CN112864502A

CN112864502A - Top cover assembly, shell and secondary battery

Info

Publication number: CN112864502A
Application number: CN201911103395.7A
Authority: CN
Inventors: 吴婷婷; 冯俊敏; 张万财
Original assignee: Shenzhen Haihan New Energy Technology Co ltd
Current assignee: Xiamen Haichen New Energy Technology Co Ltd
Priority date: 2019-11-12
Filing date: 2019-11-12
Publication date: 2021-05-28

Abstract

The application provides a top cap subassembly, shell and secondary battery belongs to secondary battery technical field. The top cover assembly of the secondary battery comprises a top cover plate, a pole, a fixing piece and a limiting piece. The top cover plate is provided with a first through hole. The pole column penetrates through the first through hole. The fixed part is fixedly connected with one end of the protruding top cover plate of the pole. At least part of the limiting piece is positioned between the fixed piece and the top cover plate to separate the fixed piece and the top cover plate. The surface of the top cover plate, which is in contact with the limiting part, is a first matching surface, the first matching surface is provided with a first matching part, the surface of the limiting part, which is in contact with the top cover plate, is a second matching surface, the second matching surface is provided with a second matching part, and the first matching part and the second matching part are in concave-convex matching to limit the limiting part to rotate by taking the axis of the first through hole as a rotating shaft. The shell of the secondary battery uses the top cover assembly, so that the mechanical damage of the tab connection part of the secondary battery under the action of external force can be improved, and the phenomenon that the short circuit fault occurs in the battery cell can be improved.

Description

Top cover assembly, shell and secondary battery

Technical Field

The application relates to the technical field of secondary batteries, in particular to a top cover assembly, a shell and a secondary battery.

Background

New energy automobiles are widely popularized in China and even in the world, but a great number of places need to be improved if fuel automobiles are completely replaced. For example, the problems of a small driving range of an automobile, a high cost of a battery pack, and reliability of the battery pack need to be further solved. In view of the above problems, higher demands have been made on secondary batteries as core parts of electric vehicles, such as the need for secondary batteries to achieve higher energy density, lower cost, and the like.

At present, the secondary battery generally adopts a square hard shell structure, the secondary battery shell comprises a shell body and a top cover assembly, the secondary battery shell provides a closed space for accommodating an electrode assembly and electrolyte, and the electric energy of the electrode assembly is led out of the closed space from the inside of the closed space through a pole of the top cover assembly. In the existing roof cover assembly, the roof cover plate is a metal plate and is provided with a through hole, and the pole is divided into a base body part and an extension part. During assembly, the base body portion is located below the top cover plate (namely inside the shell), the base body portion is connected with the pole lugs through the adapter plate, the extension portion penetrates through the through holes and then is fixed through the snap springs or in a riveting mode, and the pole is fixed on the top cover plate through the mode.

The inventor finds that after the secondary battery is installed, the secondary battery is subjected to external force, and the adapter sheet (the tab connection part) can be mechanically damaged, so that a battery cell can be short-circuited.

Disclosure of Invention

An object of this application is to provide a top cap subassembly, shell and secondary battery can improve secondary battery and make utmost point ear connection part take place mechanical destruction under receiving the exogenic action, can improve electric core and take place short circuit fault.

In a first aspect, an embodiment of the present application provides a cap assembly for a secondary battery, including a cap plate, a terminal, a fixing member, and a limiting member. The top cover plate is provided with a first through hole, the pole column penetrates through the first through hole, the fixing piece is fixedly connected with one end of the protruding top cover plate of the pole column, and at least part of the limiting piece is located between the fixing piece and the top cover plate to separate the fixing piece from the top cover plate. The surface of the top cover plate, which is in contact with the limiting part, is a first matching surface, the first matching surface is provided with a first matching part, the surface of the limiting part, which is in contact with the top cover plate, is a second matching surface, the second matching surface is provided with a second matching part, and the first matching part and the second matching part are in concave-convex matching to limit the limiting part to rotate by taking the axis of the first through hole as a rotating shaft.

The post is fixed above the top cover plate through the fixing piece, the post and the top cover plate are insulated through the limiting piece, and the safety distance inside the secondary battery is increased. Due to the concave-convex matching effect of the first matching part and the second matching part, the limiting part can be limited to rotate relative to the top cover plate. Because certain frictional force exists between the limiting part and the fixing part, the rotation of the limiting part is limited, the rotation of the fixing part and the pole fixedly connected with the fixing part can be limited to a certain extent, so that the secondary battery can relieve the rotation of the pole under the action of external force, namely the pole under the condition of external torque force. The rotation of the pole is limited, so that the mechanical damage of the pole lug connection part can be improved, and the short circuit fault of the battery cell can be further improved.

In one possible embodiment, the first mating portion is a protrusion, and the protrusion is protruded from the first mating surface of the top cover plate. The second matching part is a positioning hole formed in the limiting part, the positioning hole at least penetrates through the second matching surface of the limiting part, and the protrusion penetrates through the positioning hole. The protrusion is matched with the positioning hole, so that the limiting part can be limited to rotate relative to the top cover plate.

In a possible embodiment, the positioning hole is a positioning through hole or a positioning groove. If the positioning hole penetrates through the second matching surface, a positioning blind hole, namely a positioning groove, is formed. The protrusion is matched with the groove, the groove is formed in the direction towards the top cover plate, the notch of the groove is close to the top cover plate, the upper end of the limiting part is relatively flat, and the structural integrity is relatively good. If the locating hole runs through the second fitting surface and the surface of the limiting part opposite to the second fitting surface, the locating hole is a locating through hole, when the protrusion is arranged in the locating through hole, the protrusion enters the locating through hole from one end of the locating through hole, the other end of the locating through hole can exhaust air, and the protrusion can smoothly enter the locating through hole so as to be installed and fixed.

In one possible embodiment, the first mating portion is a groove formed in the top cover plate, and the groove penetrates through the first mating surface of the top cover plate. The second matching part is a bulge convexly arranged on the second matching surface of the limiting part, and the bulge is fixed in the groove. Set up the groove structure on the lamina tecti, set up the arch on the locating part to the rotation of restriction locating part, and the arch can be with locating part integrated into one piece, bellied material can be the plastic material, and the arch can have a small amount of deformations, with protruding setting in the recess that the lamina tecti formed after, can avoid locating part itself to suffer destruction.

In a possible embodiment, the limiting member is an annular structure, and an annular groove is formed on one side of the limiting member close to the fixing member. The mounting is the loop configuration, and the internal week and the utmost point post fixed connection of mounting, the circumference outward flange of mounting inlays locates in the ring channel.

Because the annular groove effect of locating part, the frictional force between locating part and the mounting is bigger, can further reach restriction mounting and utmost point post pivoted purpose through the rotation of restriction locating part, avoids utmost point post to take place to rotate under the condition that receives the moment of torsion power.

In a possible embodiment, the fixing member includes a first inner ring fixedly connected to the pole, and a protruding ring connected to an outer periphery of the first inner ring and embedded in the annular groove.

The annular groove formed by the limiting part coats the bulge loop, so that the coating effect of the bulge loop is better, and the rotation of the fixing part can be further limited.

In a possible embodiment, the protruding ring is provided with a notch, and the bottom of the annular groove is provided with a protrusion clamped in the notch.

Through breach and bellied setting, can further restrict the relative rotation of mounting and locating part, make utmost point post under the condition that bears great moment of torsion, also can not take place to rotate, can further avoid utmost point ear joint part on the utmost point post to suffer mechanical damage.

In a possible embodiment, 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 two ends of the third ring, so that an annular groove is formed between the second ring, the third ring and the fourth ring, the third ring is provided with a second matching portion, and the fourth ring separates the first inner ring and the protruding ring from the top cover plate.

The annular groove of the limiting part is formed by the three annular structures, so that the limiting part has a better coating effect on the protruding ring, and the friction force between the limiting part and the annular groove is larger.

In a possible embodiment, the pole comprises an extension part and a base body part, the extension part passes through the first through hole, and the extension part is fixedly connected with the fixing part; and the cap assembly further comprises: the insulating cover plate is positioned on one side, far away from the limiting part, of the top cover plate, and the base body part is abutted to the insulating cover plate to enable at least one part of the insulating cover plate to be positioned between the base body part and the top cover plate and separate the base body part from the top cover plate. The peripheral section of the base body is of a polygonal structure, and the periphery of the base body is attached to the insulating cover plate.

Through insulating cover's effect, can be with insulating between lamina tecti and the utmost point post, the circumference cross-section of base body portion is polygonized structure, the periphery and the insulating cover laminating of base body portion, can avoid taking place relative rotation between the base body portion of utmost point post and the insulating cover board through the setting of base body portion to can avoid utmost point post to take place to rotate under the condition that receives the moment of torsion power, all set up restriction utmost point post pivoted structure at the base body portion of utmost point post and the extension of utmost point post, avoid the both ends atress inequality of utmost point post.

In a possible embodiment, the insulating cover plate is provided with a stepped hole, and the extension portion is arranged at the smaller end of the stepped hole in a penetrating manner so that the base portion is attached to the hole wall at the larger end of the stepped hole.

The outer diameter of the base body part is larger than that of the extension part, so that the pole can be prevented from moving relatively due to the matching of the base body part, the insulating cover plate and the top cover plate under the condition that the pole is subjected to external tensile force; under the condition that the pole is subjected to external pressure, the extending part is matched with the fixing part and the limiting part, so that the relative motion of the pole can be avoided; under the condition that the pole is subjected to external torque force, the first matching part and the second matching part are matched, and the polygonal base body part is matched with the insulating cover plate, so that the pole can be prevented from moving relatively. Therefore, the pole can be prevented from being mechanically damaged by the adapter sheet (the pole lug connecting part) connected with the pole under the conditions of external tension, pressure and torque force, and the short circuit fault of the battery cell can be avoided.

In a possible embodiment, the base body further comprises an insulating sealing member, one end of the insulating sealing member is connected with the limiting member, and the other end of the insulating sealing member is connected with the insulating cover plate, so that the extending portion and the base body portion are insulated from the top cover plate.

Can make through insulating seal's effect, seal between the extension of the base portion of messenger's utmost point post and utmost point post, can seal the separation completely with the casing outside with secondary battery's casing is inside, avoids revealing of electrolyte, also can avoid the operation of electric core to suffer external environment's destruction, improves the stability in use of battery.

In a second aspect, embodiments of the present application provide a cap assembly of a secondary battery, including: the metal top cover plate, the pole, the metal fixing piece, the insulating plastic part, the insulating plastic cover plate and the sealing plastic part. The metal top cover plate is provided with a first through hole. The pole column penetrates through the first through hole. The metal fixing piece is fixedly connected with one end of the protruding top cover plate of the pole. At least part of the insulating plastic part is positioned between the metal fixing part and the metal top cover plate to separate the metal fixing part and the metal top cover plate. The insulating plastic cover plate is positioned on one side of the metal top cover plate, which is far away from the insulating plastic part. The inner wall of the sealing plastic part is attached to the pole, and the sealing plastic part is connected with the insulating plastic part and the insulating plastic cover plate respectively to ensure that the pole is insulated from the top cover plate. Wherein, the metal lamina tecti epirelief is equipped with the arch, is provided with the earhole on the insulating plastic part, and the arch is worn to locate in the earhole.

The insulating plastic part, the sealing plastic part and the insulating plastic cover plate are arranged from top to bottom, so that the pole and the metal top cover plate are insulated, and the electric leakage phenomenon at the pole is avoided. Insulating plastic part, sealed plastic part and insulating plastic apron components of a whole that can function independently set up, and use different materials, under the circumstances of guaranteeing top cap subassembly joint strength, can play better sealed effect. The pole is fixed above the metal top cover plate through the metal fixing piece, the protrusion and the metal top cover plate can be integrally formed, the material of the protrusion and the material of the metal top cover plate are the same, the protrusion is made of metal material, the ear hole is made of insulating plastic parts, so that the connection between the protrusion and the ear hole is firmer, the metal protrusion penetrates through the plastic ear hole, the connection between the protrusion and the ear hole is firmer, and the pole can be prevented from relatively moving under the condition that the pole is subjected to external torque force; under the condition that the pole is subjected to external tensile force, the pole can be prevented from moving relatively due to the matching of the pole, the insulating plastic cover plate and the metal top cover plate; under the condition that the pole column is subjected to external pressure, the pole column can be prevented from moving relatively due to the matching of the pole column, the metal fixing piece and the insulating plastic piece. Therefore, the pole can be prevented from being mechanically damaged by the adapter sheet (the pole lug connecting part) connected with the pole under the conditions of external tension, pressure and torque force, and the short circuit fault of the battery cell can be avoided.

In a third aspect, embodiments of the present application provide a secondary battery case, which includes a case and the above-mentioned top cover assembly, and a top cover plate is covered on the case.

In a third aspect, an embodiment of the present application provides a secondary battery, which includes an electrode assembly, an interposer, and the above-mentioned housing, where the electrode assembly is installed in the housing, one end of the interposer is connected to the electrode assembly through a tab, and the other end is connected to a post.

By using the shell, under the condition that the pole or the shell is subjected to external acting force, the rotation of the pole can be avoided, the damage to the adapter sheet connected with the pole and the pole lug can also be avoided, and the short circuit fault of the battery cell caused by the improper contact of the pole lug or the adapter sheet and the electrode assembly is avoided.

The beneficial effect that top cap subassembly, shell and secondary cell that this application embodiment provided includes:

can take place to rotate through the effect restriction locating part of first cooperation portion with second cooperation portion, because the relative effort between locating part and the mounting to restriction and mounting fixed connection's utmost point post take place to rotate, can alleviate the rotation of utmost point post. The rotation of the pole is limited, so that the mechanical damage of the pole lug connection part can be improved, and the short circuit fault of the battery cell can be further improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments are briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive efforts and also belong to the protection scope of the present application.

FIG. 1 is a first view of a cap assembly provided by an embodiment of the present application;

fig. 2 is a partial exploded view of a cap assembly provided in accordance with an embodiment of the present application;

FIG. 3 is a cross-sectional view III-III of FIG. 1;

FIG. 4 is an enlarged view taken at IV in FIG. 3;

fig. 5 is a schematic view of a polygonal structure of a base portion according to an embodiment of the present application;

FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 1;

FIG. 7 is an enlarged view taken at VII in FIG. 6;

FIG. 8 is a cross-sectional view of one embodiment of the mating of the first mating portion and the second mating portion of the cap assembly provided by an example of the present application;

FIG. 9 is a cross-sectional view of another embodiment of a first mating portion and a second mating portion of a cap assembly provided in an example of the present application;

fig. 10 is a cross-sectional view of another embodiment of the mating of the first mating portion and the second mating portion of the cap assembly provided in the examples of the present application.

Icon: 10-a cap assembly; 11-a top cover plate; 12-pole column; 13-a fixing member; 14-a limit stop; 15-an insulating cover plate; 16-an insulating seal; 111-a first via; 121-a base portion; 122-an extension; 151-stepped bore; 1511-first hole; 1512-a second aperture; 112-a first plate; 113-a second plate; 152-a third plate; 153-fourth plate; 154-fifth plate; 114-a first mating portion; 141-a second mating portion; 131-a first inner ring; 132-a projecting ring; 142-a ring groove; 143-a second ring; 144-third ring; 145-fourth ring; 1321-notch; 161-fifth ring; 162-sixth ring.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

After the secondary battery is manufactured, external force is applied to, for example: is subjected to the action of external impact force during transportation or use. If the secondary battery is a secondary battery of an electric car (an electric car, an electric car or a hybrid car), the electric car may cause a short-circuit fault of a battery cell of the secondary battery due to different road surfaces or collision with other objects in an external environment during operation, and may cause smoke, fire or the like of the battery cell, or even may cause smoke, fire or explosion of a battery cell module.

The inventor researches and discovers that under the action of violent external force, the phenomenon can occur because one of the reasons is that under the condition that a pole on a top cover assembly of the secondary battery is subjected to external pulling force, pressure or torque force, the pole moves relatively, so that an adapter sheet (a pole lug connecting part) connected with the pole can be mechanically damaged, a pole lug connected with the adapter sheet can be damaged, the pole lug or the adapter sheet can be in improper contact with an electrode assembly, and the phenomenon can occur. Therefore, the connection and fixation of the pole is particularly important.

The secondary battery provided by the embodiment of the application comprises an electrode assembly, an adapter sheet and a shell, wherein the shell comprises a shell body and a top cover assembly, the shell body is fixedly connected with the top cover assembly, a cavity is formed between the shell body and the top cover assembly, and the cavity is used for placing the electrode assembly.

The electrode assembly is arranged in the shell, the electrode assembly is connected with a tab, one end of the tab, which is far away from the electrode assembly, is connected with one end of the adapter sheet, and the other end of the adapter sheet is connected with the pole of the top cover assembly, so that the electrode assembly is arranged and the electrode assembly is connected with the top cover assembly.

FIG. 1 is a first view of the cap assembly provided in the present embodiment; fig. 2 is a partial exploded view of the top cover assembly provided in this embodiment. Referring to fig. 1 and 2, the top cover assembly 10 includes a top cover plate 11, a pole post 12, a fixing member 13, a limiting member 14, an insulating cover plate 15 and an insulating sealing member 16. The two poles 12 are respectively 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 two fixing elements 13, two limiting elements 14 and two insulating sealing elements 16, the first pole is correspondingly provided with one fixing element 13, one limiting element 14 and one insulating sealing element 16, so as to mount and fix the first pole, and the second pole is correspondingly provided with one fixing element 13, one limiting element 14 and one insulating sealing element 16, so as to mount and fix the second pole.

In the embodiment of the present application, top cover plate 11 and insulating cover plate 15 are square thin plate-shaped structures, the open position of casing is covered to top cover plate 11, insulating cover plate 15 is located one side of top cover plate 11, insulating cover plate 15 is located the below of top cover plate 11, insulating cover plate 15 and the laminating of top cover plate 11, set up two first through-holes 111 on top cover plate 11, first through-hole 111 runs through the upper surface and the lower surface of top cover plate 11, also be provided with two hole structures on insulating cover plate 15, two hole structures also run through the upper surface and the lower surface of insulating cover plate 15, first utmost point post passes insulating cover plate 15 and top cover plate 11 in proper order and installs, the second utmost point post passes insulating cover plate 15 and top cover plate 11 in proper order and installs, first utmost point post is the same with the structure of second utmost point post, the connected mode of first utmost point post and second. The following description will be given taking as an example a structure and a connection mode of the first pole (hereinafter, simply referred to as "pole").

The pole post 12 includes a base portion 121 and an extension portion 122, wherein the outer diameter of the base portion 121 is larger than the outer diameter of the extension portion 122. FIG. 3 is a cross-sectional view III-III of FIG. 1; fig. 4 is an enlarged view of the point iv in fig. 3. Referring to fig. 2 to 4, a first through hole 111 is disposed on the top cover plate 11, a stepped hole 151 is disposed 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, 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 sequentially communicated, the extension 122 sequentially passes through the first hole 1511, the second hole 1512 and the first through hole 111, so that the extension 122 is disposed in the first through hole 111 and the second hole 1512, and the base portion 121 is disposed in the first hole 1511.

To avoid rotation of the base portion 121 within the first bore 1511, in the present embodiment, referring to fig. 2 and 4, the base portion 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 portion 121 and the top cover plate 11 and separates the base portion 121 and the top cover plate 11, the base portion 121 has a polygonal circumferential cross section, the outer periphery of the base portion 121 is attached to the insulating cover plate 15, the outer periphery of the base portion 121 is attached to the wall of the first hole 1511, because the outer periphery of the base part 121 is polygonal and the wall of the first hole 1511 is also polygonal, the relative rotation of the base part 121 in the first hole 1511 can be limited, thereby can avoid utmost point post 12 to a certain extent to take place to rotate under the effect that receives the external force, the structure of the switching piece of being connected with utmost point post 12 and the utmost point ear of being connected with the switching piece can not suffer destruction to can avoid electric core to take place the short circuit phenomenon to a certain extent.

Alternatively, the circumferential cross section of the base portion 121 may be a regular pentagon, a regular hexagon, a regular heptagon, or a regular octagon, so that the circumferential cross section area of the base portion 121 may be large, the rotation of the pole 12 in the first hole 1511 may be limited, and the connection firmness of the pole 12 may be better. In other embodiments, the circumferential cross section of the base portion 121 may not be a regular polygonal structure, but may be other general polygonal structures.

The following description will be given taking as an example a case where the area of the circumferential cross section of the base portion 121 is a regular hexagon or a regular octagon. Fig. 5 is a schematic view of a polygonal structure of the base portion 121 according to this embodiment. Referring to fig. 5, when the base body portion 121 of the pole 12 is provided using a cylindrical structure with the same volume, if the circumferential cross section of the base body portion 121 is a regular hexagon (a part filled in the figure), the circumferential cross-sectional area of the base body portion 121 is smaller; if the circumferential cross section of the base body 121 is octagonal, the circumferential cross section area of the base body 121 is large, the end area of the base body 121 is large, when the base body 121 is connected with the adapter sheet, the adapter sheet can be connected more firmly, the circumferential cross section area of the base body 121 is large, the strength of the base body 121 is high, the capacity of the pole 12 for bearing external tensile force can be increased to a certain extent, and the connection of the pole 12 is more reliable.

If the number of sides of the circumferential cross section of the base portion 121 is too large, the inner angle of the polygonal structure increases, and if the number of sides is too large, the inner angle approaches the circular structure, and the rotation of the base portion 121 of the pole 12 in the first hole 1511 cannot be restricted. The embodiments of the present application do not limit the number of sides of the circumferential cross section of the base portion 121, and any embodiment that can achieve the purpose of limiting the rotation of the base portion 121 in the first hole 1511 is within the scope of the present application.

In the embodiment of the application, FIG. 6 is a cross-sectional view VI-VI in FIG. 1; FIG. 7 is an enlarged view taken at VII in FIG. 6. Referring to fig. 4, 6 and 7, the top cover plate 11 includes a first plate 112 and a second plate 113, the second plate 113 is located inside the first plate 112, the second plate 113 is a circular ring structure, the second plate 113 is provided with a first through hole 111, the first through hole 111 and the second plate 113 are coaxially disposed, the thickness of the second plate 113 is smaller than that 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 stepped 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 may be made of an aluminum alloy material. (wherein "upper", "lower", "inner" and "outer" in the text refer to the directions indicated by the arrows in the drawings).

Further, the insulating cover plate 15 includes a third plate 152, a fourth plate 153 and a fifth plate 154, the fourth plate 153 is an annular structure, the fourth plate 153 is located inside the third plate 152, the fifth plate 154 is an annular structure, the fifth plate 154 is located inside the fourth plate 153, an upper surface of the third plate 152 contacts and fits with a lower surface of the first plate 112, upper surfaces of the fourth plate 153 and the fifth plate 154 are flush, upper surfaces of the fourth plate 153 and the fifth plate 154 contact and fit with a lower surface of the second plate 113, a lower surface of the fourth plate 153 and a lower surface of the third plate 152 are flush, a thickness of the fourth plate 153 is greater than a thickness of the fifth plate 154, so that a stepped hole 151 is formed between the fourth plate 153 and the fifth plate 154, a hole 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.

The surface of the base body portion 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 combining the insulating cover plate 15 and the base body portion 121 is a planar structure. The outer periphery of the first plate 112 of the top cover plate 11 protrudes beyond the outer periphery of the third plate 152, and the portion of the first plate 112 protruding beyond the third plate 152 is used for connection with the housing. Wherein the insulating cover 15 is made of an insulating plastic material, such as: the insulating cover 15 may be an insulating plastic cover, which is capable of insulating and has a certain strength.

In the embodiment of the present application, the extension portion 122 of the pole post 12 penetrates through the first through hole 111, and a part of the extension portion 122 protrudes out of the top cover plate 11, and the fixing member 13 is fixedly connected to one end of the protruding top cover plate 11 of the pole post 12. The fixing piece 13 is fixedly connected with the pole 12, and relative movement does not occur between the fixing piece 13 and the pole 12. Alternatively, the fixing member 13 is a metal fixing member 13, for example, the fixing member 13 is made of an alloy material. The fixing piece 13 is welded to the portion of the extension portion 122 of the pole post 12 protruding out of the top cover plate 11, so that the fixing piece 13 is fixed to the pole post 12.

In order to realize the insulation between the fixed member 13 and the top cover plate 11, a stopper 14 is disposed between the fixed member 13 and the top cover plate 11, and at least a portion of the stopper 14 is located between the fixed member 13 and the top cover plate 11 to separate the fixed member 13 from the top cover plate 11. In order to avoid the short circuit fault of the battery cell when the secondary battery is under the action of violent external force, the embodiment of the application. The surface of the top cover plate 11 contacting the limiting member 14 is a first mating surface, a first mating portion 114 is disposed on the first mating surface, the surface of the limiting member 14 contacting the top cover plate 11 is a second mating surface, a second mating portion 141 is disposed on the second mating surface, and the first mating portion 114 and the second mating portion 141 are in concave-convex fit to limit the limiting member 14 to rotate around the axis of the first through hole 111.

Because the top cover plate 11 is fixed on the housing, the top cover plate 11 will not rotate relative to the housing, the limiting member 14 is disposed on the upper surface of the top cover plate 11, the first engaging portion 114 is disposed on the upper surface of the top cover plate 11, the second engaging portion 141 is disposed on the lower surface of the limiting member 14, the relative rotation between the limiting member 14 and the housing (the rotation of the limiting member 14 relative to the top cover plate 11) can be limited by the concave-convex engagement of the first engaging portion 114 and the second engaging portion 141), the rotation of the limiting member 14 around the axis of the first through hole 111 (the axis of the pole 12) can be limited as a rotating shaft, because the limiting member 14 and the fixing member 13 have a certain friction force, the rotation of the fixing member 13 and the rotation of the extending portion 122 of the pole 12 fixedly connected to the fixing member 13 can be limited to a certain extent by the limiting member 14, thereby avoiding the mechanical damage of the adaptor plate connected with the pole 12, the risk that the electric core of the secondary battery has short circuit fault in the using process is reduced.

The limiting member 14 is made of an insulating material, such as: the position-limiting member 14 is an insulating plastic member, and compared with plastic, plastic has a slightly larger deformation energy, so that the concave-convex matching effect of the second matching portion 141 and the first matching portion 114 is better. Optionally, the insulating cover plate 15 is an insulating plastic cover plate, the material of the insulating plastic cover plate is different from that of the insulating plastic part, and the strength of the insulating plastic cover plate is greater than that of the insulating plastic part, so that the strength of the top cover assembly 10 is higher, and the first matching portion 114 and the second matching portion 141 are conveniently installed in a matching manner. Of course, the material of the insulating plastic cover plate can also be the same as that of the insulating plastic piece. If the limiting member 14 is to limit the rotation of the negative electrode post, the limiting member 14 may not be made of an insulating material. The application is not limiting.

The limiting member 14 is an annular structure, two first matching portions 114 may be provided, two second matching portions 141 may also be provided, the two second matching portions 141 are arranged at intervals along the circumferential direction of the limiting member 14, and the arrangement positions of the two first matching portions 114 correspond to the positions of the two second matching portions 141 one by one. Further, the two second engaging portions 141 are disposed opposite to each other with the axis of the limiting member 14 as a symmetry axis.

In one possible embodiment, please continue to refer to fig. 7, the first mating portion 114 is a protrusion protruding from the first mating surface of the top cover plate 11. The second matching portion 141 is a positioning hole formed in the limiting member 14, the positioning hole at least penetrates through the second matching surface of the limiting member 14, and the protrusion penetrates through the positioning hole.

If the positioning hole penetrates through the second mating surface of the limiting member 14 and the surface of the limiting member 14 opposite to the second mating surface, the positioning hole is a positioning through hole. The protruding upper surface (first fitting surface) of establishing at lamina tecti 11, protruding and lamina tecti 11 integrated into one piece, protruding for the metal protruding, positioning hole's pore wall is the plastic material, and positioning hole can have a small amount of deformations. Optionally, the protrusion is in interference fit with the positioning hole, so that the fit effect between the protrusion and the positioning hole is better, the relative movement of the limiting member 14 is avoided, and the relative rotation of the extension portion 122 of the pole 12 under the condition of severe external torque force is further reduced.

Optionally, the upper end of the protrusion may be flush with the upper end of the positioning through hole, and the upper end of the protrusion may also be located in the positioning through hole.

In another possible embodiment, referring to fig. 8, if the positioning hole penetrates through the second mating surface of the position-limiting member 14 and does not penetrate through the surface of the position-limiting member 14 opposite to the second mating surface, a positioning blind hole, i.e., a positioning groove, is formed, so that the structure of the upper surface of the position-limiting member 14 is more complete. The first mating portion 114 is a protrusion protruding from the first mating surface of the top cover plate 11. The bulge is fixed in the positioning groove.

In another possible embodiment, referring to fig. 9, the first mating portion 114 is a groove, and the groove penetrates through the first mating surface of the top cover plate 11. The second matching portion 141 is a protrusion protruding from the second matching surface of the limiting member 14, and the protrusion is fixed in the groove.

In another possible embodiment, referring to fig. 10, the first matching portion 114 is a through hole structure, and the through hole structure penetrates 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 protruding from the second matching surface of the limiting member 14, and the protrusion is disposed in the through hole structure.

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

The annular groove 142 has a certain wrapping effect with the circumferential outer edge of the fixing member 13, which can increase the contact area between the limiting member 14 and the fixing member 13, thereby increasing the friction force 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 with the fixing member 13.

With reference to fig. 2, fig. 4 and fig. 7, optionally, the fixing element 13 includes a first inner ring 131 and a protruding ring 132, the first inner ring 131 is fixedly connected to the post 12, the post 12 passes through a hole structure in the first inner ring 131 and is fixedly connected (e.g., welded) to the first inner ring 131, the protruding ring 132 is connected to an outer periphery of the first inner ring 131, and the protruding ring 132 is embedded in the annular groove 142.

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 two ends of the third ring 144, so that an annular groove 142 is formed among the second ring 143, the third ring 144 and the fourth ring 145, the third ring 144 is provided with a second matching portion 141, and the fourth ring 145 separates the first inner ring 131 and the protruding ring 132 from the top cover plate 11.

In a possible embodiment, the third ring 144 may not be a standard ring structure, and at the position where the second matching portion 141 is disposed, the third ring 144 slightly protrudes outwards to provide the second matching portion 141 (e.g., a second through hole) to form an ear hole structure for limiting the rotation of the limiting member 14.

In the embodiment of the present application, please refer to fig. 4 and fig. 7, the thickness of the protruding ring 132 is smaller than the thickness 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 formed by the protruding ring 132 and the first inner ring 131 completely contacts with the upper surface of the fourth ring 145, and the inner ring surface of the fourth ring 145 contacts with the outer circumferential surface of the extension portion 122 of the pole 12. The outer peripheral surface of the projecting ring 132 contacts the inner annular surface of the third ring 144, the upper surface of the projecting ring 132 contacts 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 annular surface of the second ring 143 contacts the outer peripheral surface of the first inner ring 131.

It should be noted that, with continuing reference to fig. 4 and 7, the connection point of the first inner ring 131 and the protruding ring 132 is substantially flush with the connection point of the fifth plate 154 and the fourth plate 153 (shown by the inner dashed line in fig. 7), the end point of the force applied by the limiting member 14 to the combined component (the combination of the extending portion 122 of the pole 12 and the fixing member 13) is between the inner ring surface of the second ring 143 and the outer circumferential surface of the first inner ring 131, the end point of the base portion 121 of the pole 12 and the insulating cover plate 15 is between the inner circumferential surface of the fourth plate 153 and the outer circumferential surface of the base portion 121, so that the end point of the extending portion 122 of the pole 12 and the end point of the base portion 121 of the pole 12 are substantially on the same straight line, which is substantially parallel to the axis of the pole 12, so that both end portions of the pole 12 can be subjected to substantially the same axial torsion force, that is, in the case of the pole 12 being subjected to a strong external torsion force, can avoid utmost point post 12 to take place to rotate, and the power of the restriction that receives at the both ends of utmost point post 12 is unanimous basically, can eliminate the inside moment of torsion (internal stress) of utmost point post 12, can avoid under the 12 pivoted circumstances of utmost point post, eliminate the inside moment of torsion of utmost point post 12, make the result of use of utmost point post 12 better. Further, the outer peripheral surface of the protruding ring 132 is substantially flush with the joint of the fourth plate 153 and the third plate 152 (indicated by the outer dotted line in fig. 7), so the force action point of the protruding ring 132 and the force action point of the base body portion 121 of the post 12, which is transmitted to the top cover plate 11, are substantially on the same straight line, which is substantially parallel to the axis of the post 12, further the force of the limitation received by the two ends of the post 12 is substantially the same, the internal torque force (internal stress) of the post 12 can be further eliminated, the internal torque force of the post 12 can be further eliminated under the condition of avoiding the rotation of the post 12, and the use effect of the post 12 is better.

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) clamped in the notch 1321 is provided on the bottom of the annular groove 142. The outer circumference of the protruding ring 132 is provided with a plurality of notches 1321, and the inner circumferential 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 circumferential surface of the protruding ring 132 and the inner circumferential surface of the third ring 144.

In the embodiment of the present application, set up insulating seal 16 between extension 122 and the top apron 11 and the insulating cover plate 15 of utmost point post 12, insulating seal 16 can be for sealed plastic part, can have better deformability, after forming the shell, can accomplish fine sealed effect to the inside of sealing member (in the casing) and the outside of sealing member (outside the casing). Optionally, the material of the insulating seal 16 is different from the material of the position limiting member 14, the insulating seal 16 has a higher deformability under insulating conditions, and the position limiting member 14 has a relatively lower deformability under insulating conditions, so as to have a better fixing effect on the pole post 12 under sealing conditions. Of course, the application is not limited and the material of the insulating seal 16 and the material of the stopper 14 may be the same.

Referring to fig. 4 and fig. 7, one end of the insulating sealing member 16 is connected to the limiting member 14, and the other end is connected to the insulating cover 15, so that the extending portion 122 and the base portion 121 are insulated from the top cover 11. The insulating seal member 16 is of an annular structure, and the axial section of the insulating seal member 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 annular surface of the fifth ring 161 is flush with the inner annular surface of the sixth ring 162, the inner annular surfaces of the fifth ring 161 and the sixth ring 162 are in contact with the outer circumferential surface of the extension portion 122, the upper surface of the fifth ring 161 is in contact with the lower surface of the stopper 14 (the lower surface of the fourth ring 145), the outer annular surface of the fifth ring 161 is in contact with the inner annular 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 circumferential surface of the sixth ring 162, and the lower surface of the sixth ring 162 is in contact with the inner surface of the base portion 121, so as to achieve the sealed.

The assembly method of the top cover assembly 10 provided by the embodiment of the application is as follows:

the top cover plate 11 and the insulating cover plate 15 are assembled first, so that the first through hole 111 of the top cover plate 11 and the stepped hole 151 of the insulating cover plate 15 are coaxially arranged. The insulating seal member 16 is sleeved outside the extension portion 122, and the lower surface of the insulating seal member 16 contacts the upper surface of the base portion 121. The limiting member 14 is sleeved 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 limiting member 14, and the second engaging portion 141 of the limiting member 14 is installed in cooperation with the first engaging portion 114 of the top cover plate 11 (for example, a protrusion on the top cover plate 11 is arranged in the second through hole on the limiting member 14 and is in 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 are in contact with the upper surface of the top cover plate 11. The extension portion 122 of the pole post 12 sequentially passes 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 limiting member 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 post 12 are firmly welded together.

After the assembly is completed, the inner annular surface of the first inner ring 131 and the outer peripheral surface of the extension portion 122 of the pole post 12 are welded together, the inner annular surface of the fourth ring 145 and the outer peripheral surface of the extension portion 122 of the pole post 12 contact each other, the inner annular surface of the seal stopper 14 and the outer peripheral surface of the extension portion 122 of the pole post 12 contact each other, the lower surface of the seal stopper 14 and the upper surface of the base portion 121 of the pole post 12 contact each other, the lower surface of the fifth plate 154 and the upper surface of the base portion 121 of the pole post 12 contact each other, and the inner annular surface of the fourth plate 153 and the outer peripheral surface of.

The beneficial effects of the above-mentioned cap assembly 10 include:

under the circumstances that utmost point post 12 received external pulling force, the upper end of the extension 122 of utmost point post 12 received under the effect of external pulling force, because utmost point post 12 assembles from making progress down, the power that utmost point post 12 received can be followed the base portion 121 of utmost point post 12 and is acted on top cover plate 11, can avoid utmost point post 12 to take place relative motion. Under the condition that utmost point post 12 received ambient pressure, the upper end of the extension 122 of utmost point post 12 received the ambient pressure under the condition, because the upper end of the extension 122 of utmost point post 12 welds with mounting 13, the power that utmost point post 12 received can be followed mounting 13 and is acted on top cover plate 11, can avoid utmost point post 12 to take place relative motion. Under the condition that the pole 12 is subjected to external torque force, the second matching part 141 on the limiting part 14 is matched with the first matching part 114 on the top cover plate 11, so that the rotation of the limiting part 14 can be limited, the limiting part 14 and the fixing part 13 have large friction force, and the extension part 122 (upper end) of the pole 12 is limited to rotate under the action of the torque force; the base portion 121 of the post 12 has a polygonal circumferential cross section and is fitted to the inner wall of the larger end of the stepped hole 151 of the insulating cover 15, so that the rotation of the base portion 121 (lower end) of the post 12 under the action of torque can be restricted, and the relative movement of the post 12 can be avoided.

Further, since the joint of the first inner ring 131 and the protruding ring 132 is substantially flush with the joint of the fifth plate 154 and the fourth plate 153, and the outer peripheral surface of the protruding ring 132 is substantially flush with the joint of the fourth plate 153 and the third plate 152, the torque force (internal stress) inside the pole 12 can be eliminated, and the use effect of the pole 12 is better.

Therefore, under the condition that the secondary battery is subjected to external violent impact, the pole 12 of the top cover assembly 10 can be prevented from moving relatively regardless of the tensile force, the pressure or the torque force, so that the adapter sheet (the pole lug connecting part) connected with the pole 12 is prevented from being damaged mechanically, and the short circuit fault of the battery core can be avoided.

The above description is only a few examples of the present application and is not intended to limit the present application, and various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cap assembly of a secondary battery, comprising:

a top cover plate having a first through hole;

the pole column penetrates through the first through hole;

the fixing piece is fixedly connected with one end of the pole, which protrudes out of the top cover plate;

the limiting piece is at least partially positioned between the fixing piece and the top cover plate to separate the fixing piece from the top cover plate;

the surface of the top cover plate contacting with the limiting part is a first matching surface, the first matching surface is provided with a first matching portion, the surface of the limiting part contacting with the top cover plate is a second matching surface, the second matching surface is provided with a second matching portion, and the first matching portion and the second matching portion are in concave-convex matching to limit the limiting part to rotate by taking the axis of the first through hole as a rotating shaft.

2. The header assembly of claim 1, wherein the first mating portion is a protrusion that is raised from the first mating surface of the header plate;

the second matching part is a positioning hole formed in the limiting part, the positioning hole at least penetrates through the second matching surface of the limiting part, and the protrusion penetrates through the positioning hole.

3. The header assembly of claim 2, wherein the locating holes are locating through holes or locating grooves.

4. The header assembly of claim 1, wherein the first mating portion is a recess formed in the header plate, the recess extending through the first mating surface of the header plate;

the second matching part is a protrusion which is convexly arranged on the second matching surface of the limiting part, and the protrusion is fixed in the groove.

5. The cap assembly of any one of claims 1-4, wherein the retaining member is an annular structure, and an annular groove is formed in a side of the retaining member adjacent to the fixing member;

the fixing piece is of an annular structure, the inner periphery of the fixing piece is fixedly connected with the pole, and the circumferential outer edge of the fixing piece is embedded in the annular groove.

6. The cap assembly of claim 5, wherein the securing member includes a first inner ring fixedly connected to the post and a protruding ring connected to an outer periphery of the first inner ring, the protruding ring being embedded in the annular groove.

7. The cap assembly of claim 6, wherein the raised ring has a notch, and the bottom of the annular groove has a protrusion that engages the notch.

8. The cap assembly according to claim 6 or 7, wherein the retaining member comprises 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 two ends of the third ring, so that the annular groove is formed among the second ring, the third ring and the fourth ring, the third ring is provided with the second matching portion, and the fourth ring separates the first inner ring and the protruding ring from the top cap plate.

9. The cap assembly of any one of claims 1-4, wherein the post includes an extension portion and a base portion, the extension portion passing through the first through hole and the extension portion being fixedly connected to the fixture; and the cap assembly further comprises:

an insulating cover plate located on one side of the top cover plate away from the limiting member, wherein the base body portion abuts against the insulating cover plate so that at least a part of the insulating cover plate is located between the base body portion and the top cover plate and separates the base body portion from the top cover plate;

the circumferential section of the base body is of a polygonal structure, and the periphery of the base body is attached to the insulating cover plate.

10. The header assembly of claim 9, wherein the insulating cover plate defines a stepped bore, and the extension is disposed through a smaller end of the stepped bore to engage the base portion with a bore wall at a larger end of the stepped bore.

11. The header assembly of claim 9, further comprising an insulating seal coupled at one end to the retainer and at another end to the insulating cover plate to insulate the extension and the base portion from the header plate.

12. A cap assembly of a secondary battery, comprising:

a metal top cover plate having a first through hole;

the pole column penetrates through the first through hole;

the metal fixing piece is fixedly connected with one end of the pole, which protrudes out of the top cover plate;

the insulating plastic part is at least partially positioned 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 positioned on one side, far away from the insulating plastic part, of the metal top cover plate;

the inner wall of the sealing plastic part is attached to the pole, and the sealing plastic part is respectively connected with the insulating plastic part and the insulating plastic cover plate to insulate the pole from the top cover plate;

the metal top cover plate is convexly provided with a bulge, the insulating plastic part is provided with an ear hole, and the bulge is arranged in the ear hole in a penetrating mode.

13. A secondary battery case comprising a case body and the top cover assembly of any one of claims 1 to 12, wherein the top cover plate is fitted to the case body.

14. A secondary battery comprising an electrode assembly, an interposer and the case of claim 13, wherein the electrode assembly is mounted in the case, one end of the interposer is connected to the electrode assembly via a tab, and the other end is connected to the terminal.