Battery cell bottom tray, single battery and battery pack
By designing exhaust vents and channels in the cell bottom tray, the problem of gas not being able to be quickly discharged during thermal runaway of the cell is solved, enabling rapid gas discharge and reducing the risk of explosion of individual cells and battery packs.
Patent Information
- Application Number
- CN202423219646.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Existing single-cell batteries are prone to explosion when the cell experiences thermal runaway, mainly because the gas cannot be quickly expelled.
Design a cell bottom tray with vent holes and recessed vent channels along the thickness direction. The vent holes and channels are interconnected. The support surface is set between the electrode assembly and the explosion-proof valve to ensure rapid gas discharge.
Through the design of the exhaust vents and channels, gas can be quickly discharged from the explosion-proof valve, reducing the probability of single-cell battery explosion, and reducing the weight of the substrate and the volume of the molten material, further reducing the risk of explosion.
Smart Images
Figure CN223828588U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of battery manufacturing, and in particular, to a cell bottom tray, a single battery and a battery pack. BACKGROUND
[0002] In the existing single battery, the explosion-proof valve can be arranged at the bottom of the battery shell, and a tray is usually arranged between the cell and the explosion-proof valve to support the cell. However, after the tray is arranged in the existing single battery, the single battery is prone to explosion when the cell is in thermal runaway. SUMMARY
[0003] The present disclosure provides a cell bottom tray, a single battery and a battery pack, which can facilitate the rapid discharge of the gas generated after the cell is in thermal runaway to the explosion-proof valve.
[0004] According to one aspect of the present disclosure, a cell bottom tray is provided, comprising:
[0005] a base having two support surfaces distributed along a thickness direction; at least one of the support surfaces is provided with a plurality of exhaust holes and an exhaust channel recessed along the thickness direction, the exhaust channel comprises a plurality of exhaust grooves in communication with each other, and adjacent two of the exhaust holes are communicated by at least one of the exhaust grooves, and the depth of the exhaust groove is less than the thickness of the base.
[0006] In an exemplary embodiment of the present disclosure, the plurality of exhaust holes are arranged in a first direction and a second direction, the exhaust holes are polygonal structures surrounded by a plurality of side walls, and adjacent two of the exhaust holes share at least one side wall; at least part of the side walls are provided with at least one of the exhaust grooves;
[0007] wherein the first direction and the second direction are both perpendicular to the thickness direction.
[0008] In an exemplary embodiment of the present disclosure, at least part of the polygonal structures are hexagons.
[0009] In an exemplary embodiment of the present disclosure, the side walls of the exhaust holes include first type side walls and second type side walls, the first type side walls extend along the first direction, and the extension direction of the second type side walls intersects with the first direction; the exhaust grooves are arranged on the second type side walls.
[0010] In an exemplary embodiment of the present disclosure, each side wall of the exhaust holes intersects with the first direction, and each of the side walls is provided with at least one of the exhaust grooves.
[0011] In an exemplary embodiment of the present disclosure, the thickness of the substrate is greater than or equal to 0.2 mm and less than or equal to 6 mm; and / or, the depth of the exhaust groove is greater than or equal to 0.05 mm.
[0012] In an exemplary embodiment of the present disclosure, the length of the sidewall of the exhaust through hole is greater than or equal to 0.5 mm and less than or equal to 30 mm; and / or, the extension length of the exhaust groove is greater than or equal to 0.05 mm and less than the extension length of the sidewall of the exhaust through hole.
[0013] According to an aspect of the present disclosure, a single battery is provided, comprising:
[0014] A battery housing having a side plate, a bottom plate and a top cover, the side plate, the bottom plate and the top cover enclosing a receiving cavity, the bottom plate being provided with an explosion-proof valve;
[0015] An electrode assembly arranged in the receiving cavity;
[0016] An electric core bottom tray arranged in the receiving cavity and located between the electrode assembly and the explosion-proof valve, the electric core bottom tray being the electric core bottom tray of any one of the above-mentioned embodiments, and the substrate being provided with one of the support surfaces of the exhaust passage facing the explosion-proof valve.
[0017] In an exemplary embodiment of the present disclosure, the center of the substrate is located within the range of the orthographic projection of the explosion-proof valve on the substrate.
[0018] According to an aspect of the present disclosure, a battery pack is provided, comprising a plurality of single batteries, the single battery being the single battery of any one of the above-mentioned embodiments.
[0019] The electric core bottom tray, the single battery and the battery pack of the present disclosure are provided with a plurality of exhaust through holes and an exhaust passage recessed in the thickness direction at least one support surface. The gas generated after the thermal runaway of the electric core can be quickly conducted to the explosion-proof valve through the exhaust through hole and the exhaust passage, so as to avoid the accumulation of gas in the single battery, and the probability of explosion of the single battery can be reduced. Moreover, by providing the exhaust through hole, the volume of the solid structure in the substrate can be reduced, so as to reduce the weight of the electric core bottom tray, and when the high-temperature molten electric core bottom tray is generated after the thermal runaway of the electric core, the volume of the molten material can be reduced, the electric core bottom tray can be prevented from being blocked, and the probability of explosion of the single battery can be further reduced.
[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS
[0021] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, further serve to explain the principles of the present disclosure. It is to be understood that the drawings are only schematic, and that they do not necessarily represent a limiting
[0022] Figure 1 A perspective view of an embodiment of the bottom tray of the battery cell according to the present disclosure.
[0023] Figure 2 A cross-sectional view of the A-A section in Figure 1
[0024] Figure 3 A perspective view of another embodiment of the bottom tray of the battery cell according to the present disclosure.
[0025] Figure 4 A perspective view of an embodiment of the exhaust hole and the exhaust groove according to the present disclosure. BRIEF DESCRIPTION OF DRAWINGS
[0027] 1. Base; 10. Support surface; 10a. Exhaust hole; 10b. Exhaust passage; 10c. Exhaust groove; 11. Side wall; 111. First type of side wall; 112. Second type of side wall;
[0028] X. First direction; Y. Second direction; Z. Thickness direction. DETAILED DESCRIPTION
[0029] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided as non-limiting examples so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the description. Additionally, the drawings are merely schematic and are not drawn to scale.
[0030] The terms "one", "a", "the", "said", and "at least one" are used to indicate the existence of one or more elements / components / etc.; the terms "including" and "having" are used to indicate the inclusion of one or more elements / components / etc. without excluding the presence of additional elements / components / etc.; the terms "first", "second", etc. are used only to identify one or more elements / components / etc. and are not to be construed as limiting the number of such elements / components / etc.
[0031] The single battery can be a four-prism battery, which mainly refers to a prism shape, but is not strictly limited to whether each side of the prism is a straight line in the strict sense, and the corner between the sides can be a circular arc transition. The battery shell of the single battery can include a quadrilateral bottom plate, a quadrilateral top cover, and a side plate arranged around the quadrilateral bottom plate and the quadrilateral top cover.
[0032] The single battery can be a four-prism battery, which mainly refers to a prism shape, but is not strictly limited to whether each side of the prism is a straight line in the strict sense, and the corner between the sides can be a circular arc transition. The battery shell of the single battery can include a quadrilateral bottom plate, a quadrilateral top cover, and a side plate arranged around the quadrilateral bottom plate and the quadrilateral top cover.
[0033] The single battery can also be a cylindrical battery, and the battery shell of the cylindrical battery can include a circular bottom plate, a circular top cover, and a curved side plate between the circular bottom plate and the circular top cover.
[0034] The electrode assembly can include a battery cell. The battery cell can include positive and negative electrode sheets and a separator between the positive and negative electrode sheets, and the positive and negative electrode sheets can include a current collector and an active material on at least one side of the current collector.
[0035] The single battery can be a stacked battery, which is not only convenient to group, but also can be processed to obtain a battery with a longer length. Specifically, the battery cell of the stacked battery can be a stacked battery cell, and the battery cell can have positive and negative electrode sheets stacked with each other and a separator arranged between the positive and negative electrode sheets, so that a plurality of pairs of positive and negative electrode sheets are stacked to form a stacked battery cell.
[0036] The single battery can also be a wound battery. Specifically, the battery cell of the wound battery can be a wound battery cell, i.e., the positive and negative electrode sheets and the separator arranged between the positive and negative electrode sheets are wound to obtain a wound battery cell.
[0037] The bottom plate of the battery shell can be provided with a pressure relief valve. When the battery cell is in thermal runaway, the pressure relief valve can be blown open, and the gas generated by the battery cell can be discharged to the outside of the single battery through the pressure relief valve to avoid explosion of the single battery. The pressure relief valve can be arranged at the center of the bottom plate to improve the discharge speed of the gas and further reduce the probability of explosion of the single battery. However, the pressure relief valve can also be arranged at other positions of the bottom plate.
[0038] The electrode assembly can also include a pole and a tab. The pole can be arranged on the top cover, and the tab is used to connect the battery cell and the pole. The pole can have a positive pole and a negative pole, and the tab can have a positive tab and a negative tab. The positive tab can be used to connect the positive electrode sheet and the positive pole, and the negative tab can be used to connect the negative electrode sheet and the negative pole. By arranging the pole on the top cover and the pressure relief valve on the bottom plate, the pole and the pressure relief valve can be located on opposite sides of the single battery, which can prevent the electrolyte from being sprayed out of the pressure relief valve when the battery cell is in thermal runaway, and can also prevent the residue of the positive and negative electrode sheets from contacting the pole and causing short circuit when the battery cell is in thermal runaway.
[0039] The electrode assembly may also include an insulating film that covers the outer periphery of the cell to insulate the cell from the battery casing and prevent short circuits between the cell and the battery casing.
[0040] like Figures 1 to 4 As shown, the cell bottom tray may include a base 1, which may have two support surfaces 10 distributed along the thickness direction Z. The cell bottom tray may be disposed between the electrode assembly and the base plate, and the two support surfaces 10 may be used to support the electrode assembly and the base plate respectively.
[0041] At least one support surface 10 may be provided with multiple vent holes 10a and vent channels 10b recessed along the thickness direction Z. The vent channels 10b may include multiple interconnected vent grooves 10c. Two adjacent vent holes 10a can be connected through at least one vent groove 10c. The depth of the vent groove 10c may be less than the thickness of the substrate 1. Thus, the gas generated after thermal runaway of the battery cell can be quickly conducted to the explosion-proof valve through the vent holes 10a and vent channels 10b, so as to avoid gas accumulation in the single battery cell and reduce the probability of single battery cell explosion. Furthermore, by providing vent holes 10a, the volume of the solid structure in the substrate 1 can be reduced, thereby reducing the weight of the battery cell bottom tray. When the high-temperature melting of the battery cell bottom tray occurs after thermal runaway of the battery cell, the volume of the molten material can be reduced, avoiding blockage of the battery cell bottom tray, and further reducing the probability of single battery cell explosion.
[0042] In some embodiments of this disclosure, multiple vent holes 10a can be arranged in an array along a first direction X and a second direction Y, both of which can be perpendicular to the thickness direction Z. The vent holes 10a can be polygonal structures formed by multiple sidewalls 11, with adjacent vent holes 10a sharing a sidewall 11, and at least a portion of the sidewall 11 being provided with at least one vent groove 10c. Through the above arrangement, the weight of the cell bottom tray can be further reduced, and the structural strength of the cell bottom tray can be improved.
[0043] In some embodiments, the first direction X, the second direction Y, and the thickness direction Z can be perpendicular to each other to increase the number of venting holes 10a that can be arrayed on the substrate 1, thereby further improving the venting capacity of the cell bottom tray and further reducing the weight of the cell bottom tray.
[0044] At least some of the polygonal structures can be hexagonal to further ensure that the cell base tray has high structural strength. However, it is not limited to this; the polygonal structure can also be quadrilateral, pentagonal, octagonal, decagonal, etc., and can be selected according to actual needs.
[0045] The polygonal structure at the edge of the base 1 can not be a hexagon, and other polygonal structures can all be hexagons, so as to further improve the structural strength of the bottom tray of the battery cell, and meanwhile, the polygonal structure at the edge of the base 1 can be used to adapt to the edge shape of the substrate.
[0046] In some embodiments, as shown in Figure 1 , the side wall 11 of the exhaust hole 10a can include a first type of side wall 111 and a second type of side wall 112, the first type of side wall 111 can extend along the first direction X, and the extension direction of the second type of side wall 112 can intersect the first direction X. The above-mentioned exhaust groove 10c can be arranged on the second type of side wall 112, that is, no exhaust groove 10c is arranged on the first type of side wall 111. In this way, the gas can be quickly discharged to the middle position of the substrate along the first direction X, so that the gas can reach the explosion-proof valve more quickly, further improving the gas discharge speed and reducing the probability of explosion of the single battery. At the same time, in this way, the speed of the gas along the first direction X to the middle position of the substrate can be reduced due to the flow of the gas from the first type of side wall 111, and the probability of explosion of the single battery can be further reduced.
[0047] In other embodiments, as shown in Figure 2 , each side wall 11 of the exhaust hole 10a can intersect the first direction X, and each side wall 11 is provided with at least one exhaust groove 10c. In this way, the gas can be discharged along the first direction X to the middle position of the substrate through each exhaust groove 10c (the direction of the gas discharge is shown by the arrow M in Figure 1 ), and the gas can also reach the explosion-proof valve more quickly. Moreover, since each side wall 11 is provided with at least one exhaust groove 10c, compared with the previous embodiment, the number of exhaust grooves 10c is larger, which can further improve the gas discharge speed and further reduce the probability of explosion of the single battery.
[0048] It should be noted that the quick discharge of the gas along the first direction X to the middle position of the substrate refers to the overall flow direction of the gas being along the first direction X, rather than the gas flowing along the first direction X at any position and at any time.
[0049] In some embodiments, as shown in Figure 2 and Figure 4 , the center line perpendicular to the extension direction of the exhaust groove 10c and the center line perpendicular to the extension direction of the side wall 11 can be collinear to improve the efficiency and speed of the gas flow. However, the center line perpendicular to the extension direction of the exhaust groove 10c and the center line perpendicular to the extension direction of the side wall 11 can also be separated from each other.
[0050] In some embodiments, the thickness H1 of the substrate 1 can be greater than or equal to 0.2 mm and less than or equal to 6 mm, for example, the thickness H1 of the substrate 1 can be 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc. This can avoid the problem of poor structural strength of the substrate 1 due to the thickness H1 of the substrate 1 being too thin, and can avoid the problem of the substrate 1 occupying too much internal space of the single battery due to the thickness H1 of the substrate 1 being too thick.
[0051] The depth H2 of the exhaust groove 10c can be greater than or equal to 0.05 mm and less than the thickness H1 of the substrate 1. For example, the depth H2 of the exhaust groove 10c can be 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 5.9 mm, etc. This can ensure that the exhaust groove 10c has sufficient depth H2, ensuring that the exhaust groove 10c has high exhaust efficiency.
[0052] The extension length L1 of the side wall 11 of the exhaust through hole 10a can be greater than or equal to 0.5 mm and less than or equal to 30 mm. For example, the extension length L1 of the side wall 11 of the exhaust through hole 10a can be 0.5 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 21 mm, 23 mm, 25 mm, 27 mm, 29 mm, 30 mm, etc.
[0053] The extension length L2 of the exhaust groove 10c can be greater than or equal to 0.05 mm and less than the extension length L1 of the side wall 11 of the exhaust through hole 10a, for example, the extension length L2 of the exhaust groove 10c can be 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 21 mm, 23 mm, 25 mm, 27 mm, 29 mm, etc. This can ensure that the exhaust groove 10c has sufficient extension length L2, ensuring that the exhaust groove 10c has high exhaust efficiency.
[0054] In some embodiments, the cell bottom tray can be located between the electrode assembly and the explosion-proof valve, and one support surface 10 of the exhaust passage 10b provided by the substrate 1 can face the explosion-proof valve. The gas generated after the thermal runaway of the cell can enter between the cell bottom tray and the explosion-proof valve through the exhaust through hole 10a, and be quickly discharged to the explosion-proof valve through the exhaust passage 10b facing the explosion-proof valve, so as to utilize the explosion-proof valve to discharge the gas to the outside of the single battery.
[0055] In some embodiments, the center of the substrate 1 can be located within the range of the normal projection of the explosion-proof valve on the substrate 1. Since the gas generated after the thermal runaway of the battery cell can flow to the center of the substrate 1 along the first direction X through the exhaust grooves 10c, by the above arrangement, the gas can be more beneficially flowed to the explosion-proof valve, the gas can be more beneficially discharged, and the risk of explosion of the single battery can be further reduced.
[0056] The embodiments of the present disclosure also provide a battery pack, such as Figures 1 to 4 As shown, the battery pack can include the single battery of any of the above embodiments, and the specific structure of the single battery will not be described here.
[0057] Since the battery pack of the present disclosure includes the single battery of any of the above embodiments, the single battery includes the battery cell bottom tray provided with the plurality of exhaust through holes 10a and the exhaust channel 10b recessed along the thickness direction Z on the at least one support surface 10. The gas generated after the thermal runaway of the battery cell can be quickly conducted to the explosion-proof valve through the exhaust through holes 10a and the exhaust channel 10b, so as to avoid the accumulation of the gas in the single battery, reduce the probability of explosion of the single battery, and further reduce the probability of explosion of the battery pack. Moreover, by arranging the exhaust through holes 10a, the volume of the solid structure in the substrate 1 can be reduced, so as to reduce the weight of the battery cell bottom tray, and when the high-temperature molten battery cell bottom tray is generated after the thermal runaway of the battery cell, the volume of the molten material can be reduced, the battery cell bottom tray can be prevented from being blocked, and thus the probability of explosion of the battery pack can be further reduced.
[0058] Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the utility disclosed herein. This application is intended to cover any variations, uses or adaptive changes of the present disclosure along with their equivalents that incorporate the general principles of the present disclosure and include known expedients or ones that are obvious in light of the present disclosure. The specification and examples are to be considered exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.
Claims
1. A battery cell bottom tray, characterized in that, include: The substrate has two support surfaces distributed along the thickness direction; at least one of the support surfaces is provided with a plurality of vent holes and a vent channel recessed along the thickness direction, the vent channel including a plurality of interconnected vent grooves, two adjacent vent holes being connected through at least one of the vent grooves, the depth of the vent groove being less than the thickness of the substrate.
2. The cell bottom tray according to claim 1, characterized in that, The plurality of exhaust holes are arranged in an array along a first direction and a second direction. The exhaust holes are polygonal structures surrounded by a plurality of sidewalls, and two adjacent exhaust holes share at least one sidewall. At least a portion of the sidewalls are provided with at least one exhaust groove. Wherein, both the first direction and the second direction are perpendicular to the thickness direction.
3. The cell bottom tray according to claim 2, characterized in that, At least part of the polygonal structure is hexagonal.
4. The cell bottom tray according to claim 2, characterized in that, The sidewall of the exhaust port includes a first type of sidewall and a second type of sidewall. The first type of sidewall extends along the first direction, and the extension direction of the second type of sidewall intersects with the first direction. The exhaust groove is provided on the second type of sidewall.
5. The cell bottom tray according to claim 2, characterized in that, Each sidewall of the exhaust vent intersects the first direction, and each sidewall is provided with at least one exhaust groove.
6. The cell bottom tray according to any one of claims 1 to 5, characterized in that, The thickness of the substrate is greater than or equal to 0.2 mm and less than or equal to 6 mm; and / or the depth of the venting groove is greater than or equal to 0.05 mm.
7. The cell bottom tray according to any one of claims 2 to 5, characterized in that, The extension length of the sidewall of the exhaust port is greater than or equal to 0.5 mm and less than or equal to 30 mm; and / or, the extension length of the exhaust groove is greater than or equal to 0.05 mm and less than the extension length of the sidewall of the exhaust port.
8. A single-cell battery, characterized in that, include: The battery casing has a side plate, a bottom plate, and a top cover, which together form a receiving cavity. An explosion-proof valve is provided on the bottom plate. The electrode assembly is disposed within the receiving cavity; A cell bottom tray is disposed within the receiving cavity and located between the electrode assembly and the explosion-proof valve. The cell bottom tray is the cell bottom tray as described in any one of claims 1 to 7. The base is provided with a support surface of the exhaust channel facing the explosion-proof valve.
9. The single-cell battery according to claim 8, characterized in that, The center of the base is located within the range of the orthographic projection of the explosion-proof valve onto the base.
10. A battery pack, characterized in that, The battery pack includes a plurality of individual cells, wherein the individual cells are the individual cells described in any one of claims 8 or 9 above.