Battery assembly and electrical power system

Abstract

An electrical power system (200), comprising a battery assembly (100). The battery assembly (100) comprises battery cell groups (110), each battery cell group (110) comprises a plurality of battery cells (10), each battery cell (10) comprises an electrode assembly (11) and a casing (12), the electrode assembly (11) is arranged in the casing (12), and the electrode assembly (11) and a first surface (121) of the casing (12) are spaced apart from each other. A plurality of battery cell groups (110) are provided, and first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) are arranged opposite to each other. The sum of the temperature difference caused within a preset time by the thermal resistance of a spacing region between the electrode assembly (11) and the first surface (121) of the casing (12) and the temperature difference caused within the preset time by the thermal resistance of the first surface (121) of the casing (12) is A, the temperature decreased in the region between the first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) within the preset time is B, the minimum temperature of the first surface (13) of the battery cell (10) at the moment when the battery cell (10) triggers thermal runaway is T, and the tolerance temperature of a material system of the battery cell (10) is N, wherein A, B, T, and N satisfy the relational expression: T-N≤A+B≤500.

Description

Battery components and power systems

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on January 19, 2024, with application number 202410084598.0 and titled “Battery Assembly and Power System,” the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a battery assembly and a power system. Background Art

[0004] With the rapid development of new energy vehicles, battery safety has drawn considerable attention from the market. During production and use, batteries can be subject to mechanical or internal short-circuit abuse, making thermal runaway a serious risk. If the heat generated by a cell experiencing thermal runaway is not controlled, it can quickly impact the safety of other cells in the battery pack. Therefore, battery solutions that prevent or control thermal spread have become a common challenge within the industry.

[0005] In related art, thermal diffusion design for battery modules and enclosures primarily involves adding insulation materials between battery cells to achieve thermal insulation and inhibit heat transfer, thereby limiting heat diffusion within the battery. However, due to limited space within modules and enclosures, insulation materials occupy a significant amount of space. Excessive insulation reduces the battery's volumetric energy, while insufficient insulation fails to effectively inhibit heat diffusion.

[0006] Public content

[0007] The present disclosure aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present disclosure is to provide a battery assembly that can suppress heat diffusion and ensure volume energy density.

[0008] Another object of the present disclosure is to provide an electricity consumption system.

[0009] According to an embodiment of the present disclosure, a battery assembly includes: a battery cell group, the battery cell group includes at least one battery cell, the battery cell includes a pole core and a shell, the pole core is arranged in the shell, and the pole core and the first surface of the shell are spaced apart from each other; there are multiple battery cell groups, and the first surfaces of the battery cells in two adjacent battery cell groups correspond to each other; the sum of the temperature difference caused by the thermal resistance of the interval area between the pole core and the first surface of the shell within a preset time and the temperature difference caused by the thermal resistance of the first surface of the shell within a preset time is A, the temperature that can be reduced between the first surfaces of the battery cells in two adjacent battery cell groups within a preset time is B, the lowest temperature of the first surface of the battery cell when thermal runaway is triggered is T, the tolerance temperature of the battery cell material system is N, and A, B, T and N satisfy the relationship: TN≤A+B≤500.

[0010] Therefore, by limiting the sum of the temperature difference caused by the thermal resistance of the interval area between the pole core and the first surface of the shell within the preset time and the temperature difference caused by the thermal resistance of the first surface of the shell within the preset time to A, the temperature that can be reduced between the first surfaces of the battery cells in two adjacent battery cell groups within the preset time is B, and the relationship TN≤A+B≤500 is satisfied, not only can the heat diffusion from one battery cell group to another battery cell group in the battery assembly be suppressed, but also the volume energy density of the battery assembly can be guaranteed to ensure the energy endurance of the battery assembly.

[0011] In some examples of the present disclosure, the thickness of the battery cell is D, the distance between the first surfaces of the battery cells in two adjacent battery cell groups is x, a first material layer is provided between the first surfaces of the battery cells in two adjacent battery cell groups, the thermal conductivity of the first material layer is λ1, and B, x, λ1 and D satisfy the relationship: B=160*(x / 0.5)*(0.03 / λ1)*(13.5 / D).

[0012] In some examples of the present disclosure, x satisfies the relationship: x>0, and the first material layer is at least one of an insulating heat-insulating layer, an insulating heat-dissipating layer, and an air layer.

[0013] In some examples of the present disclosure, x satisfies the relationship: x=0, and the first surfaces of the battery cells in two adjacent battery cell groups are in contact with each other.

[0014] In some examples of the present disclosure, λ1 satisfies the relationship: λ1<3W / (m*K).

[0015] In some examples of the present disclosure, D satisfies the relationship: 0.01m<D<1m.

[0016] In some examples of the present disclosure, the distance between the pole core and the inner wall corresponding to the first surface of the shell is d, the wall thickness of the shell is a, the thermal conductivity coefficient of the shell is λ2, and d, a and A satisfy the relationship: A=20*(d / 2)*(0.3 / a)*(160 / λ2).

[0017] In some examples of the present disclosure, a second material layer is provided in a spacing area between the pole core and the first surface of the shell.

[0018] In some examples of the present disclosure, the second material layer is at least one of an insulating heat-insulating layer, an insulating heat-dissipating layer, and an air layer.

[0019] In some examples of the present disclosure, d satisfies the relationship: 0.002m<d<0.012m.

[0020] In some examples of the present disclosure, an insulating layer is provided between the second surfaces of two adjacent battery cells in each battery cell group.

[0021] In some examples of the present disclosure, both sides of the battery cell in the thickness direction are second surfaces, each of the battery cell groups includes at least two battery cells whose second surfaces are bonded to each other, the second surfaces are perpendicular to the first surfaces of the battery cells, and the area of ​​the second surfaces is greater than the area of ​​the first surfaces of the battery cells.

[0022] In some examples of the present disclosure, a third material layer is provided between the second surfaces of two adjacent battery cells in each battery cell group.

[0023] In some examples of the present disclosure, the third material layer is at least one of an insulating heat-insulating layer, an insulating heat-dissipating layer, and an air layer.

[0024] In some examples of the present disclosure, the area of ​​the second surface is greater than the area of ​​the first surface of the battery cell.

[0025] In some examples of the present disclosure, the battery assembly further includes a tray and a cold plate, one side of the tray is open, the cold plate is disposed on the open side of the tray, and the plurality of battery cells are disposed in the tray.

[0026] The power consumption system according to the present disclosure includes the battery assembly described above.

[0027] Additional aspects and advantages of the present disclosure will be given in part in the description that follows and, in part, will be obvious from the description that follows, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present disclosure will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] FIG1 is a schematic diagram of a battery cell according to an embodiment of the present disclosure;

[0030] FIG2 is a perspective view of a battery cell according to an embodiment of the present disclosure;

[0031] FIG3 is a schematic diagram of a battery cell group according to an embodiment of the present disclosure;

[0032] FIG4 is a schematic diagram of a battery assembly according to an embodiment of the present disclosure;

[0033] FIG5 is a schematic diagram of a battery assembly from another perspective according to an embodiment of the present disclosure;

[0034] FIG6 is a schematic diagram of a battery assembly according to an embodiment of the present disclosure from another perspective;

[0035] FIG7 is a schematic diagram of a battery assembly from another perspective according to an embodiment of the present disclosure;

[0036] FIG8 is a schematic block diagram of a power consumption system according to an embodiment of the present disclosure.

[0037] Figure numerals: 100, battery assembly; 110, battery cell group; 10, battery cell; 11, pole core; 12, shell; 121, first side of shell; 122, second side; 123, third side; 13, first side of battery cell; 20, first material layer; 30, second material layer; 40, third material layer; 200, power system; 30, tray; 31, cold plate. DETAILED DESCRIPTION

[0038] Embodiments of the present disclosure are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0039] A battery assembly 100 according to an embodiment of the present disclosure will be described below with reference to FIG. 1 to FIG. 7 .

[0040] 1 to 7 , the battery assembly 100 according to the present disclosure may mainly include a cell group 110, wherein the cell group 110 includes at least one cell 10, the cell 10 includes a pole core 11 and a shell 12, the pole core 11 is arranged in the shell 12, and the pole core 11 and the first surface 121 of the shell 12 are spaced apart from each other. There are multiple cell groups 110, and the first surfaces 13 of the cells 10 in two adjacent cell groups 110 are arranged relative to each other.

[0041] Specifically, both heating and puncture can cause thermal runaway of the battery cell 10 in the battery assembly 100. The location where thermal runaway occurs in the battery cell 10 can be the middle of the battery cell 10 or the edge of the battery cell 10. The shell 12 includes a first surface 121 of the shell 12. The pole core 11 and the first surface 121 of the shell 12 are spaced apart from each other. In this way, when thermal runaway occurs in the pole core 11, direct contact between the pole core 11 and the shell 12 can be prevented, so that a large amount of heat can be transferred to the outside of the battery cell 10 through the shell 12 quickly. This can prevent the thermal runaway battery cell 10 from causing thermal runaway in other non-thermal runaway battery cells 10, thereby reducing the occurrence of safety problems in the battery assembly 100. The pole core 11 and the first surface 121 of the shell 12 are spaced apart from each other, so that the heat generated by thermal runaway on the pole core 11 can be preferentially transferred to the thermal runaway pole core 11 and quickly dissipated through the heat dissipation device.

[0042] Furthermore, the battery assembly 100 may include multiple cell groups 110 consisting of multiple battery cells 10, which can increase the battery capacity of the battery assembly 100 and improve the battery life of the battery assembly 100. Both sides of the width direction of the battery cell 10 include the first surface 13 of the battery cell 10. The first surfaces 13 of the battery cells 10 in two adjacent cell groups 110 are arranged opposite each other, so that heat can be transferred through the first surfaces 13 of the battery cells 10 in the two adjacent cell groups 110.

[0043] Furthermore, when a cell 10 in a cell group 110 experiences thermal runaway, the heat diffusion path in the battery assembly 100 includes the space between the electrode 11 experiencing thermal runaway and the corresponding first surface 121 of the housing 12, the area between the first surface 121 of the housing 12 corresponding to the electrode 11 experiencing thermal runaway and the first surfaces 13 of the cells 10 in two adjacent cell groups 110, and heat transfer to other adjacent cells 10 in a direction perpendicular to the second surfaces 122 of the cells 10. The sum of the temperature difference caused by the thermal resistance of the space between the electrode 11 and the first surface 121 of the housing 12 within a preset time and the temperature difference caused by the thermal resistance of the first surface 121 of the housing 12 within a preset time is A, the temperature that can be reduced in the area between the first surfaces 13 of the cells 10 in two adjacent cell groups 110 within a preset time is B, the temperature of the first surface 13 of the cell 10 at the time thermal runaway is T, the temperature tolerance of the material system of the cell 10 is N, and A, B, T, and N satisfy the relationship: TN≤A+B≤500. The requirements within the above range can ensure that when a battery cell 10 in a battery cell group 110 experiences thermal runaway, heat diffusion only occurs within the battery cell group 110 and is not transferred to the battery cells 10 in adjacent battery cell groups 110. This can effectively suppress heat diffusion in the battery assembly 100 and can also ensure the volume energy density of the battery assembly 100 to ensure the energy endurance of the battery assembly 100.

[0044] In the embodiments of the present disclosure, the preset time includes, but is not limited to, 10 minutes. The temperature tolerance of the material system in battery assembly 100 is the minimum thermal runaway temperature of the material of battery cell 10. When the temperature in the material system exceeds its temperature tolerance, thermal runaway occurs in battery cell 10. The material system of battery cell 10 includes, but is not limited to, a lithium iron phosphate system and a ternary system. The temperature tolerance of the lithium iron phosphate system is 220°C, and the temperature tolerance of the ternary system is 180°C. In actual measurements, T satisfies the relationship 300≤T≤800.

[0045] Furthermore, TN is the temperature difference between the first surface 13 of the battery cell 10 and the material system of the battery cell 10. According to some embodiments of the present disclosure, the temperature difference caused by the thermal resistance of the interval area between the pole core 11 and the first surface 121 of the shell 12 within a preset time, the temperature difference caused by the thermal resistance of the first surface 121 of the shell 12 within a preset time, and the temperature that can be reduced in the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 within a preset time exceed the temperature difference between the first surface 13 of the battery cell 10 and the material system of the battery cell 10 when the battery cell 10 triggers thermal runaway. At this time, the heat diffuses outward from the pole core 11 and can be absorbed by the interval area between the pole core 11 and the first surface 121 of the shell 12. The amount of heat transfer is reduced in the isolation area, the first surface 121 of the shell 12, and the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110. This allows the heat generated by the thermal runaway battery cell 10 to be transferred through the second surface 122 toward the pole core 11 of the adjacent battery cell 10 that has not experienced thermal runaway when thermal runaway is triggered, extending the time for the heat to be transferred, thereby achieving a thermal insulation and heat dissipation balance. This prevents heat from accumulating on the battery cells 10 in the adjacent battery cell groups 110 that have not experienced thermal runaway, exceeding the tolerance temperature of the battery cells 10, and effectively suppresses the diffusion of heat in the battery assembly 100.

[0046] According to other embodiments of the present disclosure, the temperature difference caused by the thermal resistance of the spacing area between the pole core 11 and the first surface 121 of the shell 12 within a preset time, the temperature difference caused by the thermal resistance of the first surface 121 of the shell 12 within a preset time, and the temperature that can be reduced in the area between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110 within a preset time are equal to the temperature difference between the first surface 13 of the battery cell 10 and the material system of the battery cell 10. At this time, when heat diffuses outward from the pole core 11, it can be blocked by the spacing area between the pole core 11 and the first surface 121 of the shell 12, the first surface 121 of the shell 12, and the area between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110, thereby reducing Heat transfer, so that when the thermal runaway battery cell 10 triggers thermal runaway, the heat generated by it can be prolonged to transfer the heat through the second surface 122 toward the pole core 11 of the adjacent battery cell 10 that has not experienced thermal runaway, thereby achieving a heat insulation and heat dissipation balance. This not only inhibits the heat from spreading between the two adjacent battery cell groups 110 in the battery assembly 100, but also makes the spacing area between the pole core 11 and the first surface 121 of the shell 12, the first surface 121 of the shell 12 and the area between the first surface 13 of the battery cells 10 in the two adjacent battery cell groups 110 occupy the least space in the battery assembly 100, so that more battery cells 10 can be arranged in the battery assembly 100, thereby improving the volume energy density of the battery assembly 100.

[0047] Furthermore, the sum of the temperature difference caused by the thermal resistance of the spacing area between the pole core 11 and the first surface 121 of the shell 12 within a preset time, the temperature difference caused by the thermal resistance of the first surface 121 of the shell 12 within a preset time, and the temperature that can be reduced in the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 within a preset time is set to not exceed 500°C. This can prevent the spacing area between the pole core 11 and the first surface 121 of the shell 12, the first surface 121 of the shell 12, and the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 from occupying too much space in the battery assembly 100, thereby ensuring the volume energy density of the battery assembly 100 and helping to reduce the production and use costs of the battery assembly 100.

[0048] It should also be noted that if the sum of the temperature difference caused by the thermal resistance of the spacing area between the pole core 11 and the first surface 121 of the shell 12 within a preset time, the temperature difference caused by the thermal resistance of the first surface 121 of the shell 12 within a preset time, and the temperature that can be reduced in the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 within a preset time is less than the temperature difference between the first surface 13 of the battery cell 10 and the material system of the battery cell 10, then the spacing area between the pole core 11 and the first surface 121 of the shell 12, the first surface 121 of the shell 12, and the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 cannot completely isolate or dissipate the heat generated by the pole core 11 and transferred to the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110. The excess heat will enter the battery cells 10 through the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110 and be transferred to the pole core 11, which may easily cause thermal runaway of the battery cells 10 in the adjacent battery cell groups 110.

[0049] If the sum of the temperature difference caused by the thermal resistance of the spacing area between the pole core 11 and the first surface 121 of the shell 12 within a preset time, the temperature difference caused by the thermal resistance of the first surface 121 of the shell 12 within a preset time, and the temperature that can be reduced in the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 within a preset time exceeds 500°C, this can effectively suppress the heat diffusion of the battery assembly 100, but the spacing area between the pole core 11 and the first surface 121 of the shell 12, the first surface 121 of the shell 12, and the area between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 occupy too high a space in the battery assembly 100, resulting in a reduction in the number of battery cells 10, thereby reducing the volume energy density of the battery assembly 100 and affecting the battery life of the battery assembly 100.

[0050] As shown in Figure 5, the thickness of the battery cell 10 is D, the distance between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 is x, and a first material layer 20 is provided between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110. The thermal conductivity coefficient of the first material layer 20 is λ1, and the values ​​of B, x, λ1 and D satisfy the relationship: B = 160*(x / 0.5)*(0.03 / λ1)*(13.5 / D). Specifically, when heat is transferred between two adjacent battery cell groups 110, it passes through the spacing area between the pole core 11 and the first surface 121 of the shell 12, the first surface 121 of the shell 12, and the spacing area between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110 in the thickness direction of the battery cell 10. In this way, the temperature of the area between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110 that can be reduced within a preset time can be calculated based on the thickness of the battery cell 10, the distance between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110, and the thermal conductivity coefficient of the first material layer 20.

[0051] Furthermore, the battery cells 10 in two adjacent battery cell groups 110 are arranged at intervals, which can provide a setting position for the first material layer 20 between the two adjacent battery cell groups 110, and can prevent the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110 from directly contacting each other and causing heat diffusion of the battery assembly 100.

[0052] According to some embodiments of the present disclosure, when x satisfies the relationship: x>0, the first material layer 20 is at least one of an insulating thermal insulation layer, an insulating heat dissipation layer, and an air layer. Specifically, when x>0, a gap exists between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, which can be used to provide at least one of the insulating thermal insulation layer, the insulating heat dissipation layer, and the air layer.

[0053] Furthermore, the insulating heat-insulating layer has a heat-insulating effect on the heat transferred between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, which can enhance the inhibitory effect on heat transfer and further prevent the diffusion of heat in the battery assembly 100. The insulating heat-dissipating layer can quickly transfer and dissipate the heat between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, and can accelerate the heat dissipation rate before the heat reaches the first surfaces 13 of the battery cells 10 in the battery cell group 110 that has not experienced thermal runaway, thereby reducing the heat transferred to the first surfaces 13 of the battery cells 10 in the battery cell group 110 that has not experienced thermal runaway, thereby enhancing the effect of suppressing thermal diffusion of the battery assembly 100. An air layer can also be provided between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110. The air layer can isolate heat transfer, which is beneficial for suppressing thermal diffusion of the entire battery assembly 100.

[0054] According to some embodiments of the present disclosure, when an insulating heat-insulating layer is filled between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, λ1 satisfies the relationship: λ1 < 3W / (m*K). Specifically, setting the thermal conductivity of the first material layer 20 to be less than 3W / (m*K) can ensure the reliability of the first material layer 20 in suppressing the heat generated by the thermal runaway battery cell group 110 from diffusing to the battery cell group 110 that has not experienced thermal runaway. If the thermal conductivity of the first material layer 20 is greater than 3W / (m*K), the thermal conductivity of the first material layer 20 is too large, requiring more space for thermal insulation, which will reduce the volume energy density of the battery assembly 100.

[0055] According to other embodiments of the present disclosure, when the first material layer 20 is filled between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, λ1 satisfies the relationship: λ1>3W / (m*K). Specifically, by setting the thermal conductivity of the first material layer 20 to be greater than 3W / (m*K), heat can be transferred to the first material layer 20 for rapid dissipation, thereby reducing the temperature of heat diffusion, thereby reducing the probability of thermal runaway of the battery cell group 110 that has not experienced thermal runaway. If the thermal conductivity of the first material layer 20 is set to be less than 3W / (m*K), the heat dissipation capacity of the first material layer 20 is limited, and heat will be transferred to the surrounding battery cells 10 that have not experienced thermal runaway.

[0056] According to an embodiment of the present disclosure, D satisfies the relationship: 0.01m<D<1m. Specifically, if the thickness of the battery cell 10 is set to be less than 0.01m, the structural strength of the battery cell 10 is too weak, affecting the structural reliability of the battery cell 10. If the thickness of the battery cell 10 is set to be greater than 1m, it is not conducive to the heat dissipation of the battery cell 10, affecting the safety of the battery cell 10. Therefore, setting the thickness of the battery cell 10 between 0.01m and 1m can not only ensure the structural strength of the battery cell 10, but also ensure the heat dissipation of the battery cell 10, so that the battery cell 10 that experiences thermal runaway can quickly dissipate heat and reduce the risk of heat diffusion in the battery assembly 100.

[0057] According to an embodiment of the present disclosure, the distance between the inner walls corresponding to the pole core 11 and the first surface 121 of the shell 12 is d, the wall thickness of the shell 12 is a, and the thermal conductivity of the shell 12 is λ2. The values ​​of d, a, and A satisfy the relationship: A = 20*(d / 2)*(0.3 / a)*(160 / λ2). Specifically, based on the distance between the inner walls corresponding to the pole core 11 and the first surface 121 of the shell 12, the wall thickness of the shell 12, and the thermal conductivity of the shell 12, the temperature difference caused by the thermal resistance of the interval area between the pole core 11 and the first surface 121 of the shell 12 within a preset time and the temperature difference caused by the thermal resistance of the first surface 121 of the shell 12 within a preset time can be calculated.

[0058] As shown in FIG1 , a second material layer 30 is disposed in the gap between the pole core 11 and the first surface 121 of the housing 12. Specifically, the second material layer 30 can reduce the amount of heat transferred from the pole core 11 to the first surface 13 of the battery cell 10, thereby inhibiting heat transfer to the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110. This can prevent heat from a battery cell 10 experiencing thermal runaway from being transferred to a battery cell 10 that is not experiencing thermal runaway, thereby preventing thermal runaway in the battery cell 10 that is not experiencing thermal runaway, thereby improving the operating safety of the battery assembly 100.

[0059] According to an embodiment of the present disclosure, the second material layer 30 is at least one of an insulating heat-insulating layer, an insulating heat-dissipating layer, and an air layer. Specifically, the insulating heat-insulating layer has a heat-insulating effect on the heat transferred to the gap area between the pole core 11 and the first surface 121 of the shell 12, which can enhance the inhibitory effect on heat transfer and further prevent heat from diffusing in the battery assembly 100. The insulating heat-dissipating layer can quickly transfer and dissipate the heat in the gap area between the pole core 11 and the first surface 121 of the shell 12, and can accelerate the heat dissipation rate before reaching the first surface 13 of the non-thermal runaway battery cell 10, thereby reducing the heat transferred to the first surface 13 of the non-thermal runaway battery cell 10, thereby enhancing the effect of suppressing heat diffusion of the battery assembly 100. An air layer can also be provided in the gap area between the pole core 11 and the first surface 121 of the shell 12. The air layer can isolate heat transfer, which is beneficial to suppressing heat diffusion of the entire battery assembly 100.

[0060] As shown in Figure 1, d satisfies the relationship: 0.002m<d<0.012m. Specifically, if the distance between the inner walls corresponding to the pole core 11 and the first side 121 of the shell 12 is set to no more than 0.002m, the distance between the pole core 11 and the shell 12 is too close, and it is not convenient to assemble the second material layer 30 between the inner walls corresponding to the pole core 11 and the first side 121 of the shell 12. If the distance between the inner walls corresponding to the pole core 11 and the first side 121 of the shell 12 is set to exceed 0.012m, the capacity density of the battery cell 10 is affected. Setting the distance between the inner walls corresponding to the pole core 11 and the first side 121 of the shell 12 between 0.002m and 0.012m can not only facilitate the assembly of the second material layer 30, but also ensure the volume energy density of the battery cell 10.

[0061] In an embodiment of the present invention, the distance between the inner wall corresponding to the pole core 11 and the first surface 121 of the housing 12 is preferably set to between 0.002m and 0.008m. The space between the inner wall corresponding to the pole core 11 and the first surface 121 of the housing 12 can be filled with an insulating member, including but not limited to a polypropylene spacer, or a thermal insulation member, including but not limited to polyurethane foam. In addition, the space between the inner wall corresponding to the pole core 11 and the first surface 121 of the housing 12 can be left unfilled.

[0062] As shown in Figure 6, three battery cells 10 are stacked along the second surface 122 to form a battery cell group 110, and the three battery cell groups 110 are arranged in a direction perpendicular to the first surface 13 of the battery cell 10. The battery cell group 110 located in the middle is punctured to trigger thermal diffusion of the topmost battery cell 10 in the battery cell group 110, and after the thermal runaway ends, the adjacent battery cell 10 is observed to see whether thermal runaway occurs (i.e., whether thermal diffusion occurs). For a single battery cell 10, d, a, λ1, x, D and λ2 are designed and taken values ​​respectively, wherein the battery cells 10 all adopt a lithium iron phosphate system. The measured value of T is 400°C, and the values ​​of λ1 and λ2 are measured by a thermal conductivity meter. The following table shows the values ​​of multiple groups of embodiments and the corresponding experimental results:

[0063] Comparing Examples 1-4 with Comparative Examples 1-2 in the table shows that when the value of A+B is greater than or equal to the value of TN, thermal diffusion does not occur within the entire battery assembly 100, meaning that the cell group 110 adjacent to the thermal runaway cell group 110 does not experience thermal runaway. However, when the value of A+B is less than TN, thermal diffusion occurs within the battery assembly 100. Therefore, when the value of A+B is greater than or equal to TN, thermal insulation between two adjacent cell groups 110 can be ensured, preventing the spread of safety risks within the battery assembly 100, ensuring the safety of adjacent cell groups 110, and improving the overall safety of the battery assembly 100.

[0064] Comparing Examples 1-4 with Comparative Example 3 in the table shows that when the value of A+B is greater than 500, the volumetric energy density of the entire battery assembly 100 is less than 250Wh / L, failing to meet the design requirements of the battery cell 10. Specifically, when the distance between the pole core 11 and the first surface 121 of the housing 12 is too large, heat is difficult to transfer through the first surface 121 of the housing 12 to the adjacent battery cell group 110. While the risk of thermal diffusion in the battery pack 100 is low, the volume occupied by the pole core 11 in the battery cell 10 is too small, resulting in an excessively low volumetric energy density of the battery cell 10, which in turn causes the battery cell 10 to fail to meet the normal operating requirements of the battery pack 100.

[0065] As shown in Figures 3 to 6, the two sides of the battery cell 10 in the thickness direction are respectively the second surfaces 122, and each battery cell group 110 includes at least two battery cells 10 whose second surfaces 122 are bonded to each other. That is, in the two battery cells 10 bonded to each other, the second surfaces 122 of the two are bonded to each other, and the second surfaces 122 are perpendicular to the first surfaces 13 of the battery cell 10. Specifically, the two sides of the battery cell 10 in the thickness direction are respectively set as the second surfaces 122, and the second surfaces 122 are perpendicular to the first surfaces 13 of the battery cell 10. When thermal runaway occurs in the battery cell 10, it can be transmitted to the outside in two different directions through the first surface 13 and the second surface 122 of the battery cell 10. In the embodiment of the present disclosure, the structure of the pole core 11 includes a laminated structure and a winding structure. When the pole core 11 is a laminated structure, the area of ​​the second surface 122 is larger than the area of ​​the first surface 13 of the battery cell 10. When the electrode core 11 has a wound structure, the larger of the first and second surfaces 13, 122 of the battery cell 10 serves as the contact surface between two adjacent battery cells 10 in each battery cell group 110. The following describes the battery cells 10 having a laminated structure. In the embodiments of the present disclosure, each battery cell group 110 may also include only one battery cell 10.

[0066] Furthermore, the area of ​​the second surface 122 of the battery cell 10 is larger than the area of ​​the first surface 13 of the battery cell 10, that is, the heat transfer rate of the first surface 13 of the battery cell 10 is lower than the heat transfer rate of the second surface 122. When thermal runaway occurs in the electrode core 11, the amount of heat transferred through the first surface 13 of the battery cell 10 is less than the amount of heat transferred through the second surface 122. This can reduce the amount of heat transferred through the first surface 13 of the battery cell 10 to the battery cells 10 in the adjacent battery cell group 110, thereby effectively reducing the heat transfer between adjacent battery cell groups 110 in the battery assembly 100. In this way, when the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 are arranged relative to each other, the amount of heat transferred from the battery cell group 110 experiencing thermal runaway to the battery cell group 110 not experiencing thermal runaway can be reduced, and the diffusion of heat between adjacent battery cell groups 110 can be suppressed, thereby suppressing the diffusion of heat in the battery assembly 100.

[0067] In addition, the area of ​​the first surface of the battery cell 10 is smaller than the second surface 122, which can reduce the volume of the first material layer 20 arranged between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, and can reduce the insulation space between the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110, which is beneficial to improving the space utilization of the battery assembly 100.

[0068] In an embodiment of the present disclosure, the battery cell 10 further includes a third surface 123 on both sides of the length direction. According to some embodiments of the present disclosure, at least one of the first surface 13, the second surface 122, and the third surface 123 of the battery cell 10 is provided with a pole and an explosion-proof valve. According to other embodiments of the present disclosure, at least two of the first surface 13, the second surface 122, and the third surface 123 of the battery cell 10 are provided with a pole and an explosion-proof valve.

[0069] As shown in FIG3 , a third material layer 40 is disposed between the second surfaces 122 of two adjacent battery cells 10 in each battery cell group 110. Specifically, the third material layer 40 can reduce the amount of heat transferred from the electrode core 11 to the second surfaces 122 of the battery cells 10, thereby inhibiting heat transfer between the second surfaces 122 of two adjacent battery cells 10. This can prevent heat from a battery cell 10 experiencing thermal runaway from being transferred to a battery cell 10 that is not experiencing thermal runaway, thereby preventing thermal runaway in the battery cell 10 that is not experiencing thermal runaway, thereby improving the operating safety of the battery assembly 100.

[0070] According to an embodiment of the present disclosure, the third material layer 40 is at least one of an insulating heat-insulating layer, an insulating heat-dissipating layer, and an air layer. Specifically, the insulating heat-insulating layer has a heat-insulating effect on the heat transferred between the second surfaces 122 of two adjacent battery cells 10, which can enhance the inhibitory effect on heat transfer and further prevent heat from diffusing in the battery assembly 100. The insulating heat-dissipating layer can quickly transfer and dissipate the heat between the second surfaces 122 of two adjacent battery cells 10, and can accelerate the heat dissipation rate before reaching the second surface 122 of the non-thermal runaway battery cell 10, thereby reducing the heat transferred to the second surface 122 of the non-thermal runaway battery cell 10, thereby enhancing the effect of the battery assembly 100 in suppressing heat diffusion. An air layer can also be provided between the second surfaces 122 of two adjacent battery cells 10. The air layer can isolate heat transfer, which is beneficial to suppressing heat diffusion of the entire battery assembly 100.

[0071] In an embodiment of the present disclosure, as shown in FIG7 , the battery assembly 100 further includes a tray 30 and a cold plate 31 . One side of the tray 30 is open, and the cold plate 31 is disposed on the open side of the tray 30 . The battery cells 10 are all disposed in the tray 30 . The cold plate 31 may be disposed in locations including, but not limited to, between the tray 30 and the battery cells, between two adjacent battery cells, and on top of the battery cells. This arrangement not only facilitates the placement of the battery assembly 100 , but also helps the battery assembly 100 dissipate heat quickly. The battery cells 10 are disposed on the upper side of the tray 30 , so that the heat generated in the battery cells 10 can be quickly dissipated through the tray 30 . This allows the heat to be quickly dissipated through the tray 30 when the battery cells 10 experience thermal runaway. In addition, the battery cells 10 can also dissipate heat through the cold plate 31 when thermal runaway occurs, thereby preventing the heat from spreading in the battery assembly 100 and affecting the operating safety of other battery cells 10 in the battery assembly 100 .

[0072] According to some embodiments of the present disclosure, the first surface 13 of the bottom battery cell 10 in the multiple battery cell groups 110 is in contact with the cold plate 31. According to other embodiments of the present disclosure, the second surface 122 of the bottom battery cell 10 in the multiple battery cell groups 110 is in contact with the cold plate 31. According to still other embodiments of the present disclosure, both the first surface 13 and the second surface 122 of the bottom battery cell 10 in the multiple battery cell groups 110 are in contact with the cold plate 31. With such an arrangement, the heat generated by the thermal runaway battery cell 10 in the battery assembly 100 can be transferred to the cold plate 31 through the bottom battery cell 10, so that the heat can be diffused to the heat dissipation device through the cold plate 31, thereby accelerating the heat dissipation in the battery assembly 100.

[0073] According to some embodiments of the present disclosure, the second side 122 of the battery cells 10 in one or more battery cell groups 110 in the battery assembly 100 may be connected to the tray 30 or the cold plate 31, wherein the connection method between the second side 122 of the battery cell 10 and the tray 30 or the cold plate 31 includes but is not limited to direct contact, bonding, screwing, and riveting. According to other embodiments of the present disclosure, the first side 13 of the battery cells 10 in one or more battery cell groups 110 in the battery assembly 100 may be in direct contact with the tray 30 or the cold plate 31, wherein the connection method between the first side 13 of the battery cell 10 and the tray 30 or the cold plate 31 includes but is not limited to direct contact, bonding, screwing, and riveting.

[0074] According to some disclosed embodiments, when the number of battery cells 10 in the same battery cell group 110 exceeds two, the second side 122 of the battery cell 10 is in close contact with the cold plate 31. In the event of thermal runaway of the battery cell 10, heat can be transferred from the cold plate 31 to the heat dissipation device, thereby accelerating the cooling rate of the battery cell 10 and reducing the probability of diffusion of the battery cell 10. In this way, even if one of the battery cells 10 experiences thermal runaway, it will not cause thermal runaway in the adjacent battery cell group 110, slowing down the diffusion of heat and reducing the safety issues caused by the battery assembly 100. In the embodiments of the present disclosure, an insulating heat-insulating layer or an insulating heat-dissipating layer may be filled between two adjacent battery cells 10 in the same battery cell group 110, or an insulating heat-insulating layer or an insulating heat-dissipating layer may not be filled. An insulating heat-insulating layer or an insulating heat-dissipating layer may be filled between two adjacent battery cell groups 110, and an insulating heat-insulating layer or an insulating heat-dissipating layer may be filled between the battery cell group 110 and the shell 12.

[0075] According to other embodiments of the present disclosure, when there is only one battery cell 10 in the same battery cell group 110, the second surface 122 of the battery cell 10 is in close contact with the cold plate 31. In the event of thermal runaway of the battery cell 10, heat can be transferred from the cold plate 31 to the heat dissipation device, accelerating the cooling rate of the battery cell 10 without causing thermal runaway in adjacent battery cell groups 110, slowing heat diffusion and reducing safety issues associated with the battery assembly 100. In embodiments of the present disclosure, an insulating heat-insulating layer or an insulating heat-dissipating layer can be filled between two adjacent battery cell groups 110, and an insulating heat-insulating layer or an insulating heat-dissipating layer can be filled between the battery cell group 110 and the housing 12.

[0076] According to some further embodiments of the present disclosure, when the number of battery cells 10 in the same battery cell group 110 exceeds two, the first surface 13 of the battery cell 10 is in close contact with the cold plate 31. In the event of thermal runaway of any of the battery cells 10 other than the battery cell 10 in close contact with the cold plate 31, the heat may or may not cause thermal diffusion of the other battery cells 10 in the battery cell group 110. Heat can be evenly diffused within the battery cell group 110 by the second surfaces 122 of adjacent battery cells 10 in the same battery cell group 110 being adhered to the battery cell group 110, while reducing the temperature of heat diffusion, thereby preventing thermal runaway of adjacent battery cell groups 110, slowing down heat diffusion, and reducing safety issues caused to the battery assembly 100. In the embodiments of the present disclosure, an insulating heat-insulating layer or an insulating heat-dissipating layer can be filled between two adjacent battery cell groups 110, and an insulating heat-insulating layer or an insulating heat-dissipating layer can be filled between the battery cell group 110 and the housing 12.

[0077] According to the embodiments of the present disclosure, adjacent battery cells 10 in the same battery cell group 110 are positioned with their largest surfaces aligned, while adjacent battery cells 10 in adjacent battery cell groups 110 are positioned with their smaller surfaces facing each other. This structure for suppressing thermal diffusion in the battery assembly 100 is not only applicable to any battery, module, or package subject to thermal runaway, but can also be used to place high thermal conductivity materials within the battery to closely adhere to the electrode core or to the housing 12 to achieve uniform temperature. The embodiments of the present disclosure can also be applied between modules to prevent thermal diffusion between modules.

[0078] According to the power consumption system disclosed in the present invention, the battery assembly 100 in the embodiment of the present invention is configured. By setting the size of the fitting surface between adjacent battery cells 10 and the size of the fitting surface between adjacent battery cell groups 110, a large amount of heat can be suppressed from being transferred and diffused between adjacent battery cells 10 when thermal runaway occurs in the battery cell 10, thereby effectively improving the working safety of the battery assembly 100 and further improving the safety of the power consumption system.

[0079] In the description of the present disclosure, 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", "circumferential", "radial", "circumferential" and the like to 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 disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present disclosure.

[0080] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0081] Although the embodiments of the present disclosure have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery assembly (100), wherein, Comprising: A battery cell group (110), the battery cell group (110) includes at least one battery cell (10), the battery cell (10) includes an electrode core (11) and a housing (12), the electrode core (11) is disposed within the housing (12), and the electrode core (11) is spaced apart from a first surface (121) of the housing (12). Wherein, there are multiple battery cell groups (110), and first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) are disposed opposite to each other. The sum of the temperature difference brought by the thermal resistance in the interval region between the electrode core (11) and the first surface (121) of the housing (12) within a preset time and the temperature difference brought by the thermal resistance of the first surface (121) of the housing (12) within the preset time is A, the temperature drop in the region between the first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) within the preset time is B, the lowest temperature of the first surface (13) when the battery cell (10) triggers thermal runaway is T, and the tolerance temperature of the material system of the battery cell (10) is N. A, B, T, and N satisfy the relation: T - N ≤ A + B ≤ 500.

2. The battery assembly (100) according to claim 1, wherein, The thickness of the battery cell (10) is D, the distance between the first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) is x, a first material layer (20) is disposed between the first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110), the thermal conductivity of the first material layer (20) is λ1, and B, x, λ1, and D satisfy the relation: B = 160 * (x / 0.5) * (0.03 / λ1) * (13.5 / D).

3. The battery assembly (100) according to claim 2, wherein, x satisfies the relation: x > 0, and the first material layer (20) is at least one of an insulating and heat-insulating layer, an insulating and heat-dissipating layer, and an air layer.

4. The battery assembly (100) according to claim 2 or 3, wherein, x satisfies the relation: x = 0, and the first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) are in mutual contact.

5. The battery assembly (100) according to any one of claims 2-4, wherein, λ1 satisfies the relation: λ1 < 3 W / (m*K).

6. The battery assembly (100) according to any one of claims 2-5, wherein, D satisfies the relation: 0.01 m < D < 1 m.

7. The battery assembly (100) according to any one of claims 2-6, wherein, The distance between the electrode core (11) and the inner wall corresponding to the first surface (121) of the housing (12) is d, the wall thickness of the housing (12) is a, the thermal conductivity of the housing (12) is λ2, and d, a, and A satisfy the relation: A = 20 * (d / 2) * (0.3 / a) * (160 / λ2).

8. The battery assembly (100) according to claim 7, wherein, A second material layer (30) is disposed in the interval region between the electrode core (11) and the first surface (121).

9. The battery assembly (100) according to claim 8, wherein, The second material layer (30) is at least one of an insulating and heat-insulating layer, an insulating and heat-dissipating layer, and an air layer.

10. The battery assembly (100) according to claim 7 or 8, wherein, d satisfies the relation: 0.002 m < d < 0.012 m.

11. The battery assembly (100) according to any one of claims 2-10, wherein, On both sides in the thickness direction of the battery cell (10) are second surfaces (122), each battery cell group (110) includes at least two battery cells (10) with the second surfaces (122) in mutual contact, and the second surface (122) is perpendicular to the first surface (13) of the battery cell (10).

12. The battery assembly (100) according to claim 11, wherein, A third material layer (40) is disposed between the second surfaces (122) of two adjacent ones of the battery cells (10) in each of the battery cell groups (110).

13. The battery assembly (100) according to claim 12, wherein, The third material layer (40) is at least one of an insulating and heat-insulating layer, an insulating and heat-dissipating layer, and an air layer.

14. The battery assembly (100) according to any one of claims 11-13, wherein, The area of the second surface (122) is larger than the area of the first surface (13) of the battery cell (10).

15. The battery assembly (100) according to any one of claims 1-14, wherein, It further includes a tray (30) and a cold plate (31). One side of the tray (30) is open, the cold plate (31) is disposed on the open side of the tray (30), and a plurality of the battery cells (10) are all disposed in the tray (30).

16. An electrical power system (200), wherein, It includes the battery assembly (100) according to any one of claims 1-15.

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