Battery module and battery pack

Abstract

The utility model belongs to the technical field of power batteries, and particularly relates to a battery module and a battery pack. The battery module comprises a battery cell stacking body, a shell and quartz sand, the battery cell stacking body is mounted in the shell, and the shell is provided with an exhaust structure suitable for exhausting smoke in the shell when the battery cell stacking body is in thermal runaway; and the quartz sand is filled between the shell and the battery core stacking body so as to filter flue gas flowing to the exhaust structure. The quartz sand is filled between the shell and the cell stack, flue gas generated by the cell stack during thermal runaway needs to flow through the quartz sand and then is discharged from the exhaust structure, and the quartz sand can adsorb particles in the flue gas and purify the flue gas, so that the flue gas is prevented from blocking the exhaust structure; besides, the quartz sand has adsorbability, high temperature resistance, high thermal conductivity and good insulativity, not only can absorb heat generated during normal operation of the cell stack, but also can be used as an arc extinguishing medium to absorb arc energy, so that the thermal runaway risk of the cell stack is reduced, and the safety performance of the battery module and the battery pack is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power batteries, and in particular relates to a battery module and a battery pack. Background Art

[0002] With the booming development of the new energy vehicle industry, people's requirements for charging time of electric vehicles are getting shorter and shorter. Many car companies have proposed fast charging solutions, which has led to larger and larger charging currents for batteries and increased safety risks for electric vehicles.

[0003] An important reason for thermal runaway of batteries is that they work in a high-temperature environment for a long time. High temperature will increase the side reactions inside the battery and increase the probability of thermal runaway, such as lithium-ion batteries. After the battery cell has thermal runaway, a large amount of high-temperature flue gas will be discharged. The high-temperature flue gas causes the pressure in the battery module and battery pack to increase sharply. In order to discharge the high-temperature flue gas, an exhaust valve is generally set in the battery pack or battery module. When the pressure in the battery pack reaches a certain level, the exhaust valve will be opened to discharge the high-temperature flue gas. When a small number of batteries have thermal runaway, the exhaust valve can generally discharge the high-temperature flue gas generated by the battery cell smoothly. However, when a large number of batteries have thermal runaway almost at the same time, the unburned particles in the high-temperature flue gas will gather and condense at the mesh of the exhaust valve, causing the exhaust valve outlet to be blocked, resulting in the high-temperature flue gas cannot be discharged smoothly, and the heat contained in the flue gas cannot be discharged smoothly from the outside of the battery pack, which will further increase the internal pressure of the battery pack and increase the temperature, further inducing thermal runaway of other batteries. In a vicious cycle, the entire battery pack will eventually cause thermal runaway. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a battery module and a battery pack, which are used to solve the problem in the prior art that the high-temperature smoke generated when the battery cell has thermal runaway cannot be discharged in time, so as to improve the safety performance of the battery module and the battery pack.

[0005] In order to achieve the above-mentioned purpose and other related purposes, the utility model provides a battery module, including:

[0006] Battery cell stack;

[0007] a housing in which the battery cell stack is installed, the housing having an exhaust structure suitable for exhausting smoke in the housing when the battery cell stack has a thermal runaway; and

[0008] Quartz sand is filled between the shell and the battery cell stack to filter the smoke flowing toward the exhaust structure.

[0009] Optionally, the shell includes an end plate, the battery cell stack has a pole ear side facing the end plate, and the quartz sand is filled between the end plate and the pole ear side of the battery cell stack.

[0010] Optionally, the battery module also includes a bus bar bracket, which is located between the end plate and the pole ear side of the battery cell stack, the gap between the bus bar bracket and the end plate forms a first gap area, and the gap between the bus bar bracket and the pole ear side of the battery cell stack forms a second gap area, and the first gap area and the second gap area are both filled with the quartz sand.

[0011] Optionally, paraffin particles are filled between the shell and the battery cell stack.

[0012] Optionally, the quartz sand and the paraffin particles fill the gap between the shell and the tab side of the battery cell stack, and the volume occupied by the paraffin particles is less than 5% of the volume of the gap between the shell and the tab side of the battery cell stack.

[0013] Optionally, the mesh size of the paraffin particles is a, and a>400 mesh.

[0014] Optionally, the exhaust structure includes an explosion-proof valve, which is mounted on the end plate and is suitable for exhausting smoke in the shell when opened.

[0015] Optionally, the mesh number of the quartz sand is b, 200 mesh ≤ b ≤ 325 mesh.

[0016] Optionally, at least a portion of the paraffin particles are disposed in gaps in the quartz sand.

[0017] To achieve the above objectives and other related objectives, the present application also provides a battery pack, including the battery module as described above.

[0018] As described above, the battery module and battery pack of the utility model have at least the following beneficial effects: quartz sand is filled between the shell and the battery cell stack, and the smoke generated by the battery cell stack during thermal runaway needs to flow through the quartz sand before it can be discharged from the exhaust structure. The quartz sand can absorb particles in the smoke, purify the smoke, and prevent the smoke from clogging the exhaust structure. In addition, quartz sand has adsorptive properties and is resistant to high temperatures, has high thermal conductivity, and has good insulation properties. It can not only absorb the heat generated by the battery cell stack during normal operation, but also can act as an arc extinguishing medium to absorb arc energy, thereby reducing the risk of thermal runaway of the battery cell stack and improving the safety performance of the battery module and battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a battery module embodiment 1 of the present utility model;

[0020] Figure 2 for Figure 1 Schematic diagram of the internal structure of the battery module;

[0021] Figure 3 It is a cross-sectional view of the second embodiment of the battery module of the present utility model.

[0022] Part Number Description

[0023] Shell 1, end plate 11, bottom plate 12, top cover 13, battery cell stack 2, positive electrode ear 21, negative electrode ear 22, quartz sand 3, busbar bracket 4, paraffin particles 5, structural adhesive 6, high-voltage output connector 7, foam 8. DETAILED DESCRIPTION

[0024] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0025] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0026] See also Figures 1 to 3 In some optional embodiments, the present application provides a battery pack, which includes a battery module.

[0027] See also Figures 1 to 3 In some optional embodiments, the battery module provided by the present application includes a battery cell stack 2, a shell 1 and quartz sand 3; in addition to the above components, the battery module may also include a busbar bracket 4 and / or a busbar and / or a high-voltage output connector 7. The battery cell stack 2 is installed in the shell 1, and the shell 1 has an exhaust structure (not shown) suitable for exhausting the smoke in the shell 1 when the battery cell stack 2 is thermally runaway; the quartz sand 3 is filled between the shell 1 and the battery cell stack 2 to filter the smoke flowing to the exhaust structure.

[0028] Optionally, the battery cell stack 2 has a tab side, the battery cell stack 2 includes a plurality of stacked battery cells, foam 8 is provided between adjacent battery cells, and tabs are provided at both ends of the battery cell along its length direction, one end of which is a positive tab 21, and the other end is a negative tab 22, and the tab end of the battery cell is on the same side as the tab side of the battery cell stack 2, that is, quartz sand 3 is filled between the positive tab 21 of the battery cell and the shell 1, and quartz sand 3 is filled between the negative tab 22 of the battery cell and the shell 1. Further, the battery cell includes a soft-pack battery cell.

[0029] Optionally, the high-voltage output connector 7 is electrically connected to the battery cell stack 2 to achieve external output of electrical energy from the battery cell stack 2 .

[0030] Optionally, the quartz sand 3 can be in granular form, and the gaps between the quartz sand 3 particles can allow the high-temperature flue gas to pass through, while the particles in the high-temperature flue gas cannot pass through the gaps between the quartz sand 3 particles. After the high-temperature flue gas passes through the quartz sand 3, the particles in the high-temperature flue gas can be adsorbed by the quartz sand 3, avoiding the particles in the high-temperature flue gas from gathering in the exhaust structure and causing blockage. The filtered and purified high-temperature flue gas can be smoothly discharged from the exhaust structure, and the exhaust structure is not easy to be blocked. In addition, the temperature of the flue gas generated when the battery cell has thermal runaway is relatively high, and the melting point of quartz sand 3 is relatively high, generally reaching 1750°C, and the density is relatively large, about 2.2-2.3g / cm 3 , which can absorb the heat of high-temperature flue gas and reduce the risk of thermal runaway of adjacent battery cells caused by the spread of high-temperature flue gas; and quartz sand 3 also has high thermal conductivity and insulation, which can absorb the heat of the battery cell and other electrical connectors when the battery cell is operating normally, and inhibit thermal runaway of the battery cell; quartz sand 3 can also act as an arc extinguishing medium, which is convenient for absorbing arc energy, allowing the arc to cool rapidly and reducing the risk of thermal runaway of the battery cell.

[0031] In the battery module of the above embodiment, quartz sand 3 is filled between the shell 1 and the battery cell stack 2, so that the flue gas discharged through the exhaust structure needs to pass through the quartz sand 3 before being discharged through the exhaust structure. The quartz sand 3 has adsorptive properties, high temperature resistance, thermal conductivity and insulation. It can adsorb particles in the high-temperature flue gas and absorb heat when thermal runaway occurs in the battery cell stack 2, which is conducive to the smooth discharge of flue gas from the shell 1, reducing the risk of thermal runaway of other battery cells, thereby reducing the risk of thermal runaway of the battery module as a whole, thereby improving the safety performance of the battery module.

[0032] See also Figures 1 to 3 In some optional embodiments, the housing 1 includes an end plate 11 , the tab side of the battery cell stack 2 faces the end plate 11 , and the quartz sand 3 is filled between the end plate 11 and the tab side of the battery cell stack 2 .

[0033] Optionally, the quartz sand 3 may cover the tab side of the battery cell, that is, the positive tab 21 and the negative tab 22 of the battery cell may be completely immersed in the quartz sand 3 .

[0034] Optionally, the busbar support 4 is located between the end plate 11 and the tab side of the battery cell stack 2, the gap between the busbar support 4 and the end plate 11 forms a first gap area, the gap between the busbar support 4 and the tab side of the battery cell stack 2 forms a second gap area, and both the first gap area and the second gap area are filled with quartz sand 3. The busbar support 4 has insulation and can provide support for the busbar of the battery module.

[0035] Optionally, the mesh number of the quartz sand 3 is b, 200 mesh ≤ b ≤ 325 mesh, that is, the mesh number of the quartz sand 3 is 200 mesh to 325 mesh. Further, the mesh number of the quartz sand 3 can be any value of 200 mesh, 210 mesh, 260 mesh, 300 mesh or 325 mesh.

[0036] Optionally, the high-voltage output connector 7 can be located on the pole ear side of the battery cell stack 2, and the bus bracket 4 insulates at least part of the battery cell stack 2 from the high-voltage output connector 7. Sealant is filled between the high-voltage output connector 7 and the bus bracket 4. The high-voltage output connector 7 can pass through the end plate 11 and extend to the outside of the shell 1 for external connection.

[0037] Optionally, the exhaust structure includes an explosion-proof valve, which is mounted on the end plate 11 and is suitable for exhausting smoke in the shell 1 when opened.

[0038] In the battery module of the above embodiment, the quartz sand 3 is arranged between the pole ear side of the battery cell stack 2 and the end plate 11. When thermal runaway occurs in the battery cells in the battery cell stack 2, the high-temperature flue gas discharged from the vicinity of the positive pole ear 21 and the negative pole ear 22 can quickly flow through the quartz sand 3 and be discharged from the exhaust structure, which is beneficial to reduce the risk of thermal runaway spreading and improve the safety performance of the battery module.

[0039] See also Figure 1 and Figure 3 In some optional embodiments, a phase change material is filled between the shell 1 and the battery cell stack 2. The phase change material may be in a granular form, such as spherical particles.

[0040] Optionally, the phase change material includes paraffin, fatty acids, alcohols, salt hydrates or other materials that can absorb heat and reduce the temperature of high-temperature flue gas. Furthermore, paraffin particles 5 are filled between the shell 1 and the battery cell stack 2, and the paraffin particles 5 can be spherical; optionally, at least a portion of the paraffin particles 5 are arranged in the gaps of the quartz sand 3; that is, the paraffin particles 5 and the quartz sand 3 are mixed; preferably, the paraffin particles 5 and the quartz sand 3 are uniformly mixed. Specifically, the paraffin particles 5 and the quartz sand 3 can be mixed together and then filled between the shell 1 and the battery cell stack 2. It can be understood that the filling order and method of the paraffin particles 5 and the quartz sand 3 are not limited to the listed mixing first and then filling together, and can also be filled separately in sequence.

[0041] Optionally, the quartz sand 3 and the wax particles 5 fill the gap between the shell 1 and the tab side of the battery cell stack 2, or in other words, the quartz sand 3 and the wax particles 5 fill the gap between the end plate 11 and the tab side of the battery cell stack 2, and the volume occupied by the wax particles 5 is less than 5% of the volume of the gap between the shell 1 and the tab side of the battery cell stack 2. Further, the wax particles 5 are filled in the first gap area and / or the second gap area, the quartz sand 3 and the wax particles 5 fill the first gap area and the second gap area, and the volume occupied by the wax particles 5 is less than 5% of the sum of the volumes of the first gap area and the second gap area.

[0042] Optionally, the mesh number of the paraffin particles 5 is a, a>400 mesh, that is, the mesh number of the paraffin particles 5 is greater than 400 mesh. Further, the mesh number of the paraffin particles 5 can be any value such as 401 mesh, 450 mesh, 480 mesh, 550 mesh or 600 mesh.

[0043] In the battery module of the above embodiment, phase change material is filled between the shell 1 and the battery cell stack 2, especially paraffin particles 5, which can greatly increase the heat absorption of the quartz sand 3, further reduce the temperature of the high-temperature flue gas, and reduce the risk of thermal runaway of the adjacent normal battery cells; in addition, when the battery cells are operating normally, the quartz sand 3 will also transfer the heat absorbed from the battery cells and other electrical connectors to the paraffin particles 5, which is beneficial to reduce the temperature of the battery cells and electrical connectors.

[0044] See also Figures 1 to 3 In some optional embodiments, the shell 1 also includes a bottom plate 12 and a top cover 13, the top cover 13 and the bottom plate 12 are arranged relative to each other, the battery cell stack 2 is located between the bottom plate 12 and the top cover 13, the bottom of the battery cell stack 2 is bonded and fixed to the bottom plate 12 by the structural adhesive 6, and the top of the battery cell stack 2 is bonded and fixed to the top cover 13 by the structural adhesive 6.

[0045] Optionally, the housing 1 further includes two side plates arranged opposite to each other, and the two side plates are connected through the bottom plate 12 to form a U-shaped frame with an opening toward the top cover 13. Further, the two side plates and the bottom plate 12 can be an integrally formed U-shaped frame, and the U-shaped frame, the end plate 11 and the top cover are welded to seal the quartz sand 3 and the battery cell stack 2 inside the housing 1.

[0046] In the battery module of the above embodiment, the connection between the cell stack 2 and the shell 1 is simple and firm, which is conducive to improving the structural stability of the cell stack 2, so that the cell stack 2 can be stably installed in the shell 1, thereby helping to improve the safety performance of the battery module.

[0047] In the battery module and battery pack of the utility model, quartz sand 3 is filled between the shell 1 and the battery cell stack 2. The quartz sand 3 absorbs particles and heat in the high-temperature flue gas, thereby reducing the risk of blockage of the exhaust structure and the risk of thermal runaway of the battery cells spreading. The flue gas can be discharged in time to avoid the increase of pressure and temperature in the battery module and battery pack due to the failure to discharge the flue gas in time, thereby reducing the risk of thermal runaway. In addition, the quartz sand 3 can also absorb heat and arc energy when the battery cell stack 2 is operating normally, which is conducive to further reducing the risk of thermal runaway of the battery cells, thereby improving the safety performance of the battery module and battery pack.

[0048] In the description of this specification, the description with reference to the terms "this embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0049] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A battery module, characterized in that: include: Battery cell stack; A housing, in which the battery cell stack is installed, and the housing has an exhaust structure suitable for exhausting smoke in the housing when the battery cell stack has thermal runaway; as well as Quartz sand is filled between the shell and the battery cell stack to filter the smoke flowing toward the exhaust structure.

2. The battery module according to claim 1, characterized in that: The housing includes an end plate, the battery cell stack has a tab side facing the end plate, and the quartz sand is filled between the end plate and the tab side of the battery cell stack.

3. The battery module according to claim 2, characterized in that: The battery module also includes a busbar bracket, which is located between the end plate and the pole ear side of the battery cell stack. The gap between the busbar bracket and the end plate forms a first gap area, and the gap between the busbar bracket and the pole ear side of the battery cell stack forms a second gap area. The first gap area and the second gap area are both filled with the quartz sand.

4. The battery module according to claim 1, characterized in that: The space between the shell and the battery cell stack is filled with paraffin particles.

5. The battery module according to claim 4, characterized in that: The quartz sand and the paraffin particles fill the gap between the shell and the tab side of the battery cell stack, and the volume occupied by the paraffin particles is less than 5% of the volume of the gap between the shell and the tab side of the battery cell stack.

6. The battery module according to claim 4, characterized in that: The mesh number of the paraffin wax particles is a, and a>400 meshes.

7. The battery module according to claim 2, characterized in that: The exhaust structure comprises an explosion-proof valve, which is mounted on the end plate and is suitable for exhausting smoke in the shell when opened.

8. The battery module according to any one of claims 1 to 7, characterized in that: The mesh number of the quartz sand is b, 200 mesh≤b≤325 mesh.

9. The battery module according to claim 4, characterized in that: At least a portion of the paraffin wax particles are disposed in gaps in the quartz sand.

10. A battery pack, characterized in that: Comprising a battery module as claimed in any one of claims 1 to 9.

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