Top cover assembly of battery cell, battery cell, battery and electric equipment
By using fusible explosion-proof and protective sheets in the battery cell top cover assembly, the problem of unsmooth pressure relief when the battery cell is thermally out of control is solved, the safety and corrosion resistance of the battery cell are improved, and the explosion and cracking of the battery cell is reduced. Risk of opening.
Patent Information
- Application Number
- CN202420689057.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-03
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-04-03
AI Technical Summary
When the existing battery cells are thermally out of control, the dimensional processing accuracy of the explosion-proof plate is high, resulting in unsmooth or delayed pressure relief. The air pressure damage explosion-proof plate is strictly sized, affecting the battery cell design.
Design a battery cell top cover assembly, including a top cover plate, explosion-proof plate, seal and protective plate. The explosion-proof plate melts at a preset temperature, and the protective plate opens under the action of air pressure or temperature to remove the protection of the explosion-proof plate and allow high temperature. High-pressure gas relieves pressure smoothly.
Improve the reliability of opening the valve and pressure relief when the battery cell is thermally out of control, reduce the possibility of explosion and cracking of the battery cell shell under high temperature and high pressure, and improve the corrosion resistance and chemical stability of the explosion-proof plate through appropriate melting points and materials. sex.
Smart Images
Figure CN222300744U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and in particular to a top cover assembly of a battery cell, a battery cell, a battery and an electrical device. Background Art
[0002] In the related art, when the battery cell thermally runs away, the internal air pressure is high, and a pressure relief port is provided on the top cover of the battery cell, and an explosion-proof plate is provided corresponding to the pressure relief port to relieve the pressure. The strength of the explosion-proof plate is set by controlling the thickness of the explosion-proof plate and making local notches on the explosion-proof plate. When the battery cell thermally runs away, the internal gas expands and breaks through the explosion-proof plate when a certain pressure is reached. However, the dimensional processing accuracy of the explosion-proof plate is high, and the fluctuation of the size of the explosion-proof plate may cause the valve to be unable to open smoothly or delay the opening of the valve. In addition, the size requirements of the air pressure destruction type explosion-proof plate are strict, which will have a great impact on the battery cell design. Utility Model Content
[0003] In view of this, the first aspect of the embodiments of the present application is intended to provide a top cover assembly of a battery cell to improve the reliability of opening the valve to release pressure when the battery cell is in thermal runaway. The top cover assembly includes a top cover plate, an explosion-proof sheet, a seal and a protective sheet. The top cover plate is provided with an explosion-proof hole; the explosion-proof sheet is located on the top cover plate and is arranged corresponding to the explosion-proof hole; the seal is located on the top cover plate so that the explosion-proof sheet seals the explosion-proof hole; the protective sheet is located on the top cover plate and is arranged above the explosion-proof sheet corresponding to the explosion-proof hole; wherein the explosion-proof sheet is configured so that when the battery cell reaches a preset temperature, the explosion-proof sheet can melt to release pressure from the battery cell.
[0004] The top cover assembly of the battery cell provided in the embodiment of the present application is such that when the battery cell is in thermal runaway, the high-temperature and high-pressure gas will flow toward the explosion-proof hole in a concentrated manner. When the battery cell reaches a preset temperature, the explosion-proof sheet will melt, and the protective sheet will open under the action of air pressure or temperature, thereby releasing the protective effect of the explosion-proof sheet. The high-temperature and high-pressure gas in the battery cell can be smoothly discharged from the explosion-proof hole, thereby reducing the possibility of explosion and cracking of the battery cell shell under high temperature and high pressure.
[0005] In some embodiments, the explosion-proof disk has a melting point of 80°C-200°C.
[0006] The melting point of the explosion-proof disk is set to a suitable temperature to reduce the adverse effect of insufficient temperature resistance of the explosion-proof disk on explosion-proof reliability.
[0007] In some embodiments, the explosion-proof disk is made of thermoplastic plastic.
[0008] In this way, the corrosion resistance and chemical stability of the explosion-proof disk can be improved, and the explosion-proof disk can effectively withstand the erosion of the electrolyte.
[0009] In some embodiments, the protection sheet is made of metal.
[0010] The metal protection plate has high strength and can reduce the damage caused to the explosion-proof plate by tools and personnel errors during the manufacturing process.
[0011] In some embodiments, the protection sheet is made of plastic.
[0012] The protective sheet made of plastic is easy to process, has good corrosion resistance and low cost.
[0013] In some embodiments, the protection sheet is configured to melt to release the pressure of the battery cell when the battery cell exceeds a preset temperature.
[0014] When the battery cell exceeds the preset temperature, the explosion-proof plate has reached the melting point and melted, and the protective plate has also reached the melting point, so that the high-temperature and high-pressure gas can be discharged smoothly. At the same time, it can reduce the space above the battery cell occupied by the protective plate when the valve is opened.
[0015] In some embodiments, the top cover assembly further includes a pressure ring, which is disposed on the explosion-proof disk and connected to the top cover plate to press the explosion-proof disk onto the top cover plate.
[0016] In this way, the structural strength between the explosion-proof disk and the top cover plate can be improved by the pressure ring.
[0017] In some embodiments, the top cover plate forms an annular first step portion and an annular second step portion in the explosion-proof hole, the second step portion is located above the first step portion, and the first step portion is located on the inner side of the second step portion; the seal, the explosion-proof plate and the pressure ring are sequentially arranged on the first step portion along the thickness direction of the top cover plate, and the protective plate is arranged on the second step portion.
[0018] The seal, the burst disk and the pressure ring can be installed on the first step portion in sequence, and then the protection sheet can be installed on the second step portion to facilitate the installation and positioning of the seal, the burst disk, the pressure ring and the protection sheet.
[0019] In some embodiments, the top cover plate further forms an annular third step portion in the explosion-proof hole, the third step portion is located between the first step portion and the second step portion, the pressure ring is welded to the top cover plate, and the upper portion of the pressure ring is flush with the step surface of the second step portion.
[0020] The third step portion is provided to facilitate laser welding at the junction of the pressure ring and the top cover plate.
[0021] In some embodiments, the top cover plate further has an annular groove arranged on the step surface of the first step portion, and the sealing member is an annular sealing ring, which is arranged in the annular groove and protrudes from the annular groove in an initial state so that the explosion-proof disk can squeeze the sealing ring.
[0022] The sealing ring can be effectively fixed by the ring groove, thereby improving the sealing reliability.
[0023] A second aspect of the embodiments of the present application provides a battery cell, comprising a housing and a top cover assembly as described in any one of the above items. The housing has an open end; and the top cover assembly is disposed at the open end of the housing.
[0024] A third aspect of an embodiment of the present application provides a battery, comprising a box and a plurality of the above-mentioned battery cells, which are arranged in the box.
[0025] A fourth aspect of an embodiment of the present application provides an electrical device, characterized in that it includes the battery described above and is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 is a schematic structural diagram of a top cover assembly according to one or more embodiments;
[0027] Figure 2 for Figure 1 Exploded diagram of
[0028] Figure 3 for Figure 1 A top view of
[0029] Figure 4 for Figure 2 AA cross-sectional diagram of ;
[0030] Figure 5 for Figure 4 An enlarged schematic diagram of point D;
[0031] Figure 6 for Figure 1 Front view of
[0032] Figure 7 for Figure 1 Bottom view of
[0033] Figure 8 is a schematic diagram of the structure of an explosion-proof disk according to one or more embodiments;
[0034] Fig. 9 for Figure 8 A top view of
[0035] Fig.10 for Figure 8 Front view of
[0036] Fig.11 for Fig. 9 Side view of
[0037] Fig.12 is a schematic structural diagram of a sealing member according to one or more embodiments;
[0038] Fig.13 for Fig.12 A top view of
[0039] Fig.14 for Fig.13 Schematic diagram of CC cross section;
[0040] Fig.15 for Fig.12 Front view of
[0041] Fig.16 for Fig.13 Side view of
[0042] Fig.17 is a schematic structural diagram of a protection sheet according to one or more embodiments;
[0043] Fig.18 for Fig.17 A top view of
[0044] Fig.19 is a bottom view of a protection sheet and a backing adhesive according to one or more embodiments;
[0045] Fig. 20 for Fig.19 Front view of
[0046] Fig.21 for Fig. 20 An enlarged schematic diagram of point G;
[0047] Fig. 22 is a schematic diagram of the structure of a pressure ring according to one or more embodiments;
[0048] Fig.23 for Fig. 22 A top view of
[0049] Fig.24 for Fig. 22 Front view of
[0050] Fig.25 for Fig.23 Side view of
[0051] Fig.26 is a schematic structural diagram of a top cover plate according to one or more embodiments;
[0052] Fig. 27 for Fig.26 An enlarged schematic diagram of point E;
[0053] Fig.28 for Fig.26 A top view of
[0054] Fig.29 for Fig.28 BB cross-sectional diagram;
[0055] Fig.30 for Fig.29 An enlarged schematic diagram of point F;
[0056] Fig.31 for Fig.26 Front view of
[0057] Fig.32 for Fig.28 Side view of
[0058] Fig.33 is a schematic diagram of the structure of a battery cell according to one or more embodiments;
[0059] Fig.34 for Fig.33 Exploded diagram of
[0060] Fig.35 for Fig.33 Front view of
[0061] Fig.36 is an exploded view of a battery according to one or more embodiments;
[0062] Fig.37 for Fig.36 Axonometric diagram of .
[0063] Description of Reference Numerals
[0064] Top cover assembly 100; top cover plate 10; explosion-proof hole 10a; first step portion 11; step surface 111; annular groove 111a; vertical surface 112; second step portion 12; third step portion 13; explosion-proof disk 20; sealing member 30; protective sheet 40; pressure ring 50; backing glue 60; pole 70; shell 110; open end 110a; battery cell 200; box 210; battery 300. DETAILED DESCRIPTION
[0065] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.
[0066] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms "upper", "top", "inside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.
[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The terms "including" and "having" and any variations thereof of the present application are intended to cover non-exclusive inclusions.
[0068] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.
[0069] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0070] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.
[0071] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.
[0072] In a battery, multiple cells can be connected in series, in parallel, or in a mixed connection. A mixed connection means that multiple cells are connected in series and in parallel. Multiple cells can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple cells is placed in a battery box; of course, the battery can also be a battery module formed by connecting multiple cells in series, in parallel, or in a mixed connection, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and placed in a battery box.
[0073] The battery can be used in electrical devices that use the battery as a power source or in various energy storage systems that use the battery as an energy storage element, such as an energy storage container.
[0074] The battery may be a secondary battery, which refers to a battery that can be continuously used by activating the active material by charging after the battery is discharged.
[0075] The battery can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery or a lead storage battery, etc.
[0076] The battery cell may be a cylindrical battery cell, a prismatic battery cell or other shapes. The prismatic battery cell includes a square shell battery cell or a multi-prismatic battery cell, and the multi-prismatic battery cell is, for example, a hexagonal battery cell, etc., and the present application has no particular limitation.
[0077] In the related art, the battery cell will go through the following three stages when thermal runaway occurs, namely the self-heating stage, the temperature of this stage is 50-140℃; the thermal runaway stage, the temperature of this stage is 140-850℃; the thermal runaway termination stage, the temperature of this stage is 850℃-normal temperature. The traditional explosive explosion-proof disc needs to reach the stage of large-scale gas production during thermal runaway, and the gas pressure reaches 0.5Mpa or above before the valve can be opened to release the pressure. And when the size processing accuracy of the notched explosion-proof disc does not meet the requirements, the connection strength between the explosion-proof disc and the top cover plate is too high, which will cause the explosion-proof disc to fail to open the valve to release the pressure, causing the battery cell shell to explode. Therefore, the size processing accuracy of the explosion-proof disc is required to be high, and the fluctuation of the size of the explosion-proof disc may cause the valve to be unable to open smoothly or delay the valve opening. And the size requirements of the air pressure destruction type explosion-proof disc are strict, which will have a great impact on the battery cell design.
[0078] In view of this, please refer to Figure 1-Figure 7 , the embodiment of the present application hopes to provide a top cover assembly 100 of a battery cell, so as to improve the reliability of valve opening when the battery cell has thermal runaway. The top cover assembly 100 includes a top cover plate 10, an explosion-proof disc 20, a seal 30 and a protective sheet 40. The top cover plate 10 is provided with an explosion-proof hole 10a; the explosion-proof disc 20 is located on the top cover plate 10 and is arranged corresponding to the explosion-proof hole 10a; the seal 30 is located on the top cover plate 10 so that the explosion-proof disc 20 seals the explosion-proof hole 10a; the protective sheet 40 is located on the top cover plate 10 and is arranged above the explosion-proof disc 20 corresponding to the explosion-proof hole 10a; wherein the explosion-proof disc 20 is configured so that when the battery cell reaches a preset temperature, the explosion-proof disc 20 can melt to relieve the pressure of the battery cell.
[0079] See also Figure 8-Figure 18The explosion-proof hole 10a is used to make the high-temperature and high-pressure gas generated by the thermal runaway of the battery cell flow to the explosion-proof plate 20, so that the explosion-proof plate 20 can be opened in time to relieve pressure and prevent explosion. The sealing member 30 is used to strengthen the sealing between the explosion-proof plate 20 and the top cover plate 10, reduce the possibility of electrolyte leakage from the explosion-proof plate 20, and protect the internal structure of the battery cell from contamination and damage. The protective plate 40 is used to protect the explosion-proof plate 20, reducing the possibility of damage to the explosion-proof plate 20 caused by foreign objects or during the manufacturing process.
[0080] The top cover assembly 100 of the battery cell provided in the embodiment of the present application, when the battery cell is in thermal runaway, the high-temperature and high-pressure gas flows to the explosion-proof hole 10a in a concentrated manner, and when the battery cell reaches a preset temperature, the explosion-proof plate 20 melts, and the protective plate 40 opens under the action of air pressure or temperature, releasing the protective effect of the explosion-proof plate 20, and the high-temperature and high-pressure gas in the battery cell can be smoothly discharged from the explosion-proof hole 10a, reducing the possibility of the battery cell shell 110 exploding and cracking under high temperature and high pressure. Compared with the air pressure-destructible explosion-proof plate 20 that relies on pressure to break through the explosion-proof structure of the explosion-proof plate 20, the top cover assembly 100 of the battery cell provided in the present application has a better explosion-proof effect. It can be understood that the protective plate 40 can be set to a metal material or a high-temperature resistant plastic material, and the protective plate 40 is generally connected to the top cover plate 10 by means of snap-on, adhesive backing, etc. When the battery cell reaches a preset temperature, it is relatively easy to open the protective plate 40 by air pressure.
[0081] For example, see Figure 2 The top cover assembly 100 also includes a pole 70. The top cover plate 10 is provided with a mounting hole (not shown in the figure). The pole 70 is electrically connected to the pole tab through the mounting hole. The pole 70 can be directly connected to the pole tab, or indirectly connected to the pole tab through a transition component. The pole 70 includes a positive pole and a negative pole. The poles 70 of two cells can be connected through a bar.
[0082] In some embodiments, the melting point of the bursting disk 20 is 80°C-200°C.
[0083] The melting point of the explosion-proof disc 20 can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, etc. The melting point of the explosion-proof disc 20 is set to a suitable temperature to reduce the adverse effects of insufficient temperature resistance of the explosion-proof disc 20 on the explosion-proof reliability, and to reduce the possibility that the melting point of the explosion-proof disc 20 is too high, resulting in a long valve opening time and affecting the timely pressure relief of the battery cell.
[0084] In some embodiments, the material of the explosion-proof disc 20 is thermoplastic. For example, ethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyamide (PA), polyoxymethylene (POM), ABS, etc. The physical state of thermoplastics can change with the change of temperature, and has a relatively low melting point, and the melting point temperature is generally between 100°C and 300°C. According to the design requirements of the explosion-proof disc 20, a thermoplastic with a suitable melting point temperature can be selected. In this way, the corrosion resistance and chemical stability of the explosion-proof disc 20 can be improved, and it can effectively withstand the erosion of the electrolyte.
[0085] In some embodiments, the protection sheet 40 is made of metal.
[0086] For example, when there is sufficient valve opening space above the battery cell, the material of the protective sheet 40 can be set to metal, such as thin aluminum sheet, thin steel sheet, etc. The metal protective sheet 40 has high strength, and the metal protective sheet 40 has a better protective effect on the internal explosion-proof sheet 20 during the battery cell production process, which can reduce the damage to the explosion-proof sheet 20 caused by work fixtures, personnel operating errors, etc. in the process. When the battery cell has thermal runaway, the internal air pressure of the battery cell increases, and the protective sheet 40 can be easily opened to the outside of the battery cell to relieve the pressure of the battery cell.
[0087] Exemplarily, the protection sheet 40 and the top cover plate 10 are interference fit, and the fixing strength is relatively low. When the battery cell 200 thermally runs away, they can be easily opened to reduce the possibility of explosion-proof failure.
[0088] In some embodiments, the material of the protection sheet 40 is plastic. The protection sheet made of plastic is easy to process, has good corrosion resistance and low cost.
[0089] For example, when the valve opening space above the battery cell 200 is large, the material of the protective sheet 40 can be set to be a thermosetting plastic, such as phenolic plastic, epoxy plastic, amino plastic, unsaturated polyester or alkyd plastic, etc. The protective sheet 40 can be connected to the top cover plate 10 by adhesive, and opened by air pressure when the battery cell reaches a preset temperature.
[0090] The protective sheet 40 can also be configured as a thermoplastic plastic, such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyamide (PA), polyoxymethylene (POM), ABS, etc., which can melt at high temperatures to achieve the purpose of pressure relief. In this way, the space above the battery cell occupied by the protective sheet 40 when the valve is opened can be reduced.
[0091] In some embodiments, the protection sheet 40 is configured to melt when the battery cell reaches a preset temperature to release the pressure of the battery cell. For example, the material of the protection sheet 40 is thermoplastic.
[0092] It is understandable that when the battery core exceeds the preset temperature, the explosion-proof disc 20 has reached the melting point and melted, and the protection sheet 40 has also reached the melting point, so that the high-temperature and high-pressure gas can be discharged smoothly. In the same battery core, the material of the protection sheet 40 can be the same as that of the explosion-proof disc 20, or have the same melting point.
[0093] For example, see Figure 19-21 The material of the protective sheet 40 is plastic, and the material of the top cover plate 10 is metal. The protective sheet 40 is fixed to the top cover plate 10 by applying adhesive 60 in the annular area. The fixing strength of the protective sheet 40 and the top cover plate 10 can meet the fixing requirements of the protective sheet 40.
[0094] For some examples, see Figure 22-Figure 25 The top cover assembly 100 further includes a pressing ring 50 , which is disposed on the explosion-proof disc 20 and connected to the top cover plate 10 , so as to press the explosion-proof disc 20 onto the top cover plate 10 .
[0095] In this way, the structural strength between the explosion-proof disk 20 and the top cover plate 10 can be improved by the pressure ring 50 .
[0096] Exemplarily, the pressure ring 50 and the top cover plate 10 are made of the same material and are easily combined after welding and melting. For example, the pressure ring 50 and the top cover plate 10 are both made of aluminum.
[0097] For some examples, see Figure 26-Figure 32 The top cover plate 10 is formed with an annular first step portion 11 and an annular second step portion 12 in the explosion-proof hole 10a, the second step portion 12 is located above the first step portion 11, and the first step portion 11 is located on the inner side of the second step portion 12; the sealing member 30, the explosion-proof disk 20 and the pressure ring 50 are sequentially arranged on the first step portion 11 along the thickness direction of the top cover plate 10, and the protective sheet 40 is arranged on the second step portion 12.
[0098] In this embodiment, the seal 30, the explosion-proof disk 20 and the pressure ring 50 can be installed on the first step portion 11 in sequence, and then the protection sheet 40 can be installed on the second step portion 12, so as to facilitate the installation and positioning of the seal 30, the explosion-proof disk 20, the pressure ring 50 and the protection sheet 40. For example, the pressure ring 50 can be connected to the first step portion 11 through an annular fillet weld, which can improve the structural stability of the top cover assembly 100, improve the sealing performance of the top cover assembly 100, and reduce the possibility of electrolyte leakage in the battery cell.
[0099] Exemplarily, the protection sheet 40 is fixed on the second step portion 12 by means of adhesive 60 .
[0100] For some examples, see Fig. 27 and Fig.30The top cover plate 10 also forms an annular third step portion 13 in the explosion-proof hole 10a, and the third step portion 13 is located between the first step portion 11 and the second step portion 12. The pressure ring 50 is welded to the top cover plate 10, and the upper part of the pressure ring 50 is flush with the step surface 111 of the second step portion 12.
[0101] It is understandable that the first step portion 11 includes a step surface 111 and a vertical surface 112. The side surface of the pressure ring 50 is connected to the vertical surface 112 of the first step portion 11, and the side surface of the explosion-proof disk 20 is also connected to the vertical surface 112 of the first step portion 11.
[0102] In this embodiment, the third step portion 13 is provided to facilitate laser welding at the junction of the pressure ring 50 and the top cover plate 10 .
[0103] Exemplarily, after the pressing ring 50 is pressed to be flush with the step surface 111 of the first step portion 11 by a contouring tool, it is welded to the top cover plate 10 .
[0104] Exemplarily, the pressure ring 50 is fixed to the top cover plate 10 by laser welding, and the welding direction is aligned with the vertical surface 112 of the first step portion 11. In this way, the welding efficiency and welding cost can be improved, and the connection strength between the pressure ring 50 and the top cover plate 10 can be improved.
[0105] For some examples, see Fig.30 The top cover plate 10 also has an annular groove 111a arranged on the step surface 111 of the first step portion 11. The sealing member 30 is an annular sealing ring, which is arranged in the annular groove 111a and protrudes from the annular groove 111a in the initial state, so that the explosion-proof disk 20 can squeeze the sealing ring.
[0106] In this embodiment, the sealing ring can be effectively fixed by the annular groove 111a, thereby improving the reliability of the seal. Since the sealing ring protrudes from the annular groove 111a in the initial state, the explosion-proof disk 20 can squeeze the sealing ring, thereby improving the sealing effect between the explosion-proof disk 20 and the top cover plate 10. Moreover, the sealing ring is arranged in the annular groove 111a, which can simplify the installation process and reduce the installation and maintenance costs.
[0107] In some embodiments, a top cover assembly 100 of a battery cell improves the reliability of valve opening when the battery cell is in thermal runaway. The top cover assembly 100 includes a top cover plate 10, an explosion-proof plate 20, a seal 30, a protective plate 40 and a pressure ring 50. The top cover plate 10 is provided with an explosion-proof hole 10a, and the top cover plate 10 is formed with an annular first step portion 11, an annular second step portion 12 and an annular third step portion 13 in the explosion-proof hole 10a, the second step portion 12 is located above the first step portion 11, the first step portion 11 is located on the inner side of the second step portion 12, the third step portion 13 is located between the first step portion 11 and the second step portion 12, and an annular groove 111a is formed on the step surface 111 of the first step portion 11. The seal 30 is an annular sealing ring, which is arranged in the annular groove 111a and protrudes from the annular groove 111a in the initial state. The explosion-proof disc 20 and the pressure ring 50 are sequentially arranged on the first step portion 11 along the thickness direction of the top cover plate 10, and the explosion-proof disc 20 can squeeze the sealing ring. The pressure ring 50 is welded to the top cover plate 10, and the upper part of the pressure ring 50 is flush with the step surface of the second step portion 12; the protective sheet 40 is arranged on the second step portion 12 through the annular adhesive 60, and the corresponding explosion-proof hole 10a is arranged above the explosion-proof disc 20, and the material of the protective sheet 40 is plastic. Among them, the explosion-proof disc 20 is configured so that when the battery cell reaches a preset temperature, the explosion-proof disc 20 can melt to relieve the pressure of the battery cell. For example, the material of the explosion-proof disc 20 is thermoplastic plastic with a melting point of 100°C. When the battery cell reaches a preset temperature, the protective sheet 40 can melt to relieve the pressure of the battery cell. In this way, when the battery cell is thermally runaway, the explosion-proof disc 20 melts when it reaches 100°C, and the protective sheet 40 also melts, and the high-temperature and high-pressure gas can smoothly flow out of the explosion-proof hole 10a to relieve the pressure of the battery cell.
[0108] The present application also provides a battery cell 200, see Figure 33-Figure 35 The battery cell 200 includes a housing 110 and any of the above-mentioned top cover components 100. The housing 110 has an open end 110a; the top cover component 100 is disposed at the open end 110a of the housing 110. The top cover component 100 is welded to the housing 110.
[0109] The present application also provides a battery 300, see Fig.36 and Fig.37 , including a box body 210 and a plurality of the above-mentioned battery cells 200, which are arranged in the box body 210. For example, a plurality of battery cells 200 are arranged in the box body 210, and the battery cells 200 are connected in series, in parallel or in mixed connection.
[0110] The embodiment of the present application further provides an electric device, including the above-mentioned battery 300, for providing electric energy. For example, the battery 300 provides electric energy for the electric device itself, or provides electric energy for devices outside the electric device.
[0111] Electrical devices include, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.
[0112] The various embodiments / implementations provided in this application can be combined with each other without causing any contradiction.
[0113] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A top cover assembly of a battery cell, characterized in that: include: The top cover plate is provided with explosion-proof holes; An explosion-proof plate, located on the top cover plate and arranged corresponding to the explosion-proof hole; A sealing member, located on the top cover plate, so that the explosion-proof disc seals the explosion-proof hole; A protection sheet, located on the top cover plate and arranged above the explosion-proof sheet corresponding to the explosion-proof hole; Wherein, the explosion-proof plate is configured so that when the battery core reaches a preset temperature, the explosion-proof plate can melt to relieve the pressure of the battery core.
2. The top cover assembly according to claim 1, characterized in that: The melting point of the explosion-proof disk is 80° C.-200° C.; and / or the material of the explosion-proof disk is thermoplastic plastic.
3. The top cover assembly according to claim 1, characterized in that: The material of the protection sheet is metal or plastic.
4. The top cover assembly according to claim 1, characterized in that: The protection sheet is configured such that when the battery cell exceeds a preset temperature, the protection sheet can melt to release the pressure of the battery cell.
5. The top cover assembly according to claim 1, characterized in that: The top cover assembly also includes a pressure ring, which is arranged on the explosion-proof disk and connected to the top cover plate to press the explosion-proof disk onto the top cover plate.
6. The top cover assembly according to claim 5, characterized in that: The top cover plate is formed with an annular first step portion and an annular second step portion in the explosion-proof hole, wherein the second step portion is located above the first step portion, and the first step portion is located inside the second step portion; The sealing member, the explosion-proof sheet and the pressure ring are sequentially arranged on the first step portion along the thickness direction of the top cover plate, and the protection sheet is arranged on the second step portion.
7. The top cover assembly according to claim 6, characterized in that: The top cover plate also forms an annular third step portion in the explosion-proof hole, and the third step portion is located between the first step portion and the second step portion. The pressure ring is welded to the top cover plate, and the upper portion of the pressure ring is flush with the step surface of the second step portion.
8. The top cover assembly according to claim 6, characterized in that: The top cover plate also has an annular groove arranged on the step surface of the first step portion, and the sealing member is an annular sealing ring, which is arranged in the annular groove and protrudes from the annular groove in an initial state, so that the explosion-proof disk can squeeze the sealing ring.
9. A battery cell, characterized in that: include: a housing having an open end; The top cover assembly according to any one of claims 1 to 8 is arranged at the open end of the shell.
10. A battery, characterized in that: include: Box; A plurality of battery cells according to claim 9 are arranged in the box.
11. An electrical device, characterized in that: The battery according to claim 10 is used to provide electrical energy.