Battery, battery pack and energy storage system

Abstract

The utility model relates to the technical field of batteries, in particular to a battery, a battery pack and an energy storage system. The utility model aims to reduce the risk of lithium intercalation corrosion of the shell. The embodiment of the utility model provides a battery which comprises a battery cell, a shell and a top cover, and the top cover comprises a top cover piece and a positive pole. The top cover plate is provided with a first polar hole, the positive pole comprises a first section and a second section, the second sealing ring sleeves the second section and is in contact with the outer surface of the top cover plate, and the conductivity of the second sealing ring is relatively good, so that the potential difference between the positive pole and the shell can be eliminated, and the situation that the potential difference between the shell and the negative pole is too low to cause lithium-embedded corrosion of the shell is prevented. The first sealing ring is located between the first section and the hole wall of the first polar hole, sealing between the positive pole and the first polar hole can be achieved through the first sealing ring and the second sealing ring, electrolyte is prevented from overflowing, and the sealing performance of the top cover and the safety performance of the battery are improved.

Description

Technical Field

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

[0002] Lithium-ion batteries have been widely used due to their good performance. The battery generally includes a shell, a battery cell arranged in the shell, and a top cover covered on the shell. The top cover is provided with a pole hole, and the positive pole is inserted into the pole hole and connected to the battery cell. A sealing ring is provided between the positive pole and the top cover, resulting in a low potential difference between the shell and the negative pole, which is prone to lithium corrosion. Utility Model Content

[0003] The embodiments of the present application provide a battery, a battery pack, and an energy storage system, which can reduce the risk of lithium-embedded corrosion of the shell.

[0004] In a first aspect, an embodiment of the present application provides a battery including a cell, a shell and a top cover, wherein the cell is arranged inside the shell, the shell has an opening, and the top cover is buckled on the opening. The top cover includes a top cover sheet and a positive pole, the top cover sheet is provided with a first pole hole, the positive pole column includes a first section and a second section, the first section is inserted into the first pole hole, and the second section is located outside the first pole hole and the shell. The first sealing ring is sleeved on the first section, the first sealing ring is located between the first section and the hole wall of the first pole hole; the second sealing ring is sleeved on the second section and contacts the outer surface of the top cover sheet. The resistivity of the first sealing ring is greater than the resistivity of the second sealing ring, that is, the conductivity of the first sealing ring is worse than that of the second sealing ring.

[0005] Through the above arrangement, the conductivity of the second sealing ring is good, and the electrical connection between the positive pole and the top cover sheet can be achieved, thereby eliminating the potential difference between the positive pole and the shell, and preventing the potential difference between the shell and the negative pole from being too low, which causes lithium corrosion in the shell. At the same time, the first sealing ring is located at a position where the distance between the positive pole and the hole wall of the first pole hole is small, and the insulation of the first sealing ring is good, which can avoid being punctured, and ensure good insulation between the positive pole and the top cover sheet. In addition, the first sealing ring and the second sealing ring can achieve sealing between the positive pole and the first pole hole, prevent electrolyte overflow, and improve the sealing performance of the top cover and the safety performance of the battery.

[0006] In some embodiments that may include the above embodiments, a first annular groove is provided on the outer surface of the top cover sheet, and the inner diameter of the first annular groove is equal to the aperture of the first polar hole. A first sealing ring is provided on the outer wall of the first sealing ring, and the first sealing ring is located in the first annular groove. In this way, the contact area between the top cover sheet and the sealing material (the first sealing ring and the first sealing ring) is increased, and the sealing performance of the battery is improved.

[0007] In some embodiments that may include the above embodiments, the first sealing ring and the first sealing ring are an integrated structure. The integrated structure formed by injection molding, stamping, etc. reduces the structural complexity of the top cover and reduces the difficulty of assembly. In addition, the first sealing ring and the first sealing ring of the integrated structure avoid the generation of a gap between the first sealing ring and the first sealing ring, further avoiding the positive pole and the top cover sheet from being punctured, and avoiding affecting the sealing performance of the battery.

[0008] In some embodiments that may include the above embodiments, a first step structure is provided at a position of the first section near the first pole hole, a second sealing ring is provided on the inner wall of the first sealing ring, and the second sealing ring cooperates with the first step structure. In this way, the contact area between the first section and the sealing material (the first sealing ring and the second sealing ring) is increased, thereby improving the sealing performance of the battery.

[0009] In some embodiments that may include the above embodiments, the second sealing ring and the first sealing ring are an integrated structure. The integrated structure formed by injection molding, stamping, etc. reduces the structural complexity of the top cover and reduces the difficulty of assembly. In addition, the second sealing ring and the first sealing ring of the integrated structure avoid the generation of a gap between the second sealing ring and the first sealing ring, further avoiding the breakdown of the positive electrode column and the top cover sheet, and avoiding affecting the sealing performance of the battery.

[0010] In some embodiments that may include the above embodiments, a second step structure is provided at a position of the second section near the first pole hole, a third sealing ring is provided on the inner wall of the second sealing ring, the third sealing ring and the second sealing ring are an integral structure, and the third sealing ring cooperates with the second step structure. In this way, the contact area between the second section and the sealing material (the second sealing ring and the third sealing ring) is increased, and the sealing performance of the battery is further improved. In addition, the third sealing ring and the second sealing ring of the integral structure avoid the generation of a gap between the third sealing ring and the second sealing ring, avoid affecting the connection between the positive pole and the top cover sheet, and avoid affecting the sealing performance of the battery.

[0011] In some embodiments that may include the above embodiments, the resistance value of the first sealing ring is greater than or equal to 10 8 Ω, the resistance value of the second sealing ring is [10Ω-10 5 Ω]. This arrangement can prevent the potential difference between the shell and the negative electrode from being lower than the corrosion potential, thereby preventing the shell from corroding and leaking.

[0012] In some embodiments that may include the above embodiments, the second sealing ring includes a polymer ring and a doping structure, the doping structure is doped in the polymer ring, the resistivity of the doping structure is less than the resistivity of the polymer ring, the polymer ring includes polyphenylene sulfide, and the doping structure includes at least one of metal powder, carbon black powder, and conductive fiber. In this way, by adjusting the doping ratio of the doping structure, the conductivity of the second sealing ring can be changed, which is convenient for eliminating the potential difference between the shell and the positive pole, and preventing the shell from being corroded.

[0013] In some embodiments that may include the above embodiments, the first sealing ring and the second sealing ring are an integrated structure. Such an arrangement can further simplify the structure of the top cover and reduce the difficulty of assembly.

[0014] In some embodiments that may include the above embodiments, the positive electrode column further includes a first baffle located at one end of the first section away from the second section, the first baffle covers the inner surface of the top cover sheet, and the top cover sheet further includes a third sealing ring, the third sealing ring is located between the top cover sheet and the first baffle. In this way, the first baffle can prevent the positive electrode column from moving out of the first pole hole, and the third sealing ring is located in the gap between the top cover sheet, the first baffle and the positive electrode column to prevent the electrolyte from overflowing from the first pole hole, thereby achieving a sealing effect and improving the sealing performance of the top cover and the safety performance of the battery.

[0015] In some embodiments that may include the above embodiments, the inner surface is covered with an insulating layer, a first receiving hole connected to the first pole hole is provided on the insulating layer, the aperture of the first receiving hole is larger than the aperture of the first pole hole, and the third sealing ring is located in the receiving hole. In this way, the first receiving hole can fix the position of the third sealing ring, so that the third sealing ring is closely attached to the top cover sheet and the first baffle, which can further improve the sealing performance of the battery.

[0016] In some embodiments that may include the above embodiments, a first annular flange is provided on the insulating layer, and the first annular flange is arranged outside the first baffle and contacts the first baffle. In this way, the first annular flange is in close contact with the outer surface of the first baffle, and the position of the first baffle and the positive electrode column can be fixed, and the first baffle is prevented from contacting the top cover sheet, thereby avoiding a short circuit of the battery.

[0017] In a second aspect, an embodiment of the present application provides a battery pack, comprising a plurality of the above-mentioned batteries, wherein the plurality of batteries are connected in series or in parallel. The circuit board is electrically connected to the batteries.

[0018] The battery pack provided in the embodiments of the present application includes the battery in any of the above embodiments, so the two can solve the same technical problems and achieve the same technical effects.

[0019] In a third aspect, an embodiment of the present application provides an energy storage system, including a power converter and the above-mentioned battery pack, wherein the power converter is used to convert the power output by an external power source and output it to the battery pack.

[0020] The energy storage system provided in the embodiments of the present application includes the battery pack in any of the above embodiments, so the two can solve the same technical problems and achieve the same technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A cross-sectional view of a battery provided in an embodiment of the present application;

[0022] Figure 2 is the potential diagram of lithium aluminum alloy;

[0023] Figure 3 An exploded view of a top cover of a battery provided in an embodiment of the present application;

[0024] Figure 4 A cross section of the top cover of the battery provided in the embodiment of the present application Figure 1 ;

[0025] Figure 5 for Figure 4 A partial enlarged view of point a in the middle;

[0026] Figure 6 A cross section of the top cover of the battery provided in the embodiment of the present application Figure 2 ;

[0027] Figure 7 A circuit diagram of the positive and negative electrodes and aluminum shell of the battery provided in the embodiment of the present application;

[0028] Figure 8 A schematic diagram of a battery pack provided in an embodiment of the present application;

[0029] Fig. 9 A schematic diagram of an energy storage system provided in an embodiment of the present application.

[0030] Description of reference numerals: 10: battery; 11: battery cell; 12: housing; 13: top cover; 14: top cover sheet; 15: positive pole; 16: negative pole; 141: first pole hole; 142: second pole hole; 151: first section; 152: second section; 153: first baffle; 161: second baffle; 171: first sealing ring; 172: second sealing ring; 173: third sealing ring; 174: fourth sealing ring; 175: fifth sealing ring; 191: first sealing ring; 192: second sealing ring; 193: third sealing ring; 1 9a: first annular groove; 19b: first step structure; 19b1: first part; 19b2: second part; 19c: second step structure; 19c1: third part; 19c2: fourth part; 19d: second annular groove; 19e: third annular groove; 18: insulating layer; 181: first accommodating hole; 182: first annular flange; 183: second accommodating hole; 184: second annular groove; 15a: first resistor; 16a: second resistor; 20: battery pack; 30: energy storage system; 31: power converter. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] Please refer to Figure 1 The battery 10 can be applied to electronic devices such as mobile phones and tablet computers, and energy storage devices such as battery packs. The battery 10 includes a battery cell 11, a shell 12, and a top cover 13. The battery cell 11 is arranged in a cavity surrounded by the shell 12. One end (top end) of the shell 12 has an opening, which is connected to the cavity. The top cover 13 is buckled on the opening to close the opening.

[0033] In some related technologies, in an implementation in which the battery 10 includes a lithium-ion battery, when the potential difference between the shell 12 and the negative electrode is lower than the corrosion potential, lithium ions are preferentially embedded in the shell 12 through the electrolyte to produce lithium-intercalated aluminum compounds, that is, lithium-intercalated corrosion occurs in the shell 12. Figure 2 , Figure 2 The potential diagram of lithium aluminum alloy formed by lithium corrosion of the shell 12 is shown in the figure. The horizontal axis represents the valence state of lithium in the lithium aluminum alloy, and the vertical axis represents the voltage. When the potential of the shell 12 to the negative electrode 16 is reduced to about 0.26V, lithium ions will be embedded in the shell 12 to form lithium aluminum alloy, which may easily cause leakage of the shell 12, that is, the corrosion potential is about 0.26V.

[0034] It is understandable that the material of the shell 12 may include aluminum, steel, etc.; the shell 12 may include regular shapes such as a rectangular parallelepiped and a cylindrical shape, and of course the shell 12 may also be in other irregular shapes. The embodiment of the present application does not limit the specific structure of the battery cell 11. For example, a winding core may be used, and a stacked core may also be used. In the implementation mode of the battery cell 11 using a winding core, the winding core generally includes a positive electrode sheet, a negative electrode sheet and a diaphragm, and the diaphragm is sandwiched between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet, the negative electrode sheet and the diaphragm constitute a diaphragm, and the diaphragm is wound or folded to form a winding core. In the implementation mode of the battery cell 11 using a stacked core, the stacked core generally includes a positive electrode sheet, a negative electrode sheet and a diaphragm, and the diaphragm is sandwiched between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet, the negative electrode sheet and the diaphragm constitute a diaphragm, and the diaphragm is folded at least once to form a stacked core. A positive electrode ear is provided on the positive electrode sheet, and a negative electrode ear is provided on the negative electrode sheet. The positive electrode ear and the negative electrode ear are used to supply power to the outside. The diaphragm is used to absorb the electrolyte to ensure that the electrolyte is filled between the positive electrode and the negative electrode.

[0035] In some embodiments, the battery 10 may be a lithium-ion battery, and accordingly, the material of the positive electrode sheet may include at least one of lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, ternary material nickel cobalt manganese oxide, nickel cobalt aluminum oxide, etc., and the material of the negative electrode sheet may include graphite, graphene, etc. The material of the electrolyte may include at least one of propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, lithium tetrafluoroborate, lithium hexafluorophosphate, vinylene carbonate, fluoroethylene carbonate, etc.

[0036] Please refer to Figure 1 and Figure 3 , the top cover 13 of the battery 10 provided in the embodiment of the present application includes a top cover sheet 14, a positive electrode column 15 and a negative electrode column 16. The top cover 13 is used to protect the battery 10 and cover the internal structure of the battery 10 to prevent the battery 10 from being subjected to external collision or wear. The material of the top cover sheet 14 may include metal materials such as steel, iron, aluminum, and copper. It can be understood that the material of the top cover sheet 14 is the same as the material of the shell 12. In the implementation method in which the material of the shell 12 is aluminum, the material of the top cover sheet 14 may also be aluminum. The positive electrode column 15 is used to connect the positive electrode ear, and the negative electrode column 16 is used to connect the negative electrode ear. The battery cell 11 supplies power to the outside through the positive electrode column 15 and the negative electrode column 16. Exemplarily, the materials of the positive electrode column 15 and the negative electrode column 16 may include aluminum, copper, etc. The embodiment of the present application does not limit the materials of the positive electrode column 15 and the negative electrode column 16, as long as the battery cell 11 can supply power to the outside through the positive electrode column 15 and the negative electrode column 16.

[0037] Please refer to Figure 4, a first pole hole 141 is provided on the top cover sheet 14, and the positive electrode column 15 includes a first section 151 and a second section 152. The first section 151 is inserted into the first pole hole 141, and the second section 152 is located outside the first pole hole 141 and the shell 12, that is, located outside the battery 10. The first section 151 is connected to the positive electrode ear to achieve the connection between the positive electrode column and the positive electrode ear, and the second section 152 is used to supply power to the outside. Exemplarily, the first section 151 and the second section 152 can be an integral structure to reduce the difficulty of manufacturing and assembling the top cover 13. Of course, the first section 151 and the second section 152 can also be connected by welding or bolting. The embodiment of the present application is not limited to this, as long as the electrical connection between the first section 151 and the second section 152 is guaranteed. Continue to refer to Figure 3 A second pole hole 142 is also provided on the top cover sheet 14, and the second pole hole 142 is spaced apart from the first pole hole 141. A portion of the negative pole column 16 is passed through the second pole hole 142 to be connected to the negative pole ear, and a portion of the negative pole column 16 extends out of the second pole hole 142 to supply power to the outside.

[0038] It can be understood that the cross-section of the positive electrode column 15 is circular, rectangular, etc., and the cross-section of the first polar hole 141 can be circular, rectangular, etc. The cross-section of the positive electrode column 15 can be the same as or different from the cross-section of the first polar hole 141. In some implementations, the cross-section of the positive electrode column 15 and the cross-section of the first polar hole 141 are both circular, and accordingly, the cross-sectional diameter of the positive electrode column 15 is smaller than the cross-sectional diameter of the first polar hole 141, so that the positive electrode column 15 can be inserted into the first polar hole 141.

[0039] Continue to refer to Figure 4 The top cover 13 also includes a first sealing ring 171 and a second sealing ring 172. The first sealing ring 171 is sleeved on the first section 151, and the first sealing ring 171 is located between the first section 151 and the hole wall of the first pole hole 141. It can be understood that the first sealing ring 171 is located in the gap between the first pole hole 141 and the positive pole column 15 to prevent the electrolyte from overflowing from the first pole hole 141, thereby achieving a sealing effect, improving the sealing performance of the battery top cover 13 and Figure 1 The safety performance of the battery 10 shown in the figure. The second sealing ring 172 is sleeved on the second section 152, and the second sealing ring 172 is in contact with the outer surface of the top cover sheet 14. It can be understood that the second sealing ring 172 is located outside the shell 12, the inner edge of the second sealing ring 172 is in close contact with the second section 152 of the positive electrode column 15, and the lower surface of the second sealing ring 172 is in close contact with the first sealing ring 171 and the outer surface of the top cover sheet 14. The second sealing ring 172 can further achieve sealing between the positive electrode column 15 and the first pole hole 141, further prevent electrolyte overflow, and improve the sealing performance of the top cover 13 and the safety performance of the battery 10.

[0040] In the embodiment of the present application, the resistivity of the first sealing ring 171 is greater than the resistivity of the second sealing ring 172. It should be noted that the resistivity is a 1m long and 1m cross-sectional area made of corresponding materials. 2 The electrical resistance of a conductor at room temperature. It can be understood that, since the resistivity of the first sealing ring 171 is greater than that of the second sealing ring 172, the conductivity of the first sealing ring 171 is worse than that of the second sealing ring 172 and is less likely to be broken down. Figure 4 , the first sealing ring 171 is located between the positive electrode column 15 and the first pole hole 141. It can be understood that the first sealing ring 171 is located at a position where the distance between the positive electrode column 15 and the hole wall of the first pole hole 141 is small, and this position is easy to be broken down. However, the first sealing ring 171 has good insulation and can avoid being broken down, ensuring that there is good insulation between the positive electrode column 15 and the top cover sheet 14. The second sealing ring 172 is located on the outer surface of the top cover sheet 14. The second sealing ring 172 is located at a position where the distance between the positive electrode column 15 and the top cover sheet 14 is large, and this position is not easy to be broken down. The conductivity of the second sealing ring 172 is higher than that of the first sealing ring 171. The positive electrode column 15 and the top cover sheet 14 can be electrically connected through the second sealing ring 172, eliminating the potential difference between the positive electrode column 15 and the shell 12, and preventing the potential difference between the shell 12 and the negative electrode column from being too low, resulting in corrosion of the shell 12 (lithium insertion corrosion).

[0041] In this way, the second sealing ring 172 in the battery 10 provided in the embodiment of the present application has good conductivity, which can eliminate the potential difference between the positive electrode column 15 and the shell 12, and prevent the potential difference between the shell 12 and the negative electrode column 16 from being too low, resulting in lithium corrosion of the shell 12. At the same time, the first sealing ring 171 has good insulation, which can avoid being punctured, and ensure good insulation between the positive electrode column 15 and the top cover sheet 14. In addition, the first sealing ring 171 and the second sealing ring 172 can be used to achieve sealing between the positive electrode column 15 and the first pole hole 141, prevent electrolyte overflow, and improve the sealing performance of the top cover 13 and the safety performance of the battery 10.

[0042] Please refer to Figure 5 In some implementations, a first annular groove 19a is provided on the outer surface of the top cover sheet 14, and the inner diameter of the first annular groove 19a is equal to the aperture of the first pole hole 141. It can be understood that the outer diameter of the first annular groove 19a is greater than the aperture of the first pole hole 141. A first sealing ring 191 is provided on the outer wall of the first sealing ring 171, and the first sealing ring 191 is located in the first annular groove 19a. In this way, the contact area between the top cover sheet 14 and the sealing material (the first sealing ring 171 and the first sealing ring 191) is increased, and the sealing performance of the battery 10 is improved.

[0043] In some implementations, the first sealing ring 191 and the first sealing ring 171 are an integrated structure, and the integrated structure formed by injection molding, stamping, etc. reduces the structural complexity of the top cover 13 and reduces the difficulty of assembly. In addition, the first sealing ring 191 and the first sealing ring 171 of the integrated structure avoid the generation of a gap between the first sealing ring 191 and the first sealing ring 171, further avoiding the positive electrode column 15 and the top cover sheet 14 from being punctured, and avoiding affecting the sealing performance of the battery 10.

[0044] In other implementations, the first sealing ring 191 and the first sealing ring 171 may also be independent structures, and the first sealing ring 191 and the first sealing ring 171 are respectively injection molded and connected together by an adhesive, or the first sealing ring 191 and the first sealing ring 171 are respectively injection molded, and after installation, the first sealing ring 191 and the first sealing ring 171 are in close contact to ensure sealing. It is understandable that the first sealing ring 191 and the first sealing ring 171 can be made of the same material.

[0045] Continue to refer to Figure 5 In some implementations, a first step structure 19b is provided at a position of the first section 151 near the first pole hole 141. A second sealing ring 192 is provided on the inner wall of the first sealing ring 171, and the second sealing ring 192 cooperates with the first step structure 19b. It can be understood that the first step structure 19b causes the side wall of the first section 151 to have a first portion 19b1 and a second portion 19b2 with different diameters, and the diameter of the first portion 19b1 is smaller than the diameter of the second portion 19b2. The second sealing ring 192 corresponds to the shape of the first step structure 19b and fits with the first step structure 19b. In this way, the contact area between the first section 151 and the sealing material (the first sealing ring 171 and the second sealing ring 192) is increased, and the sealing performance of the battery top cover 13 is improved.

[0046] In some implementations, the second sealing ring 192 and the first sealing ring 171 are an integrated structure, and the integrated structure formed by injection molding, stamping, etc. reduces the structural complexity of the top cover 13 and reduces the difficulty of assembly. In addition, the second sealing ring 192 and the first sealing ring 171 of the integrated structure avoid the generation of a gap between the second sealing ring 192 and the first sealing ring 171, further avoiding the positive electrode column 15 and the top cover sheet 14 from being punctured, and avoiding affecting the sealing performance of the battery 10.

[0047] In other implementations, the second sealing ring 192 and the first sealing ring 171 may also be independent structures, and the second sealing ring 192 and the first sealing ring 171 are respectively injection molded and connected together by an adhesive, or the second sealing ring 192 and the first sealing ring 171 are respectively injection molded, and after installation, the second sealing ring 192 and the first sealing ring 171 are in close contact to ensure sealing. It is understandable that the second sealing ring 192 and the first sealing ring 171 can be made of the same material.

[0048] In some embodiments, a first annular groove 19a is provided on the outer surface of the top cover sheet 14, and the inner diameter of the first annular groove 19a is equal to the aperture of the first pole hole 141; and a first step structure 19b is provided at a position of the first section 151 close to the first pole hole 141. Correspondingly, a first sealing ring 191 is provided on the outer wall of the first sealing ring 171, and the first sealing ring 191 is located in the first annular groove 19a, and a second sealing ring 192 is provided on the inner wall of the first sealing ring 171, and the second sealing ring 192 cooperates with the first step structure 19b to further improve the sealing of the battery 10. Exemplarily, the first sealing ring 171, the first sealing ring 191 and the second sealing ring 192 can be an integrated structure to further reduce the structural complexity of the top cover 13.

[0049] Continue to refer to Figure 5 In some implementations, a second step structure 19c is provided at a position of the second section 152 close to the first pole hole 141. A third sealing ring 193 is provided on the inner wall of the second sealing ring 172, and the third sealing ring 193 cooperates with the second step structure 19c. It can be understood that the second step structure 19c causes the side wall of the second section 152 to have a third portion 19c1 and a fourth portion 19c2 with different diameters, and the diameter of the third portion 19c1 is smaller than the diameter of the fourth portion 19c2. The second sealing ring 192 corresponds to the shape of the second step structure 19c and fits with the second step structure 19c. In this way, the contact area between the second section 152 and the sealing material (the second sealing ring 172 and the third sealing ring 193) is increased, and the sealing performance of the battery 10 is further improved.

[0050] It is understandable that in an implementation in which the first step structure 19b is provided on the first section 151, the diameter of the third portion 19c1 may be equal to the diameter of the first portion 19b1 so that the third sealing ring 193 may contact the second sealing ring 192 to further improve the sealing performance.

[0051] In some implementations, the third sealing ring 193 and the second sealing ring 172 are an integrated structure, and the integrated structure formed by injection molding, stamping, etc. reduces the structural complexity of the top cover 13 and reduces the difficulty of assembly. In addition, the third sealing ring 193 and the second sealing ring 172 of the integrated structure avoid the generation of a gap between the third sealing ring 193 and the second sealing ring 172, avoid affecting the connection between the positive electrode column 15 and the top cover sheet 14, and avoid affecting the sealing performance of the battery 10.

[0052] In other implementations, the third sealing ring 193 and the second sealing ring 172 may also be independent structures, and the third sealing ring 193 and the second sealing ring 172 may be connected together by an adhesive after being injection molded separately, or the third sealing ring 193 and the second sealing ring 172 may be injection molded separately, and the third sealing ring 193 and the second sealing ring 172 may be in close contact with each other after installation to ensure sealing. It is understood that the third sealing ring 193 and the second sealing ring 172 may be made of the same material.

[0053] Please refer to Figure 6 A second annular groove 19d is provided on the outer surface of the top cover sheet 14, and the inner diameter of the second annular groove 19d is equal to the aperture of the second pole hole 142. A third annular groove 19e is provided at a position of the negative pole column 16 close to the second pole hole 142. The top cover 13 also includes a fourth sealing ring 174, which is sleeved on the negative pole column 16, a part of the fourth sealing ring 174 is located in the second annular groove 19d, and a part of the fourth sealing ring 174 is located in the third annular groove 19e. In this way, the contact area between the fourth sealing ring 174 and the negative pole column 16 and the top cover sheet 14 is increased, the electrolyte is prevented from overflowing from the second pole hole 142, and the sealing performance of the battery 10 is improved. It can be understood that the material of the fourth sealing ring 174 can be the same as that of the first sealing ring.

[0054] Please refer to Figure 7 , the positive electrode is connected to the housing 12 via the first resistor 15a (second sealing ring 172), and the negative electrode is connected to the housing 12 via the second resistor 16a (fourth sealing ring 174). It can be understood that when the power supply voltage is set to U and the first resistor 15a is set to R P , the second resistor 16a is set to R N In the implementation mode, the voltage of the housing 12 to the negative electrode is (UR N ) / (R P +R N ).

[0055] In some implementations, the resistance value of the first sealing ring 171 is greater than or equal to 10 8 Ω (e.g. 10 8 Ω、2×108Ω、10 9Ω, 10 10 Ω), the resistance value of the second sealing ring 172 is [10Ω-10 5 Ω] (e.g. 10Ω, 10 2 Ω, 10 3 Ω, 10 4 Ω, 10 5 It can be understood that the resistance value of the fourth sealing ring 174 is also greater than or equal to 10 8 Ω (e.g. 10 8 Ω、2×108Ω、10 9 Ω, 10 10 Ω). In this way, the potential difference between the shell 12 and the negative electrode 16 can be prevented from being lower than the corrosion potential, thereby preventing the shell 12 from corroding and leaking.

[0056] In the implementation of the battery 10 being a lithium iron phosphate battery, the battery voltage can be [2.5V-3.65V]. In the implementation of the battery voltage being 2.5V, the resistance value of the first sealing ring 171 being 108Ω, and the resistance value of the second sealing ring 172 being 10Ω, the voltage of the shell 12 to the negative electrode is about 2.5V, which is much greater than the corrosion potential of 0.26V. In the implementation of the battery voltage being 2.5V, the resistance value of the first sealing ring 171 being 108Ω, and the resistance value of the second sealing ring 172 being 10Ω, the voltage of the shell 12 to the negative electrode is about 2.5V, which is much greater than the corrosion potential of 0.26V. 5 In the implementation of Ω, the voltage of the housing 12 to the negative electrode is about 2.5V, which is much larger than the corrosion potential of 0.26V. It can be seen that the resistance value of the first sealing ring 171 is greater than or equal to 10 8 Ω, the resistance value of the second sealing ring 172 is [10Ω-10 5 Ω], which can ensure that the voltage of the shell 12 to the negative electrode is always greater than the corrosion potential to avoid lithium insertion corrosion.

[0057] In some implementations, the first sealing ring 171 may include a polyphenylene sulfide (PPS) ring. In other implementations, the material of the first sealing ring 171 may include PPS and a doping material. It is understood that the material of the doping material can be reasonably selected according to the actual use requirements. For example, the doping material may include an antioxidant to improve the antioxidant capacity of the first sealing ring 171, thereby improving the service life. The embodiment of the present application does not limit the antioxidant. It is understood that the antioxidant may include a phenolic antioxidant and an amine antioxidant. The phenolic antioxidant includes monophenol, bisphenol, triphenol, polyphenol, hydroquinone, thiobisphenol, etc.; the amine antioxidant includes naphthylamine, diphenylamine, p-phenylenediamine and quinoline derivatives, and there are also phosphites, thioesters, etc.

[0058] In some implementations, the second sealing ring 172 includes a polymer ring and a doping structure, the polymer ring includes a PPS ring, the doping structure is doped in the polymer ring, and the resistivity of the doping structure is less than the resistivity of the polymer ring. It can be understood that the conductivity of the doping structure is better than that of the polymer ring, and the conductivity of the second sealing ring 172 can be changed by adding doping structures with different doping ratios.

[0059] In some implementations, the doping structure includes at least one of metal powder, carbon black powder, and conductive fiber. For example, the metal powder may include copper powder, aluminum powder, iron powder, tungsten powder, etc.; the conductive fiber may include carbon black fiber, conductive polymer fiber (e.g., polyacetylene, polyaniline, polypyrrole, polythiophene, etc.); the conductive polymer may include polyacetylene, polyaniline, polypyrrole, polythiophene, etc.

[0060] It is understandable that the higher the doping ratio of the doping structure, the lower the resistance value of the second sealing ring 172 and the better the conductivity. For example, in an implementation with a doping ratio of 50%, the resistance value of the second sealing ring 172 is 10Ω; in an implementation with a doping ratio of 0.001%, the resistance value of the second sealing ring 172 is 10Ω. 5 Ω.

[0061] In some implementations, the first sealing ring 171 and the second sealing ring 172 may be an integrated structure to further simplify the structure of the battery top cover 13 and reduce the difficulty of assembly. Exemplarily, the injection mold has two connected cavities. During injection molding, the material constituting the first sealing ring 171 is injected into one cavity, and the material constituting the second sealing ring 172 is injected into the other cavity to form the first sealing ring 171 and the second sealing ring 172 of the integrated structure.

[0062] In the above implementation, the first sealing ring is a PPS ring, and the polymer ring of the second sealing ring is also a PPS ring, so that the base materials constituting the first sealing ring 171 and the second sealing ring 172 are the same, which can improve the connection force between the first sealing ring 171 and the second sealing ring 172.

[0063] In other implementations, the first sealing ring 171 and the second sealing ring 172 may also be independent structures. For example, during injection molding, the material constituting the first sealing ring 171 is injected into the cavity of one injection mold, and the material constituting the second sealing ring 172 is injected into the cavity of another injection mold to form the first sealing ring 171 and the second sealing ring 172 of independent structures. It is understood that the first sealing ring 171 and the second sealing ring 172 may be connected together by an adhesive or in close contact after installation to ensure sealing.

[0064] Continue to refer to Figure 4In some implementations, the positive electrode column 15 further includes a first baffle 153 located at one end of the first section 151 away from the second section 152, and the first baffle 153 covers the inner surface of the top cover sheet 14, and the positive electrode ear can be connected to the first baffle 153 to achieve electrical connection between the positive electrode ear and the positive electrode column 15. It can be understood that the first baffle 153 and the positive electrode column 15 can be an integral structure to further simplify the structure of the battery top cover 13 and reduce the difficulty of assembly. In other implementations, the first baffle 153 and the positive electrode column 15 can be formed separately by casting or stamping, and then the first baffle 153 and the positive electrode column 15 are connected by welding or bolting. The first baffle 153 can prevent the positive electrode column 15 from moving out of the first pole hole 141.

[0065] Continue to refer to Figure 4 In the above implementation, the top cover sheet 14 further includes a third sealing ring 173, and the third sealing ring 173 is located between the top cover sheet 14 and the first baffle 153. The third sealing ring 173 may include a silicone rubber ring, a nitrile rubber ring, a chloroprene rubber ring, a fluororubber ring, etc. In this way, the third sealing ring 173 is located in the gap between the top cover sheet 14 and the positive electrode column 15 of the first baffle 153, preventing the electrolyte from overflowing from the first electrode hole 141, achieving a sealing effect, and improving the sealing performance of the top cover 13 and Figure 1 The safety performance of the battery 10 is shown.

[0066] Continue to refer to Figure 4 In some implementations, the inner surface of the top cover sheet is covered with an insulating layer 18. It is understandable that the material of the insulating layer 18 may include plastics such as polyethylene, polypropylene, and polystyrene. In this way, the insulating layer 18 can prevent the electrolyte from contacting the bottom of the top cover sheet 14, thereby improving the sealing performance of the battery top cover 13. A first receiving hole 181 connected to the first pole hole 141 is provided on the insulating layer 18, and the third sealing ring 173 is located in the first receiving hole 181. In this way, the first receiving hole 181 can fix the position of the third sealing ring 173, so that the third sealing ring 173 is close to the top cover sheet 14 and the first baffle 153, which can further improve the sealing performance of the battery 10.

[0067] In some implementations, a first annular flange 182 is provided on the insulating layer 18, and the first annular flange 182 is arranged outside the first baffle 153 and contacts the first baffle 153. In this way, the first annular flange 182 is in close contact with the outer surface of the first baffle 153, which can fix the position of the first baffle 153 and the positive electrode column 15, prevent the first baffle 153 from contacting the top cover sheet 14, and avoid short circuit of the battery 10. Exemplarily, the first annular flange 182 and the insulating layer 18 can be an integral structure to simplify the structure of the top cover 13.

[0068] Continue to refer to Figure 6, the negative electrode column 16 also includes a second baffle 161, which is located at one end of the negative electrode column 16 away from the outside of the battery 10. The second baffle 161 covers the inner surface of the top cover sheet 14, and the negative electrode ear can be connected to the second baffle 161 to achieve electrical connection between the negative electrode ear and the negative electrode column 16. It can be understood that the second baffle 161 and the negative electrode column 16 can be an integral structure to further simplify the structure of the battery top cover 13 and reduce the difficulty of assembly. In other implementations, the second baffle 161 and the negative electrode column 16 can be formed separately by casting or stamping, and then the second baffle 161 and the negative electrode column 16 are connected by welding or bolting. The second baffle 161 can prevent the negative electrode column 16 from moving out of the second pole hole 142.

[0069] Continue to refer to Figure 6 The top cover sheet 14 further includes a fifth sealing ring 175, which is located between the top cover sheet 14 and the second baffle 161. The material of the fifth sealing ring 175 can be the same as that of the third sealing ring 173. In this way, the fifth sealing ring 175 is located in the gap between the top cover sheet 14 and the second baffle 161 and the negative electrode column 16, preventing the electrolyte from overflowing from the second electrode hole 142, achieving a sealing effect, and improving the sealing performance of the top cover 13. Figure 1 The safety performance of the battery 10 is shown.

[0070] Continue to refer to Figure 6 The insulating layer 18 is provided with a second receiving hole 183 communicating with the second pole hole 142, and the fifth sealing ring 175 is located in the second receiving hole 183. In this way, the second receiving hole 183 can fix the position of the fifth sealing ring 175, so that the fifth sealing ring 175 is closely attached to the top cover sheet 14 and the second blocking sheet 161, which can further improve the sealing performance of the battery 10.

[0071] In some implementations, a second annular flange 184 is provided on the insulating layer 18, and the second annular flange 184 is wound around the second baffle 161 and contacts the second baffle 161. In this way, the second annular flange 184 is in close contact with the outer surface of the second baffle 161, which can fix the position of the second baffle 161 and the negative electrode column 16, and prevent the second baffle 161 from contacting the top cover sheet 14, resulting in too low a potential difference between the negative electrode and the shell 12, causing corrosion of the shell 12. Exemplarily, the second annular flange 184 and the insulating layer 18 can be an integral structure to simplify the structure of the top cover 13.

[0072] Please refer to Figure 8 The embodiment of the present application further provides a battery pack 20, including a plurality of batteries 10, wherein the plurality of batteries 10 are connected in series or in parallel. It is understood that the voltage of the battery pack 20 can be adjusted by changing the connection mode between the batteries 10.

[0073] Please refer to Fig. 9 The embodiment of the present application further provides an energy storage system 30 , which includes a power converter 31 and a battery pack 20 , wherein the power converter 31 is used to convert the power output by an external power source and output it to the battery pack 20 .

[0074] It should be noted that in the description of the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, or an integral connection; it can also be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled 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.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized in that: It comprises a battery cell, a shell and a top cover, wherein the battery cell is arranged inside the shell, the shell has an opening, and the top cover is buckled on the opening; The top cover comprises: A top cover sheet, wherein the top cover sheet is provided with a first pole hole; A positive electrode column, the positive electrode column comprising a first section and a second section, the first section is inserted into the first electrode hole, and the second section is located outside the first electrode hole and the shell; A first sealing ring, wherein the first sealing ring is sleeved on the first section and is located between the first section and the hole wall of the first pole hole; a second sealing ring, wherein the second sealing ring is sleeved on the second section and contacts with an outer surface of the top cover sheet; The resistivity of the first sealing ring is greater than the resistivity of the second sealing ring.

2. The battery according to claim 1, characterized in that A first annular groove is arranged on the outer surface, the inner diameter of the first annular groove is equal to the aperture of the first pole hole, a first sealing ring is arranged on the outer wall of the first sealing ring, and the first sealing ring is located in the first annular groove.

3. The battery according to claim 2, characterized in that The first sealing ring and the first sealing ring are an integral structure.

4. The battery according to any one of claims 1 to 3, characterized in that: A first step structure is provided at a position of the first section close to the first pole hole, a second sealing ring is provided on an inner wall of the first sealing ring, and the second sealing ring cooperates with the first step structure.

5. The battery according to claim 4, characterized in that The second sealing ring and the first sealing ring are an integral structure.

6. The battery according to any one of claims 1 to 3, characterized in that: A second step structure is provided at a position of the second section close to the first pole hole, a third sealing ring is provided on the inner wall of the second sealing ring, the third sealing ring and the second sealing ring are an integral structure, and the third sealing ring cooperates with the second step structure.

7. The battery according to any one of claims 1 to 3, characterized in that: The resistance value of the first sealing ring is greater than or equal to 10 8 Ω, the resistance value of the second sealing ring is [10Ω-10 5 Ω].

8. The battery according to any one of claims 1 to 3, characterized in that: The second sealing ring includes a polymer ring and a doping structure, wherein the doping structure is doped in the polymer ring, and the resistivity of the doping structure is lower than the resistivity of the polymer ring.

9. The battery according to claim 8, characterized in that The polymer ring includes a polyphenylene sulfide ring, and the doping structure includes at least one of metal powder, carbon black powder, and conductive fiber.

10. The battery according to any one of claims 1 to 3, characterized in that: The first sealing ring and the second sealing ring are an integrated structure.

11. The battery according to any one of claims 1 to 3, characterized in that: The positive electrode column also includes a first blocking piece located at one end of the first section away from the second section, and the first blocking piece covers the inner surface of the top cover sheet; the top cover sheet also includes a third sealing ring, and the third sealing ring is located between the top cover sheet and the first blocking piece.

12. The battery according to claim 11, characterized in that The inner surface is covered with an insulating layer, a first accommodating hole communicating with the first pole hole is arranged on the insulating layer, the aperture of the first accommodating hole is larger than the aperture of the first pole hole, and the third sealing ring is located in the first accommodating hole.

13. The battery according to claim 12, characterized in that A first annular flange is arranged on the insulating layer, and the first annular flange is arranged around the outside of the first blocking piece and is in contact with the first blocking piece.

14. A battery pack, characterized in that: The method comprises a plurality of batteries according to any one of claims 1 to 13, wherein the plurality of batteries are connected in series or in parallel.

15. An energy storage system, characterized in that: It comprises a battery pack and a power converter as described in claim 14, wherein the power converter is used to convert the power output by an external power source and output it to the battery pack.

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