Top cover assembly, housing and secondary battery

Abstract

The present application provides a top cover assembly, a shell and a secondary battery, which belongs to the technical field of secondary batteries. The top cover assembly of the secondary battery includes a top cover plate, a pole, a fixing member and a limiting member. The top cover plate has a first through hole. The pole is inserted into the first through hole. The fixing member is fixedly connected to one end of the pole protruding from the top cover plate. At least part of the limiting member is located between the fixing member and the top cover plate to separate the fixing member from the top cover plate. Among them, the surface of the top cover plate in contact with the limiting member is a first mating surface, and the first mating surface is provided with a first mating portion, and the surface of the limiting member in contact with the top cover plate is a second mating surface, and the second mating surface is provided with a second mating portion, and the first mating portion and the second mating portion are concave-convex mating to limit the limiting member from rotating with the axis of the first through hole as the rotating axis. The shell of the secondary battery uses the above-mentioned top cover assembly, which can improve the mechanical damage of the pole ear connection part of the secondary battery under the action of external force, and can improve the occurrence of short circuit failure of the battery cell.

Description

Technical Field

[0001] The present application relates to the technical field of secondary batteries, and in particular to a top cover assembly, a housing and a secondary battery. Background Art

[0002] New energy vehicles are being widely promoted in China and even around the world, but there are still many areas that need to be improved to completely replace fuel vehicles. For example, the vehicle's mileage is low, the battery pack cost is high, and the reliability of the battery pack needs to be further resolved. Based on the above problems, higher requirements are put forward for secondary batteries, the core parts of electric vehicles, such as requiring secondary batteries to achieve higher energy density and lower cost.

[0003] At present, secondary batteries generally adopt a square hard shell structure. The secondary battery shell includes a shell and a top cover assembly. The secondary battery shell provides a closed space to accommodate the electrode assembly and the electrolyte. The electric energy of the electrode assembly is led out of the closed space through the pole of the top cover assembly. In the existing top cover assembly, the top cover plate is a metal plate with a through hole, and the pole is divided into a base part and an extension part. During assembly, the base part is located below the top cover plate (i.e., inside the shell), and the base part is connected to the pole ear through a transfer plate. After the extension part passes through the through hole, the extension part is fixed by a retaining spring or riveting. In this way, the pole is fixed to the top cover plate.

[0004] The inventor has found through research that after the secondary battery is installed, the secondary battery may be subjected to external force, which may cause the adapter (the terminal ear connection part) to be mechanically damaged, thereby causing the battery cell to short-circuit. Summary of the invention

[0005] The purpose of the present application is to provide a top cover assembly, a housing and a secondary battery, which can improve the mechanical damage of the tab connection part of the secondary battery under the action of external force and improve the short circuit failure of the battery cell.

[0006] In the first aspect, the embodiment of the present application provides a top cover assembly of a secondary battery, including a top cover plate, a pole, a fixing member and a limiting member. The top cover plate has a first through hole, the pole is passed through the first through hole, the fixing member is fixedly connected to one end of the pole protruding from the top cover plate, and at least part of the limiting member is located between the fixing member and the top cover plate to separate the fixing member from the top cover plate. Among them, the surface of the top cover plate in contact with the limiting member is a first mating surface, and the first mating surface is provided with a first mating portion, and the surface of the limiting member in contact with the top cover plate is a second mating surface, and the second mating surface is provided with a second mating portion, and the first mating portion and the second mating portion are concave-convexly matched to limit the limiting member from rotating with the axis of the first through hole as the rotating axis.

[0007] The pole is fixed above the top cover plate by a fixing member, and the pole and the top cover plate are insulated by a limiting member, thereby increasing the safety distance inside the secondary battery. Due to the concave-convex cooperation of the first matching part and the second matching part, the limiting member can be limited to rotate relative to the top cover plate. Since there is a certain friction between the limiting member and the fixing member, the rotation of the limiting member is limited, and the rotation of the fixing member and the pole fixedly connected to the fixing member can be limited to a certain extent, so that the secondary battery can be relieved from the rotation of the pole under the action of external force, that is, when the pole is subjected to external torque. If the rotation of the pole is limited, the mechanical damage of the pole ear connection part can be improved, and the short circuit failure of the battery cell can be further improved.

[0008] In a possible implementation, the first matching portion is a protrusion, which is protruded from the first matching surface of the top cover plate. The second matching portion is a positioning hole formed in the position-limiting member, which at least passes through the second matching surface of the position-limiting member, and the protrusion is inserted into the positioning hole. The protrusion cooperates with the positioning hole to limit the rotation of the position-limiting member relative to the top cover plate.

[0009] In a possible implementation, the positioning hole is a positioning through hole or a positioning groove. If the positioning hole passes through the second mating surface, a positioning blind hole, i.e., a positioning groove, is formed. The protrusion cooperates with the groove, the groove is opened toward the direction of the top cover plate, the notch of the groove is close to the top cover plate, the upper end of the limiter is relatively flat, and the structural integrity is better. If the positioning hole passes through the second mating surface and the surface of the limiter opposite to the second mating surface, the positioning hole is a positioning through hole, and when the protrusion is set in the positioning through hole, the protrusion enters the positioning through hole from one end of the positioning through hole, and the other end of the positioning through hole can be exhausted, so that the protrusion can smoothly enter the positioning through hole, so as to facilitate the installation and fixation of the protrusion.

[0010] In a possible implementation, the first matching portion is a groove formed on the top cover plate, and the groove passes through the first matching surface of the top cover plate. The second matching portion is a protrusion protruding from the second matching surface of the limiter, and the protrusion is fixed in the groove. A groove structure is provided on the top cover plate, and a protrusion is provided on the limiter to limit the rotation of the limiter, and the protrusion can be integrally formed with the limiter, and the material of the protrusion can be a plastic material, and the protrusion can have a small amount of deformation. After the protrusion is set in the groove formed by the top cover plate, the limiter itself can be prevented from being damaged.

[0011] In a possible implementation, the position limiting member is an annular structure, and an annular groove is provided on one side of the position limiting member close to the fixing member. The fixing member is an annular structure, the inner periphery of the fixing member is fixedly connected to the pole, and the circumferential outer edge of the fixing member is embedded in the annular groove.

[0012] Due to the annular groove of the limiting member, the friction between the limiting member and the fixing member is greater, and the rotation of the fixing member and the pole can be further limited by limiting the rotation of the limiting member, thereby preventing the pole from rotating when subjected to torque.

[0013] In a possible implementation, the fixing member includes a first inner ring and a protruding ring, the first inner ring is fixedly connected to the pole, the protruding ring is connected to the outer circumference of the first inner ring, and the protruding ring is embedded in the annular groove.

[0014] The annular groove formed by the limiting member covers the protruding ring, which can make the covering effect of the protruding ring better and further limit the rotation of the fixing member.

[0015] In a possible implementation manner, a notch is provided on the protruding ring, and a protrusion that is locked in the notch is provided at the bottom of the annular groove.

[0016] The notch and the protrusion can further limit the relative rotation between the fixing member and the limiting member, so that the pole will not rotate even when subjected to a large torque force, and the lug connection part on the pole can be further prevented from being mechanically damaged.

[0017] In a possible embodiment, the limiter includes a second ring, a third ring and a fourth ring distributed along the axial direction, the second ring and the fourth ring are respectively connected to the two ends of the third ring, so that an annular groove is formed between the second ring, the third ring and the fourth ring, a second matching portion is provided on the third ring, and the fourth ring separates the first inner ring and the protruding ring from the top cover plate.

[0018] The annular groove of the limiting member is formed by three annular structures, so that the limiting member can better cover the protruding ring and the friction between the limiting member and the annular groove is greater.

[0019] In a possible embodiment, the pole includes an extension portion and a base portion, the extension portion passes through the first through hole and is fixedly connected to the fixing member; and the top cover assembly further includes: an insulating cover plate, the insulating cover plate is located on a side of the top cover plate away from the stopper, the base portion abuts against the insulating cover plate so that at least a portion of the insulating cover plate is located between the base portion and the top cover plate and separates the base portion from the top cover plate. The circumferential cross section of the base portion is a polygonal structure, and the outer periphery of the base portion fits the insulating cover plate.

[0020] The insulating cover plate can insulate the top cover plate from the pole. The circumferential cross-section of the base is a polygonal structure. The outer periphery of the base is fitted with the insulating cover plate. The base can be arranged to avoid relative rotation between the base of the pole and the insulating cover plate, thereby preventing the pole from rotating when subjected to torque. Structures that limit the rotation of the pole are arranged on the base of the pole and the extension of the pole to avoid uneven force on both ends of the pole.

[0021] In a possible implementation, a stepped hole is provided on the insulating cover plate, and the extension portion is passed through the smaller end of the stepped hole so that the base portion fits with the hole wall of the larger end of the stepped hole.

[0022] The outer diameter of the base is larger than that of the extension. When the pole is subjected to external tension, the base cooperates with the insulating cover plate and the top cover plate to prevent the pole from relative movement. When the pole is subjected to external pressure, the extension cooperates with the fixing member and the limiter to prevent the pole from relative movement. When the pole is subjected to external torque, the first matching part and the second matching part cooperate as well as the polygonal base cooperate with the insulating cover plate to prevent the pole from relative movement. This can prevent the adapter (ear connection part) connected to the pole from being mechanically damaged when the pole is subjected to external tension, pressure, and torque, and can prevent the battery cell from short-circuiting.

[0023] In a possible implementation manner, an insulating seal is further included, one end of the insulating seal is connected to the limiter, and the other end of the insulating seal is connected to the insulating cover plate, so that the extension part and the base part are insulated from the top cover plate.

[0024] The insulating seal can be used to seal the base portion of the pole and the extension portion of the pole, and the inside of the secondary battery shell can be completely sealed and separated from the outside of the shell to avoid leakage of electrolyte, and to prevent the operation of the battery cell from being damaged by the external environment, thereby improving the stability of battery use.

[0025] In a second aspect, an embodiment of the present application provides a top cover assembly of a secondary battery, comprising: a metal top cover plate, a pole, a metal fixing, an insulating plastic part, an insulating plastic cover plate and a sealing plastic part. The metal top cover plate has a first through hole. The pole is passed through the first through hole. The metal fixing is fixedly connected to one end of the pole protruding from the top cover plate. At least part of the insulating plastic part is located between the metal fixing part and the metal top cover plate to separate the metal fixing part from the metal top cover plate. The insulating plastic cover plate is located on the side of the metal top cover plate away from the insulating plastic part. The inner wall of the sealing plastic part is fitted with the pole, and the sealing plastic part is respectively connected to the insulating plastic part and the insulating plastic cover plate to insulate the pole from the top cover plate. Among them, a protrusion is convexly provided on the metal top cover plate, and an ear hole is provided on the insulating plastic part, and the protrusion is passed through the ear hole.

[0026] Insulating plastic parts, sealing plastic parts and insulating plastic cover plates are arranged from top to bottom to insulate the pole from the metal top cover plate and avoid leakage at the pole. The insulating plastic parts, sealing plastic parts and insulating plastic cover plates are arranged separately and use different materials, which can achieve a better sealing effect while ensuring the connection strength of the top cover assembly. The pole is fixed on the top of the metal top cover plate by a metal fixing part, and the protrusion can be integrally formed with the metal top cover plate. The two are made of the same material, the protrusion is a metal material, and the ear hole is an insulating plastic part, so that the connection between the protrusion and the ear hole is more secure, and the metal protrusion is inserted into the plastic ear hole, and the connection between the two is more secure. When the pole is subjected to external torque force, the relative movement of the pole can be avoided; when the pole is subjected to external tension, the pole can be avoided due to the cooperation between the pole, the insulating plastic cover plate and the metal top cover plate; when the pole is subjected to external pressure, the pole can be avoided due to the cooperation between the pole, the metal fixing part and the insulating plastic part. This can prevent the adapter (ear connection part) connected to the pole from being mechanically damaged when the pole is subjected to external tension, pressure, and torque, and can avoid short-circuit failure of the battery cell.

[0027] In a third aspect, an embodiment of the present application provides a secondary battery housing, comprising a shell and the above-mentioned top cover assembly, wherein the top cover plate is mounted on the shell.

[0028] In a third aspect, an embodiment of the present application provides a secondary battery, comprising an electrode assembly, a converter and the above-mentioned shell, wherein the electrode assembly is installed in the shell, one end of the converter is connected to the electrode assembly through a pole ear, and the other end is connected to the pole.

[0029] By using the above-mentioned shell, when the pole or the shell is subjected to external force, the pole can be prevented from rotating, and the adapter and the pole ear connected to the pole can be prevented from being damaged, and the improper contact between the pole ear or the adapter and the electrode assembly can be prevented from causing a short circuit failure in the battery cell.

[0030] The beneficial effects of the top cover assembly, housing and secondary battery provided by the embodiments of the present application include:

[0031] The first matching part and the second matching part can be used to limit the rotation of the limiter. Due to the relative force between the limiter and the fixing part, the pole fixedly connected to the fixing part is limited to rotate, which can alleviate the rotation of the pole. The rotation of the pole is limited, which can improve the mechanical damage of the pole ear connection part and further improve the occurrence of short circuit failure of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, without paying any creative work, other related drawings can be obtained based on these drawings and they also belong to the protection scope of the present application.

[0033] Figure 1 A first view of a top cover assembly provided in an embodiment of the present application;

[0034] Figure 2 A partial exploded view of a top cover assembly provided in an embodiment of the present application;

[0035] Figure 3 for Figure 1 The III-III section view in FIG.

[0036] Figure 4 for Figure 3 The enlarged view of the middle IV;

[0037] Figure 5 A schematic diagram of a polygonal structure of a base portion provided in an embodiment of the present application;

[0038] Figure 6 for Figure 1 VI-VI cross-sectional view in FIG.

[0039] Figure 7 for Figure 6 The enlarged view of the middle VII;

[0040] Figure 8 A cross-sectional view of an implementation of the cooperation between the first mating portion and the second mating portion of the top cover assembly provided in an embodiment of the present application;

[0041] Fig. 9 A cross-sectional view of another embodiment of the cooperation between the first mating portion and the second mating portion of the top cover assembly provided in an embodiment of the present application;

[0042] Fig.10 A cross-sectional view of another implementation of the cooperation between the first mating portion and the second mating portion of the top cover assembly provided in an embodiment of the present application.

[0043] Icons: 10-top cover assembly; 11-top cover plate; 12-pole; 13-fixing piece; 14-limiting piece; 15-insulating cover plate; 16-insulating seal; 111-first through hole; 121-base; 122-extension portion; 151-step hole; 1511-first hole; 1512-second hole; 112-first plate; 113-second plate; 152-third plate; 153-fourth plate; 154-fifth plate; 114-first matching portion; 141-second matching portion; 131-first inner ring; 132-protruding ring; 142-annular groove; 143-second ring; 144-third ring; 145-fourth ring; 1321-notch; 161-fifth ring; 162-sixth ring. DETAILED DESCRIPTION

[0044] 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 described below in conjunction with the drawings in the embodiments of the present application.

[0045] After the secondary battery is manufactured, it will be subjected to external forces, such as external collision during transportation or use. If the secondary battery is a secondary battery for a tram (electric vehicle, electric vehicle or hybrid vehicle), the tram may cause a short circuit failure in the secondary battery cell due to different road surfaces or collisions with other objects in the external environment during operation, which may cause the cell to smoke, catch fire, etc., and may even cause the cell module to smoke, catch fire or explode.

[0046] The inventor has found that one of the reasons why the above phenomenon occurs when the secondary battery is subjected to a violent external force is that when the pole on the top cover assembly of the secondary battery is subjected to external tension, pressure or torque, the pole moves relative to the pole, so that the adapter (ear connection part) connected to the pole will be mechanically damaged, and the ear connected to the adapter will also be damaged, which may cause the ear or adapter to cause improper contact with the electrode assembly, thereby causing the above phenomenon. Therefore, the connection and fixation of the pole is particularly important.

[0047] The secondary battery provided in the embodiment of the present application includes an electrode assembly, a converter and a shell. The shell includes a shell and a top cover assembly. The shell and the top cover assembly are fixedly connected to form a cavity between the shell and the top cover assembly. The cavity is used to place the electrode assembly.

[0048] The electrode assembly is installed in the shell, and a pole ear is connected to the electrode assembly. The end of the pole ear away from the electrode assembly is connected to one end of the adapter, and the other end of the adapter is connected to the pole of the top cover assembly, thereby realizing the installation of the electrode assembly and the connection between the electrode assembly and the top cover assembly.

[0049] Figure 1A first view of the top cover assembly provided for this embodiment; Figure 2 A partial exploded view of the top cover assembly provided in this embodiment. Figure 1 and Figure 2 The top cover assembly 10 includes a top cover plate 11, a pole 12, a fixing member 13, a limiting member 14, an insulating cover plate 15 and an insulating seal 16. Among them, there are two poles 12, namely a first pole and a second pole, and the polarities of the first pole and the second pole are opposite. For example: the first pole is a positive electrode, and the second pole is a negative electrode; or the first pole is a negative electrode, and the second pole is a positive electrode. Correspondingly, there are also two fixing members 13, limiting members 14 and insulating seals 16. The first pole is correspondingly provided with a fixing member 13, a limiting member 14 and an insulating seal 16, so as to install and fix the first pole, and the second pole is correspondingly provided with a fixing member 13, a limiting member 14 and an insulating seal 16, so as to install and fix the second pole.

[0050] In the embodiment of the present application, the top cover plate 11 and the insulating cover plate 15 are both square thin plate structures, the top cover plate 11 is installed at the opening position of the shell, the insulating cover plate 15 is located on one side of the top cover plate 11, the insulating cover plate 15 is located below the top cover plate 11, the insulating cover plate 15 is fitted with the top cover plate 11, two first through holes 111 are arranged on the top cover plate 11, the first through holes 111 pass through the upper surface and the lower surface of the top cover plate 11, the insulating cover plate 15 is also provided with two hole structures, the two hole structures also pass through the upper surface and the lower surface of the insulating cover plate 15, the first pole is installed through the insulating cover plate 15 and the top cover plate 11 in sequence, the second pole is installed through the insulating cover plate 15 and the top cover plate 11 in sequence, the first pole has the same structure as the second pole, and the connection method of the first pole is also the same as the second pole. The structure and connection method of the first pole (hereinafter abbreviated as "pole") are described below as an example.

[0051] The pole 12 includes a base portion 121 and an extension portion 122 , wherein an outer diameter of the base portion 121 is greater than an outer diameter of the extension portion 122 . Figure 3 for Figure 1 The III-III section view in FIG. Figure 4 for Figure 3 See the enlarged view of point IV in the figure. Figure 2-Figure 4A first through hole 111 is provided on the top cover plate 11, and a stepped hole 151 is provided on the insulating cover plate 15. The stepped hole 151 has a larger end and a smaller end. The larger end of the stepped hole 151 is a first hole 1511, and the smaller end of the stepped hole 151 is a second hole 1512. The first through hole 111, the second hole 1512 and the first hole 1511 are connected in sequence, and the extension portion 122 passes through the first hole 1511, the second hole 1512 and the first through hole 111 in sequence, so that the extension portion 122 is located in the first through hole 111 and the second hole 1512, and the base portion 121 is located in the first hole 1511.

[0052] In order to prevent the base portion 121 from rotating in the first hole 1511, in the embodiment of the present application, please refer to Figure 2 and Figure 4 The base 121 abuts against the insulating cover plate 15 so that at least a portion of the insulating cover plate 15 is located between the base 121 and the top cover plate 11 and separates the base 121 from the top cover plate 11. The circumferential cross-section of the base 121 is a polygonal structure. The outer periphery of the base 121 fits with the insulating cover plate 15. The outer periphery of the base 121 fits with the hole wall of the first hole 1511. Since the outer periphery of the base 121 is a polygonal structure, the hole wall of the first hole 1511 is also a polygonal structure, which can limit the relative rotation of the base 121 in the first hole 1511, thereby preventing the pole 12 from rotating under the action of external force to a certain extent, and the structure of the adapter connected to the pole 12 and the pole ear connected to the adapter will not be damaged, thereby preventing the battery cell from short-circuiting to a certain extent.

[0053] Optionally, the circumferential cross section of the base portion 121 may be a regular pentagon, a regular hexagon, a regular heptagon or a regular octagon, which may make the circumferential cross section area of ​​the base portion 121 larger, and may limit the pole 12 from rotating in the first hole 1511, which may make the connection firmness of the pole 12 better. In other embodiments, the circumferential cross section of the base portion 121 may not be a regular polygon structure, but other general polygon structures.

[0054] The following description will be made by taking the case where the area of ​​the circumferential cross section of the base portion 121 is a regular hexagon or a regular octagon as an example. Figure 5 This is a schematic diagram of the polygonal structure of the base portion 121 provided in this embodiment. Figure 5When a cylindrical structure of the same volume is used to set the base portion 121 of the pole 12, if the circumferential cross-section of the base portion 121 is a regular hexagon (the filled part in the figure), the circumferential cross-sectional area of ​​the base portion 121 is smaller; if the circumferential cross-section of the base portion 121 is an octagon, the circumferential cross-sectional area of ​​the base portion 121 is larger. The larger the circumferential cross-sectional area of ​​the base portion 121, the larger the end area of ​​the base portion 121. When the base portion 121 is connected to the adapter, the connection of the adapter can be made more secure. The circumferential cross-sectional area of ​​the base portion 121 is larger, and the strength of the base portion 121 is higher, which can increase the ability of the pole 12 to withstand external tension to a certain extent, making the connection of the pole 12 more reliable.

[0055] It should be noted that if the number of sides of the circumferential cross section of the base portion 121 is too many, the inner angle of the polygonal structure will increase, and the more sides, the closer it will be to a circular structure, thereby failing to achieve the purpose of limiting the rotation of the base portion 121 of the pole 12 in the first hole 1511. The embodiment of the present application does not limit the number of sides of the circumferential cross section of the base portion 121, and any solution that can achieve the purpose of limiting the rotation of the base portion 121 in the first hole 1511 is within the protection scope of the present application.

[0056] In the embodiment of the present application, Figure 6 for Figure 1 VI-VI cross-sectional view in FIG. Figure 7 for Figure 6 See the enlarged view of point VII in the middle. Figure 4 , Figure 6 and Figure 7 The top cover plate 11 includes a first plate 112 and a second plate 113, wherein the second plate 113 is located inside the first plate 112, the second plate 113 is a circular ring structure, a first through hole 111 is provided on the second plate 113, the first through hole 111 and the second plate 113 are coaxially arranged, the thickness of the second plate 113 is less than the thickness of the first plate 112, the upper surface of the first plate 112 is flush with the upper surface of the second plate 113, and a step structure is formed between the lower surface of the first plate 112 and the lower surface of the second plate 113. The top cover plate 11 is a metal cover plate, and optionally, the top cover plate 11 can be made of an aluminum alloy material. (Wherein, the "upper", "lower", "inside" and "outside" in the text shall be based on the directions marked by the arrows in the figure).

[0057] Furthermore, the insulating cover plate 15 includes a third plate 152, a fourth plate 153 and a fifth plate 154, the fourth plate 153 is a circular ring structure, the fourth plate 153 is located inside the third plate 152, the fifth plate 154 is a circular ring structure, the fifth plate 154 is located inside the fourth plate 153, the upper surface of the third plate 152 is in contact with and fits with the lower surface of the first plate 112, the upper surfaces of the fourth plate 153 and the fifth plate 154 are flush, the upper surfaces of the fourth plate 153 and the fifth plate 154 are in contact with and fit with the lower surface of the second plate 113, the lower surface of the fourth plate 153 and the third plate 152 are flush, the thickness of the fourth plate 153 is greater than the thickness of the fifth plate 154, so that a stepped hole 151 is formed between the fourth plate 153 and the fifth plate 154, the inner wall of the hole at the fourth plate 153 forms a first hole 1511 with a polygonal structure, and a second hole 1512 is formed inside the fifth plate 154.

[0058] The surface of the base 121 is flush with the lower surfaces of the third plate 152 and the fourth plate 153, so that the lower surface of the structure formed by the insulating cover plate 15 and the base 121 is a flat structure. The outer periphery of the first plate 112 of the top cover plate 11 protrudes from the outer periphery of the third plate 152, and the portion of the first plate 112 protruding from the third plate 152 is used to connect with the shell. Among them, the insulating cover plate 15 is made of insulating plastic material, for example: the insulating cover plate 15 can be an insulating plastic cover plate, which can be insulated and has a certain strength.

[0059] In the embodiment of the present application, the extension portion 122 of the pole 12 is inserted into the first through hole 111, and part of the extension portion 122 protrudes from the top cover plate 11, and the fixing member 13 is fixedly connected to one end of the pole 12 protruding from the top cover plate 11. The fixing member 13 is fixedly connected to the pole 12, and there is no relative movement between the fixing member 13 and the pole 12. Optionally, the fixing member 13 is a metal fixing member 13, for example, the fixing member 13 is made of an alloy material. The fixing member 13 is welded to the part of the extension portion 122 of the pole 12 protruding from the top cover plate 11 to achieve the fixing of the fixing member 13 to the pole 12.

[0060] In order to achieve insulation between the fixing member 13 and the top cover plate 11, a limiting member 14 is arranged between the fixing member 13 and the top cover plate 11, and at least a part of the limiting member 14 is located between the fixing member 13 and the top cover plate 11 to separate the fixing member 13 from the top cover plate 11. In order to avoid a short circuit failure of the secondary battery when it is subjected to a violent external force, in an embodiment of the present application. The surface of the top cover plate 11 that contacts the limiting member 14 is a first mating surface, and a first mating portion 114 is arranged on the first mating surface. The surface of the limiting member 14 that contacts the top cover plate 11 is a second mating surface, and a second mating portion 141 is arranged on the second mating surface. The first mating portion 114 and the second mating portion 141 are matched in a concave-convex manner to limit the limiting member 14 from rotating with the axis of the first through hole 111 as the axis.

[0061] Since the top cover plate 11 is fixed on the shell, the top cover plate 11 will not rotate relative to the shell. The limit member 14 is arranged on the upper surface of the top cover plate 11, and a first matching portion 114 is arranged on the upper surface of the top cover plate 11, and a second matching portion 141 is arranged on the lower surface of the limit member 14. Through the concave-convex matching of the first matching portion 114 and the second matching portion 141, the limit member 14 can be limited to rotate relative to the shell (limit the limit member 14 to rotate relative to the top cover plate 11), and the limit member 14 can be limited to rotate around the axis of the first through hole 111 (the axis of the pole 12) as the rotating shaft. Since there is a certain friction between the limit member 14 and the fixing member 13, the limit member 14 limits the rotation, which can limit the rotation of the fixing member 13 and the extension portion 122 of the pole 12 fixedly connected to the fixing member 13 to a certain extent, thereby avoiding mechanical damage to the adapter connected to the pole 12 and the pole ear connected to the adapter, and reducing the risk of short circuit failure of the battery cell of the secondary battery during use.

[0062] Among them, the limiter 14 is made of insulating material, for example: the limiter 14 is an insulating plastic part. Compared with plastic, plastic has a slightly larger deformation energy, so that the concave-convex matching effect of the second matching part 141 and the first matching part 114 is better. Optionally, the insulating cover 15 is an insulating plastic cover. The material of the insulating plastic cover is different from the material of the insulating plastic part. The strength of the insulating plastic cover is greater than the strength of the insulating plastic part, so that the strength of the top cover assembly 10 is higher and the matching installation of the first matching part 114 and the second matching part 141 is convenient. Of course, the material of the insulating plastic cover can also be consistent with the material of the insulating plastic part. If the limiter 14 is to limit the rotation of the negative pole, the limiter 14 may not be made of insulating material. This application is not limited.

[0063] The position-limiting member 14 is an annular structure, and two first matching portions 114 may be provided, and two second matching portions 141 may also be provided, and the two second matching portions 141 are arranged at intervals along the circumference of the position-limiting member 14, and the arrangement positions of the two first matching portions 114 correspond one to one to the positions of the two second matching portions 141. Furthermore, the two second matching portions 141 are arranged relatively to each other with the axis of the position-limiting member 14 as the axis of symmetry.

[0064] In one possible implementation, please refer to Figure 7 The first matching portion 114 is a protrusion, which is protruded from the first matching surface of the top cover plate 11. The second matching portion 141 is a positioning hole formed in the limiting member 14, which at least passes through the second matching surface of the limiting member 14, and the protrusion is penetrated in the positioning hole.

[0065] If the positioning hole passes through the second mating surface of the limiter 14 and the surface of the limiter 14 opposite to the second mating surface, the positioning hole is a positioning through hole. The protrusion is convexly arranged on the upper surface (first mating surface) of the top cover plate 11, the protrusion is integrally formed with the top cover plate 11, the protrusion is a metal protrusion, the hole wall of the positioning through hole is a plastic material, and the positioning through hole can have a small amount of deformation. Optionally, the protrusion and the positioning through hole have an interference fit, which can make the matching effect between the protrusion and the positioning through hole better, avoid relative movement of the limiter 14, and further reduce the relative rotation of the extension portion 122 of the pole 12 when subjected to severe external torque.

[0066] Optionally, the upper end of the protrusion may be flush with the upper end of the positioning through hole, or may be located within the positioning through hole. This application does not impose any limitation thereto, as long as the rotation of the limit member 14 can be limited by the cooperation between the protrusion and the positioning through hole.

[0067] In another possible implementation, see Figure 8 If the positioning hole passes through the second mating surface of the stopper 14 and does not pass through the surface of the stopper 14 opposite to the second mating surface, a blind positioning hole, i.e., a positioning groove, is formed, which can make the structure of the upper surface of the stopper 14 relatively complete. The first mating portion 114 is a protrusion, which is protruded from the first mating surface of the top cover plate 11. The protrusion is fixed in the positioning groove.

[0068] In another possible implementation, see Fig. 9 The first matching portion 114 is a groove that penetrates the first matching surface of the top cover plate 11. The second matching portion 141 is a protrusion that is protruding from the second matching surface of the stopper 14 and is fixed in the groove.

[0069] In another possible implementation, see Fig.10 The first matching portion 114 is a through hole structure, which passes through the first matching surface and the surface opposite to the first matching surface of the top cover plate 11. The second matching portion 141 is a protrusion, which is protruded on the second matching surface of the stopper 14 and is arranged in the through hole structure.

[0070] The limiting member 14 is an annular structure, and at least part of the structure of the limiting member 14 is arranged on the outer periphery of the fixing member 13. An annular groove 142 is arranged on the side of the limiting member 14 close to the fixing member 13. The fixing member 13 is an annular structure, and the inner periphery of the fixing member 13 is fixedly connected to the pole 12, and the circumferential outer edge of the fixing member 13 is embedded in the annular groove 142.

[0071] The annular groove 142 and the circumferential outer edge of the fixing member 13 have a certain wrapping effect, which can increase the contact area between the limiting member 14 and the fixing member 13, thereby increasing the friction between the limiting member 14 and the fixing member 13, so as to further limit the rotation of the fixing member 13 and the pole 12 fixedly connected to the fixing member 13.

[0072] Please continue reading Figure 2 , Figure 4 and Figure 7 Optionally, the fixing member 13 includes a first inner ring 131 and a protruding ring 132, the first inner ring 131 is fixedly connected to the pole 12, the pole 12 passes through the hole structure in the first inner ring 131 and is fixedly connected to the first inner ring 131 (for example, welded), the protruding ring 132 is connected to the outer periphery of the first inner ring 131, and the protruding ring 132 is embedded in the annular groove 142.

[0073] The limiting member 14 includes a second ring 143, a third ring 144 and a fourth ring 145 distributed along the axial direction. The second ring 143 and the fourth ring 145 are respectively connected to the two ends of the third ring 144, so that an annular groove 142 is formed between the second ring 143, the third ring 144 and the fourth ring 145. A second matching portion 141 is provided on the third ring 144, and the fourth ring 145 separates the first inner ring 131 and the protruding ring 132 from the top cover plate 11.

[0074] In a possible embodiment, the third ring 144 may not be a standard ring structure. At the position where the second matching portion 141 is set, the third ring 144 protrudes slightly outward to be used to set the second matching portion 141 (for example, the second through hole) to form an ear hole structure for limiting the rotation of the limit member 14.

[0075] In this application example, please continue to refer to Figure 4 and Figure 7 The thickness of the protruding ring 132 is less than that of the first inner ring 131, the lower surface of the protruding ring 132 is flush with the lower surface of the first inner ring 131, the upper surface of the second ring 143 is flush with the upper end surface of the third ring 144, the lower end surface of the fourth ring 145 is flush with the lower end surface of the third ring 144, the lower surface of the fixing member 13 composed of the protruding ring 132 and the first inner ring 131 is in full contact with the upper surface of the fourth ring 145, and the inner ring surface of the fourth ring 145 is in contact with the outer peripheral surface of the extension portion 122 of the pole 12. The outer peripheral surface of the protruding ring 132 is in contact with the inner ring surface of the third ring 144, the upper surface of the protruding ring 132 is in contact with the lower surface of the second ring 143, the upper surface of the first inner ring 131 is flush with the upper surface of the second ring 143, and the inner ring surface of the second ring 143 is in contact with the outer peripheral surface of the first inner ring 131.

[0076] Please refer to Figure 4 and Figure 7, the connection between the first inner ring 131 and the protruding ring 132 is substantially flush with the connection between the fifth plate 154 and the fourth plate 153 ( Figure 7 The end point of the force exerted by the stopper 14 on the combined component (the combination of the extension 122 of the pole 12 and the fixing member 13) is between the inner ring surface of the second ring 143 and the outer peripheral surface of the first inner ring 131, and the end point of the base 121 of the pole 12 and the insulating cover 15 is between the inner peripheral surface of the fourth plate 153 and the outer peripheral surface of the base 121. Therefore, the end point of the extension 122 of the pole 12 and the end point of the base 121 of the pole 12 are basically at On the same straight line, the straight line is substantially parallel to the axis of the pole 12, so both ends of the pole 12 can be subjected to substantially the same axial torque, that is, when the pole 12 is subjected to an intense external torque, the pole 12 can be prevented from rotating, and the limiting forces on both ends of the pole 12 are substantially the same, which can eliminate the torque (internal stress) inside the pole 12, and eliminate the torque inside the pole 12 while preventing the pole 12 from rotating, so that the use effect of the pole 12 is better. Further, the outer peripheral surface of the protruding ring 132 is substantially flush with the connection between the fourth plate 153 and the third plate 152 ( Figure 7 Therefore, the force application point of the protruding ring 132 and the force application point transmitted to the top cover plate 11 by the base portion 121 of the pole 12 are substantially on the same straight line, and the straight line is substantially parallel to the axis of the pole 12, which can further make the limiting forces on both ends of the pole 12 substantially consistent, further eliminate the torque force (internal stress) inside the pole 12, and further eliminate the torque force inside the pole 12 while avoiding the rotation of the pole 12, so that the use effect of the pole 12 is better.

[0077] In order to further limit the relative rotation between the fixing member 13 and the limiting member 14, optionally, a notch 1321 is provided on the protruding ring 132, and a protrusion (not shown) is provided at the bottom of the annular groove 142 to be clamped in the notch 1321. The outer periphery of the protruding ring 132 is provided with a plurality of notches 1321, and the inner ring surface of the third ring 144 is provided with a plurality of protrusions clamped in the notches 1321, so that an annular restriction is formed between the outer peripheral surface of the protruding ring 132 and the inner peripheral surface of the third ring 144.

[0078] In the embodiment of the present application, an insulating seal 16 is provided between the extension 122 of the pole 12 and the top cover plate 11 and the insulating cover plate 15. The insulating seal 16 may be a sealing plastic part, which may have good deformation force. After the outer shell is formed, a good sealing effect may be achieved for the inside of the seal (inside the shell) and the outside of the seal (outside the shell). Optionally, the material of the insulating seal 16 is different from that of the stopper 14. The insulating seal 16 has a strong deformation ability under insulation conditions, while the stopper 14 has a relatively weak deformation ability under insulation conditions, so as to have a better fixing effect on the pole 12 under sealing conditions. Of course, the present application is not limited thereto, and the material of the insulating seal 16 and the material of the stopper 14 may also be the same.

[0079] Please continue reading Figure 4 and Figure 7 One end of the insulating seal 16 is connected to the stopper 14, and the other end is connected to the insulating cover plate 15, so that the extension portion 122 and the base portion 121 are insulated from the top cover plate 11. The insulating seal 16 is an annular structure, and the axial cross section of the insulating seal 16 is L-shaped. The insulating seal 16 includes a fifth ring 161 and a sixth ring 162. The fifth ring 161 is located at the upper end of the sixth ring 162. The inner ring surface of the fifth ring 161 is flush with the inner ring surface of the sixth ring 162. The inner ring surfaces of the fifth ring 161 and the sixth ring 162 are in contact with the outer peripheral surface of the extension portion 122. The upper surface of the fifth ring 161 is in contact with the lower surface of the limit member 14 (the lower surface of the fourth ring 145). The outer ring surface of the fifth ring 161 is in contact with the inner ring surface of the second plate 113. The lower surface of the second plate 113 is in contact with the upper surface of the sixth ring 162. The inner surface of the fifth plate 154 is in contact with the outer peripheral surface of the sixth ring 162. The lower surface of the sixth ring 162 is in contact with the inner surface of the base portion 121, thereby realizing the sealed installation of the pole 12.

[0080] The assembly method of the top cover assembly 10 provided in the embodiment of the present application is as follows:

[0081] First, assemble the top cover plate 11 and the insulating cover plate 15, so that the first through hole 111 on the top cover plate 11 is coaxially arranged with the stepped hole 151 on the insulating cover plate 15. Sleeve the insulating seal 16 outside the extension portion 122, and the lower surface of the insulating seal 16 contacts the upper surface of the base portion 121. Sleeve the limiter 14 outside the fixing member 13, so that the protruding ring 132 of the fixing member 13 is clamped in the annular groove 142 of the limiter 14, and the second matching portion 141 of the limiter 14 is matched and installed with the first matching portion 114 of the top cover plate 11 (for example: the protrusion on the top cover plate 11 is set in the second through hole on the limiter 14 and has an interference fit with the second through hole), so that the lower surface of the fourth ring 145 and the lower end surface of the third ring 144 contact the upper surface of the top cover plate 11. The extension portion 122 of the pole 12 is passed through the stepped hole 151 of the insulating cover plate 15, the first through hole 111 of the top cover plate 11, the middle hole structure of the limiter 14 and the middle hole structure of the fixing member 13 from bottom to top, and the inner annular surface of the fixing member 13 and the outer peripheral surface of the extension portion 122 of the pole 12 are firmly welded together.

[0082] After assembly is completed, the inner ring surface of the first inner ring 131 is welded together with the outer peripheral surface of the extension portion 122 of the pole 12, the inner ring surface of the fourth ring 145 contacts the outer peripheral surface of the extension portion 122 of the pole 12, the inner ring surface of the sealing limiter 14 contacts the outer peripheral surface of the extension portion 122 of the pole 12, the lower surface of the sealing limiter 14 contacts the upper surface of the base portion 121 of the pole 12, the lower surface of the fifth plate 154 contacts the upper surface of the base portion 121 of the pole 12, and the inner ring surface of the fourth plate 153 fits with the outer peripheral surface of the base portion 121 of the pole 12.

[0083] The beneficial effects of the top cover assembly 10 include:

[0084] When the pole 12 is subjected to external tension, the upper end of the extension portion 122 of the pole 12 is subjected to external tension. Since the pole 12 is assembled from bottom to top, the force applied to the pole 12 will act on the top cover plate 11 from the base portion 121 of the pole 12, thereby preventing the pole 12 from relative movement. When the pole 12 is subjected to external pressure, the upper end of the extension portion 122 of the pole 12 is subjected to external pressure. Since the upper end of the extension portion 122 of the pole 12 is welded to the fixing member 13, the force applied to the pole 12 will act on the top cover plate 11 from the fixing member 13, thereby preventing the pole 12 from relative movement. When the pole 12 is subjected to external torque, the second matching portion 141 on the limiting member 14 cooperates with the first matching portion 114 on the top cover plate 11 to limit the rotation of the limiting member 14, and the limiting member 14 and the fixing member 13 have a large friction force, thereby limiting the extension portion 122 (upper end) of the pole 12 from rotating under the action of the torque; and the circumferential cross-section of the base portion 121 of the pole 12 is a polygonal structure, which fits with the inner wall of the larger end of the stepped hole 151 of the insulating cover plate 15, which can limit the base portion 121 (lower end) of the pole 12 from rotating under the action of the torque, thereby avoiding relative movement of the pole 12.

[0085] Furthermore, since the connection between the first inner ring 131 and the protruding ring 132 is basically flush with the connection between the fifth plate 154 and the fourth plate 153, and the outer peripheral surface of the protruding ring 132 is basically flush with the connection between the fourth plate 153 and the third plate 152, the torque force (internal stress) inside the pole 12 can be eliminated, making the use effect of the pole 12 better.

[0086] Therefore, when the secondary battery is subjected to a violent external impact, the pole 12 of the top cover assembly 10 can avoid relative movement of the pole 12 regardless of the tension, pressure or torque, thereby preventing the adapter (pole ear connection part) connected to the pole 12 from being mechanically damaged, and avoiding short circuit failure of the battery cell.

[0087] The above is only a part of the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A top cover assembly of a secondary battery, characterized in that: include: A top cover plate, wherein the top cover plate has a first through hole; A pole, the pole being passed through the first through hole; A fixing member, the fixing member being fixedly connected to an end of the pole protruding from the top cover plate; a limiting member, wherein at least a portion of the limiting member is located between the fixing member and the top cover plate to separate the fixing member from the top cover plate; The surface of the top cover plate in contact with the position-limiting member is a first mating surface, the first mating surface is provided with a first mating portion, the surface of the position-limiting member in contact with the top cover plate is a second mating surface, the second mating surface is provided with a second mating portion, the first mating portion and the second mating portion are mated in a concave-convex manner to limit the position-limiting member from rotating about the axis of the first through hole as the rotating axis, The limiting member is an annular structure, and a side of the limiting member close to the fixing member is provided with an annular groove; The fixing member is an annular structure, the inner circumference of the fixing member is fixedly connected to the pole, and the circumferential outer edge of the fixing member is embedded in the annular groove. The pole comprises an extension portion and a base portion, the extension portion passes through the first through hole and is fixedly connected to the fixing member.

2. The top cover assembly according to claim 1, characterized in that: The first matching portion is a protrusion, and the protrusion is protruding from the first matching surface of the top cover plate; The second matching portion is a positioning hole formed in the limiting member, the positioning hole at least passes through the second matching surface of the limiting member, and the protrusion is penetrated in the positioning hole.

3. The top cover assembly according to claim 2, characterized in that: The positioning hole is a positioning through hole or a positioning groove.

4. The top cover assembly according to claim 1, characterized in that: The first matching portion is a groove formed on the top cover plate, and the groove passes through the first matching surface of the top cover plate; The second matching portion is a protrusion convexly provided on the second matching surface of the limiting member, and the protrusion is fixed in the groove.

5. The top cover assembly according to claim 1, characterized in that: The fixing member comprises a first inner ring and a protruding ring, the first inner ring is fixedly connected to the pole, the protruding ring is connected to the outer circumference of the first inner ring, and the protruding ring is embedded in the annular groove.

6. The top cover assembly according to claim 5, characterized in that: The protruding ring is provided with a notch, and the bottom of the annular groove is provided with a protrusion which is clamped in the notch.

7. The top cover assembly according to claim 5 or 6, characterized in that: The limiting member includes a second ring, a third ring and a fourth ring distributed along the axial direction, the second ring and the fourth ring are respectively connected to the two ends of the third ring, so that the annular groove is formed between the second ring, the third ring and the fourth ring, the second matching portion is provided on the third ring, and the fourth ring separates the first inner ring and the protruding ring from the top cover plate.

8. The top cover assembly according to any one of claims 1 to 4, characterized in that: The top cover assembly also includes: an insulating cover plate, the insulating cover plate being located on a side of the top cover plate away from the stopper, the base portion abutting against the insulating cover plate so that at least a portion of the insulating cover plate is located between the base portion and the top cover plate and the base portion is separated from the top cover plate; The circumferential cross-section of the base portion is a polygonal structure, and the outer periphery of the base portion is in contact with the insulating cover plate.

9. The top cover assembly according to claim 8, characterized in that: The insulating cover plate is provided with a stepped hole, and the extension portion is penetrated through the smaller end of the stepped hole so that the base portion fits with the hole wall of the larger end of the stepped hole.

10. The top cover assembly according to claim 8, characterized in that: It also includes an insulating seal, one end of which is connected to the limiting member, and the other end of which is connected to the insulating cover plate, so that the extension part and the base part are insulated from the top cover plate.

11. A top cover assembly of a secondary battery, characterized in that: include: A metal top cover plate, wherein the metal top cover plate has a first through hole; A pole, the pole being passed through the first through hole; A metal fixing piece, the metal fixing piece being fixedly connected to an end of the pole protruding from the top cover plate; an insulating plastic member, at least a portion of which is located between the metal fixing member and the metal top cover plate to separate the metal fixing member from the metal top cover plate; An insulating plastic cover plate, the insulating plastic cover plate being located on a side of the metal top cover plate away from the insulating plastic part; A sealing plastic part, the inner wall of which is in contact with the pole, and the sealing plastic part is respectively connected to the insulating plastic part and the insulating plastic cover plate, so that the pole and the top cover plate are insulated; Wherein, a protrusion is convexly provided on the metal top cover plate, an ear hole is provided on the insulating plastic part, and the protrusion is inserted into the ear hole. The insulating plastic part is an annular structure, and a side of the insulating plastic part close to the metal fixing part is provided with an annular groove; The metal fixing piece is an annular structure, the inner periphery of the metal fixing piece is fixedly connected to the pole, and the circumferential outer edge of the metal fixing piece is embedded in the annular groove. The pole comprises an extension portion and a base portion, the extension portion passes through the first through hole and is fixedly connected to the metal fixing piece.

12. A secondary battery housing, characterized in that: It comprises a shell and a top cover assembly according to any one of claims 1 to 11, wherein the top cover plate is mounted on the shell.

13. A secondary battery, characterized in that: It comprises an electrode assembly, a transfer sheet and the shell as claimed in claim 12, wherein the electrode assembly is installed in the shell, one end of the transfer sheet is connected to the electrode assembly through a pole ear, and the other end is connected to the pole.

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