CN209981370U

CN209981370U - Lithium ion battery's book core

Info

Publication number: CN209981370U
Application number: CN201920795964.8U
Authority: CN
Inventors: 李穷; 邵振东; 钱伟
Original assignee: Anhui Woboyuan Technology Co Ltd
Current assignee: Anhui Woboyuan Technology Co Ltd
Priority date: 2019-05-28
Filing date: 2019-05-28
Publication date: 2020-01-21
Anticipated expiration: 2029-05-28

Abstract

The utility model provides a winding core of a lithium ion battery, which comprises a positive plate and a negative plate, wherein the winding core is formed after the positive plate and the negative plate are wound; the positive plate comprises a positive current collector and a positive active material layer, the positive current collector comprises a first surface and a second surface opposite to the first surface, the first surface and the second surface are both in a sawtooth shape, the positive current collector is provided with a plurality of first through holes penetrating through the first surface and the second surface at intervals, and the positive active material layer on the first surface is mutually connected with the positive active material layer on the second surface through the plurality of first through holes; the negative pole piece includes negative pole mass flow body and negative pole active material layer, and the negative pole mass flow body includes third surface and fourth surface, and third surface and fourth surface are the cockscomb structure, and the negative pole mass flow body interval is equipped with a plurality of second through-holes that run through third surface and fourth surface, and negative pole active material layer on the third surface and the negative pole active material layer on the fourth surface pass through a plurality of second through-hole interconnect.

Description

Lithium ion battery's book core

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of battery materials, in particular to a winding core of a lithium ion battery.

[ background of the invention ]

In recent years, lithium ion batteries have been widely used in the fields of electronics and electric vehicles because of their advantages of high production consistency, high safety, high production efficiency, and the like. With the development of electric automobiles, the energy density of batteries is required to be higher and higher, and the energy density of lithium ion batteries is increased at a rate of 7% -10% per year. Currently, the energy density of 18650 batteries produced by battery enterprises reaches more than 250Wh/kg, and the energy density of 21700 batteries reaches more than 300 Wh/kg. In the process of charging and discharging of the high-energy-density lithium ion battery, the active material of the pole piece is easy to separate from the current collector, and powder falling occurs, so that the conductivity of the electrode is poor, and the performance of the battery is influenced.

In view of the above, it is necessary to provide a new winding core of a lithium ion battery to overcome the above drawbacks.

[ summary of the invention ]

The invention aims to provide a winding core of a lithium ion battery, which can improve the adhesive capacity of an active material and a current collector, avoid powder falling, improve the capacity of the lithium ion battery and improve the charge and discharge performance of the battery.

In order to achieve the purpose, the invention provides a winding core of a lithium ion battery, which comprises a positive plate and a negative plate, wherein the positive plate and the negative plate form the winding core after being wound; the positive plate comprises a positive current collector and positive active material layers coated on two surfaces of the positive current collector, the positive current collector comprises a first surface and a second surface opposite to the first surface, the first surface and the second surface are both in a sawtooth shape, the positive current collector is provided with a plurality of first through holes penetrating through the first surface and the second surface at intervals, and the positive active material layer on the first surface is connected with the positive active material layer on the second surface through the plurality of first through holes; the negative pole piece includes the negative pole mass flow body and coats the negative pole active material layer on the negative pole mass flow body two sides, the negative pole mass flow body includes the third surface and the fourth surface relative with the third surface, third surface and fourth surface are the cockscomb structure, a plurality of runs through have been seted up at negative pole mass flow body interval the second through-hole on third surface and fourth surface, negative pole active material layer on the third surface and the negative pole active material layer on the fourth surface pass through a plurality of second through-hole interconnect.

In one preferred embodiment, the first surface of the positive electrode current collector includes a first positive electrode blank area, which is not coated with a positive electrode active material layer; the second surface of the positive current collector comprises a second positive blank area opposite to the first positive blank area, and the second positive blank area is not coated with a positive active material layer; the positions of the first positive electrode blank area and the second positive electrode blank area are used for welding positive electrode lugs; the third surface of the negative current collector comprises a first negative blank area, and the first negative blank area is not coated with a negative active material layer; after the positive plate and the negative plate are wound, the first negative pole blank area is opposite to the first positive pole blank area and the second positive pole blank area.

In a preferred embodiment, the first positive electrode blank area and the second positive electrode blank area are located in the middle of the positive electrode current collector; the first negative pole blank region is located the middle position of the negative pole mass flow body.

In a preferred embodiment, the width of the first positive electrode blank area and the second positive electrode blank area is 8-10 mm, the width of the positive electrode tab is 4-6 mm, and the thickness of the positive electrode tab is 0.8-1.2 mm.

In a preferred embodiment, the width in the blank area of first negative pole is 2 ~ 4mm big than the width in first positive pole blank area and the blank area of second positive pole, the blank area subsides of first negative pole have adhesive tape, the width of the adhesive tape in the blank area of first negative pole is 1 ~ 2mm big than the width in the blank area of first negative pole, adhesive tape is that silica gel or ya keli glue.

In a preferred embodiment, the third surface of the negative electrode current collector comprises a second negative electrode blank area, the second negative electrode blank area is located at one end of the negative electrode current collector, the second negative electrode blank area is not coated with a negative electrode active material layer, and the second negative electrode blank area is used for welding a negative electrode tab.

In a preferred embodiment, the width of the second negative electrode blank area is 8-10 mm, the width of the negative electrode tab is 4-6 mm, and the thickness of the negative electrode tab is 0.8-1.2 mm.

In a preferred embodiment, the thickness of the positive electrode active material layer and the negative electrode active material layer is 0.05mm to 0.3 mm.

Compared with the prior art, the winding core of the lithium ion battery provided by the invention has the advantages that the adhesion capability of the active material and the current collector is improved, the powder falling in the charging and discharging process is avoided, the capacity of the lithium ion battery is improved, and the charging and discharging performance of the battery is improved.

[ description of the drawings ]

Fig. 1 is a schematic structural diagram of a positive plate of a winding core of a lithium ion battery provided by the invention;

fig. 2 is a schematic structural diagram of a negative plate of a winding core of a lithium ion battery provided by the invention;

FIG. 3 is an enlarged view taken at A in FIG. 1;

fig. 4 is an enlarged view at B in fig. 2.

[ detailed description ] embodiments

In order to make the objects, technical solutions and advantageous effects of the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Referring to fig. 1 and fig. 2, the present invention provides a winding core of a lithium ion battery, including a positive plate 10 and a negative plate 20, wherein the positive plate 10 and the negative plate 20 are wound to form the winding core.

Referring to fig. 3 and 4, the positive plate 10 includes a positive electrode collector 11 and positive electrode active material layers 12 coated on two sides of the positive electrode collector 11, the positive electrode collector 11 includes a first surface 111 and a second surface 112 opposite to the first surface 111, the first surface 111 and the second surface 112 are both in a zigzag shape, the positive electrode collector 11 is provided with a plurality of first through holes 113 penetrating through the first surface 111 and the second surface 112 at intervals, the positive electrode active material layers 12 on the first surface 111 and the positive electrode active material layers 12 on the second surface 112 are connected to each other through the plurality of first through holes 113, that is, the positive electrode active material layers 12 fill the first through holes 113, and the positive electrode active material layers 12 on the first surface 111 and the positive electrode active material layers 12 on the second surface 112 are communicated with the positive electrode active material layers 12 in the first through holes 113; the negative electrode sheet 20 includes a negative electrode current collector 21 and negative electrode active material layers 22 coated on two sides of the negative electrode current collector 21, the negative electrode current collector 21 includes a third surface 211 and a fourth surface 212 opposite to the third surface 211, the third surface 211 and the fourth surface 212 are both saw-toothed, a plurality of second through holes 213 penetrating through the third surface 211 and the fourth surface 212 are formed at intervals on the negative electrode current collector 21, the negative electrode active material layer 22 on the third surface 211 and the negative electrode active material layer 22 on the fourth surface 212 are connected with each other through the plurality of second through holes 213, that is, the second through holes 213 are filled with the negative electrode active material layer 22, and the negative electrode active material layer 22 on the third surface 211 and the negative electrode active material layer 22 on the fourth surface 212 are communicated with the negative electrode active material layer 22 in the second through holes 213.

The first surface 111 of the positive electrode current collector 11 comprises a first positive electrode blank area 114, and the first positive electrode blank area 114 is not coated with the positive electrode active material layer 12; the second surface 112 of the positive electrode collector 11 includes a second positive electrode blank area 115 opposite to the first positive electrode blank area 114, and the second positive electrode blank area 115 is not coated with the positive electrode active material layer 12; the positions of the first positive electrode blank area 114 and the second positive electrode blank area 115 are used for welding positive electrode tabs; the third surface 211 of the negative electrode current collector 21 includes a first negative electrode blank area 214, the first negative electrode blank area 214 being not coated with the negative electrode active material layer 22; after the positive electrode sheet 10 and the negative electrode sheet 20 are wound, the first negative electrode blank area 214 is opposite to the first positive electrode blank area 114 and the second positive electrode blank area 115; in the process of charging and discharging of the lithium ion battery, the negative electrode active material layer 22 expands, so that great pressure is generated on the position of the positive electrode tab, and the situation of breakage of the positive electrode tab can be caused.

In this embodiment, the first positive electrode blank area 114 and the second positive electrode blank area 115 are located in the middle of the positive electrode current collector 11; the first negative blank area 214 is located in the middle of the negative current collector 21.

The width of first anodal blank region 114 and the blank region 115 of second anodal is 8 ~ 10mm, the width of anodal utmost point ear is 4 ~ 6mm, the thickness of anodal utmost point ear is 0.8 ~ 1.2mm, the width of first anodal blank region 114 and the blank region 115 of second anodal is greater than the width of anodal utmost point ear. Specifically, the high temperature resistant adhesive tape of tawny is pasted on anodal utmost point ear, and the width that the width of adhesive tape will be greater than about 1 ~ 2mm of the width of first anodal blank region 114 and the blank region 115 of second anodal, and the adhesive tape be silica gel or ya keli and glue, and the base member of adhesive tape is PVC or PET material, and the insulating properties of anodal utmost point ear department has been guaranteed to the adhesive tape, prevents to roll up the inside short circuit of core, has improved lithium ion battery's security performance.

The width of first negative pole blank region 214 is than the 2 ~ 4mm that the width of first positive pole blank region 114 and the blank region 115 of second positive pole is big, the blank region 214 of first negative pole is pasted and is covered gummed paper, the width of the gummed paper of the blank region 214 department of first negative pole is 1 ~ 2mm big than the width of the blank region 214 of first negative pole, gummed paper is that silica gel or ya keli glue.

The third surface 211 of the negative electrode current collector 21 includes second negative electrode blank area 215, the second negative electrode blank area 215 is located the one end of the negative electrode current collector 21, the second negative electrode blank area 215 is not coated with the negative electrode active material layer 22, the second negative electrode blank area 215 is used for welding the negative electrode tab. The width of the blank area 215 of the second negative electrode is 8-10 mm, the width of the negative electrode tab is 4-6 mm, the thickness of the negative electrode tab is 0.8-1.2 mm, namely, the width of the blank area 215 of the second negative electrode is greater than the width of the negative electrode tab.

In the winding core of the lithium ion battery, the first surface 111 and the second surface 112 of the positive current collector 11 are both in a sawtooth shape, so that the contact area between the positive active material layer 12 and the two surfaces of the positive current collector 11 is greatly increased, the adhesion force between the positive active material layer 12 and the positive current collector 11 is increased, the positive active material layer 12 fills the first through hole 113, the positive active material layer 12 on the first surface 111 and the positive active material layer 12 on the second surface 112 are communicated with the positive active material layer 12 in the first through hole 113, the positive active material layers 12 on the two surfaces of the positive current collector 11 are integrally bonded, and the adhesion force between the positive active material layer 12 and the positive current collector 11 is further enhanced; the third surface 211 and the fourth surface 212 of the negative electrode current collector 21 are both in a zigzag shape, so that the contact area between the negative electrode active material layer 22 and the two surfaces of the negative electrode current collector 21 is greatly increased, the adhesion force between the negative electrode active material layer 22 and the negative electrode current collector 21 is increased, the second through hole 213 is filled with the negative electrode active material layer 22, the negative electrode active material layer 22 on the third surface 211 is communicated with the negative electrode active material layer 22 on the fourth surface 212 and the negative electrode active material layer 22 in the second through hole 213, the negative electrode active material layers 22 on the two surfaces of the negative electrode current collector 21 are integrally bonded, and the adhesion force between the negative electrode active material layer 22 and the positive electrode current collector 21 is further increased; the thickness of the positive active material layer 12 and the negative active material layer 22 reaches 0.05 mm-0.3 mm, and the performance of the lithium ion battery is improved.

The winding core of the lithium ion battery provided by the invention improves the adhesion capability of the active material and the current collector, avoids powder falling in the charging and discharging process, improves the capacity of the lithium ion battery, and improves the charging and discharging performance of the battery.

The invention is not limited solely to that described in the specification and embodiments, and additional advantages and modifications will readily occur to those skilled in the art, so that the invention is not limited to the specific details, representative apparatus, and illustrative examples shown and described herein, without departing from the spirit and scope of the general concept as defined by the appended claims and their equivalents.

Claims

1. The utility model provides a lithium ion battery's book core which characterized in that: the winding structure comprises a positive plate and a negative plate, wherein the positive plate and the negative plate form a winding core after being wound; the positive plate comprises a positive current collector and positive active material layers coated on two surfaces of the positive current collector, the positive current collector comprises a first surface and a second surface opposite to the first surface, the first surface and the second surface are both in a sawtooth shape, the positive current collector is provided with a plurality of first through holes penetrating through the first surface and the second surface at intervals, and the positive active material layer on the first surface is connected with the positive active material layer on the second surface through the plurality of first through holes; the negative pole piece includes the negative pole mass flow body and coats the negative pole active material layer on the negative pole mass flow body two sides, the negative pole mass flow body includes the third surface and the fourth surface relative with the third surface, third surface and fourth surface are the cockscomb structure, a plurality of runs through have been seted up at negative pole mass flow body interval the second through-hole on third surface and fourth surface, negative pole active material layer on the third surface and the negative pole active material layer on the fourth surface pass through a plurality of second through-hole interconnect.

2. The winding core of the lithium ion battery of claim 1, wherein: the first surface of the positive current collector comprises a first positive blank area, and the first positive blank area is not coated with a positive active material layer; the second surface of the positive current collector comprises a second positive blank area opposite to the first positive blank area, and the second positive blank area is not coated with a positive active material layer; the positions of the first positive electrode blank area and the second positive electrode blank area are used for welding positive electrode lugs; the third surface of the negative current collector comprises a first negative blank area, and the first negative blank area is not coated with a negative active material layer; after the positive plate and the negative plate are wound, the first negative pole blank area is opposite to the first positive pole blank area and the second positive pole blank area.

3. The winding core of the lithium ion battery of claim 2, wherein: the first positive electrode blank area and the second positive electrode blank area are positioned in the middle of the positive electrode current collector; the first negative pole blank region is located the middle position of the negative pole mass flow body.

4. The winding core of the lithium ion battery of claim 3, wherein: the width in first anodal blank region and the blank region of second positive pole is 8 ~ 10mm, the width of anodal utmost point ear is 4 ~ 6mm, the thickness of anodal utmost point ear is 0.8 ~ 1.2 mm.

5. The winding core of the lithium ion battery of claim 4, wherein: the width in the blank area of first negative pole is than the width in the blank area of first positive pole and the blank area of second positive pole 2 ~ 4mm big, the blank area subsides of first negative pole have gummed paper, the width of the gummed paper in the blank area of first negative pole is 1 ~ 2mm big than the width in the blank area of first negative pole, gummed paper is that silica gel or ya keli glue.

6. The winding core of the lithium ion battery of claim 5, wherein: the third surface of the negative pole mass flow body includes the blank area of second negative pole, the blank area of second negative pole is located the one end of the negative pole mass flow body, the blank area of second negative pole does not coat the negative pole active material layer, the blank area of second negative pole is used for welding negative pole utmost point ear.

7. The winding core of the lithium ion battery of claim 6, wherein: the width in the blank area of second negative pole is 8 ~ 10mm, the width of negative pole utmost point ear is 4 ~ 6mm, the thickness of negative pole utmost point ear is 0.8 ~ 1.2 mm.

8. The winding core of the lithium ion battery of claim 7, wherein: the thickness of the positive electrode active material layer and the negative electrode active material layer is 0.05 mm-0.3 mm.