Secondary battery, battery pack, and electronic device

Abstract

The utility model provides a secondary battery, a battery pack and an electronic device. The secondary battery comprises a shell, an electrode assembly, a pole and an insulating sealing element, the shell comprises an end wall and a side wall surrounding the end wall, a pole hole is formed in the end wall, and electrolyte is contained in the shell; the electrode assembly is arranged in the shell; the pole penetrates through the pole hole, is fixed on the end wall in an insulating manner and is electrically connected with the electrode assembly; the insulating sealing element surrounds the pole and is at least partially positioned between the electrode assembly and the end wall; a sealing structure is arranged between the edge of the insulation sealing piece and the shell, the sealing structure, the insulation sealing piece and the shell define a sealing area, and the sealing area is isolated from the electrolyte; the technical problem of continuous concentrated corrosion of the free electrolyte on the shell can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery technical field, concretely relates to a secondary battery, battery pack and electronic device. BACKGROUND

[0002] Large cylindrical batteries are widely used in new energy vehicles, energy storage power stations, electric tools and high-end consumer electronics due to their simple structure, good heat dissipation performance, high energy density and ease of mass production.

[0003] The shell of the large cylindrical battery usually adopts a pre-plated nickel electroplating process. Before stamping, a low-carbon steel strip is deposited with a nickel layer through electroplating and annealed to make the nickel layer tightly combined with the steel strip, facilitating processing. However, the electroplated nickel layer has poor resistance to electrolyte corrosion, and free electrolyte can enter the gap between the shell and the insulating sealing element, causing persistent and concentrated corrosion of the shell. Ni 2 + and Fe2+ in the corrosion products are easy to enter the inside of the electrode assembly, depositing Ni and Fe on the negative electrode plate, causing self-discharge, affecting battery performance and life, and posing a safety hazard. SUMMARY

[0004] The utility model provides a secondary battery, battery pack and electronic device to improve the technical problem that free electrolyte causes persistent and concentrated corrosion of the shell.

[0005] To achieve the above-mentioned and other related purposes, the utility model provides a secondary battery, battery pack and electronic device, which comprises a shell, an electrode assembly, a pole and an insulating sealing element; the shell comprises an end wall and a side wall surrounding the end wall, the end wall is provided with a pole hole, and the shell contains electrolyte; the electrode assembly is arranged in the shell; the pole penetrates the pole hole and is insulatively fixed to the end wall, and the pole is electrically connected with the electrode assembly; the insulating sealing element surrounds the pole and is at least partially located between the electrode assembly and the end wall; a sealing structure is arranged between the edge of the insulating sealing element and the shell, the sealing structure, the insulating sealing element and the shell enclose a sealed area, and the sealed area is isolated from the electrolyte.

[0006] In the above technical solution, the insulating sealing element surrounds the pole and is located between the electrode assembly and the end wall to isolate the electrode assembly and the end wall. A sealing structure is arranged between the insulating sealing element and the shell, the sealing structure, the insulating sealing element and the shell enclose a sealed area, and the sealed area is isolated from the electrolyte. This can isolate the electrolyte from the gap between the shell and the insulating sealing element. It can alleviate the persistent and concentrated corrosion of the shell at the above-mentioned gap caused by free electrolyte, reduce the occurrence of battery self-discharge, and thus improve battery performance and life and reduce safety hazards.

[0007] In an example of the secondary battery of the utility model, the insulating sealing element and the side wall are in interference fit.

[0008] In the technical solution, the extrusion seal is formed by the interference fit between the insulating seal and the side wall. The technical solution does not increase new parts and assembly processes, and achieves the effect of blocking the electrolyte from entering the gap between the end wall and the insulating seal. The continuous and concentrated corrosion of the electrolyte on the shell is alleviated, the battery performance and service life are improved, and the safety hazard is reduced.

[0009] In the secondary battery example of the utility model, the secondary battery further includes a current collecting member, the current collecting member is electrically connected with the electrode assembly and located between the electrode assembly and the insulating seal, the current collecting member includes a first protrusion arranged on one side facing the insulating seal, and / or the insulating seal includes a second protrusion on one side facing the current collecting member, the first protrusion is pressed against the insulating seal, and the second protrusion is pressed against the current collecting member.

[0010] In the technical solution, the first protrusion is arranged on the current collecting member and / or the second protrusion is arranged on the insulating seal, and the first protrusion is pressed against the insulating seal and the second protrusion is pressed against the current collecting member. The first protrusion and the second protrusion can both support the insulating seal to prevent the insulating seal from sagging or loosening and causing sealing failure.

[0011] In the secondary battery example of the utility model, the compression rate of the insulating seal at the position pressed by the first protrusion and the second protrusion is greater than 30% and less than 50%.

[0012] In the technical solution, the compression rate of the insulating seal at the position pressed by the first protrusion and the second protrusion is limited to be greater than 30%, which is beneficial to increase the contact pressure of the insulating seal and more effectively prevent the insulating seal from sagging or loosening and causing sealing failure. The compression rate is limited to be less than 50%, which can limit the contact pressure of the insulating seal to prevent the insulating seal from generating excessive rebound force and causing the fixed connection between the current collecting member and the pole to fail.

[0013] In the secondary battery example of the utility model, a sealing ring is arranged between the edge of the insulating seal and the shell.

[0014] In the technical solution, the sealing is achieved by arranging the sealing ring, which achieves the effect of blocking the electrolyte from entering the gap between the end wall and the insulating seal. The sealing ring can independently play its sealing role, so that the balance between strength and sealing performance is not needed. This design allows the sealing ring to be made of high-compression fluororubber or other materials with better sealing effect, thereby significantly improving the sealing performance.

[0015] In the secondary battery example of the utility model, the sealing ring is arranged on the outer circumferential edge of the side of the insulating sealing element facing the electrode assembly, the sealing ring comprises a first bending part and a second bending part which are connected by bending, the first bending part is clamped between the insulating sealing element and the side wall, and the second bending part is located on the side of the insulating sealing element facing the electrode assembly.

[0016] In the above technical solution, the sealing ring is arranged in an annular bending structure, the first bending part and the second bending part which are connected by bending can play the role of mutual limiting, thereby reducing the assembly difficulty.

[0017] In the secondary battery example of the utility model, the sealing ring is arranged between the insulating sealing element and the end wall, the insulating sealing element comprises a groove around the pole which is arranged on the side facing the end wall, one end of the sealing ring is embedded in the groove, and the other end is pressed against the end wall.

[0018] In the above technical solution, the sealing ring is arranged between the end wall and the insulating sealing element, and the sealing element is pressed against the end wall by the insulating sealing element and the end wall to realize sealing.

[0019] In the secondary battery example of the utility model, the sealing ring is fixedly connected with the insulating sealing element.

[0020] In the above technical solution, the sealing ring and the insulating sealing element are first fixed, and then assembled into the shell.

[0021] In the secondary battery example of the utility model, the insulating sealing element and the side wall are fixedly connected through ultraviolet curing glue.

[0022] In the above technical solution, the ultraviolet curing glue is in a liquid state when being injected into the gap between the insulating sealing element and the side wall, and then the ultraviolet curing glue is cured through ultraviolet rays.

[0023] The utility model also provides a battery pack, and the battery pack comprises the secondary battery of any one of the above.

[0024] The utility model also provides an electronic device, and the electronic device comprises the battery pack.

[0025] The utility model discloses secondary battery, insulating seal piece surrounds the pole, and is located between electrode assembly and end wall to insulate electrode assembly and end wall. There is sealing structure between insulating seal piece and shell, and sealing structure, insulating seal piece and shell enclose the sealed area, and the sealed area is isolated with electrolyte. Can realize the electrolyte isolation in the shell and the crack of insulating seal piece. Can alleviate the free electrolyte to the shell of the crack place and produce the persistent concentrated corrosion, reduce the occurrence of battery self -discharge, and then improve the battery performance and life, reduce the security hidden danger. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, below will to the drawing needed to use in the embodiment or prior art description simple introduction, obviously, below description in the drawing only some embodiments of the utility model, for the ordinary skilled person in the art comes, under the premise of not paying the creative labor, can also obtain other embodiments according to these drawings.

[0027] Figure 1 It is the whole structure schematic diagram of secondary battery one example of the utility model;

[0028] Figure 2 It is electrode assembly structure schematic diagram of secondary battery one example of the utility model;

[0029] Figure 3 It is Figure 1 The partial close-up view of A in the comparative example;

[0030] Figure 4 It is Figure 3 The partial close-up view of B;

[0031] Figure 5 It is Figure 1 The partial close-up view of A in one example;

[0032] Figure 6 It is Figure 5 The partial close-up view of C;

[0033] Figure 7 It is Figure 1 The partial close-up view of A in one example;

[0034] Figure 8 It is Figure 7 The partial close-up view of D;

[0035] Figure 9 It is Figure 1 The partial close-up view of A in one example;

[0036] Figure 10 It is Figure 9 The partial close-up view of E;

[0037] Figure 11 For Figure 1 A local enlarged view at A in an example;

[0038] Figure 12 For Figure 11 A local enlarged view at F;

[0039] Figure 13 For Figure 1 A local enlarged view at A in an example;

[0040] Figure 14 For Figure 13 A local enlarged view at G;

[0041] Figure 15 A schematic view of an example of the battery pack of the present application;

[0042] Figure 16 A schematic view of an example of the electronic device of the present application.

[0043] Element number explanation:

[0044] 1, electronic device; 10, battery pack; 11, working part; 101, box body; 102, box cover; 100, secondary battery; 110, shell; 111, end wall; 1111, pole hole; 112, side wall; 113, opening; 120, electrode assembly; 121, positive pole piece; 1211, positive pole current collector; 1212, first coating area; 1213, first non-coating area; 122, diaphragm; 123, negative pole piece; 1231, negative pole current collector; 1232, second coating area; 1233, second non-coating area; 124, negative pole lug; 125, positive pole lug; 130, end cover; 140, pole; 150, insulating sealing piece; 151, second protrusion; 152, groove; 160, sealing structure; 161, first sealing ring; 1611, first bending part; 1612, second bending part; 162, second sealing ring; 170, current collecting member; 171, first protrusion. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present application. The present application can also be implemented or applied through different specific embodiments, and the details in the present application can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present application are used to describe specific specific embodiments, but not to limit the protection scope of the present application. The test methods not specified in the following embodiments are usually performed under conventional conditions or under the conditions recommended by the manufacturers.

[0046] When the embodiments give a numerical range, it should be understood that, unless otherwise stated by the present application, each numerical range of two endpoints and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application are used by those skilled in the art and the present application, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present application can be used to realize the present application.

[0047] It should be understood that the terms such as "up", "down", "left", "right", "middle" and "one" in the present application are only for the convenience of clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship is also considered as the scope of the present application without substantial change of the technical content.

[0048] The secondary battery includes an electrode assembly, which is a component in which an electrochemical reaction occurs in the secondary battery, and can include one or more electrode assemblies.

[0049] The secondary battery further includes a case, an end cover and a pole, the case includes an end wall and a side wall surrounding the end wall, one end of the side wall has an opening, the electrode assembly can be assembled into the case through the opening of the case, the end cover is used to cover the opening of the case to achieve sealing, and the pole is electrically connected with the electrode assembly through the end wall to guide the electrical energy generated by the electrode assembly out.

[0050] In some related technologies, the shell adopts a pre-plated electroplated nickel process, and a low-carbon steel strip is plated with a nickel layer before stamping and is annealed for heat treatment to make the nickel layer tightly combined with the steel strip, facilitating processing. In order to reduce the risk of short circuit, it is necessary to insulate the pole and the end wall, and to insulate the electrode assembly and the end wall. Usually, an insulating piece is arranged between the pole and the end wall, and the insulating piece is at least partially located between the pole and the end wall to insulate the pole and the end wall, and extends along the radial direction of the end wall to the side wall to insulate the electrode assembly and the end wall. However, the inventors have found that the electroplated nickel layer has poor resistance to electrolyte corrosion, and there is a gap between the insulating sealing piece and the end wall. Free electrolyte can enter the gap between the shell and the insulating sealing piece, causing continuous and concentrated corrosion of the shell. Ni 2 + and Fe2+ in the corrosion products are easy to enter the inside of the electrode assembly, depositing Ni and Fe on the negative electrode plate, causing self-discharge, affecting the performance and life of the battery, and also posing a safety hazard.

[0051] In view of this, the utility model provides a technical scheme, a sealing structure is arranged between the insulating sealing piece and the shell, the sealing structure, the insulating sealing piece and the shell enclose a sealed area, and the sealed area is isolated from the electrolyte. The electrolyte can be isolated outside the gap between the shell and the insulating sealing piece. The continuous and concentrated corrosion of the shell at the gap by the free electrolyte can be alleviated, the occurrence of self-discharge of the battery can be reduced, the performance and life of the battery can be improved, and the safety hazard can be reduced.

[0052] Please refer to Figures 1 to 16 The utility model provides a secondary battery 100, the secondary battery 100 includes shell 110, electrode assembly 120, pole 140 and insulating sealing piece 150.

[0053] Please refer to Figure 1The shell 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111, the end wall 111 is provided with a pole hole 1111, and the shell 110 contains electrolyte. The connection between the end wall 111 and the side wall 112 can be achieved in various ways, such as one-piece stamping, one-piece casting or separate welding, as long as a stable sealing and electrical connection relationship can be formed. The surrounding of the side wall 112 is not limited, which can be cylindrical or prismatic, or can be any other closed loop profile that can match the end wall 111. In the embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 is cylindrical and surrounds the outer edge of the end wall 111, and a circular opening 113 is formed at one end of the side wall 112 away from the end wall 111. The shell 110 surrounded by the end wall 111 and the side wall 112 forms a containing cavity for containing the electrode assembly 120, electrolyte and other necessary components of the battery. Specifically, the diameter of the shell 110 can be determined according to the specific size of the electrode assembly 120, such as 18mm, 21mm, 46mm, etc. The material of the shell 110 can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. In order to prevent rusting of the shell 110 during long-term use, a layer of anti-rust material such as metal nickel can be plated on the surface of the shell 110.

[0054] Please refer to Figures 1 to 2 The electrode assembly 120 is arranged inside the shell 110, and the electrode assembly 120 is a component that generates an electrochemical reaction in the secondary battery 100. The shell 110 can contain one or more electrode assemblies 120. The electrode assembly 120 includes a pole piece and a diaphragm 122, which are wound to form a winding structure. Specifically, in the embodiment, the electrode assembly 120 includes a positive pole piece 121, a diaphragm 122 and a negative pole piece 123 wound axially around the shell 110.

[0055] Please refer to Figures 1 to 2 The positive pole piece 121 includes a positive current collector 1211 and a positive active material layer coated on the positive current collector 1211, and a first coated area 1212 coated with the positive active material layer and a first uncoated area 1213 not coated with the positive active material layer are formed on the positive current collector 1211. The first coated area 1212 and the first uncoated area 1213 are arranged axially along the shell 110, the first uncoated area 1213 extends to the outside of the diaphragm 122 at one end of the secondary battery 100 in the height direction, and is bent towards the axis of the shell 110 to form a stacked positive tab 125.

[0056] Please refer to Figures 1 to 2The negative electrode sheet 123 includes a negative electrode current collector 1231 and a negative electrode active material layer coated on the negative electrode current collector 1231, and a second coated area 1232 coated with the negative electrode active material layer and a second uncoated area 1233 not coated with the negative electrode active material layer are formed on the negative electrode current collector 1231, the second coated area 1232 and the second uncoated area 1233 are arranged axially along the shell 110, the second uncoated area 1233 extends to the outside of the diaphragm 122 towards the other end of the height direction of the secondary battery 100, and is bent towards the axis of the shell 110 to form a stacked negative electrode tab 124.

[0057] Referring to Figures 1 to 2 The diaphragm 122 is arranged between the positive electrode sheet 121 and the negative electrode sheet 123 to separate the positive electrode active material layer and the negative electrode active material layer. Taking the lithium ion secondary battery 100 as an example, the material of the positive electrode current collector 1211 can be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The material of the negative electrode current collector 1231 can be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. The base material of the diaphragm 122 can be polypropylene (PP) or polyethylene (PE), etc. In order to protect and insulate the battery cell, an insulating film can be wrapped outside the battery cell, and the insulating film can be synthesized by PP, PE, polyethylene terephthalate (PET), polyvinyl chloride (PVC), or other high polymer materials.

[0058] Referring to Figure 1 and Figure 2 Further, in the utility model, the positive electrode tab 125 faces the end wall 111 or the opening 113, and the negative electrode tab 124 faces the other end of the shell 110. In the embodiment, the positive electrode tab 125 faces the end wall 111 and is electrically connected with the pole 140 to make the pole 140 positively charged, and the negative electrode tab 124 faces the opening 113 and is electrically connected with the shell 110 to be negatively charged. However, in another embodiment, the negative electrode tab 124 can be connected with the pole 140, and the positive electrode tab 125 can be connected with the shell 110.

[0059] Referring to Figure 5The pole 140 penetrates the pole hole 1111 and is fixed to the end wall 111 in an insulating manner. The pole 140 is electrically connected to the electrode assembly 120. Specifically, the end of the pole 140 that is directed towards the electrode assembly 120 is directly or indirectly electrically connected to the positive electrode tab 125 by penetrating the end wall 111. The pole 140 can have any suitable form that allows it to be electrically connected to the positive electrode tab 125 of the electrode assembly 120, such as a circular, square, prismatic or any other suitable cross-section that allows stable electrical conduction. The pole hole 1111 corresponds to the shape of the pole 140. In the present embodiment, the pole 140 has a circular cross-section.

[0060] Referring to Figure 3 and Figure 5 , in order to reduce the risk of short circuit, an insulating seal 150 is provided to insulate the electrode assembly 120 and the end wall 111. The insulating seal 150 surrounds the pole 140 and is at least partially located between the electrode assembly 120 and the end wall 111. In some embodiments, the insulating seal 150 is only provided between the electrode assembly 120 and the end wall 111, as long as it can achieve the effect of insulating the electrode assembly 120 and the end wall 111. In other embodiments, the insulating seal 150 includes a first portion provided between the electrode assembly 120 and the end wall 111 and a portion provided between the end wall 111 and the pole 140, which can simultaneously achieve the insulating effect of the electrode assembly 120 and the end wall 111 and the end wall 111 and the pole 140. The material of the insulating seal 150 can be any one of soluble polytetrafluoroethylene (PFA), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), PP, polyphenylene sulfide (PPS) and polycarbonate (PC), without being limited thereto.

[0061] Referring to Figure 1 , the end cover 130 is sealingly mounted to the opening 113. The outer edge of the end cover 130 corresponds to the shape of the opening 113 and is connected to the side wall 112 to seal the opening 113. The mounting method of the end cover 130 includes but is not limited to mechanical sealing or welding sealing. In the present embodiment, the end cover 130 is sealingly mounted to the opening 113 by mechanical sealing.

[0062] Referring to Figure 3 and Figure 4 , Figure 3 is Figure 1 a partial enlarged view of A in the comparative example, Figure 4 isFigure 3 The local enlarged view at the middle B, there is a gap between the insulation seal 150 and the end wall 111, the free electrolyte can enter the gap between the shell 110 and the insulation seal 150, and the shell 110 is continuously concentratedly corroded. The Ni 2 + and Fe2+ in the corrosion product are easy to enter the inside of the electrode assembly 120, deposit Ni and Fe on the negative electrode plate 123, cause self-discharge, affect the performance and life of the battery, and there is a safety hazard.

[0063] Please refer to Figures 5 to 14 In an example of the secondary battery 100 of the utility model, a sealing structure 160 is arranged between the edge of the insulation seal 150 and the shell 110, and the sealing structure 160 can be of various types, for example, interference fit sealing, sealing gasket sealing or sealing glue sealing, and the like, which are not limited. As long as the sealing structure 160, the insulation seal 150 and the shell 110 can form a sealed area, and the sealed area can be isolated from the electrolyte.

[0064] In the above technical solution, the sealing structure 160 is arranged between the insulation seal 150 and the shell 110, the sealing structure 160, the insulation seal 150 and the shell 110 form a sealed area, and the sealed area is isolated from the electrolyte. The electrolyte can be isolated outside the gap between the shell 110 and the insulation seal 150. The continuous and concentrated corrosion of the shell 110 at the gap by the free electrolyte can be alleviated, the occurrence of battery self-discharge can be reduced, and the performance and life of the battery can be improved, and the safety hazard can be reduced.

[0065] Please refer to Figures 5 to 8 In an example of the secondary battery 100 of the utility model, the insulation seal 150 and the side wall 112 are interference fit. The extrusion sealing is formed by the interference fit between the insulation seal 150 and the side wall 112. The technical solution does not increase new parts and assembly process, and achieves the effect of blocking the electrolyte from entering the gap between the end wall 111 and the insulation seal 150. The continuous and concentrated corrosion of the shell 110 by the free electrolyte is alleviated, the performance and life of the battery are improved, and the safety hazard is reduced.

[0066] Please refer to Figure 1In the secondary battery 100 example, in order to improve the connection effect and yield between the pole post 140 and the electrode assembly 120, the secondary battery 100 further comprises a current collecting member 170, the current collecting member 170 is electrically connected with the electrode assembly 120, so as to realize the switching electrical connection between the pole post 140 and the electrode assembly 120 through the current collecting member 170. The material of the current collecting member 170 is selected according to the polarity of the pole piece connected therewith, for example, if the current collecting member 170 is connected with the positive pole piece 121, the current collecting member 170 can be selected as aluminum metal, if the current collecting member 170 is connected with the negative pole piece 123, the current collecting member 170 can be selected as copper metal. The current collecting member 170 in the embodiment is connected with the positive pole piece 121, so the current collecting member 170 is selected as aluminum metal. The shape and structure of the current collecting member 170 are not limited, and the stable and reliable electrical connection relationship can be realized.

[0067] Please refer to Figure 6 , Figure 8 , Figure 10 and Figure 12 , the current collecting member 170 is located between the electrode assembly 120 and the insulating sealing member 150, the current collecting member 170 comprises a first protrusion 171 arranged on one side facing the insulating sealing member 150, and / or the insulating sealing member 150 comprises a second protrusion 151 arranged on one side facing the current collecting member 170. For example, in an embodiment, please refer to Figure 8 , the first protrusion 171 is arranged on one side of the current collecting member 170 facing the insulating sealing member 150. In another embodiment, please refer to Figure 6 , Figure 10 and Figure 12 , the second protrusion 151 is arranged on one side of the insulating sealing member 150 facing the current collecting member 170. In still another embodiment, the first protrusion 171 is arranged on one side facing the insulating sealing member 150, and the second protrusion 151 is arranged on one side facing the current collecting member 170. The first protrusion 171 is pressed against the insulating sealing member 150, and the second protrusion 151 is pressed against the current collecting member 170. Both the first protrusion 171 and the second protrusion 151 can support the insulating sealing member 150, so as to prevent the insulating sealing member 150 from sagging or loosening and causing sealing failure.

[0068] Please refer to Figure 6 , Figure 8 , Figure 10 and Figure 12In the secondary battery 100 example of the utility model, the compression rate of the insulating sealing piece 150 under the pressure of the position of the first protrusion 171 and the second protrusion 151 is greater than 30% and less than 50%. The compression rate of the insulating sealing piece 150 under the pressure of the position of the first protrusion 171 and the second protrusion 151 is limited to be greater than 30%, which is conducive to increasing the contact pressure of the insulating sealing piece 150 and preventing the insulating sealing piece 150 from sagging or loosening to cause sealing failure. The compression rate is limited to be less than 50%, which can limit the contact pressure of the insulating sealing piece 150 to prevent the insulating sealing piece 150 from generating excessive rebound force, causing the fixed connection between the current collecting member 170 and the pole 140 to fail.

[0069] Please refer to Figures 9 to 12 In the secondary battery 100 example of the utility model, a sealing ring is arranged between the edge of the insulating sealing piece 150 and the shell 110. The sealing ring is made of any one of silicone, fluororubber, EPDM or thermoplastic elastomer, and the like, without limitation. The sealing ring is used to achieve sealing, which can prevent electrolyte from entering the gap between the end wall 111 and the insulating sealing piece 150. The sealing ring can independently play its sealing role, so that the balance between strength and sealing performance is not required. This design allows the sealing ring to be made of fluororubber with high compression rate and better sealing effect, thereby significantly improving the sealing performance.

[0070] Please refer to Figures 9 to 10 In the secondary battery 100 example of the utility model, the sealing ring is arranged on the outer periphery of the side of the insulating sealing piece 150 facing the electrode assembly 120. In order to distinguish from other embodiments, the sealing ring in this embodiment is defined as a first sealing ring 161, which includes a first bending part 1611 and a second bending part 1612 connected by bending. The first bending part 1611 is clamped between the insulating sealing piece 150 and the side wall 112, and the second bending part 1612 is located on the side of the insulating sealing piece 150 facing the electrode assembly 120. The first sealing ring 161 is arranged in an annular bending structure, and the first bending part 1611 and the second bending part 1612 connected by bending can limit each other, reducing the assembly difficulty. The first sealing ring 161 of this structure increases the contact area with the insulating sealing piece 150, and has better sealing effect.

[0071] Please refer to Figures 11 to 12In the secondary battery 100 example of the utility model, in order to distinguish from other embodiments, the sealing ring in this embodiment is defined as the second sealing ring 162, the second sealing ring 162 is arranged between the insulating sealing member 150 and the end wall 111, the insulating sealing member 150 includes the groove 152 that is arranged to the one side of facing the end wall 111 and surrounds the pole 140, one end of the second sealing ring 162 is embedded in the groove 152, and the other end is pressed against the end wall 111.The second sealing ring 162 is arranged between the end wall 111 and the insulating sealing member 150, and the sealing member is pressed tightly by the insulating sealing member 150 and the end wall 111 to realize sealing.The second sealing ring 162 does not occur assembly interference with the shell 110 when entering the shell, facilitating the entry into the shell, and reducing the assembly difficulty.In addition, the groove 152 can realize the positioning of the sealing ring in the radial direction, one end of the second sealing ring 162 is embedded in the groove 152, and the other end is pressed against the end wall 111, improving the sealing performance.

[0072] In the secondary battery 100 example of the utility model, the sealing ring (including the first sealing ring 161 and the second sealing ring 162) is fixedly connected with the insulating sealing member 150.The sealing ring and the insulating sealing member 150 are first fixed, and then assembled into the shell.The sealing ring and the insulating sealing member 150 can be fixed in various ways, such as heating and pressing, embedded fixing or adhesive fixing, which are not limited.The setting can prevent the sealing ring from falling off or misplacing due to interference during assembly into the shell.Further, the assembly time is reduced, and the sealing effect of the sealing ring is improved.

[0073] Please refer to Figures 13 to 14 In the secondary battery 100 example of the utility model, the insulating sealing member 150 and the side wall 112 are fixedly connected by ultraviolet curing adhesive.The ultraviolet curing adhesive is in liquid state when injected into the gap between the insulating sealing member 150 and the side wall 112, and then the ultraviolet curing adhesive is cured by ultraviolet rays.The sealing method has good sealing effect and simple assembly.Further, the assembly efficiency is improved, and the sealing effect is improved.

[0074] Please refer to Figure 15 The utility model also provides a battery pack 10, the battery pack 10 includes any one of the secondary battery 100, in the utility model battery pack 10 one embodiment, the battery pack 10 includes box 101, box cover 102 and multiple secondary batteries 100, multiple secondary batteries 100 are placed in box 101, and are in series or parallel with each other, or series and parallel hybrid, and the box cover 102 is capped on the box 101 to protect multiple secondary batteries 100.It needs to be explained that the battery pack 10 can also include the battery pack 10 thermal management system, circuit board and other parts in addition to the secondary battery 100 of the utility model, and the battery pack 10 can be a battery module or a battery pack, and can be an energy storage cabinet, which will not be described one by one here.

[0075] Please refer toFigure 16 The utility model further provides an electronic device 1, electronic device 1 includes the battery pack 10 of above-mentioned. Work department 11 is electrically connected with battery pack 10 to obtain the electric energy support. As an example, electronic device 1 is vehicle, and vehicle can be fuel automobile, gas automobile or new energy automobile, and new energy automobile can be pure electric vehicle, hybrid vehicle or range extended vehicle etc., but not limited to this. Work department 11 is the vehicle body, and battery pack 10 is arranged at the bottom of vehicle body, and provides the electric energy support for the running of vehicle or the operation of electrical element in vehicle. However, in some other embodiments, electronic device 1 can also be mobile phone, portable device, notebook computer, ship, spacecraft, electric toy and electric tool etc. Spacecraft includes airplane, rocket, space shuttle and spaceship etc. Work department 11 can be the unit component that can obtain the electric energy of battery pack 10 and make corresponding work, for example, fan blade rotating unit of fan, dust collection work unit of dust collector etc. Electric toy includes fixed or mobile electric toy, for example, game machine, electric car toy, electric ship toy and electric plane toy etc. Electric tool includes metal cutting electric tool, grinding electric tool, assembly electric tool and railway electric tool, for example, electric drill, electric grinder, electric wrench, electric screwdriver, electric hammer, impact drill, concrete vibrator and electric planer etc. The embodiment of the application does not specially limit the above-mentioned electronic device 1.

[0076] The utility model discloses a secondary battery, which is provided with a sealing structure between the insulating sealing element and the shell. The sealing structure, the insulating sealing element and the shell enclose a sealed area, which is isolated from the electrolyte. The electrolyte can be isolated outside the gap between the shell and the insulating sealing element. The continuous and concentrated corrosion of the free electrolyte on the shell in the gap can be alleviated, the occurrence of self-discharge of the battery can be reduced, the performance and the service life of the battery can be improved, and the safety hazard can be reduced. Therefore, the utility model effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance. The above-mentioned embodiments only exemplarily illustrate the principle and the effect of the utility model, and are not used to limit the utility model. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and the scope of the utility model. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and the technical thought disclosed by the utility model should be covered by the claims of the utility model.

Claims

1. A secondary battery characterized by comprising: The secondary battery comprises: a shell comprising an end wall and a side wall surrounding the end wall, the end wall being provided with a pole hole, and the shell containing an electrolyte; an electrode assembly arranged in the shell; a pole penetrating through the pole hole and being fixedly insulated to the end wall, the pole being electrically connected to the electrode assembly; an insulating seal member surrounding the pole and at least partially located between the electrode assembly and the end wall; wherein a sealing structure is arranged between the edge of the insulating seal member and the shell, the sealing structure, the insulating seal member and the shell forming a sealed area, and the sealed area is isolated from the electrolyte.

2. The secondary battery according to claim 1, characterized by The insulating seal member and the side wall are in interference fit.

3. The secondary battery according to claim 2, characterized by The secondary battery further comprises a current collecting member electrically connected to the electrode assembly and located between the electrode assembly and the insulating seal member, the current collecting member comprising a first protrusion arranged on a side facing the insulating seal member, and / or the insulating seal member comprising a second protrusion arranged on a side facing the current collecting member.

4. The secondary battery according to claim 3, characterized by The compression rate of the insulating seal member at the positions of the first protrusion and the second protrusion is greater than 30% and less than 50%.

5. The secondary battery according to claim 1, characterized by A sealing ring is arranged between the edge of the insulating seal member and the shell.

6. The secondary battery according to claim 5, characterized by The sealing ring is arranged on the outer circumferential edge of the side of the insulating seal member facing the electrode assembly, and the sealing ring comprises a first bending portion and a second bending portion connected by bending, the first bending portion being clamped between the insulating seal member and the side wall, and the second bending portion being located on the side of the insulating seal member facing the electrode assembly.

7. The secondary battery according to claim 5, characterized by The sealing ring is arranged between the insulating seal member and the end wall, the insulating seal member comprising a groove surrounding the pole arranged on a side facing the end wall, one end of the sealing ring being embedded in the groove, and the other end of the sealing ring being pressed against the end wall.

8. The secondary battery according to any one of claims 5 to 7, characterized by, The sealing ring is fixedly connected to the insulating seal member.

9. The secondary battery according to claim 1, characterized by The insulating seal member and the side wall are fixedly connected by ultraviolet curing glue.

10. A battery pack characterized by comprising: The secondary battery of any one of claims 1 to 9 is provided.

11. An electronic device, comprising: The battery pack of claim 10 is provided.

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