CN215418348U - Lithium ion battery's top cap subassembly and lithium ion battery - Google Patents

Abstract

The utility model provides a lithium ion battery's top cap subassembly and lithium ion battery relates to lithium ion battery technical field, and the top cap subassembly includes: the top cover plate, the anode unit, the cathode unit and the lower injection molding piece are fixedly arranged on the bottom surface of the top cover plate, the anode unit and the cathode unit are respectively positioned on one side of the top cover plate, two ends of the top cover plate along the length direction of the top cover plate are respectively provided with an electrode hole, the anode unit and the cathode unit partially cover the corresponding electrode holes, and the rest part of the anode unit and the cathode unit extends to the upper part of the top surface of the top cover plate; the positive electrode unit and the negative electrode unit respectively comprise an electrode post, a fixing piece, a sealing ring and a connecting piece, a through hole is formed in the position, corresponding to the electrode post, of the lower plastic piece, and the bottom surface of the connecting piece is exposed out of the through hole. The lithium ion battery of the present disclosure uses the above-described cap assembly; the top cover assembly simplifies the assembly process of the top cover assembly, improves the assembly yield of the top cover, and can reduce the occupation of the top cover assembly on the internal space of the lithium ion square aluminum shell battery, thereby improving the energy density of the secondary battery.

Description

Lithium ion battery's top cap subassembly and lithium ion battery

Technical Field

The present disclosure relates to the field of lithium ion batteries, and particularly to a top cap assembly of a lithium ion battery and a lithium ion battery.

Background

The battery type that power battery trade generally adopted at present is square aluminum hull electricity core, and the main component of square aluminum hull electricity core is electric core aluminum hull and top cap subassembly, and electric core aluminum hull mainly functions is that an airtight space is held to holding electrode subassembly and electrolyte for the electricity core, and the electrode internal assembly realizes electrochemical reaction through being connected with the positive negative terminal of top cap subassembly.

Among the current top cap subassembly, lower injection molding piece generally is laser hot melt fit with the top cap cooperation, and assembly process is comparatively complicated, can not do over again after not only can influence the assembly efficiency of top cap and assemble the problem, influences top cap subassembly assembly yield, and then influences the top cap cost.

In the current common lithium ion square aluminum shell battery process, the connection mode of the Mylar sheet and the lower injection molding piece is hot melting, the lower injection molding piece needs a certain height to facilitate the hot melting of the Mylar sheet, and the lower injection molding piece structure reduces the internal space occupancy of the battery and is not beneficial to the improvement of energy density.

In view of the above, there is a need for an improved lid assembly of the prior art to solve the above problems.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a top cover assembly of a lithium ion battery and the lithium ion battery, which simplify the assembly process of the top cover assembly, improve the assembly yield of the top cover, and reduce the occupation of the top cover assembly on the internal space of the lithium ion square aluminum shell battery, thereby improving the energy density of the secondary battery.

In order to achieve the above purpose, the embodiment of the utility model adopts the following technical scheme:

in one aspect, a cap assembly for a lithium ion battery is provided, comprising: the lower injection molding piece is fixedly arranged on the bottom surface of the top cover piece, the positive electrode unit and the negative electrode unit are respectively positioned on one side of the top cover piece, two ends of the top cover piece along the length direction of the top cover piece are respectively provided with an electrode hole, the positive electrode unit and the negative electrode unit partially cover the corresponding electrode holes, and the rest part of the positive electrode unit and the rest part of the negative electrode unit extend to the upper part of the top surface of the top cover piece;

the positive electrode unit and the negative electrode unit respectively comprise an electrode post, a fixing piece, a sealing ring and a connecting piece, the fixing piece is provided with an accommodating cavity matched with the shape of the electrode post, and the electrode post is positioned in the accommodating cavity; one part of the fixing piece is positioned between the pole and the top cover piece, and the other part of the fixing piece is positioned above the top cover piece; the sealing ring is positioned among the connecting piece, the pole and the top cover plate, and the connecting piece is positioned below the pole and connected with the pole;

the lower plastic part is provided with a through hole at the position corresponding to the pole, and the bottom surface of the connecting piece is exposed out of the through hole.

In combination with one aspect, in a possible implementation manner, the positive electrode unit and the negative electrode unit further include a glue pulling ring respectively, the glue pulling ring is located between the pole, the fixing member and the top cover plate, and the pole and the fixing member are fixed to the top cover plate by the glue pulling ring.

In combination with one aspect, in one possible implementation, the glue pulling ring is combined with the fixing member and surrounds the pole, and the glue pulling ring fixes the pole and the fixing member to the top cover plate.

In combination with one aspect, in one possible implementation manner, the glue pulling ring includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the fixing member, and the second connecting portion is connected to the connecting member.

In combination with one aspect, in a possible implementation manner, the peripheral wall of the pole column is provided with a protruding portion, the accommodating cavity of the fixing member is provided with a recessed portion corresponding to the protruding portion, and the protruding portion is arranged in the recessed portion so as to achieve relative fixing of the pole column and the fixing member.

In combination with one aspect, in one possible implementation manner, the sealing ring is disposed between the fixing member and the top cover plate, and the sealing ring is disposed around the electrode hole.

In combination with one aspect, in a possible implementation manner, the lower injection molding piece includes an injection molding body and two bosses corresponding to the electrode holes, and the bosses correspond to the two electrode holes of the top cover plate;

the through hole is opened in the boss, the body of moulding plastics with the bottom surface laminating of top cap piece and fixed.

In combination with one aspect, in a possible implementation manner, the portable terminal further includes a first flexible connector and a second flexible connector, where the first flexible connector and the second flexible connector are oppositely disposed along a length direction of the top cover piece;

the first soft connecting piece and the second soft connecting piece are attached to the lower surface of the lower injection molding piece and fixed on the lower injection molding piece.

On the other hand, a lithium ion battery is provided, which comprises a shell body and a top cover assembly, wherein the top cover assembly uses the top cover assembly of the lithium ion battery;

the top cover component is arranged at the opening of the shell body, and the bottom surface of the top cover component is in contact with the outer brim at the opening of the shell body.

In the present disclosure, at least the following technical effects or advantages are provided:

according to the embodiment of the utility model, the parts of the top cover assembly are reduced, the assembly process of the top cover assembly is simplified, the assembly yield of the top cover is improved, and the occupation of the top cover assembly on the internal space of the lithium ion square aluminum shell battery can be reduced, so that the energy density of the secondary battery is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments of the present invention or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is an exploded view of a cap assembly of a lithium-ion battery provided in accordance with some embodiments of the present disclosure;

FIG. 2 is a top view of the cap assembly of FIG. 1;

FIG. 3 is a schematic sectional view of FIG. 2 taken along the section line A-A;

FIG. 4 is an enlarged view of a portion of FIG. 3;

FIG. 5 is a schematic cross-sectional view of FIG. 2 taken along the cross-sectional line B-B;

FIG. 6 is a partial enlarged view of part of (i) of FIG. 5;

FIG. 7 is a partial enlarged view of the second section of FIG. 5;

fig. 8 is an exploded view two of a cap assembly of a lithium ion battery provided in accordance with some embodiments of the present disclosure;

FIG. 9 is a top view of the cap assembly of FIG. 8;

FIG. 10 is a schematic cross-sectional view of FIG. 9 taken along the cross-sectional line C-C;

FIG. 11 is a partially enlarged view of the third part of FIG. 10;

reference numerals: 100-a cap assembly; 11-a top cover sheet; 21-a fixing member; 22-pole; 23-pulling a rubber ring; 24-a sealing ring; 25-a connector; 26-electrode hole; 33-lower molding; 34-a first flexible connection; 35-a second flexible connection; 36-electrode hole; 44-an explosion-proof valve; 45-protective sheet; 46-liquid injection hole; 201-connector radial projection; 202-lower molding bumps; 204 — a first flange; 205-receiving slots; 206-a trough body; 207-a first connection; 208-a second connection; 209-transition.

Detailed Description

The present disclosure is described in detail with reference to the embodiments shown in the drawings, but it should be understood that these embodiments are not intended to limit the present disclosure, and those skilled in the art should understand that the functional, methodological, or structural equivalents of these embodiments or substitutions may be included in the scope of the present disclosure.

In the description of the embodiments of the present disclosure, it is to be understood that the terms "central," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings, which are merely for convenience in describing the utility model and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be construed as limiting the utility model.

Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to a number of indicated technical features. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the utility model, the meaning of "a plurality" is two or more unless otherwise specified.

The terms "mounted," "connected," and "coupled" are to be construed broadly and may, for example, be fixedly coupled, detachably coupled, or integrally coupled; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the creation of the present invention can be understood by those of ordinary skill in the art through specific situations.

Referring to fig. 1 to 11, an embodiment of the present disclosure provides a top cap assembly 100 of a lithium ion battery, including: the top cover plate 11, the anode unit, the cathode unit and the lower molding piece 33, wherein the lower molding piece 33 is fixedly arranged on the bottom surface of the top cover plate 11, the anode unit and the cathode unit are respectively positioned on one side of the top cover plate 11, two ends of the top cover plate 11 along the length direction are respectively provided with an electrode hole 26, the anode unit and the cathode unit partially cover the corresponding electrode holes 26, and the rest part extends to the upper part of the top surface of the top cover plate 11; the positive electrode unit and the negative electrode unit respectively comprise an electrode post 22, a fixing piece 21, a sealing ring 24 and a connecting piece 25, the fixing piece 21 is provided with an accommodating cavity matched with the electrode post 22 in shape, and the electrode post 22 is positioned in the accommodating cavity; one part of the fixing piece 21 is positioned between the pole post 22 and the top cover plate 11, and the other part is positioned above the top cover plate 11; the sealing ring 24 is positioned among the connecting piece 25, the pole 22 and the top cover plate 11, and the connecting piece 25 is positioned below the pole 22 and connected with the pole 22; the lower plastic piece 33 is provided with a through hole corresponding to the pole 22, and the bottom surface of the connecting piece 25 is exposed out of the through hole.

The top cover plate 11 of the present embodiment is in a thin plate shape, and has a size and a shape matched with the opening of the housing body of the lithium ion battery, so as to be connected with the opening of the housing body in a matching manner. The top cover sheet 11 is made of a metal material, and for example, the same metal material as that of the case body can be selected. In the present embodiment, the top cover plate 11 is provided with an electrode hole 26, and the electrode hole 26 is also called an electrode lead-out hole, and the electrode lead-out hole can be arbitrarily changed according to the shape of the pole 22 so as to be adapted to the pole 22, and may be, for example, a circle, a square, an ellipse, a rectangle, and the like. The top cover plate 11 is provided with a liquid injection hole 46 according to a specified size, and the purpose is that the top cover plate 11 can be hermetically matched with the opening of the shell body and then can be injected with electrolyte in a sealed space of the shell body through liquid injection.

It is preferable that the top cover sheet 11 of the present embodiment is provided with an explosion-proof valve 4444 assembly substantially at the center, and the explosion-proof valve 4444 assembly may adopt an existing structure (for example, a manner of providing an explosion-proof sheet), and when the lithium ion battery generates gas due to overcharge, overdischarge, or overheating of the battery, so that the internal pressure of the lithium ion battery becomes excessive, the explosion-proof valve 4444 assembly may be broken, so that the gas formed inside the secondary battery may be discharged to the outside through the through-hole of the explosion-proof valve 4444 assembly, thereby preventing the explosion of the lithium ion battery.

The lower injection molding piece 33 of this embodiment is insulation board down also, and lower insulation board is located top cap piece 11 below, is connected with top cap piece 11 through connecting piece 25, and the fixed lower insulation piece of connecting piece 25, four sides of connecting piece 25 are connected with four sides of top cap piece 11, connect back connecting piece 25 and top cap piece 11 parallel and level. Preferably, the connection mode of the top cover plate 11 and the connecting piece 25 is laser welding, the small side edge of the radial protrusion of the connecting piece 25 is clamped and fixed with the protrusion of the lower molding piece 33, and in this example, the number of the radial protrusions of the connecting piece 25 is two, but may be four, six, and the like. The connection mode of the lower injection molding part 33 and the top cover plate 11 has simple process and easy operation, and compared with the conventional hot melting connection of the lower injection molding part 33 and the top cover plate 11, the connection mode is easy to rework and can improve the assembly yield, so the method has simple process for manufacturing the top cover and relatively lower manufacturing cost.

With continued reference to fig. 1, 2, 8, and 9, the positive electrode unit of the embodiment of the disclosure partially covers the electrode hole 26 corresponding to the positive electrode unit, and the remaining portion extends above the top surface of the top cover 11; the positive pole unit comprises a positive pole, a fixing piece 21, a sealing ring 24 and a connecting piece 25, wherein the fixing piece 21 is provided with an accommodating cavity matched with the shape of the positive pole, and the positive pole is positioned in the accommodating cavity; one part of the fixing piece 21 is positioned between the positive pole column and the top cover plate 11, and the other part is positioned above the top cover plate 11; the sealing ring 24 is positioned among the connecting piece 25, the positive pole and the top cover plate 11, and the connecting piece 25 is positioned below the positive pole and connected with the positive pole. The negative electrode unit of the embodiment of the present disclosure partially covers the electrode hole 26 corresponding to the negative electrode unit, and the rest extends above the top surface of the top cover plate 11; the negative electrode unit comprises a negative electrode post, a fixing piece 21, a sealing ring 24 and a connecting piece 25, wherein the fixing piece 21 is provided with an accommodating cavity which is adaptive to the shape of the negative electrode post, and the negative electrode post is positioned in the accommodating cavity; one part of the fixing piece 21 is positioned between the negative pole column and the top cover piece 11, and the other part is positioned above the top cover piece 11; and the sealing ring 24 is positioned between the connecting piece 25, the negative pole column and the top cover plate 11, and the connecting piece 25 is positioned below the negative pole column and connected with the negative pole column.

In the present embodiment, in order to simplify the structure of the pole 22, the pole 22 is an independent structure and can be formed by stamping alone. Referring to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, and fig. 7, the fixing element 21 is coupled to the outer peripheral surface of the pole 22 by injection molding, and the fixing element 21 may be made of a high temperature resistant insulating plastic material by integral injection molding, for example, one or more materials of polyphenylene sulfide PPS, perfluoroalkoxy resin PEA, or polypropylene PP.

With continuing reference to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6 and fig. 7, in the present embodiment, the fixing element 21 has a receiving space adapted to the shape of the pole 22, so as to be able to receive the pole 22 plate in the receiving space and to be fixed in contact with the pole 22 plate, at this time, a part of the fixing element 21 may be sandwiched between the pole 22 plate and the top cover plate 11, and in addition, the fixing element 21 may be a revolving body structure or other structures.

With continuing reference to fig. 1, 2, 3, 4, 5, 6 and 7, in order to make the connection between the pole 22 and the fixing member 21 more stable, a protrusion and a groove are correspondingly provided between the pole 22 and the fixing member 21, and the fixing between the pole 22 and the fixing member 21 is achieved by the snap-fit of the protrusion and the groove. Exemplarily, in the present embodiment, the pole post 22 is provided with a convex portion, and the fixture 21 is provided with a groove portion corresponding to the convex portion, specifically, the convex portion is a first flange protruding from the outer circumferential surface of the pole post 22; correspondingly, the recessed portion is a receiving groove provided in the circumferential direction of the inner wall surface of the through hole of the fixing piece 21. When the fixing member 21 is sleeved on the outer periphery of the pole 22, the protruding portion of the pole 22 is inserted into the groove of the fixing member 21, that is, a part of the fixing member 21 is located on the side of the first flange departing from the top cover plate and is in abutting fit with the first flange, so that the purpose that the pole 22 and the fixing member 21 are fixed to each other is achieved.

With continued reference to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, and fig. 7, according to an embodiment of the present disclosure, the adhesive ring 23 is combined with the fixing member 21 and surrounds the periphery of the post 22, so as to fix the post 22 and the fixing member 21 to the top cover plate. In addition, the material of the rubber ring 23 is a metal material, so as to improve the stability of the connection. Illustratively, the glue ring 23 includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the fixing member 21, and the second connecting portion is connected to the connecting member 25. The grommet 23 is formed in a substantially inverted L-shape in cross section when cut in the longitudinal direction.

With continuing reference to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, and fig. 7, in particular, according to an exemplary embodiment of the present disclosure, in order to fix the pole 22 and the fixing member 21 to the top cover plate, a portion of the first connecting portion and a portion of the second connecting portion are both fixedly connected to the fixing member 21 (e.g., the first connecting portion and the second connecting portion are embedded in the fixing member 21 to be joined), and at the same time, the bottom of the second connecting portion is fixedly connected to the connecting member 25 (e.g., the second connecting portion and the connecting member 25 are joined by laser welding). Specifically, in the present embodiment, the fixing member 21 is provided with a receiving groove in the circumferential direction, the receiving groove is formed in a position near the bottom of the outer circumferential surface of the fixing member 21, and the shape of a cross section of the receiving groove cut in the longitudinal direction matches the shape of the glue-pulling ring 23.

With continued reference to fig. 1, 2, 3, 4, 5, 6, and 7, in particular, according to an exemplary embodiment of the disclosure, the first connection portion extends toward a direction close to the electronic terminal, and the second connection portion extends toward a direction away from the post 22. The second connecting portion is located keeping away from top deck one side of the first flange of utmost point post 22, and partial mounting 21 is located utmost point post 22 and draws between the glue ring 23, separate utmost point post 22 and draw glue ring 23 each other, avoid installing utmost point post 22, mounting 21, sealing washer 24 and connecting piece 25 in the top deck back, contact between utmost point post 22 and the glue ring 23 that draws (if anodal utmost point post 22 with the glue ring 23 contact that draws that corresponds the positive pole side, and negative utmost point post 22 with the glue ring 23 contact that draws that corresponds the negative pole side, because the glue ring 23 that draws of positive and negative side all with the top deck together, consequently can cause lithium ion battery short circuit problem). Therefore, the second connecting portion indirectly forms an abutting fit with the first flange of the pole 22 through the fixing member 21, thereby further pressing the pole 22 and the fixing member 21 against the top cover plate.

With continued reference to fig. 1, 2, 3, 4, 5, 6, and 7, in accordance with an exemplary embodiment of the present disclosure, to seal the electrode lead-out hole, a sealing ring 24 is disposed between the post 22 and the top cover plate and surrounds the electrode lead-out hole. In the present embodiment, specifically, the surface of the sealing ring 24 facing the top cover plate 11 is provided with a groove, and the side of the pole post 22 facing the sealing ring 24 is provided with a first flange around the electrode lead-out hole, and the first flange extends toward the direction close to the side of the electrode hole 26, and the sealing ring 24 is sleeved on the first flange, so that the first flange is received in the groove of the sealing ring 24, to position the sealing ring 24 through the first flange, and to prevent the sealing ring 24 from moving. In addition, after the terminal assembly is assembled on the top cover plate, the terminal post 22 can press the sealing ring 24 towards the top cover plate under the pressing force of the rubber pulling ring 23, so that the sealing ring 24 between the groove body and the flange of the terminal post 22 can be pressed, and the sealing ring 24 forms a sealing line between the terminal post 22 and the top cover plate. Therefore, the sealing performance between the pole post 22 and the top cover plate can be improved, and the problem of leakage caused by untight sealing between the pole post 22 and the top cover plate is avoided, so that the use reliability of the secondary battery can be further improved.

In addition, because utmost point post 22, mounting 21, utmost point post 22 and mounting 21 in sealing washer 24 and the connecting piece 25 all adopt the mode of from the top down assembly to be fixed in the lamina tecti, and draw the second connecting portion and the connecting piece 25 welded connection of glued ring 23, and sealing washer 24 bottom surface and connecting piece 25 contact cooperation, consequently can provide effectual packing force for sealing washer 24 indirectly through drawing glued ring 23 and connecting piece 25, thereby can promote the electrode and draw out the sealed effect in hole, sealing washer 24 sets up inside with the electric core top cap simultaneously, it is very little with the inside electrolyte of shell body and the probability of emergence swelling phenomenon, guarantee secondary battery's use reliability, thereby avoid in the use, the problem of sealed inefficacy appears.

With continued reference to fig. 8, 9, 10 and 11, according to the embodiment of the present disclosure, the adhesive ring 23 surrounds the periphery of the post 22 and is engaged with the fixing member 21, so as to fix the post 22 and the fixing member 21 to the top cover plate. In addition, in order to improve the stability of the connection, the rubber ring 23 is preferably made of a metal material. In an exemplary embodiment of the present disclosure, the glue pulling ring 23 includes a ring main body and a first connecting portion, and the first connecting portion is connected with the fixing member 21 and the ring main body. Illustratively, the ring body includes a transition portion and a second connection portion, the transition portion being connected between the first connection portion of the glue ring 23 and the second connection portion of the glue ring 23. The first connection portion of the glue pulling ring 23 and the second connection portion of the glue pulling ring 23 are respectively connected to two end portions of the transition portion of the glue pulling ring 23, and the first connection portion of the glue pulling ring 23 and the second connection portion of the glue pulling ring 23 respectively extend towards opposite directions, so that the cross section of the second fixing piece 21 of the glue pulling ring 23 after being longitudinally cut is formed to be approximately S-shaped.

Specifically, according to the exemplary embodiment of the present disclosure, in order to fix the pole 22 and the fixing member 21 to the top cover sheet 11, the first connection portion of the glue pulling ring 23 and the transition portion of the glue pulling ring 23 are both fixedly connected to the fixing member 21 (for example, the first connection portion and the transition portion are engaged by being embedded in the fixing member 21), while the second connection portion is fixedly connected to the connecting member 25. Specifically, in the present embodiment, the fixing member 21 is provided with a receiving groove along the inner circumferential direction, the receiving groove is annular and the opening of the receiving groove is formed at a position close to the bottom of the inner circumferential surface of the first fixing member 21, and the cross section of the receiving groove cut along the longitudinal direction is substantially S-shaped, that is, the shape of the receiving groove matches with the shape of the first connecting portion of the glue drawing ring 23 and the transition portion of the glue drawing ring 23.

Specifically, draw the second connecting portion of gluing ring 23 and be connected with connecting piece 25, connecting piece 25 carries out fixed connection with top cover plate 11 simultaneously, draws the second connecting portion and the connecting piece 25 of gluing ring 23 in this embodiment for welded connection, and connecting piece 25 also can set up in inside and draw the holding tank that glues ring 23 second connecting portion shape matching, will draw the second connecting portion and the connecting piece 25 of gluing ring 23 to carry out the joint and be connected.

With reference to fig. 1 to 11, the positive electrode unit and the negative electrode unit further include a glue pulling ring 23, respectively, the glue pulling ring 23 is located between the terminal 22, the fixing member 21 and the top cover 11, and the glue pulling ring 23 fixes the terminal 22 and the fixing member 21 to the top cover 11.

In some embodiments, it is preferable that the glue-pulling ring 23 is combined with the fixing member 21 and surrounds the pole 22, and the glue-pulling ring 23 fixes the pole 22 and the fixing member 21 to the top cover plate 11.

More specifically, it is preferable that the zipper ring 23 includes a first connecting portion connected to the fixing member 21 and a second connecting portion connected to the connecting member 25.

The peripheral wall of the pole column 22 is provided with a protruding portion, the accommodating cavity of the fixing piece 21 is provided with a groove portion corresponding to the protruding portion, and the protruding portion is arranged on the groove portion so as to realize the relative fixation of the pole column 22 and the fixing piece 21.

The sealing ring 24 of the present disclosure is disposed between the fixing member 21 and the top cover plate, and the sealing ring 24 is disposed around the electrode hole 26.

The lower injection molding part 33 comprises an injection molding body and two bosses which are arranged corresponding to the electrode holes 26 and correspond to the two electrode holes 26 of the top cover plate 11; the boss is seted up to the through-hole, and the body of moulding plastics is laminated and is fixed with the bottom surface of top cap piece 11.

The top cover assembly 100 of the lithium ion battery disclosed by the utility model comprises a top cover plate 11, a positive electrode unit, a negative electrode unit and a lower molding part 33, and also comprises a first soft connecting piece 3425 and a second soft connecting piece 3525, wherein the first soft connecting piece 3425 and the second soft connecting piece 3525 are oppositely arranged along the length direction of the top cover plate 11; the first flexible connecting member 3425 and the second flexible connecting member 3525 are fixed to the lower molding member 33 while being attached to the lower surface of the lower molding member 33.

According to the top cover assembly 100 of the lithium ion battery provided by the embodiment of the disclosure, the lower injection molding piece 33 is clamped with the top cover plate 11 through the connecting piece 25, so that the connection mode of lower injection molding and the top cover plate 11 is simplified, the production assembly and the rework are easy, the production yield is improved, and the cost of the lithium ion battery is reduced. In addition, since the sealing ring 24 and the rubber pulling ring 23 provide pressing force to the pole 22 at the same time, the sealing performance of the top cover assembly 100 is improved, and thus the sealing performance of the lithium ion battery can be further improved.

The top cover assembly 100 of the embodiment of the disclosure has a simple structure, and is easy to produce and assemble, so that the production efficiency of the lithium ion battery can be improved, and the production cost of the lithium ion battery can be reduced.

The embodiment of the present disclosure further provides a lithium ion battery, which includes a housing body and a top cover assembly 100, where the top cover assembly 100 uses the top cover assembly 100 of the lithium ion battery in the above aspect; the top cover assembly 100 is arranged at the opening of the shell body, and the bottom surface of the top cover assembly 100 is in contact with the outer edge of the opening of the shell body.

The lithium ion battery comprises a top cover assembly 100, a shell body and an electric core assembly positioned inside the shell body. The housing body may be made of a metal material, such as aluminum, aluminum alloy, or nickel-plated steel. The case body is formed in a rectangular box shape and has an opening to communicate with an accommodating space inside thereof through the opening.

The electric core assembly is generally formed by stacking or winding a positive electrode sheet, a negative electrode sheet, and a separator, wherein the separator is an insulator between the positive electrode sheet and the negative electrode sheet. In the present embodiment, the positive electrode tab and the negative electrode tab are exemplified. Similarly, in other embodiments, the positive electrode sheet may be a negative electrode sheet, and the negative electrode sheet may be an positive electrode sheet. In addition, the positive electrode sheet active material may be coated on the coating region of the positive electrode sheet, and the negative electrode sheet active material may be coated on the coating region of the negative electrode sheet. The part extending out of the coating area of the positive plate is used as a tab, namely the positive tab; the part extending from the coating region of the negative electrode sheet serves as a tab, i.e., a negative electrode tab.

The housing body is sealed by a cap assembly 100, and the cap assembly 100 is coupled to the housing body through its opening while sealing the cell assembly within the housing body. According to one embodiment of the present disclosure, the top cap assembly 100 generally includes a top cover sheet 11, a pole post 22 assembly, and a lower insulator.

In order to solve the problem that the lower molding part 33 is generally in laser hot-melt fit with the top cover in the existing top cover assembly 100, the assembly process is complex, the assembly efficiency of the top cover is affected, rework cannot be performed after the assembly is failed, the assembly yield of the top cover assembly 100 is affected, and the cost of the top cover is affected, please continue to refer to fig. 1 to 11, the lower molding part 33 of the embodiment of the disclosure includes two bosses at the corresponding positions of the top surface and the through hole of the top cover plate 11, and the top cover plate 11 is engaged with the connecting piece 25 through the bosses to complete the fit of the top cover plate 11.

In order to solve the problem that the Mylar sheet (Mylar sheet) and the lower molding member 33 are connected in a hot melting manner, in the method, the lower molding member 33 needs to have a certain height so as to be convenient for hot melting of the Mylar sheet, and the lower molding member 33 has a structure so that the occupancy rate of the internal space of the battery is reduced and the improvement of the energy density is not facilitated, please refer to fig. 1 to 11, the connecting member 25 of the embodiment of the present disclosure includes a first portion and a second portion, the connecting member 25 of the first portion preferably adopts a small protrusion connected with the lower molding member 33, and the connecting member 25 of the first portion at least includes two protrusions which are in snap fit with the lower molding member 33 from two opposite sides. The connecting piece 25 of the second part is connected with the top cover plate 11 by laser and is positioned at the same horizontal plane with the top cover plate 11. With continued reference to fig. 1 to 11, the sealing ring 24 of the embodiment of the present disclosure includes a first portion and a second portion, the sealing ring 24 of the first portion is disposed between the connecting piece and the pole 22; the sealing ring 24 of the second part is in interference fit with the pole 22 part to fix the sealed pole 22; with reference to fig. 1 to 11, the glue ring 23 of the embodiment of the disclosure includes a first portion and a second portion, the glue ring 23 of the first portion is connected to the connecting piece by laser, and the glue ring 23 of the second portion is partially embedded in the injection molding piece to further fix and seal the terminal post 22.

The above-listed detailed description is merely a specific description of possible embodiments of the present disclosure, and is not intended to limit the scope of the disclosure, which is intended to include within its scope equivalent embodiments or modifications that do not depart from the technical spirit of the present disclosure.

It will be evident to those skilled in the art that the disclosure is not limited to the details of the foregoing illustrative embodiments, and that the present disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (9)

1. A cap assembly for a lithium ion battery, comprising: the lower injection molding piece is fixedly arranged on the bottom surface of the top cover piece, the positive electrode unit and the negative electrode unit are respectively positioned on one side of the top cover piece, two ends of the top cover piece along the length direction of the top cover piece are respectively provided with an electrode hole, the positive electrode unit and the negative electrode unit partially cover the corresponding electrode holes, and the rest part of the positive electrode unit and the rest part of the negative electrode unit extend to the upper part of the top surface of the top cover piece;

the positive electrode unit and the negative electrode unit respectively comprise an electrode post, a fixing piece, a sealing ring and a connecting piece, the fixing piece is provided with an accommodating cavity matched with the shape of the electrode post, and the electrode post is positioned in the accommodating cavity; one part of the fixing piece is positioned between the pole and the top cover piece, and the other part of the fixing piece is positioned above the top cover piece; the sealing ring is positioned among the connecting piece, the pole and the top cover plate, and the connecting piece is positioned below the pole and connected with the pole;

the lower plastic part is provided with a through hole at the position corresponding to the pole, and the bottom surface of the connecting piece is exposed out of the through hole.

2. The lithium ion battery cap assembly of claim 1, wherein the positive electrode unit and the negative electrode unit further comprise a glue pulling ring respectively, the glue pulling ring is located between the pole, the fixing member and the top cover plate, and the pole and the fixing member are fixed to the top cover plate by the glue pulling ring.

3. The lithium ion battery cap assembly of claim 2, wherein the glue pulling ring is combined with the fixing member and surrounds the pole, and the glue pulling ring fixes the pole and the fixing member to the cap plate.

4. The top cap assembly of the lithium ion battery of claim 2 or 3, wherein the glue pulling ring comprises a first connecting portion and a second connecting portion, the first connecting portion is connected with the fixing member, and the second connecting portion is connected with the connecting member.

5. The top cap assembly of the lithium ion battery of claim 1, wherein the peripheral wall of the terminal post is provided with a protrusion portion, the receiving cavity of the fixing member is provided with a groove portion corresponding to the protrusion portion, and the protrusion portion is disposed in the groove portion, so as to fix the terminal post and the fixing member relatively.

6. The lithium ion battery cap assembly of claim 1, wherein the sealing ring is disposed between the fixture and the cap plate, the sealing ring being disposed around the electrode aperture.

7. The top cover assembly of the lithium ion battery as claimed in claim 1, wherein the lower molding member comprises a molding body and two bosses corresponding to the electrode holes, and the two bosses correspond to the two electrode holes of the top cover plate;

the through hole is opened in the boss, the body of moulding plastics with the bottom surface laminating of top cap piece and fixed.

8. The lithium ion battery top cap assembly of claim 1, further comprising a first soft connector and a second soft connector, wherein the first soft connector and the second soft connector are oppositely arranged along the length direction of the top cap piece;

the first soft connecting piece and the second soft connecting piece are attached to the lower surface of the lower injection molding piece and fixed on the lower injection molding piece.

9. A lithium ion battery comprising a case body and a top cap assembly, wherein the top cap assembly uses the top cap assembly of the lithium ion battery of any one of claims 1 to 8;

the top cover component is arranged at the opening of the shell body, and the bottom surface of the top cover component is in contact with the outer brim at the opening of the shell body.

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