CN204156039U - Wound lithium-ion battery construction - Google Patents

Abstract

The utility model discloses a coiling type lithium ion battery structure, it includes positive plate, negative pole piece and diaphragm, positive plate, negative pole piece and diaphragm form electric core through the coiling, be provided with the gasbag piece between electric core. The utility model discloses coiled lithium ion battery structure is through at the positive plate, negative pole piece and diaphragm are through the inside air bag piece that sets up of electric core that the coiling formed, with this increase the inside space interval of electric core, before standing into for the product and standing the back formation, carry out cold and hot pressing or the gaseous discharge of anchor clamps plastic in with the air bag piece to the battery, the interval between the positive plate of electric core and the negative pole piece has also been guaranteed simultaneously, make the product still keep electric core thickness unchangeable after the circulation charge-discharge, the deformation problem of coiled lithium ion battery after the circulation charge-discharge has been eliminated promptly, and then guarantee the charge-discharge performance and the circulation life of product.

Description

Wound lithium-ion battery construction

technical field

The utility model relates to the technical field of battery structures, in particular to a wound lithium ion battery structure.

Background technique

Lithium-ion batteries have the important advantages of high voltage and high capacity, long cycle life and good safety performance, making them have broad application prospects in portable electronic equipment, electric vehicles, space technology, defense industry, etc. widely concerned research hotspots.

At present, lithium-ion batteries mainly adopt two structures, the traditional wound type and the stacked type. Among them, the stacked structure has complex process, low efficiency and relatively many safety hazards, while the wound structure has simple process, high production efficiency, safety and consistency. Good, but after the charge-discharge cycle of the traditional winding battery, the thickness of the internal pole piece of the battery increases, the battery body is deformed, the battery body is twisted, the battery thickness increases significantly, and damages the electrical equipment.

At the same time, the gap between the pole pieces inside the battery becomes larger, and it is difficult for the pole pieces to absorb liquid when the thickness of the battery is more than 10mm, and the liquid absorption is insufficient. When charging and discharging, the internal pole pieces of the battery are charged and discharged unevenly, which will shorten the battery life.

Utility model content

Based on this, it is necessary to address the deficiencies of the prior art and provide a wound lithium-ion battery structure that can solve the deformation problem of the battery after cyclic charge and discharge, increase the energy density of the battery, and improve the charge and discharge performance and cycle life of the battery.

In order to solve the above-mentioned technical problems, the technical solution adopted by the utility model is: a winding lithium ion battery structure, which includes a positive electrode sheet, a negative electrode sheet and a separator, and the positive electrode sheet, the negative electrode sheet and the separator are wound to form a battery. core, and an air bag sheet is arranged between the battery cores.

In one embodiment, the positive tab of the positive electrode sheet is located at one end of the cell, and the negative tab of the negative sheet is located at the other end of the cell.

In one of the embodiments, the airbag sheet is sealed and surrounded by PE film.

In one embodiment, the thickness of the PE film is 11.98 μm˜12.02 μm.

In one embodiment, the PE film has a thickness of 12 μm.

In one of the embodiments, the air bag sheet is arranged at 1/3-1/2 of the number of winding turns of the battery core.

In one of the embodiments, the airbag sheet is arranged on the front or back of the battery cell.

In one of the embodiments, 5-10ml of gas is accommodated in the airbag sheet.

To sum up, the structure of the winding lithium ion battery of the utility model is provided with an airbag sheet inside the cell formed by winding the positive electrode sheet, the negative electrode sheet and the diaphragm, thereby increasing the space interval inside the cell, and injecting the product After the electrolyte is left to stand and before it is formed, the battery is subjected to cold and hot pressing or fixture shaping to discharge the gas in the air bag sheet, and also to ensure the distance between the positive electrode sheet and the negative electrode sheet of the battery cell, so that the product remains stable after cycle charge and discharge. Keeping the thickness of the battery cell constant eliminates the deformation of the wound lithium-ion battery after cyclic charging and discharging, thereby ensuring the charging and discharging performance and cycle life of the product.

Description of drawings

Fig. 1 is the structural representation of the structure of the winding type lithium-ion battery of the present invention;

Fig. 2 is a schematic cross-sectional view of the utility model wound lithium ion battery structure;

Fig. 3 is a schematic structural view of the airbag sheet of the present invention.

Detailed ways

In order to further understand the features, technical means, and specific objectives and functions of the utility model, the utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 to 3, the structure of the wound lithium ion battery of the present invention includes a positive electrode sheet 10, a negative electrode sheet 20 and a separator (not shown in the figure), and the positive electrode sheet 10, the negative electrode sheet 20 and the separator are formed by winding In the battery cell 100 , the positive tab 11 of the positive electrode sheet 10 is located at one end of the battery cell 100 , and the negative tab 21 of the negative electrode sheet 20 is located at the other side of one end of the battery cell 100 .

An airbag sheet 30 is arranged between the battery cells 100, and the airbag sheet 30 is sealed and surrounded by a PE film. The airbag sheet 30 contains 5 to 10ml of gas, and the thickness of the PE film is 11.98 μm to 12.02 μm. μm, preferably 12 μm in thickness.

Specifically, the air bag sheet 30 is arranged at 1/3 to 1/2 of the number of winding turns of the battery cell 100, so as to increase the space interval inside the battery cell 100. Before the formation, the battery is subjected to cold and hot pressing or fixture shaping to discharge the gas in the air bag sheet 30, and also to ensure the distance between the positive electrode sheet 10 and the negative electrode sheet 20 of the battery cell 100, so that the product remains stable after cyclic charging and discharging. The thickness of the battery cell 100 remains unchanged, which eliminates the deformation problem of the wound lithium-ion battery after cyclic charge and discharge, thereby ensuring the charge and discharge performance and cycle life of the product.

The airbag sheet 30 is arranged on the front or back of the battery cell 100 to prevent uneven thickness distribution of the battery cell 100 when the airbag sheet 30 is arranged on the side of the battery cell 100 and ruptures, thereby avoiding uneven charging and discharging inside the product battery. uniform.

When the utility model is specifically manufactured, the cut positive electrode sheet 10, the negative electrode sheet 20 and the separator are manually stacked in sequence, and their starting ends are wound on the main winding needle, and the main winding needle driving mechanism drives the main winding needle to rotate. Drive the positive electrode sheet 10, negative electrode sheet 20 and separator positioned at the starting end to wind up to a predetermined thickness, the driving mechanism stops, manually position the air bag sheet 30 in parallel on the surface of the battery cell 100 of the predetermined thickness, and the driving mechanism works , to drive the main winding needle to continue to rotate to complete the production of the battery cell 100, wherein the position of the air bag sheet 30 is at 1/3 to 1/2 of the number of winding turns of the battery cell 100; Before final formation, the battery is subjected to cold and hot pressing or fixture shaping to discharge the gas in the air bag sheet 30, and at the same time, the distance between the positive electrode sheet 10 and the negative electrode sheet 20 of the battery cell 100 is ensured, so that the product remains stable after cyclic charging and discharging. Keeping the thickness of the battery cell 100 constant eliminates the deformation problem of the wound lithium-ion battery after cyclic charge and discharge, thereby ensuring the charge and discharge performance and cycle life of the product.

In summary, the structure of the wound lithium-ion battery of the present invention increases the space interval inside the cell 100 by setting the air bag sheet 30 inside the battery cell 100 formed by winding the positive electrode sheet 10, the negative electrode sheet 20 and the separator. , before the electrolyte is injected into the product and left to stand for formation, the battery is subjected to cold and hot pressing or fixture shaping to discharge the gas in the air bag sheet 30, and also to ensure the distance between the positive electrode sheet 10 and the negative electrode sheet 20 of the battery cell 100 , so that the product keeps the thickness of the cell 100 unchanged after cyclic charging and discharging, which eliminates the deformation problem of the wound lithium-ion battery after cyclic charging and discharging, thereby ensuring the charging and discharging performance and cycle life of the product.

The above-mentioned embodiments only express several implementation modes of the present utility model, and the description thereof is relatively specific and detailed, but should not be construed as limiting the scope of the present utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the present utility model should be based on the appended claims.

Claims (8)

1. a coiled lithium ion battery structure, comprise positive plate (10), negative plate (20) and barrier film, described positive plate (10), negative plate (20) and barrier film form battery core (100) through winding, it is characterized in that: be provided with air bag sheet (30) between described battery core (100).

2. coiled lithium ion battery structure according to claim 1, it is characterized in that: the anode ear (11) of described positive plate (10) is positioned at described battery core (100) side, one end, the negative electrode lug (21) of described negative plate (20) is positioned at described battery core (100) one end opposite side.

3. coiled lithium ion battery structure according to claim 1 and 2, is characterized in that: described air bag sheet (30) adopts the sealing of PE film to enclose formation.

4. coiled lithium ion battery structure according to claim 3, is characterized in that: the thickness of described PE film is 11.98 μm ~ 12.02 μm.

5. coiled lithium ion battery structure according to claim 4, is characterized in that: the thickness of described PE film is 12 μm.

6. coiled lithium ion battery structure according to claim 1 and 2, is characterized in that: described air bag sheet (30) is arranged on 1/3 ~ 1/2 place of the windings of described battery core (100).

7. coiled lithium ion battery structure according to claim 1 and 2, is characterized in that: described air bag sheet (30) is arranged on front or the back side of described battery core (100).

8. coiled lithium ion battery structure according to claim 1 and 2, is characterized in that: be equipped with 5 ~ 10ml gas in described air bag sheet (30).