CN213483820U

CN213483820U - Cylindrical cathode electrode-free ear lithium ion battery

Info

Publication number: CN213483820U
Application number: CN202022859285.8U
Authority: CN
Inventors: 李宗植; 刘聪; 侯峰; 徐宁; 王永湘; 杨波; 王永月; 高�豪
Original assignee: Dongguan K Tech New Energy Co ltd; Guangdong Greenway Technology Co Ltd
Current assignee: Dongguan K Tech New Energy Co ltd; Guangdong Greenway Technology Co Ltd
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2021-06-18
Anticipated expiration: 2030-12-02

Abstract

The utility model relates to a cylindrical cathode electrodeless ear lithium ion battery, wherein the side wall and the bottom of a metal shell are integrally formed by stamping, and the inner bottom surface of the shell body of the shell is provided with a bulge; the tail end of the copper foil of the negative plate of the winding core is left white to form a negative empty copper foil, the negative empty copper foil is flattened to be made into a non-tab form in a full-tab structure and is placed on a bulge at the bottom of the shell in a mechanical contact mode to be closely connected; and welding the positive pole tab of the positive plate in the winding core with the combined cap with CID, and crimping and sealing. The utility model discloses a lithium ion battery top positive pole adopts traditional ripe utmost point ear and block welding and slot rolling to seal the mode, has both kept the safety device who takes the CID block, has very efficient packaging technology again, and the empty paper tinsel of bottom negative pole and the protruding mechanical contact's in metal casing bottom mode not only have the advantage of the improvement multiplying power performance of the full utmost point ear mode of negative pole, need not to flow the cover plate welding that dish and structure are complicated moreover, and is with low costs, and production efficiency is high.

Description

Cylindrical cathode electrode-free ear lithium ion battery

Technical Field

The utility model belongs to the technical field of lithium ion battery and specifically relates to a cylinder type negative pole electrodeless ear lithium ion battery.

Background

The lithium ion battery has the advantages of high specific energy, long cycle life, good safety, light weight, no memory effect, no pollution and the like, and is widely applied to the fields of 3C and electric tools. The typical winding type cylindrical lithium ion battery is characterized in that tabs of a positive electrode plate and a negative electrode plate are welded at one end of a current collector and then connected to a shell of the battery, if the number of the tabs is small, the contact internal resistance of the battery is relatively high, the discharge requirement of high magnification cannot be met, and the application of the battery in the field of power batteries is limited. If a multi-tab design is adopted, the structure is complex, the process difficulty is high, and a large space is occupied.

In order to obtain a high-rate cylindrical lithium ion battery, the full-tab process becomes a new power battery manufacturing scheme, at present, the general process of the full-tab is to weld a current collecting disc and a battery tab into a whole in a laser welding mode, and the other end of the current collecting disc is connected with a pole of a cover plate together in a welding or riveting mode to realize the sealing and current loop of the cylindrical lithium ion battery. However, the battery adopting the full-tab process has the disadvantages of complex structural parts, low welding efficiency, high manufacturing cost and low yield.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a cylinder type negative pole electrodeless ear lithium ion battery, this lithium ion battery top positive pole adopts traditional ripe utmost point ear and block welding and slot rolling to seal the mode, has both kept the safety device who takes the CID block, has very efficient packaging technology again, the empty paper tinsel of bottom negative pole and the protruding mechanical contact's in metal casing bottom mode not only have the advantage of the improvement multiplying power performance of the full utmost point ear mode of negative pole, and need not to flow the cover plate welding that set and structure are complicated, and is with low costs, and production efficiency is high.

The utility model discloses a following technical scheme realizes:

providing a cylindrical cathode electrodeless ear lithium ion battery, wherein a shell of the lithium ion battery is made of metal, the side wall and the bottom of the shell are integrally formed by stamping, and a bulge is arranged on the inner bottom surface of a shell of the shell; the tail end of a copper foil of a negative plate of a winding core in the lithium ion battery is left blank to form a negative empty copper foil, the negative empty copper foil is flattened to be made into a non-tab form in a full-tab structure and is placed on a bulge at the bottom of the shell in a mechanical contact mode to be closely connected; and welding the positive pole tab of the positive plate in the winding core with the combined cap with the CID, and crimping and sealing.

Further, the height of the protrusions is 0.3-0.8 mm.

Furthermore, the shape of the bulge comprises two annular circular arcs, and the two annular circular arcs have different diameters and are mutually nested concentrically; or the shape of the bulge is in a shape of a Chinese character mi.

Furthermore, the tail end of the copper foil of the negative plate is left white by 5-12mm in width.

Furthermore, the positive pole lug of the positive pole piece is of a single-pole lug structure or a multi-pole lug structure.

Further, the outer shell is a steel shell.

Further, the negative empty copper foil is placed on the bulge at the bottom of the shell in a pressing or hard contact mode to be tightly connected.

The utility model has the advantages that:

1. the top positive electrode adopts the traditional mature mode of tab and cap welding and rolling groove sealing, thereby not only retaining the safety device with the CI D cap, but also having a very high-efficiency packaging process;

2. the bottom negative electrode empty foil is in mechanical contact with the metal shell, and the bottom of the shell is provided with the bulge, so that the current of the inner and outer rings of the negative electrode is in contact conduction with the outside, a current collecting disc and a cover plate with a complex structure are not required to be welded, the cost is low, and the production efficiency is high;

3. the internal resistance of the winding core with the structure is low, and the multiplying power charge and discharge performance of the winding core is improved.

The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention can be implemented according to the content of the description, and in order to make the said and other objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the present invention is given.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like elements throughout the drawings.

In the drawings:

fig. 1 is a schematic view of a winding core provided by the present invention;

FIG. 2 is a sectional view of the steel shell of the present invention;

fig. 3 is a bottom view of the bottom of the steel shell of the present invention;

FIG. 4 is a bottom view of another steel can bottom according to the present invention;

fig. 5 is the utility model provides a roll up section schematic diagram of core after going into shell encapsulation.

Reference numerals:

101: a positive electrode tab; 102: a negative electrode bare copper foil;

201: the height of the annular arc bulge at the bottom of the steel shell is high;

301: the bottom of the steel shell is annularly and circularly convex;

302: the bottom of the steel shell is convex in a shape like a Chinese character 'mi';

401: and (6) combining the cap.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As shown in fig. 1 to 5, the present embodiment mainly relates to a cylindrical lithium ion battery, which is a connection structure of positive and negative electrode plates.

Specifically, referring to fig. 1, a positive electrode tab 101 of a positive electrode sheet of a lithium ion battery roll core is made into a single-electrode tab structure or a multi-electrode tab structure, and when designing a negative electrode coating, a copper foil of the positive electrode sheet is divided into a plurality of areas to be cut which are same in size and are adjacent in sequence, in each area to be cut, negative electrode powder is coated on the copper foil to form a negative electrode sheet, and the end of the copper foil of the negative electrode sheet is kept blank for 5-12mm, preferably 6mm, to form a negative electrode empty copper foil 102.

And rolling and slitting are carried out after coating, the slit negative plate is matched with a positive plate and a diaphragm to prepare a winding core, wherein the negative plate of the winding core is prepared into an ear-free form in a full-tab structure, and then the negative empty copper foil 102 is flattened and left for later use.

Referring to fig. 2, the metal casing of the lithium ion battery is a steel casing which is formed by integrally stamping a steel casing wall and a steel casing bottom, and the inner bottom surface of the steel casing is stamped to form a protrusion, the height 201 of the protrusion is 0.3-0.8mm, preferably 0.5mm, and the protrusion is arranged at the steel casing bottom to facilitate the close contact between the cathode empty copper foil 102 and the steel casing bottom.

Preferably, the shape of the protrusion is configured as two circular arcs 301 as shown in fig. 3, and the two circular arcs 301 have different diameters and are nested concentrically with each other. Or the shape of the protrusion is set to be a Chinese character 'mi' shape 302 as shown in fig. 4. By arranging the convex shape, the negative electrode copper foil can be better contacted with the flattened negative electrode empty copper foil 102, and matching design is realized.

Referring to fig. 5, after the roll core and the steel shell are prepared, the roll core is placed into the shell and then is rolled, baked and injected, and the cathode empty copper foil 102 which is leveled at the bottom of the roll core is placed on a bulge at the bottom of the steel shell in a mechanical contact mode such as extrusion or hard contact and the like to be tightly connected, and then the anode tab 101 and the combined cap 401 with the CID are welded in a laser mode and then are mechanically rolled and sealed.

The utility model has the advantages that:

1. the top positive electrode adopts the traditional mature mode of tab and cap welding and rolling groove sealing, thereby not only retaining the safety device with CID cap, but also having very high-efficiency packaging process;

2. the bottom negative pole empty foil is in mechanical contact with the steel shell, and the shell bottom is provided with two circular arcs or protrusions shaped like a Chinese character 'mi', so that the current of the inner and outer rings of the negative pole can be conducted in an external contact mode, a current collecting disc and a cover plate with a complex structure are not required to be welded, the cost is low, and the production efficiency is high;

It should be finally noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. The cylindrical cathode electrode-free ear lithium ion battery is characterized in that:

the shell of the lithium ion battery is made of metal, the side wall and the bottom of the shell are integrally formed by stamping, and a bulge is arranged on the inner bottom surface of the shell;

the tail end of a copper foil of a negative plate of a winding core in the lithium ion battery is left blank to form a negative empty copper foil, the negative empty copper foil is flattened to be made into a non-tab form in a full-tab structure and is placed on a bulge at the bottom of the shell in a mechanical contact mode to be closely connected;

and welding the positive pole tab of the positive plate in the winding core with the combined cap with the CID, and crimping and sealing.

2. The cylindrical negative electrode ear-free lithium ion battery as claimed in claim 1, wherein: the height of the protrusions is 0.3-0.8 mm.

3. The cylindrical negative electrode ear-free lithium ion battery as claimed in claim 2, wherein:

the shape of the bulge comprises two annular arcs, the diameters of the two annular arcs are different, and the two annular arcs are mutually nested in a concentric mode; or

The shape of the bulge is in a shape of a Chinese character mi.

4. The cylindrical negative electrode ear-free lithium ion battery as claimed in claim 1, wherein: the tail end of the copper foil of the negative plate is left white and is 5-12mm wide.

5. The cylindrical negative electrode ear-free lithium ion battery as claimed in claim 1, wherein: the positive pole lug of the positive pole piece is of a single-pole lug structure or a multi-pole lug structure.

6. The cylindrical negative electrode ear-free lithium ion battery as claimed in claim 1, wherein: the outer shell is a steel shell.

7. The cylindrical negative electrode ear-free lithium ion battery as claimed in claim 1, wherein: the negative empty copper foil is placed on the bulge at the bottom of the shell in a pressing or hard contact mode and is tightly connected with the bulge.