Battery pack and electric system

Abstract

An electric system, comprising a battery pack, wherein the battery pack comprises battery cells, and each battery cell comprises an electrode core and a casing; the electrode core is arranged in the casing, the electrode core and a first surface of the casing are spaced apart from each other, and the first surface of the casing is a first surface of the battery cell; and the thermal resistance of the spacing area between the electrode core and the first surface of the casing is A, the thermal resistance of the electrode core in a direction perpendicular to the first surface is B, and A and B satisfy the relational expression: 1 / 48＜A / B.

Description

Battery pack and power system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202410084618.4, filed with the State Intellectual Property Office of China on January 19, 2024, entitled “Battery Pack 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 pack and a power system. Background Art

[0004] With the rapid development of new energy vehicles, the safety of their batteries has also attracted considerable attention in the market. Batteries are susceptible to thermal runaway when subjected to heat or puncture during production and operation. If the heat generated by a cell experiencing thermal runaway is not suppressed, it can quickly affect the safety of other cells in the battery pack. Therefore, battery solutions that prevent or suppress thermal spread have become a common challenge within the industry.

[0005] In related art, thermal diffusion design for battery packs primarily involves adding insulation material between cells to achieve thermal insulation and inhibit heat transfer, thereby limiting heat diffusion within the battery. However, battery packs have limited space, and insulation material takes up a significant amount of space. Excessive insulation material reduces the battery's volumetric energy, while insufficient insulation fails to effectively suppress 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 object of the present disclosure is to provide a battery pack that can suppress heat diffusion and ensure volume energy.

[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 pack includes: a battery cell, wherein 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; the thermal resistance of the interval area between the pole core and the first surface of the shell is A, and the thermal resistance of the pole core in a direction perpendicular to the first surface is B, and A and B satisfy the relationship: 1 / 48<A / B.

[0010] Therefore, by setting the ratio range of the thermal resistance of the spacing area between the pole core and the first surface of the shell to the thermal resistance of the pole core along the direction perpendicular to the first surface, not only the effect of suppressing the outward diffusion of heat in the battery pack can be enhanced, but also the working safety of the battery pack can be improved.

[0011] In some examples of the present disclosure, A and B satisfy the relationship: A / B<10.

[0012] In some examples of the present disclosure, the area of ​​the second surface is greater than the area of ​​the first surface.

[0013] In some examples of the present disclosure, there are multiple battery cells, and the multiple battery cells constitute multiple battery cell groups. Each battery cell group includes at least two battery cells corresponding to the second sides. The first sides of the battery cells in two adjacent battery cell groups correspond to each other, and the second sides of the battery cells are perpendicular to the first sides of the battery cells.

[0014] In some examples of the present disclosure, the distance between the pole core and the first surface of the shell is d, the wall thickness of the shell is a, the thermal conductivity of the shell is λ1, the length of the battery core is L, d, a, L, λ1 and A satisfy the relationship: A=d / [(2*a*L)*λ1], and d, a, L are measured in the same units.

[0015] In some examples of the present disclosure, an insulating heat-insulating member or an insulating heat-dissipating member is provided in a spacing region between the pole core and the first surface of the housing.

[0016] In some examples of the present disclosure, d satisfies the relationship: 2 mm < d < 12 mm.

[0017] In some examples of the present disclosure, L satisfies the relationship: 400 mm < L < 2500 mm.

[0018] In some examples of the present disclosure, both sides of the battery cell along the width direction are the first sides of the battery cell, the length of the battery cell is L, the width of the battery cell is H, the thickness of the battery cell is D, the thermal conductivity of the pole core (11) along the direction perpendicular to the first side is λ2, H, D, λ and B satisfy the relationship: B = H / [(D*L)*λ2], and H, D, L are measured in the same unit.

[0019] In some examples of the present disclosure, H satisfies the relationship: 80 mm < H < 200 mm.

[0020] In some examples of the present disclosure, D satisfies the relationship: 10 mm < D < 1000 mm.

[0021] In some examples of the present disclosure, λ2 satisfies the relationship: 10 W / (m*K)<λ2<30 W / (m*K).

[0022] In some examples of the present disclosure, an insulating heat-isolating component or an insulating heat-dissipating component is provided between the second surfaces of two adjacent battery cells in each battery cell group; and / or the second surfaces of two adjacent battery cells in each battery cell group are in contact with and adhere to each other; and / or the second surfaces of two adjacent battery cells in each battery cell group are spaced from each other and an air layer exists between them.

[0023] In some examples of the present disclosure, an insulating heat-isolating component or an insulating heat-dissipating component is provided between the first surfaces of the battery cells in two adjacent battery cell groups; and / or the first surfaces of the battery cells in two adjacent battery cell groups are in contact with and adhere to each other; and / or the first surfaces of the battery cells in two adjacent battery cell groups are spaced from each other and an air layer exists between them.

[0024] In some examples of the present disclosure, a tray and a cold plate are further included, wherein 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.

[0025] In some examples of the present disclosure, the pole core includes multiple layers of pole pieces, the extension direction of the single-layer pole piece is the direction of the pole core perpendicular to the first surface, and the arrangement direction of the multiple layers of pole pieces is the direction of the pole core perpendicular to the second surface.

[0026] In some examples of the present disclosure, an area of ​​the first surface is smaller than an area of ​​the second surface.

[0027] The power consumption system according to the present disclosure includes the battery pack described above.

[0028] 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

[0029] 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:

[0030] FIG1 is a schematic diagram of a battery cell according to an embodiment of the present disclosure;

[0031] FIG2 is a perspective view of a battery cell according to an embodiment of the present disclosure;

[0032] FIG3 is a schematic diagram of a battery cell group according to an embodiment of the present disclosure;

[0033] FIG4 is a schematic diagram of a battery pack according to an embodiment of the present disclosure;

[0034] FIG5 is a schematic diagram of a battery pack according to an embodiment of the present disclosure from another perspective;

[0035] FIG6 is a schematic diagram of a battery pack according to an embodiment of the present disclosure from another perspective;

[0036] FIG7 is a schematic diagram of a battery pack according to an embodiment of the present disclosure from another perspective;

[0037] FIG8 is a schematic block diagram of a power consumption system according to an embodiment of the present disclosure.

[0038] Figure numerals: 100, battery pack; 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, thermal insulation material; 200, power system; 30, tray; 31, cold plate. DETAILED DESCRIPTION

[0039] Embodiments of the present disclosure are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0040] A battery pack 100 according to an embodiment of the present disclosure will be described below with reference to FIG. 1 to FIG. 7 . The battery pack 100 in the embodiment of the present disclosure may be applied to an electric power system.

[0041] 1 to 7 , the battery pack 100 according to the present disclosure may mainly include a battery cell 10 , wherein the battery cell 10 includes a pole core 11 and a shell 12 , the pole core 11 is disposed in the shell 12 , and the pole core 11 and the first surface 121 of the shell 12 are spaced apart from each other.

[0042] Specifically, both heating and needle penetration can cause thermal runaway in the battery cell 10 of the battery pack 100. Thermal runaway can occur in the middle or at the edge of the battery cell 10. The battery cell 10 includes a core 11 and a housing 12, with the core 11 disposed within the housing 12. This allows the housing 12 to protect the core 11 and prevent heat from dissipating outside the battery cell 10 when thermal runaway occurs.

[0043] Furthermore, the housing 12 includes a first surface 121 and a second surface 122. The core 11 is spaced apart from the first surface 121 of the housing 12. This prevents direct contact between the core 11 and the first surface 121 of the housing 12 in the event of thermal runaway. This prevents a cell 10 experiencing thermal runaway from causing thermal runaway in adjacent cells 10, thereby reducing safety issues in the battery pack 100. The core 11 is spaced apart from the first surface 121 of the housing 12, allowing heat generated by thermal runaway in the core 11 to preferentially transfer from the location of thermal runaway toward the first surface 13 of the cell 10 and be rapidly dissipated by the heat dissipation device. The first surface 121 of the housing 12 represents the first surface 13 of the cell 10, the second surface 122 represents the second surface of the cell 10, and the third surface 123 represents the third surface of the cell 10.

[0044] Furthermore, when thermal runaway occurs in the electrode core 11, heat diffuses in the battery pack 100 in two directions, one of which passes through the gap between the electrode core 11 experiencing thermal runaway and the corresponding first surface 121 of the housing 12. The thermal resistance of the gap between the electrode core 11 and the first surface 121 is set to A, and the thermal resistance of the electrode core 11 in a direction perpendicular to the first surface 13 is set to B. A and B satisfy the relationship: 1 / 48 < A / B.

[0045] Furthermore, the ratio of the thermal resistance of the gap region between the pole core 11 and the first surface 121 of the shell 12 to the thermal resistance of the pole core 11 in a direction perpendicular to the first surface 13 is used to represent the matching relationship between the heat transfer capacity of the gap region between the pole core 11 and the first surface 121 of the shell 12 and the heat transfer capacity of the pole core 11 in a direction perpendicular to the first surface 13. During the heat transfer process, by ensuring A / B>1 / 48, it is ensured that the pole core 11 dissipates heat in a direction perpendicular to the first surface 13 after thermal runaway occurs in the battery cell. After strengthening the thermal insulation capacity of the gap region between the pole core 11 and the first surface 121 of the shell 12, it is further ensured that the thermal runaway battery cell transfers heat only internally, reducing the impact on other battery cells in a direction perpendicular to the first surface 13, avoiding the problem of heat diffusion between two adjacent battery cells in the direction perpendicular to the first surface 13, and ensuring the safety of the battery pack.

[0046] Furthermore, according to an embodiment of the present disclosure, A and B satisfy the relationship: A / B < 10. Specifically, if the ratio of the thermal resistance of the space between the pole core 11 and the first surface 121 to the thermal resistance of the pole core 11 in a direction perpendicular to the first surface 13 is greater than 10, the space between the pole core 11 and the first surface 121 occupies too much space in the battery cell 10. Although the thermal diffusion risk of the battery cell 10 is low, the volume density and energy density of the battery cell 10 are too low, which increases the volume of the battery pack 100 and the cost of the battery pack 100.

[0047] In the embodiment of the present disclosure, the ratio of the thermal resistance of the spacing area between the pole core 11 and the first surface 121 to the thermal resistance of the pole core 11 in the direction perpendicular to the first surface 13 is set between 1 / 48 and 10. This can not only effectively prevent the heat generated by the thermal runaway battery cell 10 from diffusing in the direction perpendicular to the first surface 13 and improve the working safety of the battery pack 100, but also ensure the volume density and energy density of the battery cell 10, thereby ensuring that the energy density of the battery pack 100 meets the usage requirements.

[0048] As shown in Figures 3, 5 and 6, there are multiple battery cells 10, and the multiple battery cells 10 constitute multiple battery cell groups 110. Each battery cell group 110 includes at least two battery cells 10 whose second surfaces 122 are arranged relative to each other, and the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 are arranged relative to each other. Specifically, the battery pack 100 includes multiple battery cell groups 110 consisting of multiple battery cells 10, which can increase the battery capacity of the battery pack 100 and improve the endurance of the battery pack 100. The first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 are arranged relative to each other, and within the ratio requirements of the present application, the heat generated after thermal runaway of the battery cell is reduced and transferred through the first surfaces 13 of the battery cell 10 in the two adjacent battery cell groups 110, or the heat dissipation after the transfer is increased.

[0049] Furthermore, each cell group 110 includes at least two cells 10 with second surfaces 122 disposed opposite to each other, that is, in two cells 10 abutting each other, the second surfaces 122 of the two cells 10 abutting each other. Since the heat transfer capacity of a cell 10 in a cell group 110 is limited in a direction perpendicular to the first surface 13, when a cell 10 in each cell group 110 generates heat, the heat can be preferentially transferred to other cells 10 in the same cell group 110 through the second surface 122 of the cell 10, thereby slowing down the spread of heat to other cell groups 110 in the battery pack 100. In the embodiment of the present disclosure, the second surface 122 is perpendicular to the first surface 121, the second surface 122 of the cell 10 is parallel to the core 11, the first surface 121 is perpendicular to the core 11, the second surface 122 of the cell 10 is disposed on at least one side of the core 11 in the thickness direction, and the first surface 121 of the cell 10 is disposed on at least one side of the core 11 in the width direction.

[0050] Furthermore, as shown in FIG2 , the area of ​​the second surface 122 is greater than the area of ​​the first surface 13 of the battery cell 10 , meaning that the heat transfer efficiency of the first surface 13 of the battery cell 10 is lower than the heat transfer efficiency of the second surface 122 . When thermal runaway occurs in the electrode core 11 , the amount of heat transferred through the first surface 121 is less than the amount of heat transferred through the second surface 122 . This further reduces the amount of heat transferred from the first surface 121 of the battery cell 10 to other battery cells 10 , thereby lowering the insulation requirements between adjacent battery cell groups 110 in the battery pack 100 , reducing the insulation space, and improving the space utilization of the battery pack 100 . Thus, when the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 are positioned 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, thereby suppressing the diffusion of heat between adjacent battery cell groups 110 , and further suppressing the diffusion of heat within the battery pack 100 .

[0051] In an embodiment of the present disclosure, the pole core 11 includes a multilayer pole sheet. Specifically, the multilayer pole sheet can be formed by stacking multiple independent pieces, or can be formed by winding an independent pole sheet to form a multilayer pole sheet structure. 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 direction of the pole core 11 along the direction perpendicular to the first surface 13 is the extension direction of the single-layer pole sheet, and the direction of the pole core 11 along the direction perpendicular to the second surface 122 is the stacking direction of the multilayer pole sheet. When the pole core 11 is a winding structure, the direction of the pole core 11 along the direction perpendicular to the first surface 13 is the axial ends of the battery cell 10, and the direction of the pole core 11 along the direction perpendicular to the second surface 122 is the winding direction of the multilayer pole sheet.

[0052] In an embodiment of the present disclosure, the housing 12 further includes a third surface 123, and the first surface 121, the second surface 122, and the third surface 123 are perpendicular to each other. According to some embodiments of the present disclosure, at least one of the first surface 121, the second surface 122, and the third surface 123 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 121, the second surface 122, and the third surface 123 are provided with a pole and an explosion-proof valve.

[0053] As shown in FIG1 , the distance between the pole core 11 and 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 λ1, and the length of the battery cell 10 is L. Then, d, a, L, λ1, and A satisfy the relationship: A = d / [(2*a*L)*λ1]. Specifically, after thermal runaway occurs in the battery cell 10, heat can be transferred to the exterior of the pole core 11 along the gap between the pole core 11 and the corresponding first surface 121 of the housing 12. The thermal resistance of the gap between the pole core 11 and the corresponding first surface 121 of the housing 12 is d / [(2*a*L)*λ1]. In the embodiments of the present disclosure, d, a, and L are measured in the same units.

[0054] As shown in FIG1 , an insulating heat insulating member or an insulating heat dissipating member or an air layer is provided in the interval area between the pole core 11 and the first surface 121 of the shell 12. Specifically, the insulating heat insulating member can inhibit the transfer of heat from the pole core 11 to the first surface 13 of the battery cell 10, and can inhibit the transfer of heat to the first surface 121 of the battery cell 10 in the adjacent battery cell group 110, thereby preventing the heat of the thermal runaway battery cell 10 from being transferred to the normal battery cell 10 that has not experienced thermal runaway, and can prevent the normal battery cell 10 that has not experienced thermal runaway from experiencing thermal runaway, thereby improving the working safety of the battery pack 100. The insulating heat dissipating member can accelerate the heat dissipation between the pole core 11 and the first surface 13 of the battery cell 10, and can reduce the heat transferred to the first surface 13 of the battery cell 10, thereby effectively inhibiting heat diffusion. It should also be noted that the insulating heat insulating member or the insulating heat dissipating member are both insulating materials 20.

[0055] As shown in Figure 1, d satisfies the relationship: 2mm<d<12mm. Specifically, if the distance between the pole core 11 and the first surface 121 of the shell 12 is set to no more than 2mm, the distance between the pole core 11 and the shell 12 is too close, and it is not convenient to assemble insulating heat insulating parts or insulating heat dissipating parts between the pole core 11 and the first surface 121 of the shell 12. If the distance between the pole core 11 and the first surface 121 of the shell 12 exceeds 12mm, the capacity density of the battery cell 10 is affected. Setting the distance between the pole core 11 and the first surface 121 of the shell 12 between 2mm and 12mm can not only facilitate the assembly of insulating heat insulating parts and insulating heat dissipating parts, but also ensure the energy density of the battery cell 10.

[0056] In the embodiments of the present disclosure, the distance between the pole core 11 and the first surface 121 of the housing 12 is preferably set between 2 mm and 8 mm. An insulating member may be placed between the pole core 11 and the first surface 121 of the housing 12, including but not limited to a polypropylene spacer. A thermal insulator may also be placed between the pole core 11 and the first surface 121 of the housing 12, including but not limited to polyurethane foam. Alternatively, the space between the pole core 11 and the first surface 121 of the housing 12 may not be filled.

[0057] As shown in FIG1 , L satisfies the relationship: 400 mm < L < 2500 mm. In the embodiment of the present disclosure, the length of the battery cell 10 is set between 400 mm and 2500 mm. This allows the heat to quickly diffuse through the second surface 122 to the adjacent battery cells 10 in the same battery cell group 110 when thermal runaway occurs in the battery cell 10, thereby cooling the battery cell 10. This also reduces the amount of heat transferred to the battery cells 10 in the adjacent battery cell group 110 through the first surface 121 of the housing 12, thereby reducing the risk of causing thermal runaway in the battery cells 10 in the adjacent battery cell group 110, thereby ensuring that the battery pack 100 can suppress heat diffusion.

[0058] As shown in Figures 1 and 5, the width of the battery cell 10 is H, the two sides of the battery cell 10 along the width direction are the first side 13 of the battery cell 10, the length of the battery cell 10 is L, the width of the battery cell is H, the thickness of the battery cell 10 is D, the thermal conductivity of the pole core 11 in the direction perpendicular to the first side 13 is λ2, H, D, λ2 and B satisfy the relationship: B = H / [(D*L)*λ2], H, D, L are measured in the same unit. Specifically, the two sides of the width of the battery cell 10 are set as the first side 13 of the battery cell 10. After the battery cell 10 has thermal runaway, the thermal resistance when heat is transferred in the direction perpendicular to the first side 13 of the battery cell 10 (that is, the direction in which the battery cell groups are arranged) is H / [(D*L)*λ2]. In the embodiments of the present disclosure, H, D, and L are measured in the same unit.

[0059] Furthermore, by comparing the thermal resistance of the gap area between the pole core 11 and the first surface 121 of the corresponding shell 12 with the thermal resistance of the pole core 11 in the direction perpendicular to the first surface 13, it can be simplified that the ratio of the thermal resistance of the gap area between the pole core 11 and the first surface 121 to the thermal resistance of the pole core 11 in the direction perpendicular to the first surface 13 is {d / [(2*a)*λ1]} / {H / [(D)*λ2]}. According to an embodiment of the present disclosure, 1 / 48<{d / [(2*a)*λ1]} / {H / [(D)*λ2]}<10.

[0060] As shown in Figure 1, H satisfies the relationship: 80mm<H<200mm. Specifically, if the width of the battery cell 10 is set to be less than 80mm, the area of ​​the second side 122 of the battery cell 10 is too small. When the battery cell 10 is in thermal runaway, too little heat is transferred to the adjacent battery cell 10 in the same battery cell group 110 through the second side 122. This causes the battery cell 10 to be unable to dissipate heat and cool down quickly, and heat diffusion is likely to occur in the battery pack 100. If the width of the battery cell 10 is set to exceed 200mm, the size of the battery cell 10 is too large, which may easily cause uneven temperature or exhaust problems. Therefore, setting the width of the battery cell 10 between 80mm and 200mm can not only quickly dissipate heat and cool down the thermal runaway battery cell 10, but also maintain the normal operation of the thermal runaway battery cell 10.

[0061] As shown in Figure 1, D satisfies the relationship: 10mm<D<1000mm. Specifically, if the thickness of the battery cell 10 is set to less than 10mm, the shell of the battery cell 10 is 12-sized and too narrow, and the energy density of the battery cell is reduced. If the thickness of the battery cell 10 is set to exceed 1000mm, the shell of the battery cell 10 is 12-sized and too thick. After thermal runaway occurs at a certain position in the battery cell 10, the heat cannot be quickly transferred to the outside, which is not conducive to the heat dissipation of the thermal runaway battery cell 10. Therefore, setting the thickness of the battery cell 10 between 10mm and 1000mm can not only facilitate the arrangement of the pole core 11 and the thermal insulation material 20 in the shell 12, but also ensure the heat dissipation efficiency of the battery cell 10.

[0062] According to an embodiment of the present disclosure, λ2 satisfies the relationship: 10W / (m*K)<λ2<30W / (m*K). Specifically, according to an embodiment of the present disclosure, the thermal conductivity of the pole core 11 in a direction perpendicular to the first surface 13 ranges from 10W / (m*K) to 30W / (m*K), and the thermal conductivity of the pole core 11 in a direction perpendicular to the second surface 122 ranges from 0.1W / (m*K) to 5W / (m*K).

[0063] According to an embodiment of the present disclosure, as shown in FIG6 , 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 in the middle is punctured to trigger thermal diffusion of the topmost battery cell in the battery cell group, and after the thermal runaway ends, the adjacent battery cells are observed to see whether thermal runaway occurs (i.e., to determine whether thermal diffusion occurs). For a single battery cell, d, a, λ1, H, D, and λ2 are designed and taken values ​​respectively, wherein the battery cells all adopt a lithium iron phosphate system. The following table shows the values ​​of each group of d, a, λ1, H, D, and λ2 and the corresponding experimental results:

[0064] Comparing Examples 1-6 with Comparative Examples 1-2 in the table shows that when the A / B ratio is greater than 1 / 48, thermal diffusion does not occur throughout the battery pack, meaning that adjacent cell groups to the thermal runaway cell group do not experience thermal runaway. However, when the A / B ratio is less than 1 / 48, thermal diffusion occurs within the battery pack. Therefore, when the A / B ratio is greater than 1 / 48, thermal insulation between adjacent cell groups is maintained, preventing the spread of safety risks within the battery pack, ensuring the safety of adjacent cell groups, and improving the overall safety of the battery pack.

[0065] Comparing Examples 1-6 with Comparative Examples 3 and 4 in the table shows that when the value of A / B is greater than 10, the volumetric energy density of the entire battery cell is less than 375 WH / L, failing to meet the design requirements of the battery cell. 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. Although 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 a low volumetric energy density of the battery cell 10, which in turn causes the battery cell 10 to fail to meet the normal operation requirements of the battery pack 100.

[0066] According to some embodiments of the present disclosure, an insulating heat-isolating member or an insulating heat-dissipating member, or direct contact or an air layer is provided between the second surfaces 122 of two adjacent battery cells 10 in each battery cell group 110, which can slow down the diffusion of heat between the two adjacent battery cells 10 and inhibit the diffusion of heat in the battery pack 100. In this way, the influence of heat on the battery cells 10 in the battery pack 100 where no heat diffusion occurs can be reduced, thereby improving the working safety of the battery pack 100.

[0067] According to other embodiments of the present disclosure, the second surfaces 122 of two adjacent battery cells 10 in each battery cell group 110 are in contact and fit with each other, so that the heat generated by the battery cell 10 that has experienced thermal runaway can be preferentially transferred toward the battery cell 10 that has not experienced thermal runaway in the same battery cell group 110. This can reduce the heat transfer to other battery cell groups 110 that have not experienced thermal runaway, thereby reducing the impact of the battery cell group 110 that has experienced thermal runaway on the battery cell group 110 that has not experienced thermal runaway in the battery pack 100, and thereby improving the working safety of the battery pack 100.

[0068] According to further embodiments of the present disclosure, the second surfaces 122 of two adjacent battery cells 10 in each battery cell group 110 are spaced apart from each other, and an air layer exists between the second surfaces 122 of two adjacent battery cells 10 in each battery cell group 110. Specifically, the provision of the air layer can block the transfer of heat between two adjacent battery cells 10, thereby increasing the thermal resistance between adjacent battery cells 10 in the same battery cell group 110, thereby reducing the transfer of heat generated by the thermal runaway battery cell 10 to the battery cells 10 in the same battery cell group 110 that have not experienced thermal runaway, thereby reducing the impact of the thermal runaway battery cell 10 on the adjacent battery cells 10, and improving the operating safety of the battery pack 100.

[0069] According to some embodiments of the present disclosure, an insulating heat insulating member or an insulating heat dissipating member is provided between the first surfaces 121 of the battery cells 10 in two adjacent battery cell groups 110. Specifically, the insulating heat insulating member has a heat insulating effect on the heat transferred between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110, which can enhance the effect of suppressing heat transfer and further prevent the diffusion of heat in the battery pack 100. The insulating heat dissipating member can enhance the heat dissipation efficiency between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110, and can accelerate the heat dissipation rate before reaching the first surfaces 13 of the battery cells 10 in the non-thermal runaway battery cell group 110, thereby reducing the heat transferred to the first surfaces 13 of the battery cells 10 in the non-thermal runaway battery cell group 110, thereby enhancing the effect of suppressing heat diffusion of the battery pack 100.

[0070] 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 with the second surfaces 122 bonded to each other, and the second surfaces 122 are perpendicular to the first surfaces 13 of the battery cells 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. When thermal runaway occurs in the battery cell 10, heat can be transferred to the outside through two different directions, namely the first surface 13 and the second surface 122. 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 greater than the area of ​​the first surface. When the pole core 11 is a winding structure, the surface with the larger area of ​​the first surface 13 and the second surface 122 is the bonding surface of two adjacent battery cells 10 in each battery cell group 110. The battery cell 10 with a laminated structure is described below.

[0071] 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.

[0072] In addition, the area of ​​the first surface 13 of the battery cell 10 is smaller than the area of ​​the second surface 122. This 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.

[0073] According to further embodiments of the present disclosure, the first surfaces 13 of the battery cells 10 in two adjacent battery cell groups 110 are spaced apart from each other, and an air layer exists between the first surfaces 13 of the battery cells 10 in the two adjacent battery cell groups 110. Specifically, the provision of the air layer can block the transfer of heat between the two adjacent battery cell groups 110, thereby reducing the transfer of heat generated by the thermal runaway battery cell 10 to the battery cells 10 in the adjacent battery cell group 110 that are not experiencing thermal runaway. This can further reduce the impact of the battery cell group 110 that is experiencing thermal runaway on the battery cell group 110 that is not experiencing thermal runaway, thereby improving the operating safety of the battery pack 100.

[0074] According to some embodiments of the present disclosure, as shown in conjunction with Figures 1, 2, and 7, a battery pack 100 further includes a tray 30 and a cold plate 31. The tray 30 is open on one side, and the cold plate 31 is disposed on the open side of the tray 30. Multiple battery cells 10 are disposed within 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 above the battery cells. This arrangement not only facilitates the placement of the battery pack 100 but also helps dissipate heat quickly within the battery pack 100. Multiple battery cells 10 are disposed on the upper side of the tray 30. These multiple battery cells 10 are disposed within the tray 30, allowing heat generated within the battery cells 10 to be quickly dissipated through the tray 30. This allows for rapid heat dissipation within the battery cells 10 in the event of thermal runaway. Furthermore, in the event of thermal runaway, the battery cells 10 can dissipate heat through the cold plate 31, preventing heat from spreading within the battery pack 100 and affecting the safety of other battery cells 10 within the battery pack 100.

[0075] According to other embodiments of the present disclosure, the first surface 121 of the bottom battery cell 10 of 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 of 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 121 and the second surface 122 of the bottom battery cell 10 of 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 pack 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 pack 100.

[0076] 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 pack 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 121 of the battery cells 10 in one or more battery cell groups 110 in the battery pack 100 may be in direct contact with the tray 30 or the cold plate 31, wherein the connection method between the first side 121 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.

[0077] 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 the battery cell 10 running out of control. 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 pack 100. In the embodiments of the present disclosure, an insulating heat-insulating member or an insulating heat-dissipating member may be filled between two adjacent battery cells 10 in the same battery cell group 110, or an insulating heat-insulating member or an insulating heat-dissipating member may not be filled. An insulating heat-insulating member or an insulating heat-dissipating member may be filled between two adjacent battery cell groups 110, and an insulating heat-insulating member or an insulating heat-dissipating member may be filled between the battery cell group 110 and the housing 12.

[0078] 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 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 pack 100. In embodiments of the present disclosure, an insulating thermal insulation member or an insulating heat dissipation member can be placed between two adjacent battery cell groups 110, and between the battery cell group 110 and the housing 12.

[0079] According to 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 121 of the battery cell 10 is in close contact with the cold plate 31. In the event of thermal runaway in 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 in the other battery cells 10 in the battery pack 100. By affixing the second surfaces 122 of adjacent battery cells 10 in the same battery cell group 110, heat can be evenly diffused within the battery cell group 110, while reducing the temperature at which heat diffuses. This prevents thermal runaway in adjacent battery cell groups 110, slows down heat diffusion, and reduces safety issues with the battery pack 100. In embodiments of the present disclosure, an insulating heat-insulating member or an insulating heat-dissipating member may be filled between two adjacent battery cell groups 110, and an insulating heat-insulating member or an insulating heat-dissipating member may be filled between the battery cell group 110 and the housing 12.

[0080] In the embodiment 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 within the battery pack 100 is not only applicable to any battery, module, or package subject to thermal runaway, but can also be applied to placing high thermal conductivity materials within the battery to closely adhere to the electrode core 11 or to the housing 12 to achieve uniform temperature. The embodiment of the present disclosure can also be applied between modules to prevent thermal diffusion between modules.

[0081] According to the power consumption system of the present disclosure, as shown in Figure 7, a battery pack 100 in an embodiment of the present disclosure 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 cells 10, thereby effectively improving the working safety of the battery pack 100 and further improving the safety of the power consumption system.

[0082] 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", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 operate in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0083] 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.

[0084] 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 pack (100), wherein, Comprising: A 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), the electrode core (11) is spaced from a first surface (121) of the housing (12), and the first surface (121) of the housing (12) is the first surface (13) of the battery cell (10). Wherein, the thermal resistance of the spaced region between the electrode core (11) and the first surface (121) of the housing (12) is A, the thermal resistance of the electrode core (11) in a direction perpendicular to the first surface (13) is B, and A and B satisfy the relationship: 1 / 48 < A / B.

2. The battery pack (100) according to claim 1, wherein, A and B satisfy the relationship: A / B < 10.

3. The battery pack (100) according to claim 1 or 2, wherein, There are multiple battery cells (10), and the multiple battery cells (10) form multiple battery cell groups (110). Each battery cell group (110) includes at least two second surfaces (122) disposed opposite to the battery cell (10). The first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) are disposed opposite to each other, and the second surface (122) of the battery cell (10) is perpendicular to the first surface (13) of the battery cell (10).

4. The battery pack (100) according to any one of claims 1-3, wherein, The distance between the electrode core (11) and 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 λ1, the length of the battery cell (10) is L, and d, a, L, λ1, and A satisfy the relationship: A = d / [(2 * a * L) * λ1], and d, a, L are in the same unit.

5. The battery pack (100) according to claim 4, wherein, An insulating and heat-insulating member or an insulating and heat-dissipating member is disposed in the spaced region between the electrode core (11) and the first surface (121) of the housing (12).

6. The battery pack (100) according to claim 4 or 5, wherein, d satisfies the relationship: 2 mm < d < 12 mm.

7. The battery pack (100) according to any one of claims 4-6, wherein, L satisfies the relationship: 400 mm < L < 2500 mm.

8. The battery pack (100) according to any one of claims 1-7, wherein, On both sides of the battery cell (10) in the width direction are the first surfaces (13) of the battery cell (10). The length of the battery cell (10) is L, the width of the battery cell (10) is H, the thickness of the battery cell (10) is D, and the thermal conductivity of the electrode core (11) in a direction perpendicular to the first surface (13) is λ2. H, D, λ2, and B satisfy the relationship: B = H / [(D * L) * λ2], and H, D, L are in the same unit.

9. The battery pack (100) according to claim 8, wherein, H satisfies the relationship: 80 mm < H < 200 mm.

10. The battery pack (100) according to claim 8 or 9, wherein, D satisfies the relationship: 10 mm < D < 1000 mm.

11. The battery pack (100) according to any one of claims 8-10, wherein, λ2 satisfies the relationship: 10 W / (m*K) < λ2 < 30 W / (m*K).

12. The battery pack (100) according to any one of claims 3-11, wherein, An insulating and heat-insulating member or an insulating and heat-dissipating member is disposed between the second surfaces (122) of two adjacent battery cells (10) in each battery cell group (110); and / or The second surfaces (122) of two adjacent battery cells (10) in each battery cell group (110) are in contact and fit with each other; and / or The second surfaces (122) of two adjacent battery cells (10) in each battery cell group (110) are spaced from each other and there is an air layer therebetween.

13. The battery pack (100) according to any one of claims 1-12, wherein, An insulating and heat-insulating member or an insulating and heat-dissipating member is provided between the first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110); and / or The first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) are in contact and fit with each other; and / or The first surfaces (13) of the battery cells (10) in two adjacent battery cell groups (110) are spaced apart from each other and there is an air layer therebetween.

14. The battery pack (100) according to any one of claims 1-12, 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).

15. The battery pack (100) according to claim 3, wherein, The electrode core (11) includes multiple layers of electrode sheets. The extending direction of a single layer of the electrode sheet is the direction in which the electrode core (11) extends perpendicular to the first surface (13), and the arranging direction of the multiple layers of the electrode sheets is the direction in which the electrode core (11) extends perpendicular to the second surface (122).

16. The battery pack (100) according to claim 3 or 15, wherein, The area of the first surface (13) is smaller than the area of the second surface (122).

17. An electrical power system (200), wherein, Comprising: The battery pack (100) according to any one of claims 1-16.

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