Battery cell bottom support plate and battery cell

Abstract

The application relates to the technical field of battery cell manufacturing, and provides a battery cell bottom supporting plate and a battery cell, the battery cell bottom supporting plate comprises a first insulating sheet, a second insulating sheet and a supporting structure, the supporting structure is clamped between the first insulating sheet and the second insulating sheet; wherein the supporting structure comprises a plurality of supporting sheets arranged at intervals, gaps are formed between adjacent supporting sheets, and the melting point of the supporting sheets is greater than 600 DEG C. Through the arrangement of the supporting sheets, the battery cell group is supported, the battery cell group is prevented from pressing on the pressure relief hole in the case of thermal runaway, and the exhaust passage is prevented from being blocked. When the plastic melts under high temperature, the arranged supporting sheets can effectively support the battery cell group, the battery cell group is prevented from pressing on the pressure relief hole, and the exhaust passage is prevented from being blocked.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery cell manufacturing, and in particular to a battery cell bottom support plate and a battery cell. BACKGROUND

[0002] In order to improve the safety performance of the battery monomer, a pressure relief structure is usually arranged on the battery monomer. When gas is generated inside the battery monomer due to abnormal operation, the gas can be discharged through the pressure relief structure to avoid causing a major safety accident.

[0003] In order to maximize the capacity of the battery cell and make the battery pack more secure, it is a very effective method to adjust the pressure relief structure from the cover plate to the side wall of the shell to achieve thermal and electrical separation.

[0004] In the related art, the pressure relief valve is usually arranged at the bottom of the battery shell, away from the electrical connection structure on the cover plate, which can achieve thermal and electrical separation. However, when the battery cell is in thermal runaway, the pole group will sink to the bottom of the shell due to its own gravity, which may block the pressure relief hole. Once the pressure relief hole is blocked, the gas in the shell cannot be quickly discharged through the pressure relief valve, which leads to excessive internal gas pressure and increases the risk of explosion. Therefore, there is an urgent need for a battery cell bottom support plate structure and a battery cell that can ensure the smoothness of the pressure relief hole during thermal runaway. SUMMARY

[0005] The present application provides a battery cell bottom support plate and a battery cell to solve the defect that the pole group easily sinks and blocks the pressure relief hole when the battery cell is in thermal runaway in the prior art.

[0006] The present application provides a battery cell bottom support plate, comprising: a first insulating sheet, a second insulating sheet, and a support structure; the support structure is clamped between the first insulating sheet and the second insulating sheet; wherein the support structure comprises a plurality of support sheets arranged at intervals, a gap is formed between adjacent support sheets, and the melting point Tm of the support sheet is > 600℃.

[0007] According to the battery cell bottom support plate provided by the present application, the first insulating sheet and the second insulating sheet are hot-melt connected, and a plurality of limiting cavities are formed between the first insulating sheet and the second insulating sheet, and a plurality of support sheets are one-to-one corresponding arranged in the limiting cavities.

[0008] According to the battery cell bottom support plate provided by the present application, the support sheet comprises a mica sheet.

[0009] According to the battery cell bottom support plate provided by the present application, the support sheet is arranged on both sides of the first insulating sheet and the second insulating sheet in the width direction; or the support sheet is arranged on both sides of the first insulating sheet and the second insulating sheet in the length direction.

[0010] The thickness of the support sheet is greater than the thickness of the first insulating sheet and the second insulating sheet, so that a convex structure is formed at the position of the support sheet.

[0011] The thickness of the first insulating sheet and the second insulating sheet is 0.1mm≤t1≤1.5mm.

[0012] The thickness of the support sheet is 0.2mm≤t2≤2mm.

[0013] The extension thickness of the cell bottom support plate in the thickness direction is 0.4mm≤t3≤5mm.

[0014] The application further provides a cell, comprising: a shell, an insulating film and the cell bottom support plate provided in any one of the above.

[0015] The pressure relief hole is located directly below the gap in the cell bottom support plate.

[0016] The cell bottom support plate and the cell provided by the application can support the pole group, prevent the pole group from pressing on the pressure relief hole and blocking the exhaust passage during thermal runaway. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0018] Figure 1 It is the overall structure of the cell bottom support plate provided by the application.

[0019] Figure 2 It is one of the structure schematic diagrams of the cell bottom support plate provided by the application.

[0020] Figure 3 It is the second structure schematic diagram of the cell bottom support plate provided by the application.

[0021] Figure 4 It is the overall structure of the cell provided by the application.

[0022] Figure 5 is a schematic diagram of an internal structure of a battery cell provided by the present application.

[0023] Reference signs:

[0024] 10, bottom support plate of battery cell; 11, first insulating sheet; 12, second insulating sheet; 13, support sheet; 14, gap; 15, limiting chamber; 20, shell; 21, cover plate; 22, insulating film; 23, explosion-proof valve; 24, pressure relief hole. DETAILED DESCRIPTION

[0025] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0026] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms “center”, “longitudinal”, “transverse”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of clarifying the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms “first”, “second”, “third” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms “connected” and “connected” should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0028] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "above", "over" and "on" the second feature, which can be that the first feature is directly above or obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "under" the second feature, which can be that the first feature is directly below or obliquely below the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0029] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present specification, the illustrative description 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 appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0030] In the related art, in order to prevent the thermal runaway of the battery cell from causing a greater safety hazard, the pressure relief hole of the battery cell is arranged at the bottom of the shell, so that the pressure relief position is away from the pole position on the cover plate, thereby improving the safety performance. However, this way will block the exhaust port on the shell when the battery cell overheats, so that the gas inside the shell cannot be discharged, and the safety risk is intensified.

[0031] The following will be described in combination with Figures 1-3 The bottom support plate 10 of the battery cell is described in the present application, which comprises a first insulating sheet 11, a second insulating sheet 12 and a support structure, the support structure is clamped between the first insulating sheet 11 and the second insulating sheet 12; wherein the support structure comprises a plurality of support sheets 13 arranged at intervals, gaps 14 are formed between adjacent support sheets 13, and the melting point Tm of the support sheet 13 is > 600 ℃. When the battery cell loses control, effective support is needed to prevent the pole group from sinking and blocking the pressure relief hole 24 on the battery cell shell 20 under the action of gravity. In the present embodiment, the support sheet 13 is clamped between the first insulating sheet 11 and the second insulating sheet 12, and the support of the pole group is realized through the support sheet 13, thereby improving the stability of the overall support structure and the safety of the battery cell.

[0032] Specifically, the first and second insulation sheets 11 and 12 are in the form of a sheet structure as a whole, and are made of a material with a low melting point. For example, the first and second insulation sheets 11 and 12 are made of one of polypropylene (PP), polycarbonate (PC), and polyimide (PI).

[0033] In a preferred example, the first and second insulation sheets 11 and 12 are made of polypropylene (PP). Polypropylene (PP) has high chemical stability, heat resistance, and voltage resistance. On the one hand, it can provide stable and effective isolation and support in a normal state. On the other hand, the melting point of polypropylene (PP) is between 160 and 170 degrees Celsius. When the battery cell is in thermal runaway, polypropylene (PP) can quickly melt to form a pressure relief channel between the support sheets 13, which is in communication with the pressure relief hole 24 at the bottom of the battery cell shell 20. Thus, the battery cell can quickly release pressure when it is in thermal runaway, and the safety of the battery cell as a whole is improved.

[0034] It can be understood that the battery cell as a whole includes the shell 20 and the pole group inside the shell 20. Generally, the pressure relief hole 24 in the bottom wall of the shell 20 is provided with an explosion-proof valve 23. When the battery cell is in thermal runaway, the explosion-proof valve 23 can be broken to form an exhaust channel (i.e., the pressure relief hole 24 is opened), thereby avoiding the risk of an explosion due to excessive pressure inside the shell 20. In the present embodiment, the battery cell bottom plate 10 is arranged between the bottom of the pole group and the inner bottom wall of the shell 20, thereby providing effective support for the pole group. Generally, the temperature of the battery cell when it is in thermal runaway is between 150 and 200 degrees Celsius, and in some extreme cases, it can rise to about 500 degrees Celsius. In the present embodiment, the melting point of the support sheet 13 is limited to be higher than 600 degrees Celsius. Thus, when the battery cell is in thermal runaway, the support sheet 13 can still provide effective support, and the safety risk of the battery cell is reduced. Of course, even if the temperature of the battery cell rises sharply (if it exceeds 600 degrees Celsius) after thermal runaway in some extreme cases, the protrusions of the support sheet can effectively delay the blockage of the exhaust channel, achieve the rapid discharge of internal pressure, and reduce the risk of explosion.

[0035] When the connection and installation are performed, the gap 14 formed by the support sheet 13 is arranged above the position corresponding to the explosion-proof valve 23 of the battery cell shell 20. The first and second insulation sheets 11 and 12 can provide certain support in a normal state and can prevent the electrolyte from corroding the explosion-proof valve 23. In a thermal runaway state, the first and second insulation sheets 11 and 12 can quickly melt at high temperatures, so that the pole group inside the shell 20 is only supported by the support sheet 13. Since the gap 14 between the support sheets 13 is located above the explosion-proof valve 23, the gap 14 is directly in communication with the pressure relief hole 24, which is beneficial to the rapid discharge of internal gas to achieve rapid pressure relief and avoid the blockage of the pressure relief hole 24, thereby improving the safety performance of the battery cell.

[0036] In combination with the above embodiment, as shown in FIG. 6, the first and second insulation sheets 11 and 12 are arranged on the support sheet 13 in the form of a sheet structure as a whole. Figure 3As shown, the first insulating sheet 11 and the second insulating sheet 12 are heat fusion connected, and a plurality of limiting cavities 15 are formed between the first insulating sheet 11 and the second insulating sheet 12, and a plurality of support sheets 13 are arranged in the limiting cavities 15 one by one. The support sheet 13 needs to have a relatively stable support structure when installed, so as to avoid position movement in the battery vibration test and actual use, which causes the stability of the support to decrease. In the embodiment, the support sheet 13 is arranged in the closed cavity, which can effectively prevent the shaking of the support sheet 13 and improve the stability of the support structure of the support sheet 13.

[0037] Specifically, the first insulating sheet 11 and the second insulating sheet 12 are formed with an annular heat fusion connection area by heat fusion, a closed limiting cavity 15 is formed in the heat fusion connection area, and the support sheet 13 is located in the limiting cavity 15.

[0038] The size of the limiting cavity 15 is equivalent to the size of the support sheet 13, which makes the support sheet 13 not shake in the limiting cavity 15 and improves the stability of the overall structure of the support sheet 13. That is, after the support sheet 13 is installed in the limiting cavity, the four peripheral edges of the support sheet 13 can be limited by the limiting cavity 15, so as to avoid the shaking of the support sheet 13 from affecting the effective bearing in the thermal runaway.

[0039] In specific implementation, the support sheet 13 is arranged between the first insulating sheet 11 and the second insulating sheet 12, and then heat fusion connection is performed on one side of the support sheet 13 by heat fusion, so as to form the limiting cavity 15 in the annular heat fusion connection area and make the support sheet 13 located in the limiting cavity 15.

[0040] It can be understood that the support sheet 13 plays a supporting role and can prevent the sinking of the pole group from blocking the pressure relief hole 24 at the bottom. When the support sheet 13 supports, if the position shakes, the overall support state will be unstable, and even the support will fail. The embodiment makes the support sheet 13 be able to stably support through the arrangement of the limiting cavity 15.

[0041] In combination with the above embodiment, the support sheet 13 includes a mica sheet. The support of the pole group needs to have high temperature resistance and be able to prevent the erosion of the electrolyte. In the embodiment, the mica sheet can be selected to have stable support and effectively prevent the erosion of the electrolyte.

[0042] Specifically, a plurality of mica sheets are arranged at intervals between the first insulating sheet 11 and the second insulating sheet 12, and the mica sheets are arranged in the limiting cavities 15, so as to realize the limiting of the mica sheets and make the mica sheets be able to stably support.

[0043] It can be understood that the mica sheet is easy to break due to its material limitation, and the broken debris will affect the quality of the battery cell and may block the pressure relief hole 24. In the embodiment, the mica sheet is arranged in the limiting chamber 15 to ensure the integrity of the mica sheet and prevent the broken mica sheet from flowing and blocking the pressure relief hole 24.

[0044] In some embodiments, the support sheet 13 is arranged on both sides of the first and second insulating sheets 11 and 12 in the width direction X, or on both sides of the first and second insulating sheets 11 and 12 in the length direction Y. In the embodiment, by arranging the support sheet 13 on both sides in the width direction X or the length direction Y, the support distribution is more uniform, and the stability of the support structure is improved.

[0045] Specifically, as shown in Figure 1 、 Figure 2 , the first and second insulating sheets 11 and 12 have the same size and are both arranged in a rectangular sheet structure. The number of mica sheets is two, and the two mica sheets are arranged on both sides of the first and second insulating sheets 11 and 12 in the width direction X to form horizontal mica sheets. That is, mica sheets are arranged on both sides of the first and second insulating sheets 11 and 12 in the width direction X. When connected, the cell bottom plate 10 is arranged at the bottom of the shell 20 and can support the pole group in the shell 20. By arranging two mica sheets on both sides in the width direction X, the stress on the mica sheets is more uniform, and the stability of the support is improved.

[0046] Of course, the mica sheets can also be arranged on both sides of the first and second insulating sheets 11 and 12 in the length direction Y, that is, near the ends of the first and second insulating sheets 11 and 12, so as to form vertical mica sheets. This way can also disperse the stress on the mica sheets, thereby improving the stability of the support.

[0047] Among them, the first and second insulating sheets 11 and 12 cover the entire bottom wall in the shell 20. That is, the vertical projection of the bottom wall of the shell 20 coincides with the cell bottom plate 10, which can make the entire pole group supported by the cell bottom plate 10 to improve the stability of the support.

[0048] In an embodiment of the application, the thickness of the support sheet 13 is greater than the thickness of the first and second insulating sheets 11 and 12 to form a protruding structure at the position of the support sheet 13. The support sheet 13 is the main support stress member, and in the embodiment, it is protruded from the surface of the first and second insulating sheets 11 and 12, so that there is always a certain gap space between the pole group and the bottom of the shell 20, ensuring that the gas can be quickly relieved when the battery cell is out of control, and improving the safety of the battery cell.

[0049] Specifically, the first and second insulating sheets 11 and 12 are both in a sheet shape, and after the support sheet 13 is clamped between the two insulating sheets, a raised protruding structure is formed on both surfaces in the thickness direction Z, which makes the protruding part directly arranged between the bottom wall of the shell 20 and the pole group when the cell bottom plate 10 is connected, so that there is always a certain gap space between the pole group and the bottom wall of the shell 20, which can ensure the smoothness of the pressure relief hole 24 and improve the safety performance of the cell.

[0050] It can be understood that the first and second insulating sheets 11 and 12 are used to support the pole group and isolate the pressure relief hole 24 in the normal state, so their thickness can be appropriately reduced, and the support sheet 13 is used to support the stress and needs to provide support for the bottom of the pole group in the case of thermal runaway to avoid the sinking of the pole group causing the blockage of the pressure relief hole 24. Therefore, in the embodiment, the thickness of the support sheet 13 is set to be greater than that of the two insulating sheets, so as to effectively protrude the position of the support sheet 13, thereby always maintaining the communication of the pressure relief hole 24.

[0051] In some specific embodiments, as shown in Figure 3 In the embodiment, by limiting the thickness of the first and second insulating sheets 11 and 12, the overall volume can be limited, and effective support can be provided for the pole group.

[0052] Specifically, the thickness of the first and second insulating sheets 11 and 12 cannot be too small, because the first and second insulating sheets 11 and 12 need to play an effective isolation role in the normal state, and need to provide a certain mechanical strength to avoid deformation, rupture or failure of the cell during operation, especially under the action of impact or pressure. Of course, the thickness cannot be too thick, because there is usually a requirement for lightweight in the design of the cell, and an insulating sheet with too large thickness will increase the overall weight of the battery and reduce the energy density. Therefore, the selection of the thickness of the insulating sheet needs to consider the functional and weight requirements. Moreover, the thickness setting of the insulating sheet is directly related to the production cost. The insulating sheet with thicker material will increase the production cost, so the balance between the functional requirements and the cost needs to be considered in the design.

[0053] In the embodiment, the thickness t1 of the first and second insulating sheets 12 in the cell bottom plate 10 is set in the range of 0.1mm≤t1≤1.5mm, which is based on the comprehensive consideration of multiple factors such as electrical safety, thermal management, mechanical strength, weight optimization, production cost and material characteristics, and the purpose is to ensure the performance, safety and reliability of the battery, while optimizing the production process and cost control.

[0054] In some embodiments, the first and second insulating sheets 11, 12 have a thickness t1 of 0.1 mm, 0.5 mm, 0.8 mm, 1.2 mm, or 1.5 mm.

[0055] In some embodiments, as shown in FIG. 2, the thickness t2 of the support sheet 13 is in the range of 0.2 mm ≤ t2 ≤ 2 mm. By limiting the thickness of the support sheet 13, the support strength and the overall lightweight design are balanced. Figure 3

[0056] Specifically, the main function of the support sheet 13 is to provide physical support to withstand the internal pressure of the battery, external impact, and mechanical vibration. If the thickness of the support sheet 13 is too small, the mechanical strength will not be sufficient, and thus the support force will not be sufficient. If the thickness of the support sheet 13 is too large, it will increase unnecessary weight and volume. Further, the battery will release heat during charging and discharging. The thickness of the support sheet 13 needs to provide sufficient support while not affecting the heat dissipation. If the thickness of the support sheet 13 is too large, it will hinder heat dissipation, and if it is too small, it will not be able to effectively support the heat dissipation requirements inside the battery. As a part of the battery structure, the thickness and material of the support sheet 13 will affect the overall weight of the battery. In order to improve the energy density of the battery and reduce the weight, the thickness of the support sheet 13 needs to be reasonably designed to avoid excessive weight.

[0057] In this embodiment, the thickness t2 of the support sheet 13 is set to (0.2 mm-2 mm) based on the trade-off of mechanical strength, safety, thermal management, production process, material properties, and weight and cost of the battery, to ensure reliable performance and long-term stability of the battery under different working conditions.

[0058] In some embodiments, the thickness t2 of the support sheet 13 is 0.2 mm, 0.7 mm, 1.0 mm, or 1.5 mm, 2.0 mm.

[0059] In some embodiments, as shown in FIG. 2, the thickness t2 of the support sheet 13 is in the range of 0.2 mm ≤ t2 ≤ 2 mm. By limiting the thickness of the support sheet 13, the support strength and the overall lightweight design are balanced. Figure 3

[0060] ​​Specifically, the cell support plate 10 needs to withstand the pressure and temperature changes inside the battery, as well as the influence of the external environment. Appropriate thickness provides sufficient support to ensure the stability of the cell structure and prevent deformation or damage due to mechanical impact or vibration during use. Furthermore, the cell generates heat during charging and discharging; as part of the battery's internal structure, the support plate needs a certain thickness to aid heat dissipation and prevent overheating. An excessively thin support plate may hinder effective heat conduction, while an excessively thick one may impede rapid heat release. Moreover, the battery's volume and weight are critical design factors; the thickness of the support plate must be set while adhering to functional requirements such as strength, thermal management, and electrical isolation, while minimizing weight and volume to improve the overall energy density of the battery.

[0061] In this embodiment, the thickness t3 of the cell base plate 10 is set (0.4mm≤t3≤5mm) based on a trade-off between strength, thermal management, electrical isolation, weight and cost, in order to ensure the overall performance and safety of the cell.

[0062] In specific embodiments, the thickness t3 of the cell base plate 10 is 0.4mm, 1.7mm, 2.6mm, 3.7mm or 5.0mm.

[0063] The present invention also provides a battery cell, such as Figure 4 , Figure 5 As shown, the device includes a housing 20, an insulating film 22, and a cell base plate 10 provided in any of the above embodiments. The housing 20 has a cover plate 21 on its top and a pressure relief hole 24 on its bottom wall. An explosion-proof valve 23 is installed inside the pressure relief hole 24. The insulating film 22 is disposed inside the housing 20 and is used to wrap the electrode assembly. The cell base plate 10 is thermally fused to the insulating film 22 and is located between the bottom wall of the housing 20 and the electrode assembly. By providing a cell base plate 10 at the bottom of the cell, it can provide support for the electrode assembly. Furthermore, the support piece 13 on the cell base plate 10 ensures effective communication of the pressure relief hole 24, thus improving the safety of the cell.

[0064] Specifically, the electrode assembly within the casing 20 typically includes a positive electrode material and a negative electrode material. The insulating film 22 separates them to prevent short circuits and ensure the safety and stability of the battery. Specifically, the insulating film 22 wraps around the positive and negative electrode materials to achieve isolation between them. In this embodiment, the cell base plate 10 is connected to the insulating film 22 by heat fusion and is located on the bottom wall inside the casing 20, thereby providing support for the electrode assembly.

[0065] The battery cell provided in this embodiment has the battery cell base plate 10 of any of the aforementioned embodiments. Therefore, the battery cell in this embodiment has the characteristic effects of each of the aforementioned battery cell base plates 10. To avoid redundancy in the effect description, it will not be repeated here.

[0066] In conjunction with the above embodiments, the pressure relief hole 24 is located directly below the gap 14 inside the cell base plate 10. By limiting the position of the pressure relief hole 24 relative to the gap 14, it can quickly achieve connection and pressure relief in the event of thermal runaway, thereby improving safety performance.

[0067] Specifically, during thermal runaway, high temperatures are generated inside the casing 20, which can quickly melt the first insulating sheet 11 and the second insulating sheet 12. After the first insulating sheet 11 and the second insulating sheet 12 melt, the gap 14 is exposed and connects with the pressure relief hole 24 to form a pressure relief channel, thereby achieving rapid pressure relief and improving the response speed.

[0068] Through the above description of the embodiments, those skilled in the art can clearly understand that by providing a support plate 13 on the cell base plate 10 in each embodiment, the support plate 13 can effectively support the electrode group when the cell is in thermal runaway, thereby improving the overall safety performance of the cell. Specifically, when the first insulating sheet 11 and the second insulating sheet 12 melt at high temperatures, the provided support plate 13 can effectively support the electrode group, preventing the electrode group from sinking and pressing on the pressure relief hole 24, thus blocking the pressure relief hole 24.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell base plate, characterized in that, include: First insulating sheet; Second insulating sheet; as well as A support structure, wherein the support structure is sandwiched between the first insulating sheet and the second insulating sheet; The support structure includes multiple spaced support pieces, with gaps between adjacent support pieces, and the melting point Tm of the support pieces is greater than 600°C; the first insulating sheet and the second insulating sheet are thermally fused together, and multiple limiting chambers are formed between the first insulating sheet and the second insulating sheet, with the multiple support pieces corresponding to each other in the limiting chambers.

2. The cell base plate according to claim 1, characterized in that, The support sheet includes a mica sheet.

3. The cell base plate according to claim 1, characterized in that, The support plate is disposed on both sides of the first insulating plate and the second insulating plate in the width direction; or the support plate is disposed on both sides of the first insulating plate and the second insulating plate in the length direction.

4. The cell base plate according to claim 1, characterized in that, The thickness of the support sheet is greater than the thickness of the first insulating sheet and the second insulating sheet, so as to form a protruding structure at the location of the support sheet.

5. The cell base plate according to claim 1, characterized in that, The thickness of the first insulating sheet and the second insulating sheet is 0.1mm≤t1≤1.5mm.

6. The cell base plate according to claim 1, characterized in that, The thickness of the support sheet is 0.2mm≤t2≤2mm.

7. The cell base plate according to claim 1, characterized in that, The thickness of the cell base plate in the thickness direction is 0.4mm≤t3≤5mm.

8. A battery cell, characterized in that, include: The housing has a cover plate on its top and a pressure relief hole in its bottom wall area; An insulating film is disposed inside the housing and is used to wrap the electrode assembly; The cell base plate as described in any one of claims 1-7, wherein the cell base plate is thermally fused to the insulating film and is located between the bottom wall of the housing and the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The pressure relief hole is located directly below the gap inside the cell base plate.

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