Battery module, battery pack and energy storage system

Abstract

The utility model provides a battery module, a battery pack and an energy storage system.The battery module comprises a plurality of battery packs arranged side by side, each battery pack comprises a plurality of battery cells arranged in the arrangement direction of the battery packs, a first heat insulation buffer part is arranged between any two adjacent battery cells in each battery pack, and a second heat insulation buffer part is arranged between any two adjacent battery cells in each battery pack; a second heat insulation buffer piece is arranged between any two adjacent battery packs in each battery pack, and the thickness of the first heat insulation buffer piece is smaller than that of the second heat insulation buffer piece. Therefore, not only can the use safety of the battery module be improved, but also the situation that the length of the battery module is too large can be avoided, and when the battery module is applied to a battery pack, the energy density of the battery pack can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery module, a battery pack, and an energy storage system. Background Art

[0002] The battery pack may include: a box body and a battery module. The battery module is arranged in the box body. The battery module includes: multiple battery cells and multiple thermal insulation buffers. The thermal insulation buffer is located between two adjacent battery cells. When a battery cell experiences thermal runaway and causes expansion, the thermal insulation buffer can be compressed and provide a certain space for the battery cell to expand. It can also play a role in insulation to prevent heat from spreading to adjacent battery cells, thereby improving the safety of the battery pack.

[0003] At present, when setting up thermal insulation buffers, it is usually set that the thickness of the thermal insulation buffers at various positions is the same, that is, the thickness of the thermal insulation buffers between any two adjacent battery cells is the same. In order to ensure that when thermal runaway occurs in the battery cells at various positions, the thermal insulation buffers adjacent to them can effectively prevent heat diffusion and provide more expansion space, the thickness of the thermal insulation buffers is generally made larger. This will result in a longer length of the battery module, which is not conducive to increasing the number of battery cells in the battery pack and has an adverse effect on improving the energy density of the battery pack. Utility Model Content

[0004] The present application provides a battery module, a battery pack and an energy storage system to avoid excessive length of the battery module and improve the energy density of the battery pack.

[0005] In the first aspect, an embodiment of the present application provides a battery module, which may include: a plurality of battery packs arranged in parallel, each battery pack including a plurality of battery cells arranged along the arrangement direction of each battery pack, a first thermal insulation buffer is provided between any two adjacent battery cells in each battery pack, a second thermal insulation buffer is provided between any two adjacent battery packs in each battery pack, and the thickness of the first thermal insulation buffer is less than the thickness of the second thermal insulation buffer. In particular, when all battery cells are divided into multiple battery packs, they can be divided according to a preset acceptable range of heat spread. The range of heat spread within the battery pack can be considered to be acceptable. If a battery cell in the battery pack has thermal runaway, heat is allowed to spread within the battery pack, but the heat cannot spread to other battery packs and affect the battery cells in other battery packs. At this time, the thicker second thermal insulation buffer can effectively isolate the heat from spreading to adjacent battery packs, thereby improving the safety of the battery module. Moreover, when a thinner first thermal insulation buffer is used, it can not only reduce the impact of thermal runaway cells on adjacent cells in the same battery pack, thereby improving the safety of battery module use, but also reduce the arrangement length of the battery pack, thereby increasing the energy density of the battery module. When the battery module is applied to a battery pack, the energy density of the battery pack can be increased.

[0006] Optionally, the first thermal insulation buffer members between any two adjacent battery cells within the same battery pack have the same thickness, which further reduces the length of the battery module, reduces assembly difficulty, and improves assembly efficiency. Furthermore, the thickness of each first thermal insulation buffer member is the same, which further reduces the length of the battery module, further reduces assembly difficulty, and further improves assembly efficiency.

[0007] Optionally, the thickness of each second thermal insulation buffer member in each battery pack shows a decreasing trend in the direction from the battery pack located in the middle position to the battery packs on both sides, wherein the decreasing trend may include: gradual decrease or step decrease. The specific decreasing method to be adopted can be determined according to actual conditions and is not specifically limited here. Among them, when the battery module is assembled, it is generally assembled from both sides with one or some battery cells as the center, and compression and clamping will be performed during the assembly process to ensure that the finally assembled battery module remains stable, so that the assembly compression amount of the second thermal insulation buffer located in the middle position is larger, and the assembly compression amount of the second thermal insulation buffer located closer to the side position is smaller; therefore, the thickness of the second thermal insulation buffer located in the middle position can be set to be larger, providing more compression space to achieve assembly, and more expansion space can also be provided for the battery cell in the middle position, reducing the risk of explosion of the battery cell in the middle position; and the thickness of the second thermal insulation buffer located close to the side position is set to be smaller, which can avoid compression redundancy, provide appropriate expansion space for the battery cell, and avoid the stacking length of the battery module being too large. When the battery module is applied to the battery pack, the energy density of the battery pack is improved.

[0008] Optionally, at least one of the first and second thermally insulating buffer members includes a buffer layer and an insulation layer, with the buffer layer and insulation layer forming a sandwich structure. The buffer layer is compressible, thus providing expandable space to buffer expansion and prevent explosion of the battery cell due to a small expandable space. The insulation layer provides insulation, preventing heat transfer to adjacent battery cells. In this way, if a battery cell experiences thermal runaway and undergoes significant expansion, the sandwich structure provides more space for expansion and provides better insulation, thereby improving the safety of the battery module.

[0009] Furthermore, the thermal insulation layer is arranged between the two buffer layers, and the edges of the two buffer layers are connected to form a structure with a cavity. The thermal insulation layer is arranged in the cavity. In this way, when the battery cell experiences thermal runaway and undergoes a large expansion, the buffer layer can provide more space for the expansion of the battery cell, thereby improving the safety of the battery module.

[0010] Optionally, at least one of the first and second thermal insulation buffers includes a flexible skeleton and an insulation material, with the insulation material being absorbed within pores of the flexible skeleton. The flexible skeleton has pores within which the insulation material can be absorbed. This not only secures the insulation material in place, preventing its loss, but also provides good compressibility, providing more space for thermal expansion of the battery cell, thereby improving the safety of the battery module.

[0011] Optionally, the insulation layer can be made of materials including, but not limited to, aerogels or phase change materials. Phase change materials include inorganic and organic phase change materials. Any material with good thermal insulation properties can be used to make the insulation layer, thereby achieving thermal insulation between adjacent battery cells. Alternatively, the buffer layer can be made of materials including, but not limited to, foam, silicone rubber, gel, flexible plastic, and gaskets. Any material with high compressibility can be used to make the buffer layer, thereby providing space for the battery cells to expand.

[0012] Alternatively, the materials used to make the flexible skeleton may include but are not limited to: fibers, gels or thermoplastic elastomers, etc. Thermoplastic elastomers include but are not limited to: styrene block copolymers, etc. As long as the flexible material has pores inside, it can be used to make the flexible skeleton; alternatively, the thermal insulation material may include but is not limited to: water, aerogel or phase change material, and the phase change material includes inorganic phase change material and organic phase change material.

[0013] In a second aspect, embodiments of the present application further provide a battery pack, which may include a housing and a battery module, wherein the battery module is disposed within the housing, and wherein the battery module is such as the battery module described in the first aspect and any of the embodiments of the first aspect. Thus, by improving the performance of the battery module, the performance of the battery pack is also improved.

[0014] It should be understood that since the principle of solving the problem by the battery pack is similar to the principle of solving the problem by the aforementioned battery module, the implementation and technical effects of the battery pack can refer to the implementation and technical effects of the aforementioned battery module, and the repeated parts will not be repeated.

[0015] In a third aspect, embodiments of the present application further provide an energy storage system, comprising a battery pack and a power converter as described in the second aspect above. The power converter is configured to convert AC power outputted by an external AC power source into DC power for output to the battery pack, and / or the power converter is configured to convert DC power outputted by the battery pack into AC power for output to a load or power grid. In this manner, while improving the performance of the battery pack, the performance of the energy storage system is also improved.

[0016] It should be understood that since the principle of solving the problem by the energy storage system is similar to the principle of solving the problem by the aforementioned battery pack, the implementation and technical effects of the energy storage system can refer to the implementation and technical effects of the aforementioned battery pack, and the repeated parts will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of an energy storage system provided in an embodiment of the present application;

[0018] Figure 2 A schematic structural diagram of a battery pack provided in an embodiment of the present application;

[0019] Figure 3 A schematic structural diagram of a battery cell provided in an embodiment of the present application;

[0020] Figure 4 A schematic diagram of a top view of a battery module provided in an embodiment of the present application;

[0021] Figure 5 A schematic structural diagram of a heat-insulating buffer provided in an embodiment of the present application;

[0022] Figure 6 A schematic structural diagram of another thermal insulation buffer provided in an embodiment of the present application;

[0023] Figure 7 A schematic structural diagram of another thermal insulation buffer member provided in an embodiment of the present application;

[0024] Figure 8 A schematic top view of another battery module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0026] It should be noted that the same reference numerals in the drawings of this application represent the same or similar structures, and thus their repeated description will be omitted. The words expressing positions and directions described in this application are all explained using the drawings as examples, but they can be modified as needed, and such modifications are included in the scope of protection of this application. The drawings of this application are only for illustrating relative positional relationships and do not represent true proportions.

[0027] In order to facilitate understanding of the technical solution provided by the embodiments of the present application, its application scenario is first explained below.

[0028] The technical solutions provided in the embodiments of this application can be widely used in energy storage systems, which can be applied to, but not limited to, household energy storage, site energy, smart photovoltaics, and data center energy scenarios, for storing and providing electrical energy. Figure 1 The energy storage system shown in the figure is a schematic diagram of an energy storage system. The energy storage system may include: a battery cluster and a power converter 200. The battery cluster includes a plurality of battery packs 100 connected in series. Figure 1 Only one battery pack 100 is shown as an example. The power converter 200 can convert the AC power output by an external AC power source (such as the power grid 300) into DC power and output it to the battery pack 100 in the battery cluster to charge the battery pack 100. It can also convert the DC power output by the battery pack 100 in the battery cluster into AC power and output it to the load 400 or the power grid 300 to discharge the battery pack 100.

[0029] See also Figure 2 The structural diagram of the battery pack 100 shown in the figure, the battery pack 100 may include: a box body 101, and a battery module 102, the battery module 102 is arranged in the box body 101, the battery module 102 includes: a plurality of battery cells 20 and a plurality of thermal insulation buffers 10, the thermal insulation buffer 10 is located between two adjacent battery cells 20, when a battery cell 20 has thermal runaway and causes expansion, the thermal insulation buffer 10 can be compressed and provide a certain space for the battery cell 20 to expand, and can also play a heat insulation role to prevent heat from diffusing to adjacent battery cells 20, thereby improving the safety of the battery pack. Each battery cell 20 can be connected in series, in parallel, or in a combination of series and parallel connections, so that the battery pack 100 has a higher capacity and a higher voltage, so that it can be suitable for various application scenarios. The battery cell 20 can be, but is not limited to: sodium ion battery cells, lithium ion battery cells, potassium ion battery cells and other types of battery cells. Among them, taking the battery cell 20 as a sodium ion battery cell as an example, for each battery cell 20, such as Figure 3 The structural schematic diagram of the battery cell 20 shown in the figure shows that the battery cell 20 may include: a positive electrode 1, a negative electrode 2, a battery separator 3 and an electrolyte 4. The battery separator 3 is arranged between the positive electrode 1 and the negative electrode 2, and the electrolyte 4 infiltrates the positive electrode 1, the battery separator 3 and the negative electrode 2.

[0030] At present, when setting up thermal insulation buffers, it is usually set that the thickness of the thermal insulation buffers at various positions is the same, that is, the thickness of the thermal insulation buffers between any two adjacent battery cells is the same. In order to ensure that when thermal runaway occurs in the battery cells at various positions, the thermal insulation buffers adjacent to them can effectively prevent heat diffusion and provide more expansion space, the thickness of the thermal insulation buffers is generally made larger. This will result in a longer length of the battery module, which is not conducive to increasing the number of battery cells in the battery pack, resulting in limited improvement in the energy density of the battery pack.

[0031] Based on this, an embodiment of the present application provides a battery module, which may include: a plurality of battery packs arranged in parallel, each battery pack including a plurality of battery cells arranged along the arrangement direction of each battery pack, a first thermal insulation buffer is provided between any two adjacent battery cells in each battery pack, a second thermal insulation buffer is provided between any two adjacent battery packs in each battery pack, and the thickness of the first thermal insulation buffer is less than the thickness of the second thermal insulation buffer. Among them, when all the battery cells are divided into multiple battery packs, they can be divided according to a preset acceptable range of heat spread. The range of heat spread within the battery pack can be considered to be acceptable. If a battery cell in the battery pack has thermal runaway, heat is allowed to spread within the battery pack, but the heat cannot spread to other battery packs and affect the battery cells in other battery packs. At this time, the thicker second thermal insulation buffer can effectively isolate the heat from spreading to adjacent battery packs, thereby improving the safety of the battery module. Moreover, when a thinner first thermal insulation buffer is used, it can not only reduce the impact of thermal runaway cells on adjacent cells in the same battery pack, thereby improving the safety of battery module use, but also reduce the arrangement length of the battery pack, thereby increasing the energy density of the battery module. When the battery module is applied to a battery pack, the energy density of the battery pack can be increased.

[0032] It should be understood that the number of battery cells included in the battery pack, or the size of the acceptable range of heat spread, can be set according to other factors such as the requirements for safety of use, application scenarios, production costs, configuration requirements, etc.; for example, if the requirements for safety of use are very high and the acceptable range of heat spread is small, then a small number of battery cells can be divided into a battery pack, for example but not limited to dividing one battery cell or two battery cells into a battery pack, so that when a battery cell in the battery pack has thermal runaway, the range of heat impact is one battery cell or zero battery cells, so that more battery cells can be protected from being affected; if the requirements for safety of use are medium, but the production cost needs to be reduced to a certain extent, the acceptable range of heat spread is medium, then more battery cells can be divided into one battery pack. Battery pack, for example, but not limited to, five battery cells, six battery cells or other numbers of battery cells are divided into a battery pack, so that when a battery cell in the battery pack has thermal runaway, a certain number of battery cells can be protected from being affected, and the number of the second thermal insulation buffer parts that are more expensive and thicker can be reduced, thereby reducing the production cost of the battery module; if the use safety is lower, but the production cost needs to be reduced as much as possible, the acceptable range of heat spread is larger, and all battery cells can be divided into a battery pack at this time, that is, the entire battery module is regarded as a battery pack; based on this, the higher the use safety, the smaller the acceptable range of heat spread, and the fewer battery cells included in the battery pack, and vice versa. The specific number of battery cells included in the battery pack is not specifically limited here. If used in an electric vehicle, and the electric vehicle is configured to require the entire battery module to be within an acceptable range of heat spread, then all battery cells are divided into one battery pack, that is, the entire battery module is regarded as a battery pack; if used in a household energy storage scenario, and the acceptable range of heat spread is configured to be smaller, for example but not limited to three battery cells, then the three battery cells are divided into one battery pack; if used in a site energy storage scenario, and the acceptable range of heat spread is configured to be larger, for example but not limited to ten battery cells, then the ten battery cells are divided into one battery pack.

[0033] The battery module provided in the embodiments of the present application is described in detail below with reference to specific embodiments.

[0034] Figure 4 The schematic diagram of the structure of a battery module provided by the embodiment of the present application is shown as an example. Figure 4 As shown, the battery module may include: a plurality of battery packs 20a arranged in parallel, wherein the arrangement direction of each battery pack 20a may be defined as a first direction, that is, Figure 4In the x direction, each battery pack 20a includes: a plurality of battery cells 20 arranged along the first direction and at least one first thermal insulation buffer 10a, the first thermal insulation buffer 10a being provided between any two adjacent battery cells 20 in the battery pack 20a; wherein the number of battery cells 20 included in different battery packs 20a may be the same or different, for example, Figure 4 In the embodiment, two battery packs 20a include two battery cells 20, and the other two battery packs 20a include three battery cells 20; of course, the number of battery cells 20 included in the battery pack 20a is not limited to two or three, but can also be four, five or more, which is not specifically limited here; the battery module can also include a second thermal insulation buffer 10b, which is arranged between any two adjacent battery packs 20a; the thickness d1 of the first thermal insulation buffer 10a is less than the thickness d1 of the second thermal insulation buffer 10b (such as Figure 4 d21, d22, d23 in the figure), where Figure 4 In the figure, the rectangle filled with oblique lines represents the first thermal insulation buffer member 10a, and the rectangle filled with grid represents the second thermal insulation buffer member 10b.

[0035] When battery packs 20a are divided according to a preset acceptable range for heat spread, the area within battery pack 20a can be considered to be within an acceptable range for heat spread. If a cell 20 within battery pack 20a experiences thermal runaway, heat is allowed to spread within the battery pack 20a, but the heat cannot spread to other battery packs 20a and affect the cells 20 therein. In this case, the thicker second thermal insulation buffer 10b can effectively prevent heat from spreading to adjacent battery packs 20a, thereby improving the safety of the battery module. Furthermore, the thinner first thermal insulation buffer 10a can not only reduce the impact of the thermally runaway cell 20 on adjacent cells 20 within the same battery pack 20a, improving the safety of the battery module, but also reduce the length of the battery pack 20a, thereby increasing the energy density of the battery module. When the battery module is used in a battery pack, the energy density of the battery pack can be increased. Furthermore, setting the first thermal insulation buffer 10a and the second thermal insulation buffer 10b to different thicknesses can also reduce the manufacturing cost of the battery module.

[0036] For the first thermal insulation buffer 10a: when the battery pack 20a includes two battery cells 20, a first thermal insulation buffer 10a is provided in the battery pack 20a; when the battery pack 20a includes at least two battery cells 20, at least one first thermal insulation buffer 10a is provided in the battery pack 20a. In the same battery pack 20a, the number of first thermal insulation buffers 10a is the number of battery cells 20 minus one, so the number of first thermal insulation buffers 10a provided in the battery pack 20a is related to the number of battery cells 20.

[0037] The thickness of the first thermal insulation buffer member 10a between any two adjacent battery cells within the same battery pack 20a can be set to be the same, which further reduces the length of the battery module in the first direction, reduces assembly difficulty, and improves assembly efficiency. Furthermore, the thickness of the first thermal insulation buffer member 10a within each battery pack 20a can be set to be the same, which further reduces the length of the battery module in the first direction, further reduces assembly difficulty, and further improves assembly efficiency. Of course, the thickness of each first thermal insulation buffer member 10a can also be set to be different to meet the needs of different application scenarios and improve design flexibility.

[0038] Among them, the thickness of the first thermal insulation buffer 10a can be set according to other factors such as the energy density of the battery module and the safety requirements of use; for example, if the energy density requirement of the battery module is high, but the safety requirement of use is not high, the thickness of the first thermal insulation buffer 10a can be set to be smaller, so that more space can be saved for arranging the battery cells 20, and the number of battery cells 20 in the battery module can be increased, thereby increasing the energy density of the battery module; if the energy density requirement of the battery module is low, but the safety requirement of use is high, the thickness of the first thermal insulation buffer 10a can be set to be larger, so that more space can be provided for the expansion of the battery cells 20, and a higher thermal insulation effect can be provided, thereby improving the safety of the battery module.

[0039] For the second heat-insulating buffer member 10b: the thickness of the second heat-insulating buffer member 10b at each position can be set to be the same, for example Figure 4 The top view shows three second thermally insulating buffer members 10b. From left to right, these three second thermally insulating buffer members 10b are named: left second thermally insulating buffer member 10b, middle second thermally insulating buffer member 10b, and right second thermally insulating buffer member 10b. The thickness of the left second thermally insulating buffer member 10b is d22, the thickness of the middle second thermally insulating buffer member 10b is d21, and the thickness of the right second thermally insulating buffer member 10b is d23, where d21 = d22 = d23. This simplifies the structure of the battery module, simplifies the difficulty of battery module assembly, and thus improves battery module assembly efficiency.

[0040] Among them, the thickness of the second thermal insulation buffer member 10b, similar to that of the first thermal insulation buffer member 10a, can also be set according to other factors such as the energy density of the battery module and the safety requirements of use, which will not be detailed here.

[0041] A thermal insulation buffer may also be provided at the end of the battery module, and the thermal insulation buffer located at the end of the battery module may be a first thermal insulation buffer 10a or a second thermal insulation buffer 10b, which may be provided according to actual needs and is not specifically limited herein; for example, a first thermal insulation buffer 10a is provided at the left end of the battery module, and a second thermal insulation buffer 10b is provided at the right end of the battery module (not shown); or, a first thermal insulation buffer 10a is provided at both the left and right ends of the battery module, see Figure 4 Alternatively, a second thermal insulation buffer member 10b is provided at both the left and right ends of the battery module, which is not shown in the figure.

[0042] For example, regardless of whether it is the first thermal insulation buffer 10a or the second thermal insulation buffer 10b, the specific structure of the thermal insulation buffer may include the following configurations:

[0043] Method 1: The heat-insulating buffer may include a buffer layer 11 and a heat-insulating layer 12, wherein the buffer layer 11 and the heat-insulating layer 12 form a sandwich structure. Figure 5 As shown in (a), there are two buffer layers 11 and one heat insulating layer 12, and the heat insulating layer 12 is arranged between the two buffer layers 11, forming a sandwich structure of the buffer layer 11, the heat insulating layer 12, and the buffer layer 11; the buffer layer 11 is compressible, so it can provide an expandable space to buffer expansion and avoid battery explosion due to a small expandable space; the heat insulating layer 12 has a heat insulating effect and can prevent heat from being transferred to adjacent battery cells. In this way, when the battery cell experiences thermal runaway and a large expansion occurs, the two buffer layers 11 can provide more space for the battery cell to expand, thereby improving the safety of the battery module. Alternatively, see Figure 5 As shown in (b), two thermal insulation layers 12 are provided and one buffer layer 11 is provided. The buffer layer 11 is provided between the two thermal insulation layers 12, forming a sandwich structure of the thermal insulation layer 12, the buffer layer 11, and the thermal insulation layer 12. In this way, when the battery cell has thermal runaway and releases a lot of heat, the two thermal insulation layers 12 can effectively isolate the diffusion and spread of heat, effectively avoiding the impact on the surrounding battery cells, thereby improving the safety of the battery module.

[0044] Among them, the material for making the thermal insulation layer 12 can be a material with a lower thermal conductivity or a higher thermal absorption coefficient, and the material for making the thermal insulation layer can be set according to actual needs; for example, if the battery module is required to have a longer life, a material with a lower thermal conductivity can be used, such as but not limited to aerogel. Aerogel has a very low thermal conductivity due to its high specific surface area and low density, or a material with a higher thermal absorption coefficient, such as but not limited to inorganic phase change materials and organic phase change materials, can be used to increase the thermal insulation effect of the thermal insulation layer; if the production cost of the battery module is required to be lower, since the cost of materials with lower thermal conductivity or higher thermal absorption coefficient is higher, materials with medium thermal conductivity or medium thermal absorption coefficient and easy to obtain can be used to reduce the production cost of the battery module.

[0045] The material used to make the buffer layer 11 can be a material with certain compression performance or a certain compression coefficient, and the specific material selection can be set according to actual needs; for example, if the battery module is required to have a longer life, a material with a higher compression coefficient and a more stable material can be used, such as but not limited to foam, silicone rubber, flexible plastic, etc., so that it can maintain good compression performance for a long time and increase the buffering effect; if the shape of the battery cell is relatively special, a material that is easier to form a buffer layer of a special shape can be used, such as but not limited to gel, etc., thereby eliminating processes such as cutting and injection molding; if the production cost of the battery module is required to be lower, flexible materials and gaskets that are easy to form and have lower costs can be used to reduce the production cost of the battery module.

[0046] Method 2: The heat-insulating layer 12 is disposed between two buffer layers 11. The edges of the two buffer layers 11 are connected to form a structure having a cavity, and the heat-insulating layer 12 is disposed in the cavity. For example, see Figure 6 As shown, the buffer layer 11 is actually a shell structure with a cavity, wherein the cavity can be a closed cavity or a non-closed cavity, and the thermal insulation layer 12 is arranged in the cavity, so that the buffer layer 11 wraps the thermal insulation layer 12. In other words, the thermal insulation layer 12 is encapsulated in the cavity of the buffer layer 11. In this way, when the battery cell has thermal runaway and undergoes a large expansion, the buffer layer 11 can provide more space for the expansion of the battery cell, thereby improving the safety of the battery module.

[0047] The materials for the thermal insulation layer 12 and the buffer layer 11 can be found in the description of Method 1 above, and any repetitions will not be repeated. Furthermore, when the cavity is a closed cavity, since the thermal insulation layer 12 is disposed within the cavity, the material for the thermal insulation layer 12 can be, but is not limited to, water. Water has a low cost and a high heat absorption coefficient, making it suitable for various scenarios and expanding the application range of thermal insulation buffer components.

[0048] Method 3: The heat-insulating buffer comprises a flexible skeleton 13 and a heat-insulating material 14, wherein the heat-insulating material 14 is adsorbed in the pores of the flexible skeleton 13. For example, see Figure 7 As shown, the flexible skeleton 13 has pores. Figure 7 The pores are not marked, and the thermal insulation material 14 can be adsorbed in the pores. On the one hand, the flexible skeleton 13 can fix the thermal insulation material 14 to prevent the thermal insulation material 14 from being lost. On the other hand, the flexible skeleton 13 has good compression performance. When the battery cell undergoes thermal expansion, it can provide more space for the expansion of the battery cell, thereby improving the safety of the battery module. It should be understood that Figure 7 The figure only schematically shows the relative positional relationship between the flexible skeleton 13 and the thermal insulation material 14, and does not represent the actual appearance of the flexible skeleton 13 and the distribution of the internal pores.

[0049] The material used to make the flexible skeleton 13 can be a material with certain compression performance, or a material with a certain compression coefficient but with pores inside, and the specific material selection can be set according to actual needs; for example, if the battery module is required to have a longer life, a material with a higher compression coefficient and more stability can be used, such as but not limited to fiber, gel, etc., so that it can maintain good compression performance for a long time, and has more pores inside to increase the buffering effect; if the production cost of the battery module is required to be low, due to the low cost of thermoplastic elastomers, the flexible skeleton 13 can be made of but not limited to thermoplastic elastomers, including but not limited to styrene block copolymers, etc., to reduce the production cost of the battery module. The selection rules of the thermal insulation material 14 are similar to those of the above-mentioned thermal insulation layer 12. For details, please refer to the materials used to make the thermal insulation layer 12, which will not be described in detail here.

[0050] In summary, when setting up the thermal insulation buffer, any of the above-mentioned methods 1 to 3 can be adopted according to actual needs to meet the needs of different application scenarios and improve design flexibility. In addition, the specific structures of the first thermal insulation buffer 10a and the second thermal insulation buffer 10b can be the same or different. For example, the first thermal insulation buffer 10a and the second thermal insulation buffer 10b have the same structure and adopt any of the above-mentioned methods 1 to 3; or the first thermal insulation buffer 10a and the second thermal insulation buffer 10b have different structures, and the first thermal insulation buffer 10a and the second thermal insulation buffer 10b each independently select any of the above-mentioned methods 1 to 3. The specific configuration can be based on actual needs and is not specifically limited here.

[0051] Exemplarily, for each battery cell 20, the battery cell includes: a shell, a cover, a positive electrode, a negative electrode, a battery separator and an electrolyte. After the shell and the cover are assembled, a cavity is formed inside. The positive electrode, the negative electrode, the battery separator and the electrolyte are all arranged in the cavity. The surface of the cover facing away from the cavity can be provided with a positive electrode column m1, a negative electrode column m2 and an explosion-proof valve m3. The positive electrode column m1 is connected to the positive electrode, and the negative electrode column m2 is connected to the negative electrode. The explosion-proof valve m3 is generally located between the positive electrode column m1 and the negative electrode column m2. When the battery cell 20 has thermal runaway, the heat generated inside the battery cell 20 may push the explosion-proof valve m3 open and release gas outward. This can avoid the accumulation of heat in the battery cell 20 and the inability to discharge it, causing the battery cell 20 to explode, thereby further improving the safety of the battery cell 20. It should be understood that Figure 4 This is a top view of the battery module, so the shell and the internal structure of the battery cell 20 are not shown in this figure. Figure 4 As shown in , this is just an example to illustrate the relative position relationship between the positive pole m1, the negative pole m2 and the explosion-proof valve m3. The specific shape can be set according to actual needs and is not specifically limited here.

[0052] Figure 8 The structural diagram of another battery module provided in the embodiment of the present application is shown as an example. Figure 8 As shown, the structure of the battery module in this embodiment is similar to that of the previous embodiment. Figures 4 to 7 The structure of the battery module described in the previous section is basically similar, with the difference that at least part of the second heat-insulating buffer 10b has a different thickness. For example, the direction from the battery pack 20a in the middle to the battery packs 20a on both sides is as follows: Figure 8 In the direction indicated by the dotted arrow, the thickness of each second thermal insulation buffer 10b is decreasing, wherein the decreasing trend may include: gradual decreasing or step-by-step decreasing. The specific decreasing method can be determined according to the actual situation and is not specifically limited here. Figure 8 In the figure, three second thermal insulation buffer parts 10b are shown. In order from left to right, the three second thermal insulation buffer parts 10b are named as the second thermal insulation buffer part 10b on the left, the second thermal insulation buffer part 10b in the middle, and the second thermal insulation buffer part 10b on the right. The thickness of the second thermal insulation buffer part 10b on the left is d22, the thickness of the second thermal insulation buffer part 10b in the middle is d21, and the thickness of the second thermal insulation buffer part 10b on the right is d23. d22=d23<d21, so the thickness of the second thermal insulation buffer part 10b in the middle is the largest, and the thicknesses of the second thermal insulation buffer part 10b on the left and the second thermal insulation buffer part 10b on the right are both less than the thickness of the second thermal insulation buffer part 10b in the middle, thereby realizing a decreasing trend in the thickness of the second thermal insulation buffer part 10b along the direction from the middle position to both sides.

[0053] Among them, when the battery module is assembled, it is generally assembled from both sides with one or some battery cells 20 as the center. Compression and clamping will be performed during the assembly process to ensure that the finally assembled battery module remains stable. In this way, the assembly compression amount of the second thermal insulation buffer 10b located in the middle position is larger, and the assembly compression amount of the second thermal insulation buffer 10b closer to the side position is smaller; therefore, the thickness of the second thermal insulation buffer 10b located in the middle position can be set to be larger to provide more compression space to achieve assembly, and more expansion space can also be provided for the battery pack 20a in the middle position, reducing the risk of explosion of the battery pack 20a in the middle position; and the thickness of the second thermal insulation buffer 10b close to the side position is set to be smaller, which can avoid compression redundancy, provide appropriate expansion space for the battery pack 20a, and avoid the length of the battery module in the first direction being too large. When the battery module is applied to the battery pack, the energy density of the battery pack is improved.

[0054] It should be understood that the battery module in this embodiment is similar to the battery module in the previous embodiment. Figures 4 to 7 The similarities in the structure of the battery module introduced in can be found in the relevant introduction in the aforementioned embodiments, and the repeated parts will not be described in detail.

[0055] The present application also provides a battery module. The structure of the battery module in this embodiment is similar to that of the above embodiment. Figures 4 to 8 The structures of any of the battery modules introduced are basically similar, with the following differences: no first thermal insulation buffer is provided in the battery pack, but a second thermal insulation buffer is provided between two adjacent battery packs. This can further reduce the length of the battery module in the first direction on the basis of improving the safety of the battery module, thereby improving the energy density of the battery pack.

[0056] It should be understood that the battery module in this embodiment is similar to the battery module in the previous embodiment. Figures 4 to 8 The structural similarities of any of the battery modules described herein can be found in the relevant descriptions of the aforementioned embodiments, and the repeated parts will not be described in detail.

[0057] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include such modifications and variations.

Claims

1. A battery module, characterized in that: The battery module includes a plurality of battery packs arranged in parallel, each of the battery packs includes a plurality of battery cells arranged along the arrangement direction of the battery packs, a first thermal insulation buffer is provided between any two adjacent battery cells in each battery pack, and a second thermal insulation buffer is provided between any two adjacent battery packs in each battery pack, and the thickness of the first thermal insulation buffer is less than the thickness of the second thermal insulation buffer.

2. The battery module according to claim 1, wherein: The thickness of the first thermal insulation buffer member between any two adjacent battery cells in the same battery pack is the same.

3. The battery module according to claim 2, wherein: The thickness of each of the first thermal insulation buffer members is the same.

4. The battery module according to any one of claims 1 to 3, wherein: In each of the battery packs, the thickness of each of the second thermal insulation buffer members decreases in a direction from the battery pack located in the middle to the battery packs on both sides.

5. The battery module according to claim 1, wherein: At least one of the first thermal insulation buffer component and the second thermal insulation buffer component includes a buffer layer and a thermal insulation layer, and the buffer layer and the thermal insulation layer form a sandwich structure.

6. The battery module according to claim 5, wherein: The heat insulation layer is arranged between the two buffer layers. The edges of the two buffer layers are connected to form a structure with a cavity. The heat insulation layer is arranged in the cavity.

7. The battery module according to claim 1, wherein: At least one of the first thermal insulation buffer component and the second thermal insulation buffer component includes a flexible skeleton and a thermal insulation material, and the thermal insulation material is absorbed in the pores of the flexible skeleton.

8. The battery module according to any one of claims 5 to 7, wherein: At least one of the first thermal insulation buffer member and the second thermal insulation buffer member includes a buffer layer and a thermal insulation layer, wherein the thermal insulation layer is made of aerogel or phase change material; or the buffer layer is made of foam, silicone rubber, gel or flexible plastic; Alternatively, at least one of the first thermal insulation buffer component and the second thermal insulation buffer component includes a flexible skeleton and a thermal insulation material, and the flexible skeleton is made of fiber or gel, or the thermal insulation material includes aerogel or phase change material.

9. A battery pack, characterized in that: include: A box and a battery module according to any one of claims 1 to 8, wherein the battery module is arranged in the box.

10. An energy storage system, characterized in that: The energy storage system includes a battery pack and a power converter as described in claim 9, wherein the power converter is used to convert the AC power output by an external AC power source into DC power and output it to the battery pack, and / or the power converter is used to convert the DC power output by the battery pack into AC power and output it to a load or a power grid.

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