heat exchange plate under the action of buoyancy; the upper end of the heat exchange plate exchanges heat with the upper part of the battery cell and the cooler. The gas-phase refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate. The liquid-phase refrigerant flows along the lower ascending flow channel to the lower end of the heat exchange plate under the action of gravity, forming a refrigerant reflux, thereby realizing efficient heat exchange between the upper and lower areas of the battery cell through the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle, and effectively reducing the overall temperature difference of the battery module. Compared with the solution of providing a cooler above and below the battery cell in the height direction, the cost and weight of the battery module are reduced and the structure is simple.

[0032] In a fourth aspect, the present application provides an electrical device, comprising a battery module as described in any of the above embodiments.

[0033] The electrical equipment provided in the embodiment of the present application is provided with the battery pack in the above embodiment, which reduces the cost and weight of the battery module and improves the safety and reliability of the electrical equipment.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 It is one of the structural schematic diagrams of the heat exchange plate provided in the embodiment of the present application;

[0037] Figure 2 This is the second structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0038] Figure 3 This is one of the schematic diagrams of the assembly structure of the heat exchange plate and the battery core provided in the embodiment of the present application;

[0039] Figure 4 This is the third structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0040] Figure 5 This is the fourth structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0041] Figure 6 This is the fifth structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0042] Figure 7 This is the sixth structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0043] Figure 8 This is the second schematic diagram of the assembly structure of the heat exchange plate and the battery cell provided in the embodiment of the present application;

[0044] Fig. 9 This is the seventh structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0045] Fig.10 This is the eighth structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0046] Fig.11 This is the ninth structural schematic diagram of the heat exchange plate provided in the embodiment of the present application;

[0047] Fig.12 is a schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0048] Fig.13 It is a schematic diagram of liquid filling of a heat exchange plate provided in an embodiment of the present application.

[0049] Reference numerals:

[0050] Battery module 100;

[0051] Heat exchange plate 1, heat exchange channel 11, ascending channel 111, fourth channel 1111, fifth channel 1112, descending channel 112, first channel 1121, second channel 1122, third channel 1123, sixth channel 113, evaporation chamber 114, condensation chamber 115;

[0052] The first part 12, the second part 13, the first boss 131, the second boss 132, the groove 133, the positioning hole 134, the pressure relief valve 135, the welding bolt 136, the thinning area 137, the first avoidance groove 138, the second avoidance groove 139, and the injection pipe 14;

[0053] Battery cell 2, tray 3, cooler 4, top insulation cotton 5, bottom insulation cotton 6, bottom guard plate 7, plastic bracket 8;

[0054] Vacuum pump 81 , refrigerant storage tank 82 , stop valve 83 , connecting pipe 84 . DETAILED DESCRIPTION

[0055] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0056] Reference below Figure 1-Figure 13 The heat exchange plate 1, the battery module 100, the battery pack and the electrical equipment according to the embodiments of the present application are described.

[0057] like Figure 1 and Figure 2 As shown, the heat exchange plate 1 provided in the embodiment of the present application is arranged on the side of the battery cell 2. The heat exchange plate 1 can be integrated in the battery pack. The heat exchange plate 1 is directly attached to the battery cell 2, which can reduce the upper and lower temperature difference of the battery cell 2 along the gravity direction, improve the temperature uniformity of the battery cell 2, and reduce the risk of thermal runaway of the battery pack.

[0058] like Figure 6 As shown, the heat exchange plate 1 includes: a heat exchange channel 11 and a refrigerant arranged in the heat exchange channel 11.

[0059] Exemplarily, the refrigerant may be a conventional refrigerant R245fa, acetone or an environmentally friendly refrigerant, wherein the environmentally friendly refrigerant may be R1233zd(E), R1224yd(Z) and R1366mzz(Z).

[0060] It should be noted that the type of refrigerant needs to meet the following three aspects when selecting: First, when the battery pack is cooling, the maximum operating temperature range of the battery cell 2 is usually 35°C to 50°C, and the phase change temperature of the refrigerant arranged in the heat exchange flow channel 11 under the working pressure should be between the maximum temperature and the minimum temperature of the battery cell 2; second, considering the structural safety in the battery pack and the pressure-resistant structural cost of the heat exchange plate 1, the working pressure range of the refrigerant is recommended to be an absolute pressure of 0-5bar; third, considering the risk of refrigerant leakage in the battery pack, the selected refrigerant must also meet the requirements of high dielectric constant, non-flammability, and good compatibility with the shell material.

[0061] like Figure 5 As shown, the heat exchange flow channel 11 includes an ascending flow channel 111 and a descending flow channel 112 which are connected end to end. The ascending flow channel 111 is used for the refrigerant to pass through when it is vaporized, and the descending flow channel 112 is used for the refrigerant to pass through when it is liquefied to form a refrigerant reflux.

[0062] When the temperature difference of the battery core 2 along the height direction is greater than the temperature threshold, the ascending flow channel 111 is used to pass the refrigerant in the process of evaporation or after evaporation, and the descending flow channel 112 is used to pass the refrigerant in the process of condensation or after condensation.

[0063] In this case, the temperature difference of the heat exchange plate 1 along the height direction is greater than the temperature threshold, the ascending flow channel 111 is used for passing gaseous or gas-liquid mixed refrigerant, and the descending flow channel 112 is used for passing liquid or gas-liquid mixed refrigerant.

[0064] When the temperature difference of the battery core 2 along the height direction is less than or greater than the temperature threshold, the ascending flow channel 111 is used to pass the refrigerant before evaporation, and the descending flow channel 112 is used to pass the refrigerant before condensation.

[0065] In this case, the temperature difference of the heat exchange plate 1 along the height direction is less than or greater than the temperature threshold, and both the ascending flow channel 111 and the descending flow channel 112 can be used for the refrigerant passing through the gas-liquid mixture.

[0066] The temperature threshold may be determined according to conditions such as the type of refrigerant, the height of the battery core, and the height of the heat exchange plate 1 .

[0067] In this embodiment, after the heat exchange plate 1 is installed on the side of the battery cell 2, the ascending flow channel 111 extends from the direction of the tray 3 near the bottom of the battery cell 2 toward the direction of the cooler 4 near the top of the battery cell 2, and the descending flow channel 112 extends from the direction of the cooler 4 near the top of the battery cell 2 toward the direction of the bottom of the tray 3 near the bottom of the battery cell 2.

[0068] When the battery cell 2 is working, the temperature of the bottom area of ​​the battery cell 2 near the bottom of the tray 3 is high, and the temperature of the top of the battery cell 2 is low due to its proximity to the cooler 4. The battery cell 2 has a temperature difference in its own height direction.

[0069] like Fig.12 As shown, when the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the heat exchange plate 1 is arranged on one side or both sides of the battery cell 2, and the lower end of the heat exchange plate 1 exchanges heat with the lower part of the battery cell 2 and the tray 3, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate 1, and the refrigerant changes from liquid phase to gas phase at the lower end of the heat exchange plate 1, and the gas phase refrigerant flows to the upper end of the heat exchange plate 1 along the ascending flow channel 111 under the action of buoyancy; the upper end of the heat exchange plate 1 exchanges heat with the upper part of the battery cell 2 and the cooler 4, and the gas phase refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate 1, and the liquid phase refrigerant flows to the lower end of the heat exchange plate 1 along the lower ascending flow channel under the action of gravity, forming a refrigerant reflux, so that the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle can realize efficient heat exchange between the upper and lower areas of the battery cell 2, and effectively reduce the overall temperature difference of the battery module 100.

[0070] In order to cool the battery cells, a related technology 1 discloses a cooling structure containing an inverted T-shaped heat spreader and a micro-needle fin liquid cooling plate. The inverted T-shaped heat spreader includes a vertical heat spreader and a horizontal heat spreader, with a high thermal conductivity metal as the matrix and graphene as the main admixture. The horizontal heat spreader is located between the micro-needle fin liquid cooling plate and the bottom of the lithium battery body and is in close contact with the micro-needle fin liquid cooling plate and the lithium battery body. The vertical heat spreader is located between two adjacent battery cells and is sealed with the battery cells. The invention enhances liquid cooling heat exchange through a micro-needle fin structure, and improves the thermal conductivity of the battery cells in the vertical direction by placing a heat spreader with a high thermal conductivity coefficient between the battery cells. However, since a complex micro-rib structure needs to be processed on the liquid cooling plate, and heat spreaders are set between each battery cell, the manufacturing cost is relatively high.

[0071] Related technology 2 discloses a thermal management structure of a liquid cooling plate composite heat pipe and phase change material for large-size cylindrical batteries. The liquid cooling plate is located at the bottom of the battery. The heat pipe consists of a flat section and a vertical section. The flat section is embedded in the liquid cooling plate, and the vertical section is evenly distributed between the battery cells. Aluminum corrugated plates are symmetrically arranged on both sides. The battery box is filled with phase change material. When the battery temperature is high, the battery transfers heat to the phase change material, and then transfers the heat to the coolant in the liquid cooling plate through the corrugated plate and the heat pipe, so that the battery temperature is reduced. When the battery temperature is low, the coolant in the liquid cooling plate transfers heat to the battery through the heat pipe, and the phase change material also undergoes a liquid-solid phase change, releasing heat to the battery and increasing the battery temperature. One drawback of this solution is that it is expensive. The heat pipe used is a bidirectional heat transfer heat pipe. The capillary wick needs to be sintered inside the heat pipe, and the process flow is relatively complicated compared to the gravity heat pipe. In addition, the amount of phase change material used is large, which not only increases the cost but also increases the weight of the battery box.

[0072] Compared with other battery pack cooling solutions that combine gravity heat pipes and cooling plates, the heat exchange plate 1 of the present application can utilize the height of the battery cell 2 itself. When the temperature difference between the upper and lower parts of the battery cell 2 is large, a refrigerant reflux is formed in the ascending flow channel 111 and the descending flow channel 112 in the heat exchange plate 1, thereby realizing self-driving of the refrigerant under the action of gravity.

[0073] At the same time, by providing the ascending flow channel 111 and the descending flow channel 112 , the flow channels of the gas phase refrigerant and the liquid phase refrigerant can be separated, reducing the flow resistance of the refrigerant in the heat exchange plate 1 , thereby improving the heat exchange capacity and heat transfer limit of the heat exchange plate 1 .

[0074] The heat exchange plate 1 provided in the embodiment of the present application is provided with an ascending flow channel 111 and a descending flow channel 112 connected end to end. When the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the lower end of the heat exchange plate 1 exchanges heat with the lower part of the battery cell 2 and the tray 3, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate 1. The refrigerant changes from the liquid phase to the gas phase at the lower end of the heat exchange plate 1. The gas phase refrigerant flows along the ascending flow channel 111 to the upper end of the heat exchange plate 1 under the action of buoyancy; the upper end of the heat exchange plate 1 exchanges heat with the upper part of the battery cell 2 and the cooler 4. The gas phase refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate 1. The liquid phase refrigerant flows along the descending flow channel to the lower end of the heat exchange plate 1 under the action of gravity, forming a refrigerant reflux, thereby realizing efficient heat exchange between the upper and lower regions of the battery cell 2 through the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle, and effectively reducing the overall temperature difference of the battery module 100. Compared with the solution of arranging a cooler 4 above and below the battery cell 2 in the height direction, the cost and weight of the battery module 100 are reduced, and the structure is simple.

[0075] In some embodiments, Figure 5As shown, the heat exchange channel 11 is annular, and an ascending channel 111 is formed along the first direction between the lowest point and the highest point of the inner circle contour line of the heat exchange channel 11, and a descending channel 112 is formed along the first direction between the highest point and the lowest point of the inner circle contour line of the heat exchange channel 11.

[0076] The flow rate of the ascending flow channel 111 may be greater than, equal to, or less than the flow rate of the descending flow channel 112 , which may be specifically determined according to the working environment of the heat exchange plate 1 and the type of refrigerant.

[0077] Among them, Figure 5 As shown, the first direction may be counterclockwise, and the lowest point and the highest point of the inner circle contour line of the heat exchange channel 11 are the dividing points between the ascending channel 111 and the descending channel 112 .

[0078] The lowest point of the inner circle contour line of the heat exchange channel 11 can be located at the bottom end of the heat exchange plate 1, that is, the lowest point of the inner circle contour line of the heat exchange channel 11 is the position of the heat exchange channel 11 closest to the lower part of the battery cell 2 and the bottom of the tray 3.

[0079] The highest point of the inner circle contour line of the heat exchange channel 11 can be located at the top of the heat exchange plate 1 , that is, the highest point of the inner circle contour line of the heat exchange channel 11 is the position in the heat exchange channel 11 closest to the top of the battery cell 2 and the cooler 4 .

[0080] The top of the battery cell 2 of the battery pack is closer to the cooler 4, so the temperature drops first, forming a temperature difference with the bottom of the battery cell 2. The lowest point of the inner circle contour is close to the bottom of the heat exchange plate 1, and the bottom of the heat exchange plate 1 is located at the bottom of the battery cell 2 and close to the bottom of the tray 3, so that the refrigerant at the lowest point of the inner circle contour of the heat exchange flow channel 11 absorbs heat and evaporates into a gas-phase refrigerant; the highest point of the inner circle contour is close to the top of the heat exchange plate 1, and the top of the heat exchange plate 1 is located at the top of the battery cell 2 and close to the cooler 4, so that the gas-phase refrigerant exchanges heat with the cold energy of the cooler 4 and liquefies into a liquid-phase refrigerant.

[0081] The flow of the ascending flow channel 111 is smaller than that of the descending flow channel 112, and the flow resistance of the gas-phase refrigerant in the ascending flow channel 111 is smaller. The gas-phase refrigerant produced by evaporation tends to rise from the ascending flow channel 111. Since the flow resistance of the refrigerant circulation is reduced, the convective heat transfer capacity of the refrigerant in the heat exchange plate 1 is improved, thereby improving the heat exchange capacity between the upper and lower parts of the battery cell 2, reducing the temperature difference between the upper and lower parts of the battery cell 2, and improving the temperature uniformity of the battery cell 2.

[0082] like Figure 5 and Figure 6As shown, the working principle of the heat exchange plate 1 is as follows: when the battery pack is charged and discharged under high temperature conditions and the cooling is turned on, the top of the battery pack cell 2 is closer to the cooler 4, and the temperature drops first, forming a temperature difference with the bottom of the cell 2. Since the temperature of the lower part of the large surface of the cell 2, the bottom and the tray 3 is relatively high, the heat is transferred to the refrigerant inside the heat exchange plate 1. The refrigerant in the high temperature area of ​​the heat exchange plate 1 close to the cell 2 evaporates first, and the gas phase refrigerant formed after evaporation and the gas-liquid mixed refrigerant formed during evaporation rise along the heat exchange flow channel 11 to the top of the heat exchange plate 1 under the action of buoyancy. The gas phase refrigerant and the gas-liquid mixed refrigerant release heat to the upper part of the cell 2 and the cooler 4, and become liquid after condensation. Most of the liquid phase refrigerant and the gas-liquid mixed refrigerant in condensation flow back to the bottom of the heat exchange plate 1 along the heat exchange flow channel 11 under the action of gravity, forming an evaporation-condensation cycle.

[0083] In some embodiments, Figure 4 As shown, the descending flow channel 112 includes a first flow channel 1121, a second flow channel 1122 and a third flow channel 1123 connected in sequence, and the ascending flow channel 111 includes a fourth flow channel 1111 and a fifth flow channel 1112 connected in sequence.

[0084] The inner circle contour line of the rising flow channel 111 increases monotonically along the gravity direction, that is, the height increases sequentially from the end of the fourth flow channel 1111 away from the fifth flow channel 1112 to the end of the fifth flow channel 1112 away from the fourth flow channel 1111.

[0085] The inner circle contour line of the descending channel 112 decreases monotonically along the gravity direction, that is, the height decreases sequentially from the end of the first channel 1121 connected to the fifth channel 1112 to the end of the third channel 1123 connected to the fourth channel 1111.

[0086] The lower end of the first flow channel 1121 is connected to the upper end of the second flow channel 1122, the lower end of the second flow channel 1122 is connected to the upper end of the third flow channel 1123, the lower end of the third flow channel 1123 is connected to the lower end of the fourth flow channel 1111, the upper end of the fourth flow channel 1111 is connected to the lower end of the fifth flow channel 1112, and the upper end of the fifth flow channel 1112 is connected to the upper end of the first flow channel 1121.

[0087] The upper end of the fifth flow channel 1112 is higher than the upper end of the second flow channel 1122 along the direction of gravity, that is, the upper end of the first flow channel 1121 is higher than the lower end of the first flow channel 1121 along the direction of gravity. The first flow channel 1121 is inclined downward along the direction of gravity, and the liquid refrigerant can flow downward along the first flow channel 1121 to the second flow channel 1122 under the action of gravity.

[0088] like Figure 5As shown, when the temperature difference between the upper and lower parts of the battery core 2 is small, the working principle is as follows: due to the high temperature of the lower part of the large surface of the battery core 2, the bottom and the tray 3, the heat is transferred to the refrigerant inside the heat exchange plate 1, so that the refrigerant at the lower end of the third flow channel 1123 and the refrigerant at the lower end of the fourth flow channel 1111 evaporate first to form bubbles, and the evaporated gaseous refrigerant and the gas-liquid mixed refrigerant rise along the third flow channel 1123 and the fourth flow channel 1111 under the action of buoyancy to reach the top of the heat exchange plate 1, that is, the first At the upper end of the fifth flow channel 1112, the gaseous refrigerant releases heat to the upper part of the battery cell 2 and the cooler 4, and the gaseous refrigerant condenses into liquid. Most of the liquid and gas-liquid mixed refrigerant flow back to the bottom of the heat exchange plate 1 along the first flow channel 1121 and the second flow channel 1122 under the action of gravity. A liquid film is formed on the wall surface of the first flow channel 1121, part of the wall surface of the second flow channel 1122 and part of the wall surface of the fifth flow channel 1112, and a small amount of liquid flows back along the wall surface of the fifth flow channel 1112 to form an evaporation-condensation cycle.

[0089] In this embodiment, the first flow channel 1121 to the fifth flow channel 1112 can be straight flow channels or curved flow channels, as long as they can conform to the upward trend of the ascending flow channel 111 and the downward trend of the descending flow channel 112 .

[0090] Various combinations, splits, additions and reductions of the flow channels in the above solutions are all within the protection scope of the present invention.

[0091] In some embodiments, Figure 4 As shown, the second flow channel 1122 and the fifth flow channel 1112 extend along the gravity direction, which can reduce the circulation resistance of the refrigerant. The liquid refrigerant refluxes along the second flow channel 1122, and the gas refrigerant rises along the fifth flow channel 1112.

[0092] The flow area of ​​the fifth flow channel 1112 is larger than the flow area of ​​the second flow channel 1122, that is, the hydraulic diameter of the fifth flow channel 1112 is larger than the hydraulic diameter of the second flow channel 1122. Therefore, the flow resistance of the gaseous refrigerant in the ascending flow channel 111 is smaller, and the gaseous refrigerant generated by evaporation tends to rise from the ascending flow channel 111.

[0093] In some embodiments, the second flow channel 1122 and the fifth flow channel 1112 extend along the gravity direction, the liquid refrigerant refluxes along the second flow channel 1122, and the gas refrigerant rises along the fifth flow channel 1112, which can reduce the circulation resistance of the refrigerant.

[0094] In some embodiments, Figure 4As shown, the flow area of ​​the fifth flow channel 1112 is larger than the flow area of ​​the second flow channel 1122, that is, the hydraulic diameter d2 of the fifth flow channel 1112 is larger than the hydraulic diameter d1 of the second flow channel 1122. Therefore, the flow resistance of the gaseous refrigerant in the ascending flow channel 111 is smaller, and the gaseous refrigerant generated by evaporation tends to rise from the ascending flow channel 111.

[0095] In some embodiments, Figure 4 As shown, it satisfies: 0°<θ1≤25°, 0°<θ2≤45°, 0°<θ3≤45°, wherein θ1 is the inclination angle of the first flow channel 1121 with the horizontal direction, θ2 is the inclination angle of the third flow channel 1123 with the horizontal direction, and θ3 is the inclination angle of the fourth flow channel 1111 with the horizontal direction.

[0096] Among them, the first flow channel 1121 is inclined downward along the direction of gravity and the inclination angle θ1 with the horizontal direction can be 5°, 10°, 15°, 20° or 25°, so that the liquid refrigerant can reflux along the first flow channel 1121 to reduce the reflux resistance of the refrigerant.

[0097] The third flow channel 1123 is inclined downward along the gravity direction and the inclination angle θ2 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the liquid refrigerant can reflux along the third flow channel 1123 to reduce the reflux resistance of the refrigerant.

[0098] The fourth flow channel 1111 is inclined upward along the gravity direction and the inclination angle θ3 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the gas-phase refrigerant can rise along the third flow channel 1123 to reduce the circulation resistance of the refrigerant.

[0099] In this embodiment, by setting the inclination angles of the first flow channel 1121 , the third flow channel 1123 and the fourth flow channel 1111 , the reflux resistance of the refrigerant can be reduced and the heat exchange effect of the heat exchange plate 1 can be improved.

[0100] In some embodiments, Figure 4 As shown, the following conditions are satisfied: 0°<θ1≤25°, 0°<θ2≤45°, wherein θ1 is the inclination angle of the first flow channel 1121 with respect to the horizontal direction, and θ2 is the inclination angle of the third flow channel 1123 with respect to the horizontal direction.

[0101] Among them, the first flow channel 1121 is inclined downward along the direction of gravity and the inclination angle θ1 with the horizontal direction can be 5°, 10°, 15°, 20° or 25°, so that the liquid refrigerant can flow back along the first flow channel 1121; the third flow channel 1123 is inclined downward along the direction of gravity and the inclination angle θ2 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°.

[0102] In this embodiment, by setting the inclination angles of the first flow channel 1121 and the third flow channel 1123 , the reflux resistance of the refrigerant can be reduced and the heat exchange effect of the heat exchange plate 1 can be improved.

[0103] In some embodiments, Figure 4 As shown, it satisfies: 0°<θ1≤25°, where θ1 is the inclination angle of the first flow channel 1121 with the horizontal direction; it satisfies: 0°<θ3≤45°, where θ3 is the inclination angle of the fourth flow channel 1111 with the horizontal direction.

[0104] Among them, the first flow channel 1121 is inclined downward along the direction of gravity and the inclination angle θ1 with the horizontal direction can be 5°, 10°, 15°, 20° or 25°, so that the liquid refrigerant can flow back along the first flow channel 1121; the fourth flow channel 1111 is inclined upward along the direction of gravity and the inclination angle θ3 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the gas-phase refrigerant can rise along the third flow channel 1123.

[0105] In this embodiment, by setting the inclination angles of the first flow channel 1121 and the fourth flow channel 1111 , the reflux resistance of the refrigerant can be reduced and the heat exchange effect of the heat exchange plate 1 can be improved.

[0106] In some embodiments, Figure 4 As shown, the following conditions are satisfied: 0°<θ2≤45°, where θ2 is the inclination angle of the third flow channel 1123 with the horizontal direction; and the following conditions are satisfied: 0°<θ3≤45°, where θ3 is the inclination angle of the fourth flow channel 1111 with the horizontal direction.

[0107] The third flow channel 1123 is inclined downward along the direction of gravity and the inclination angle θ2 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the liquid refrigerant can flow back along the third flow channel 1123; the fourth flow channel 1111 is inclined upward along the direction of gravity and the inclination angle θ3 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the gas-phase refrigerant can rise along the third flow channel 1123.

[0108] In this embodiment, by setting the inclination angles of the third flow channel 1123 and the fourth flow channel 1111 , the reflux resistance of the refrigerant can be reduced and the heat exchange effect of the heat exchange plate 1 can be improved.

[0109] In some embodiments, Figure 4 As shown, it satisfies: 0°<θ1≤25°, where θ1 is the inclination angle of the first flow channel 1121 and the horizontal direction.

[0110] Among them, the first flow channel 1121 is inclined downward along the direction of gravity and the inclination angle θ1 with the horizontal direction can be 5°, 10°, 15°, 20° or 25°, so that the liquid refrigerant can reflux along the first flow channel 1121 to reduce the reflux resistance of the refrigerant.

[0111] In some embodiments, Figure 4 As shown, it satisfies: 0°<θ2≤45°, wherein θ2 is the inclination angle of the third flow channel 1123 with the horizontal direction.

[0112] The third flow channel 1123 is inclined downward along the gravity direction and the inclination angle θ2 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the liquid refrigerant can reflux along the third flow channel 1123 to reduce the reflux resistance of the refrigerant.

[0113] In some embodiments, Figure 4 As shown, it satisfies: 0°<θ3≤45°, where θ3 is the inclination angle of the fourth flow channel 1111 and the horizontal direction.

[0114] The fourth flow channel 1111 is inclined upward along the gravity direction and the inclination angle θ3 with the horizontal direction can be 5°, 15°, 25°, 30° or 45°, so that the gas-phase refrigerant can rise along the third flow channel 1123 to reduce the circulation resistance of the refrigerant.

[0115] In this embodiment, if Figure 6 As shown, the heat exchange plate 1 can form a pressure difference between the gas column and the liquid column in the ascending flow channel 111 and the descending flow channel 112 in the heat exchange plate 1 by designing the inclination angle and size of the internal flow channel and utilizing the height of the battery cell 2 itself when the temperature difference between the upper and lower parts of the battery is large, thereby realizing self-driving under the action of gravity.

[0116] In some embodiments, Figure 4 As shown, the heat exchange channel 11 further includes a sixth channel 113, which is disposed between the third channel 1123 and the fourth channel 1111, and extends in a horizontal direction and is close to the bottom end of the heat exchange plate 1 in the direction of gravity.

[0117] The sixth flow channel 113 is located at the lowest point of the heat exchange plate 1 . When a temperature difference is formed between the upper and lower parts of the battery core 2 , the refrigerant in the sixth flow channel 113 evaporates first.

[0118] By providing the sixth flow channel 113, the flow channel length of the heat exchange flow channel 11 close to the bottom of the battery cell 2 can be increased, thereby increasing the heat exchange area between the heat exchange flow channel 11 and the high temperature area at the bottom of the battery cell 2, and improving the heat exchange effect.

[0119] In some embodiments, Figure 4As shown, the inclination angle of the fourth flow channel 1111 with the horizontal direction is greater than the inclination angle of the third flow channel 1123 with the horizontal direction, so that the flow resistance of the gaseous refrigerant in the fourth flow channel 1111 is smaller, and the gaseous refrigerant generated by evaporation is more inclined to rise from the fourth flow channel 1111, thereby reducing the flow resistance of the cycle and improving the convective heat exchange capacity of the refrigerant in the heat exchange plate 1.

[0120] like Figure 6 As shown, when the heat generated by the battery core 2 is large, the temperature difference between the upper and lower parts of the battery core 2 is large. The working principle is as follows: the heat input from the battery core 2 and the tray 3 to the heat exchange plate 1 increases, so that the dryness of the refrigerant at the bottom of the heat exchange plate 1 increases. Since the horizontal inclination angle of the fourth flow channel 1111 is larger, and the hydraulic diameter of the fifth flow channel 1112 is larger than that of the second flow channel 1122, and the process of the ascending flow channel 111 is shorter than that of the descending flow channel 112, the flow resistance of the gaseous refrigerant in the ascending flow channel 111 is smaller, and the gaseous refrigerant generated by evaporation is more inclined to rise from the ascending flow channel 111; at the top of the heat exchange plate 1, the gaseous refrigerant is discharged to the upper part of the battery core 2 and the cooler 4. Heat is condensed into liquid and flows back along the first flow channel 1121 under the action of gravity, forming a liquid column in the descending flow channel 112; a height difference is formed between the liquid levels in the descending flow channel 112 and the ascending flow channel 111, and driven by the pressure difference generated by the gas-liquid density difference, the refrigerant forms a one-way circulation in the heat exchange plate 1; relative to the integrated gravity heat pipe, the heat exchange plate 1 of the present application separates the flow channels of the gaseous and liquid refrigerants, reduces the flow resistance of the circulation, and improves the convective heat exchange capacity of the refrigerant in the heat exchange plate 1, thereby improving the heat exchange capacity between the upper and lower parts of the battery cell 2, reducing the upper and lower temperature difference of the battery cell 2, and improving the temperature uniformity of the battery cell 2.

[0121] Among them, the first flow channels 1121 can be channels of equal width, or channels with a flow cross-sectional area that gradually increases or decreases; the third flow channels 1123 can be channels of equal width, or channels with a flow cross-sectional area that gradually increases or decreases; the fourth flow channels 1111 can be channels of equal width, or channels with a flow cross-sectional area that gradually increases or decreases.

[0122] The flow cross-sectional area of ​​the flow channel is determined according to the height of the battery core and the specifications of the heat exchange plate 1 .

[0123] In some embodiments, Fig. 9 As shown, the flow cross-sectional area of ​​the fourth flow channel 1111 gradually increases from the end connected to the third flow channel 1123 to the end connected to the fifth flow channel 1112 to form an evaporation chamber 114, which can increase the flow channel length of the fourth flow channel 1111 close to the bottom of the battery cell 2, thereby increasing the heat exchange area between the fourth flow channel 1111 and the high temperature zone where the bottom of the battery cell 2 is located, increasing the evaporation amount, and increasing the refrigerant circulation rate, thereby improving the heat exchange effect.

[0124] The flow cross-sectional area of ​​the first flow channel 1121 gradually increases from the end connected to the fifth flow channel 1112 to the end connected to the second flow channel 1122 to form a condensation chamber 115, which can increase the flow channel length of the first flow channel 1121 close to the top of the battery cell 2 and the cooler 4, thereby increasing the heat exchange area between the first flow channel 1121 and the low-temperature zone where the top of the battery cell 2 and the cooler 4 are located, increasing the condensation amount, and increasing the refrigerant circulation rate, thereby improving the heat exchange effect.

[0125] In some embodiments, the first flow channel 1121 includes a first guide surface and a condensation surface, the condensation surface extends along the top of the heat exchange plate 1, and the first guide surface is inclined downward along the direction of gravity from the end connected to the fifth flow channel 1112 to the end connected to the second flow channel 1122, thereby further increasing the heat exchange area between the condensation chamber 115 and the top of the battery cell 2 and the low temperature zone where the cooler 4 is located.

[0126] The fourth flow channel 1111 includes a second guide surface and an evaporation surface. The evaporation surface extends along the bottom end of the heat exchange plate 1. The second guide surface is inclined upward along the gravity direction from one end connected to the third flow channel 1123 to one end connected to the fifth flow channel 1112, thereby further increasing the heat exchange area between the fourth flow channel 1111 and the high temperature zone where the bottom of the battery cell 2 is located, increasing the evaporation amount, increasing the refrigerant circulation rate, and thus improving the heat exchange effect.

[0127] In some embodiments, Figure 5 and Fig. 9 As shown, the first flow channel 1121, the second flow channel 1122, the third flow channel 1123 and the fourth flow channel 1111 each include two groups, and the two groups of first flow channels 1121, the two groups of second flow channels 1122, the two groups of third flow channels 1123 and the two groups of fourth flow channels 1111 are symmetrically distributed on both sides of the fifth flow channel 1112 with the fifth flow channel 1112 as the axis of symmetry.

[0128] In this embodiment, the heat exchange channels 11 are symmetrically arranged, and the symmetrically arranged channels share the fifth channel 1112, which can make the refrigerant flow evenly in the first channel 1121, the second channel 1122, the third channel 1123 and the fourth channel 1111 on both sides, thereby increasing the refrigerant circulation rate, thereby improving the heat exchange effect and improving the temperature uniformity of the battery cell 2.

[0129] In some embodiments, Fig. 9 and Fig.10 As shown, the heat exchange plate 1 further includes a pressure relief valve 135 , and the pressure relief valve 135 is connected to the heat exchange flow channel 11 .

[0130] In this embodiment, the pressure relief port of the pressure relief valve 135 faces the side of the battery cell 2. When the battery cell 2 has thermal runaway, the temperature of the refrigerant rises sharply, causing the pressure in the heat exchange plate 1 to increase. When the pressure value exceeds the threshold of the pressure relief valve 135, the pressure relief valve 135 opens, and the liquid refrigerant is sprayed from the pressure relief port into the battery pack and directly contacts the battery cell 2. The liquid refrigerant absorbs the heat of the battery cell 2 and evaporates, thereby reducing the temperature of the battery cell 2, suppressing the thermal runaway of the battery cell 2, and reducing the harm of the thermal runaway of the battery cell 2.

[0131] Among them, the pressure relief valve 135 is arranged at a position of the heat exchange channel 11 close to the bottom of the heat exchange plate 1 and is arranged below the liquid surface of the refrigerant, so that when the pressure relief valve 135 is opened, the volume of the liquid phase refrigerant sprayed from the heat exchange channel 11 is increased, thereby improving the cooling effect of thermal runaway of the battery cell 2.

[0132] In some embodiments, the outer circle contour lines of the fourth flow channel 1111 located on both sides of the fifth flow channel 1112 extend in the horizontal direction and are connected, so that the liquid refrigerant on both sides can be sprayed out from the pressure relief port, thereby maximizing the cooling effect of the refrigerant inside the heat exchange plate 1 when the battery cell 2 thermally runs away.

[0133] In some embodiments, Figure 8 As shown, welding bolts 136 are provided on the heat exchange plate 1 , the welding bolts 136 are communicated with the heat exchange flow channel 11 , and the pressure relief valve 135 is sealedly connected with the welding bolts 136 .

[0134] The welding bolts 136 can be fixed to the heat exchange plate 1 by brazing, and the sealing effect can be achieved by threaded fixing on the welding bolts 136.

[0135] In some embodiments, a protrusion is provided on one side of the heat exchange plate 1 in the horizontal direction, a part of the heat exchange channel 11 is provided in the protrusion, and a welding bolt 136 is provided on one side of the protrusion.

[0136] In this embodiment, when the temperature difference between the upper and lower parts of the battery cell 2 is large, the vapor generated by the refrigerant absorbing heat cannot carry the liquid refrigerant into the fifth flow channel 1112 due to the large flow cross-sectional area of ​​the evaporation chamber 114 formed by the fourth flow channel 1111. The thermodynamic state of the refrigerant in the fifth flow channel 1112 is a saturated or superheated gas phase. The refrigerant circulates under the drive of the pressure difference formed between the second flow channel 1122 and the fifth flow channel 1112 to achieve heat exchange between the refrigerant and the battery cell 2. When the battery cell 2 has thermal runaway, the temperature of the refrigerant rises sharply, increasing the pressure in the heat exchange plate 1. When the pressure value exceeds the threshold of the pressure relief valve 135, the pressure relief valve 135 opens, and the liquid refrigerant sprays out from the pressure relief port into the battery pack and directly contacts the battery cell 2, absorbing the heat of the battery cell 2 and evaporating, thereby reducing the temperature of the battery cell 2, thereby achieving the function of suppressing the thermal runaway of the battery cell 2.

[0137] In some embodiments, Fig.11As shown, the heat exchange plate 1 is further provided with a thinning area 137 , and the thinning area 137 is located in the heat exchange channel 11 .

[0138] In this embodiment, the welding bolts and the pressure relief valve 135 in the above embodiment can be replaced by a local thinning area 137. The structural strength of the thinning area 137 is weaker than that of other areas of the heat exchange channel 11 formed by the heat exchange plate 1. Therefore, the pressure value that the thinning area 137 can withstand is smaller than the pressure value of other areas of the heat exchange channel 11.

[0139] In this embodiment, when the temperature difference between the upper and lower parts of the battery cell 2 is large, the vapor generated by the refrigerant absorbing heat cannot carry the liquid refrigerant into the fifth flow channel 1112 due to the large flow cross-sectional area of ​​the evaporation chamber 114 formed by the fourth flow channel 1111. The thermodynamic state of the refrigerant in the fifth flow channel 1112 is a saturated or superheated gas phase. The refrigerant circulates under the pressure difference formed between the second flow channel 1122 and the fifth flow channel 1112 to achieve heat exchange between the refrigerant and the battery cell 2. When the battery cell 2 has thermal runaway, the temperature of the refrigerant rises sharply, increasing the pressure in the heat exchange plate 1. When the pressure value exceeds the pressure threshold that the thinning area 137 can withstand, the refrigerant breaks through the thinning area 137, and the liquid refrigerant sprays out from the thinning area 137 into the battery pack and directly contacts the battery cell 2, absorbing the heat of the battery cell 2 and evaporating, thereby reducing the temperature of the battery cell 2, and realizing the function of suppressing the thermal runaway of the battery cell 2.

[0140] In some embodiments, the thickness range of the thinned area 137 satisfies 0.05 mm to 0.5 mm, for example, it can be 0.05 mm, 0.1 mm, 0.2 mm, 0.35 mm, 0.4 mm or 0.5 mm. The specific thickness is determined according to the actual bursting pressure requirement of the heat exchange plate 1. This structure can achieve the function of suppressing thermal runaway of the battery cell 2 at a lower cost.

[0141] In this embodiment, by providing the thinning area 137 or the pressure relief valve 135, when thermal runaway occurs in the battery cell 2, the pressure inside the heat exchange plate 1 can be used to spray the liquid refrigerant into the battery cell 2, so that the battery cell 2 can be cooled quickly and the thermal runaway process can be suppressed.

[0142] In some embodiments, Figure 7 As shown, the heat exchange plate 1 includes a first portion 12 and a second portion 13 , and the first portion 12 and the second portion 13 together define a heat exchange channel 11 .

[0143] The materials of the first part 12 and the second part 13 can be copper alloy or aluminum alloy, and the first part 12 and the second part 13 can be formed into one piece by brazing.

[0144] The heat exchange channel 11 may be disposed in the first portion 12 , or in the second portion 13 , or a portion of the channel may be disposed in the first portion 12 and another portion of the channel may be disposed in the second portion 13 .

[0145] The first part 12 and the second part 13 can be formed by a process of first stamping and then machining, and then integrated by brazing.

[0146] In some embodiments, a flow groove of the heat exchange channel 11 is provided on the inner side of the first part 12, and the port of the flow groove is open. The second part 13 is a flat plate structure. When the first part 12 and the second part 13 are connected, the second part 13 covers the notch of the flow groove of the first part 12, and the first part 12 and the second part 13 jointly define the heat exchange channel 11.

[0147] In some embodiments, a first flow channel 1121 groove of the heat exchange channel 11 is disposed on the inner side of the first part 12, and a second flow channel 1122 groove of the heat exchange channel 11 is disposed on the inner side of the second part 13. The first flow channel 1121 groove and the second flow channel 1122 groove are aligned and their ports are both open. When the first part 12 and the second part 13 are connected, the first flow channel 1121 groove and the second flow channel 1122 groove are connected to form a closed heat exchange channel 11, and the first part 12 and the second part 13 jointly define the heat exchange channel 11.

[0148] In some embodiments, the first portion 12 and the second portion 13 have at least the following structures:

[0149] First, if Figure 7 As shown, the outer side of the first part 12 and the outer side of the second part 13 are provided with a first boss 131 and a second boss 132 , which are arranged spaced apart along the gravity direction and are used to connect with the battery cell 2 .

[0150] In this embodiment, the first boss 131 and the second boss 132 are provided on both sides of the heat exchange plate 1. Both sides of the heat exchange plate 1 can exchange heat with the battery cells 2, which is suitable for the case where there are battery cells 2 on both sides.

[0151] The first boss 131 and the second boss 132 are spaced apart from each other, and a groove 133 is formed between the first boss 131 and the second boss 132 . The top surface of the first portion 12 away from the first boss 131 and the top surface of the second boss 132 away from the first portion 12 are used for connecting with the battery cell 2 .

[0152] Among them, by spacing the first boss 131 and the second boss 132 apart to form a groove 133, on the one hand, the heat leakage from the middle part of the heat exchange plate 1 along the gravity direction to the battery cell 2 can be reduced, thereby increasing the heat exchange capacity of the lower and upper parts of the battery cell 2; on the other hand, the heat leakage of the battery cell 2 under low temperature conditions can be reduced.

[0153] Second, if Figure 2As shown, a first boss 131 and a second boss 132 are disposed on the outer side of the first portion 12 . The first boss 131 and the second boss 132 are arranged spaced apart along the gravity direction. The first boss 131 and the second boss 132 are used to connect with the battery cell 2 .

[0154] The first portion 12 of the heat exchange plate 1 of this embodiment is connected to the outer side of the battery core 2 to dissipate heat on one side of the battery core 2, and is suitable for the case where there is a battery core 2 on one side.

[0155] Third, if Figure 2 As shown, a first boss 131 and a second boss 132 are disposed on the outer side of the second portion 13 . The first boss 131 and the second boss 132 are arranged spaced apart along the gravity direction. The first boss 131 and the second boss 132 are used to connect with the battery cell 2 .

[0156] The second portion 13 of the heat exchange plate 1 of this embodiment is connected to the outer side of the battery core 2 to dissipate heat on one side of the battery core 2, and is suitable for the case where there is a battery core 2 on one side.

[0157] In some embodiments, the top surface of the first boss 131 facing away from the first portion 12 and the top surface of the second boss 132 facing away from the first portion 12 are both coated with thermally conductive structural adhesive, and the first boss 131 and the second boss 132 are connected to the battery cell 2 through the thermally conductive structural adhesive.

[0158] In this embodiment, the heat exchange plate 1 is bonded and heat is transferred to the battery core 2 through a heat-conducting structural adhesive.

[0159] In some embodiments, the first portion 12 and the second portion 13 are positioned and matched to facilitate fixing of the relative positions of the first portion 12 and the second portion 13 during brazing.

[0160] For example, Figure 1 As shown, one of the first part 12 and the second part 13 is provided with a positioning hole 134, and the other of the first part 12 and the second part 13 is provided with a positioning pin; or, both the first part 12 and the second part 13 are provided with a positioning hole 134, and the heat exchange plate 1 also includes a positioning pin, which passes through the positioning hole 134 of the first part 12 and the positioning hole 134 of the second part 13.

[0161] In some embodiments, Figure 7 As shown, the heat exchange plate 1 is further provided with a liquid injection pipe 14 , which is connected to the heat exchange channel 11 for injecting refrigerant into the heat exchange channel 11 .

[0162] Among them, when the first part 12 is provided with a heat exchange channel 11, the injection pipe 14 can be formed into one with the first part 12 by brazing; or, when the second part 13 is provided with a heat exchange channel 11, the injection pipe 14 can be formed into one with the second part 13 by brazing; or, when the first part 12 and the second part 13 are both provided with a heat exchange channel 11, the injection pipe 14 can be formed into one with the first part 12 and the second part 13 by brazing.

[0163] The injection pipe 14 may be arranged at the top of the heat exchange plate 1 along the gravity direction, so as to utilize the gravity of the refrigerant itself to inject liquid and increase the injection rate.

[0164] In some embodiments, Figure 2 and Figure 7 As shown, a first avoidance groove 138 is provided on the top of the heat exchange plate 1, and the inlet of the injection pipe 14 is located in the first avoidance groove 138, so that when the heat exchange plate 1 and the battery cell 2 are assembled, the outer edge of the heat exchange plate 1 does not protrude from the outer contour of the battery cell 2.

[0165] In some embodiments, Figure 2 and Figure 7 As shown, the heat exchange plate 1 is further provided with a second avoidance groove 139 , and the second avoidance groove 139 is used to avoid the temperature detection device of the battery cell 2 .

[0166] In some embodiments, the heat exchange plate 1 satisfies: 21.5%≤V1 / V2≤64.5%. For example, V1 / V2 may be 25%, 35%, 43%, 50% or 60%. The specific filling rate may be determined by the actual minimum heat transfer resistance.

[0167] Wherein, V1 is the liquid filling amount of the refrigerant in the heat exchange flow channel 11 , V2 is the total capacity of the heat exchange flow channel 11 , and V1 / V2 is the liquid filling rate of the heat exchange flow channel 11 .

[0168] like Fig.13 As shown, the refrigerant filling method of the heat exchange plate 1 is as follows: the filling port of the heat exchange plate 1 is connected to the vacuum pump 81 and the refrigerant storage tank 82 through pipelines, the stop valve 83 is opened, and the vacuum pump 81 is started to evacuate the inside of the heat exchange channel 11 of the heat exchange plate 1 and the inside of the pipeline. After completion, the stop valve 83 is closed, and the valve on the refrigerant storage tank 82 is opened to allow the refrigerant to be poured into the heat exchange channel 11 of the heat exchange plate 1; when the filling rate reaches the set volume filling rate, the valve on the refrigerant storage tank 82 is closed to stop the filling, the filling port of the filling pipe 14 is squeezed flat by a sealing mold, the connecting pipe 84 is removed, and the filling port is welded and sealed by laser welding or argon arc welding.

[0169] In some embodiments, the heat exchange plate 1 includes a body and an insulating layer, the insulating layer is disposed on the outer surface of the body, and the heat exchange channel 11 is disposed in the body.

[0170] Before the heat exchange plate 1 is assembled with the battery cell 2, an insulating layer needs to be provided on the surface of the body of the heat exchange plate 1 to improve the insulation performance of the heat exchange plate 1, thereby reducing the risk of arcing and fire caused by opening the explosion-proof valve of the battery cell 2.

[0171] The insulating layer may be epoxy resin powder or epoxy resin paint, or a wrapping layer formed by an insulating PI film or a PET film.

[0172] The present application also provides a battery module 100, such as Figure 3 As shown, it includes a battery cell 2 and a heat exchange plate 1 as in any of the above embodiments, and the heat exchange plate 1 is arranged on the side of the battery cell 2.

[0173] During assembly, the outer contour of the edge of the heat exchange plate 1 is kept flush with the outer contour of the battery cell 2 to improve the heat dissipation effect, while reducing the encroachment of the heat exchange plate 1 on the battery box and improving the accuracy of assembly.

[0174] The battery module 100 provided in the embodiment of the present application is provided with the heat exchange plate 1 in the above embodiment on the side of the battery cell 2, and the heat exchange plate 1 is provided with an ascending flow channel 111 and a descending flow channel 112 connected end to end. When the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the lower end of the heat exchange plate 1 exchanges heat with the lower part of the battery cell 2 and the tray 3, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate 1. The refrigerant changes from liquid phase to gas phase at the lower end of the heat exchange plate 1, and the gas phase refrigerant is in the floating state. Under the action of gravity, the gaseous refrigerant flows along the ascending flow channel 111 to the upper end of the heat exchange plate 1; the upper end of the heat exchange plate 1 exchanges heat with the upper part of the battery cell 2 and the cooler 4, and the gaseous refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate 1. Under the action of gravity, the liquid refrigerant flows along the lower ascending flow channel to the lower end of the heat exchange plate 1, forming a refrigerant reflux, thereby achieving efficient heat exchange between the upper and lower areas of the battery cell 2 through the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle, and effectively reducing the overall temperature difference of the battery module 100. Compared with the solution of setting a cooler 4 above and below the battery cell 2 in the height direction, the cost and weight of the battery module 100 are reduced, and the structure is simple.

[0175] In some embodiments, the battery module 100 also includes a tray 3 and a cooler 4, the cooler 4 is arranged on the top of the battery cell 2 along the direction of gravity, the battery cell 2 and the heat exchange plate 1 are arranged on the tray 3, the top end of the heat exchange plate 1 along the direction of gravity is close to the cooler 4, and the bottom end of the heat exchange plate 1 along the direction of gravity is close to the bottom of the tray 3.

[0176] In some embodiments, Fig.12As shown, the heat exchange plate 1 is installed on both sides of the battery module 100 or in the middle of the adjacent battery module 100. Along the direction of gravity, the cooler 4 and the top insulation cotton 5 are installed from bottom to top above the battery module 100. The cooler 4, the top of the battery module 100 and the top of the heat exchange plate 1 are bonded with thermal conductive structural adhesive. The tray 3, the bottom of the battery module 100 and the bottom of the heat exchange plate 1 are bonded with thermal conductive structural adhesive. A plastic bracket 8 is placed between the tray 3 and the heat exchange plate 1 to fill the gap in the second direction of the battery pack, wherein the second direction is the horizontal direction perpendicular to the direction of gravity.

[0177] Bottom heat-insulating cotton 6 and bottom guard plate 7 are installed in sequence from top to bottom under the tray 3 .

[0178] An embodiment of the present application further provides a battery pack, comprising a battery module 100 as described in any of the above embodiments.

[0179] The battery pack provided in the embodiment of the present application is provided with the battery module 100 in the above embodiment. The battery module 100 is provided with the heat exchange plate 1 in the above embodiment on the side of the battery cell 2. The heat exchange plate 1 is provided with an ascending flow channel 111 and a descending flow channel 112 connected end to end. When the temperature difference of the battery cell along the height direction is greater than the temperature threshold, the lower end of the heat exchange plate 1 exchanges heat with the lower part of the battery cell 2 and the tray 3, and the refrigerant absorbs heat and evaporates at the lower end of the heat exchange plate 1. The refrigerant changes from a liquid phase to a liquid phase at the lower end of the heat exchange plate 1. The gas phase refrigerant flows to the upper end of the heat exchange plate 1 along the ascending flow channel 111 under the action of buoyancy; the upper end of the heat exchange plate 1 exchanges heat with the upper part of the battery cell 2 and the cooler 4, and the gas phase refrigerant releases heat and liquefies when it encounters cold at the upper end of the heat exchange plate 1, and the liquid phase refrigerant flows to the lower end of the heat exchange plate 1 along the lower ascending flow channel under the action of gravity, forming a refrigerant reflux, thereby achieving efficient heat exchange between the upper and lower areas of the battery cell 2 through the high heat transfer capacity formed by the refrigeration evaporation-condensation cycle, and effectively reducing the overall temperature difference of the battery module 100. Compared with the solution of setting a cooler 4 above and below the height direction of the battery cell 2, the cost and weight of the battery module 100 are reduced, and the structure is simple.

[0180] The embodiment of the present application further provides an electrical device, comprising a battery module 100 as described in any of the above embodiments.

[0181] Among them, the electrical equipment can be a vehicle, a water heater or other energy storage device.

[0182] The electrical equipment provided in the embodiment of the present application is provided with the battery pack in the above embodiment, which can realize all the functions of the battery pack in the above embodiment, reduce the cost and weight of the battery module 100, and improve the safety and reliability of the electrical equipment.

[0183] In the technical solution of the present application, the electric device is a device or system that relies on electric energy to work. The battery module 100 serves as the main power source of the electric device and is connected to other parts of the electric device through an output port to provide a stable and reliable power supply for the electric device.

[0184] In addition to batteries, electrical equipment may also include other components or systems for realizing its specific functions, such as control circuits, motors, sensors, etc., which are driven and controlled by electrical energy to realize various functions of the electrical equipment.

[0185] It is understandable that electrical equipment uses batteries as its main source of electricity, which has the advantages of continuous power supply, good stability, high portability, energy saving and environmental protection, and is suitable for various equipment and systems that require electrical energy to drive.

[0186] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0187] In the description of the present application, 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 application 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 application.

[0188] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0189] In the description of the present application, “plurality” means two or more.

[0190] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0191] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0192] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means 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 application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0193] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A heat exchange plate, characterized in that: Arranged on the side of the battery core, the heat exchange plate includes: refrigerant; A heat exchange flow channel, in which the refrigerant is arranged, and the heat exchange flow channel includes an ascending flow channel and a descending flow channel which are connected end to end. When the temperature difference of the battery cell along the height direction is greater than a temperature threshold, the ascending flow channel is used to pass the refrigerant in the process of evaporation or after evaporation, and the descending flow channel is used to pass the refrigerant in the process of condensation or after condensation.

2. The heat exchange plate according to claim 1, characterized in that: The heat exchange channel is annular, and the ascending channel is formed along the first direction between the lowest point and the highest point of the inner circle contour line of the heat exchange channel, and the descending channel is formed along the first direction between the highest point and the lowest point of the inner circle contour line of the heat exchange channel, and the flow rate of the ascending channel is smaller than the flow rate of the descending channel.

3. The heat exchange plate according to claim 1, characterized in that: The descending flow channel includes a first flow channel, a second flow channel and a third flow channel connected in sequence, and the ascending flow channel includes a fourth flow channel and a fifth flow channel connected in sequence; The lower end of the first flow channel is connected to the upper end of the second flow channel, the lower end of the second flow channel is connected to the upper end of the third flow channel, the lower end of the third flow channel is connected to the lower end of the fourth flow channel, the upper end of the fourth flow channel is connected to the lower end of the fifth flow channel, and the upper end of the fifth flow channel is connected to the upper end of the first flow channel; An upper end of the fifth flow channel is higher than an upper end of the second flow channel along a gravity direction.

4. The heat exchange plate according to claim 3, characterized in that: The second flow channel and the fifth flow channel extend in the direction of gravity; and / or, the flow area of ​​the fifth flow channel is larger than the flow area of ​​the second flow channel; and / or, the flow rate of the ascending flow channel is smaller than the flow rate of the descending flow channel.

5. The heat exchange plate according to claim 3, characterized in that: Satisfies: 0°<θ1≤25°, wherein θ1 is the inclination angle of the first flow channel with the horizontal direction; and / or, Satisfies: 0°<θ2≤45°, wherein θ2 is the inclination angle of the third flow channel with the horizontal direction; and / or, Satisfies: 0°<θ3≤45°, wherein θ3 is an inclination angle of the fourth flow channel with respect to the horizontal direction.

6. The heat exchange plate according to claim 3, characterized in that: The flow cross-sectional area of ​​the fourth flow channel gradually increases from the end connected to the third flow channel to the end connected to the fifth flow channel; and / or, The flow cross-sectional area of ​​the first flow channel gradually increases from an end connected to the fifth flow channel to an end connected to the second flow channel.

7. The heat exchange plate according to claim 3, characterized in that: The first flow channel, the second flow channel, the third flow channel and the fourth flow channel each include two groups, and the two groups of the first flow channels, the two groups of the second flow channels, the two groups of the third flow channels and the two groups of the fourth flow channels are symmetrically distributed on both sides of the fifth flow channel with the fifth flow channel as the axis of symmetry.

8. The heat exchange plate according to claim 3, characterized in that: The heat exchange channel also includes a sixth channel, which is disposed between the third channel and the fourth channel. The sixth channel extends in a horizontal direction and is close to the bottom end of the heat exchange plate in the direction of gravity.

9. The heat exchange plate according to claim 8, characterized in that: An inclination angle of the fourth flow channel with respect to the horizontal direction is greater than an inclination angle of the third flow channel with respect to the horizontal direction.

10. The heat exchange plate according to claim 3, characterized in that: The heat exchange plate comprises a first portion and a second portion, wherein the first portion and the second portion together define the heat exchange channel; A first boss and a second boss are disposed on the outer side of the first part and / or the outer side of the second part. The first boss and the second boss are arranged spaced apart along the gravity direction. The first boss and the second boss are used to be connected to the battery core.

11. The heat exchange plate according to claim 10, characterized in that: The first portion and the second portion are positioned and matched.

12. The heat exchange plate according to any one of claims 1 to 11, characterized in that: The heat exchange plate further includes a pressure relief valve, which is communicated with the heat exchange flow channel.

13. The heat exchange plate according to any one of claims 1 to 11, characterized in that: The heat exchange plate is also provided with a thinning area, and the thinning area is located in the heat exchange flow channel.

14. A battery module, characterized in that: It comprises a battery cell and a heat exchange plate as claimed in any one of claims 1 to 13, wherein the heat exchange plate is arranged on a side of the battery cell.

15. The battery module according to claim 14, characterized in that: It also includes a tray and a cooler, wherein the cooler is arranged on the top of the battery cell along the direction of gravity, the battery cell and the heat exchange plate are arranged on the tray, the top end of the heat exchange plate along the direction of gravity is close to the cooler, and the bottom end of the heat exchange plate along the direction of gravity is close to the bottom of the tray.

16. A battery pack, characterized in that: Comprising the battery module as claimed in claim 14 or 15.

17. An electrical equipment, characterized in that: Comprising the battery module as claimed in claim 14 or 15.

Images