CN212934696U

CN212934696U - Lithium ion battery

Info

Publication number: CN212934696U
Application number: CN202021369769.8U
Authority: CN
Inventors: 张�焕; 柯文瑜; 张灿灿; 周贵树; 许士安
Original assignee: Huizhou BYD Industrial Co Ltd
Current assignee: Huizhou BYD Industrial Co Ltd
Priority date: 2020-07-13
Filing date: 2020-07-13
Publication date: 2021-04-09
Anticipated expiration: 2030-07-13

Abstract

The utility model belongs to the technical field of the lithium cell package, especially, relate to a lithium ion battery. The lithium ion battery comprises a shell, a pole core and a swelling component, wherein the pole core and the swelling component are accommodated in the shell, the swelling component is arranged between the pole core and the inner wall of the shell to isolate the pole core and the shell, and the swelling component can swell after being soaked in electrolyte. The embodiment of the utility model provides an in, the swelling layer sets up utmost point core with between the casing, after injecting into electrolyte among the lithium ion battery, the swelling part is soaked the back inflation by electrolyte, under the prerequisite of guaranteeing insulating nature, has indirectly improved the area of contact of utmost point core and aluminum hull, reduces thermal contact resistance, improves the radiating efficiency, and the life-span improves the battery security performance to guarantee the maneuverability of production process utmost point core cover shell, the cover shell of can relaxing.

Description

Lithium ion battery

Technical Field

The utility model belongs to the technical field of the lithium cell package, especially, relate to a lithium ion battery.

Background

At present, in cylinder lithium ion battery, have certain space between utmost point core and the casing, add the locking membrane circle in utmost point core side, pack into the casing and pour into electrolyte back into when utmost point core, the locking membrane circle swells under the effect of electrolyte, makes it can with utmost point core in close contact with, fills completely the space between utmost point core and the casing, firmly fixes utmost point core and casing, and difficult production is rocked, and then avoids the risk that the battery opened circuit. However, the above-mentioned stop membrane ring is C-shaped, although it is better in cylindrical battery, it is not well matched in square aluminum cell, and in addition, the stop membrane ring mainly reduces the risk of open circuit, and does not consider the influence on heat after the stop membrane ring is added to the pole core.

After the battery is charged and discharged at a high multiplying power or at a high temperature, heat is accumulated, and if the heat cannot be effectively dissipated in time, several problems can be caused along with the heat accumulation: (1) the large heat generation quantity leads to the accelerated degradation of the battery and the reduction of the cycle/storage life; (2) heat is accumulated and difficult to dissipate, which may bring safety risk; (3) the poor heat conductivility of battery itself needs outside liquid cooling, brings the energy consumption big, the high problem of carbon emission. In order to ensure that the square battery is easy to cover, a certain gap is reserved between the end face of the pole core and the shell, and the existence of the gap causes large thermal contact resistance of the side face of the pole core and difficult heat transfer of the pole core.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: the lithium ion battery is provided aiming at the problems of large contact thermal resistance and difficult heat transfer of the pole core caused by large gap between the pole core and the shell of the existing square battery.

In order to solve the technical problem, the embodiment of the utility model provides a lithium ion battery, be in including the casing and hold utmost point core and swelling part in the casing, the swelling part sets up in order to keep apart between the inner wall of utmost point core and casing, the swelling part can take place to swell after soaking electrolyte.

Optionally, the lithium ion battery further includes an insulator disposed between the end side surface of the pole piece and the swelling member and/or between the end side surface of the pole piece and the inner wall of the case.

Optionally, the insulator is a side spacer, and the swelling member includes a first swelling layer for filling a gap between the side spacer and the pole core and a second swelling layer for filling a gap between the side spacer and the case.

Optionally, the side spacer includes a main plate, a side plate and a bottom plate, the main plate is parallel to the end side surface of the pole core, the side plate extends along the side edge of the main plate in a direction perpendicular to the main plate, the side plate is parallel to the large surface of the pole core, and the bottom plate extends along the bottom edge of the main plate in a direction perpendicular to the main plate.

Optionally, the first swelling layer is sprayed on the inner side of the main plate of the side space ring, and the second swelling layer is sprayed on the outer side of the main plate of the side space ring.

Optionally, the first swelling layer is sprayed on the inner side of the main board, and the second swelling layer is sprayed or adhered on the inner wall of the case on the side parallel to the end side face of the main board.

Optionally, the housing is an aluminum shell.

Optionally, the insulating member is an insulating sleeve, the swelling member is a third swelling layer, the insulating sleeve is sleeved on the periphery of the pole core, the third swelling layer is located between the insulating sleeve and the shell, and the third swelling layer is adhered to the inner wall of the shell in a direction parallel to the end side face of the pole core.

The embodiment of the utility model provides an in, the swelling part sets up utmost point core with between the casing, after injecting into electrolyte among the lithium ion battery, the swelling part is soaked the back inflation by electrolyte, under the prerequisite of guaranteeing insulating nature, has indirectly improved the area of contact of utmost point core and aluminum hull, reduces thermal contact resistance, improves the radiating efficiency, and the life-span improves the battery security performance to guarantee the maneuverability of production process utmost point core cover shell, the cover shell of can relaxing.

Drawings

Fig. 1 is a schematic structural view of a side space ring according to an embodiment of the present invention;

fig. 2 is a schematic view of a large-area front view structure inside a battery according to an embodiment of the present invention;

fig. 3 is a schematic view of an internal top structure of a battery according to another embodiment of the present invention;

fig. 4 is a schematic view of a battery according to another embodiment of the present invention.

The reference numerals in the specification are as follows:

1. a housing; 2. a pole piece; 3. a side space ring; 4. a first swelling layer; 5. a second swelling layer; 6. an insulating sleeve; 7. a third swelling layer.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1 to 4, an embodiment of the present invention provides a lithium ion battery, including a housing 1, a pole core 2 and a swelling member, which are accommodated in the housing 1, wherein the housing 1 is an aluminum shell, the swelling member is disposed between the pole core 2 and an inner wall of the housing 1 to isolate the pole core 2 from the housing 1, and the swelling member can swell after being soaked in an electrolyte.

After electrolyte is injected into the lithium ion battery, the swelling part is soaked by the electrolyte and then expands, so that the contact area between the pole core 2 and the shell 1 is indirectly increased on the premise of ensuring insulativity, the contact thermal resistance is reduced, the heat dissipation efficiency is improved, the service life is prolonged, the safety performance of the battery is improved, the operability of the pole core 2 shell in the production process is ensured, and the shell can be easily sleeved.

In the all-tab battery, a polymer material having swelling properties may be directly used to form the structure of the side space ring 3, the structure of the side space ring 3 is known to those skilled in the art, and the structure of the side space ring 3 is shown in fig. 1. For a full-lug battery, the insulation between the side face and the large face of the lug end needs to be ensured, the side space ring 3 with swelling property swells after being soaked by electrolyte, so that the large face and the side face of the lug can be in close contact with an aluminum shell, the thermal contact resistance of the large face and the side end face can be reduced, and the heat transmission is facilitated.

As shown in fig. 1 to 2, in an embodiment, the lithium ion battery further includes an insulator disposed between an end side surface of the pole core 2 and the swelling member and/or between an end side surface of the pole core 2 and an inner wall of the case 1.

In one embodiment, the insulating member is a side spacer 3, and the side spacer 3 is disposed between an end surface of the pole core 2 and the housing 1. The swelling part comprises a first swelling layer 4 and a second swelling layer 5, the first swelling layer 4 is used for filling a gap between the side spacer 3 and the pole core 2, the second swelling layer 5 is used for filling a gap between the side spacer 3 and the shell 1, after the side spacer 3 is soaked in electrolyte, the inner side of the side spacer 3 is in close contact with the end face of the pole core 2 through the expanded first swelling layer 4, and the outer side of the side spacer 3 is in close contact with the shell 1 through the expanded second swelling layer 5.

In an embodiment, the material of the first swelling layer 4 and the second swelling layer 5 is selected from one or more of PEO (polyethylene oxide), PMMA (polymethyl methacrylate), PVC (polyvinyl chloride), PVDF (polyvinylidene fluoride), PVB (polyvinyl butyral), PAN (polyacrylonitrile).

As shown in fig. 1, in an embodiment, in the lithium ion battery of the embodiment of the present invention, the side spacer 3 can adopt the existing conventional structure and material, two end side portions of the pole core 2 are all provided with the side spacer 3, which facilitates the casing of the pole core 2 and ensures the insulation between the pole core 2 and the casing 1. The side space ring 3 has the following specific structure: the side spacer 3 includes a main plate 31, a side plate 32, and a bottom plate 33, the main plate 31 is parallel to the end side surface of the pole core 2, the side plate 32 extends along the side edge of the main plate 31 in the direction perpendicular to the main plate 31, the side plate 32 is parallel to the large surface of the pole core 2, and the bottom plate 33 extends along the bottom edge of the main plate 31 in the direction perpendicular to the main plate 31. The material of the side space ring 3 is polypropylene.

In one embodiment, the thickness of the swelling member is calculated by calculating the gap left by the actual cell design and the swelling ratio of the swelling member in the electrolyte, the first swelling layer 4 is sprayed with a certain thickness on the inner side of the main plate 31 of the side spacer 3, the second swelling layer 5 is sprayed with a certain thickness on the outer side of the main plate 31 of the side spacer 3, the thicknesses of the first swelling layer 4 and the second swelling layer 5 are determined according to the gap in the cell shell 1 and the material of the selected swelling member, after spraying the swelling member, the first swelling layer 4 is used for filling the gap between the side spacer 3 and the pole core 2, and the second swelling layer 5 is used for filling the gap between the side spacer 3 and the shell 1.

As shown in fig. 1 to 2, in one embodiment, the first swelling layer 4 may be sprayed on the inner side of the main plate 31, and the second swelling layer 5 may be sprayed on the inner surface of the case 1 on the side parallel to the end surface of the main plate 31, or the first swelling layer 4 may be sprayed on the inner side of the main plate 31, and the second swelling layer 5 may be sprayed or adhered on the inner wall of the case 1 on the side parallel to the end surface of the main plate 31, and the second swelling layer 5 may be formed in a rectangular parallelepiped shape and directly adhered on the case 1.

As shown in fig. 3 to 4, in another embodiment, the insulating member is an insulating sleeve 6, the swelling member is a third swelling layer 7, the insulating sleeve 6 is sleeved on the periphery of the pole core 2, the third swelling layer 7 is located between the insulating sleeve 6 and the housing 1, the third swelling layer 7 is adhered to the inner wall of the housing 1 in a direction parallel to the end side surface of the pole core 2, and after the electrolyte is soaked, the third swelling layer 7 expands to fill the gap between the insulating sleeve 6 and the housing 1, so that the contact thermal resistance is reduced, and the heat dissipation effect is improved.

For the full-lug battery, in order to ensure the insulativity of the side surface and the large surface of the lug end, the insulating sleeve 6 is wrapped outside the pole core 2, and the material of the insulating sleeve 6 can be PP (polypropylene), PET (polyester resin) and the like. For the battery with the die-cutting structure, the tab is arranged at the end of the cover plate, the insulating sleeve 6 may or may not have the insulating effect, when the insulating sleeve 6 is not arranged, the third swelling layer 7 fills the gap between the pole core 2 and the shell 1, and the third swelling layer 7 is in close contact with the pole core 2 and the shell 1 after being expanded, so that the thermal contact resistance between the pole core 2 and the shell 1 can be reduced, and the heat dissipation effect is improved.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. The lithium ion battery is characterized by comprising a shell, a pole core and a swelling component, wherein the pole core and the swelling component are accommodated in the shell, the swelling component is arranged between the pole core and the inner wall of the shell to separate the pole core from the shell, and the swelling component can swell after being soaked in electrolyte.

2. The lithium ion battery according to claim 1, further comprising an insulator disposed between an end side surface of the pole core and the swelling member and/or between an end side surface of the pole core and an inner wall of the case.

3. The lithium ion battery according to claim 2, wherein the insulating member is a side spacer, and the swelling member includes a first swelling layer for filling a gap between the side spacer and the pole core and a second swelling layer for filling a gap between the side spacer and the case.

4. The lithium ion battery of claim 3, wherein the side spacer includes a main plate, a side plate, and a bottom plate, the main plate being disposed parallel to an end side face of the pole core, the side plate extending along a side edge of the main plate in a direction perpendicular to the main plate, the side plate being disposed parallel to a large face of the pole core, the bottom plate extending along a bottom edge of the main plate in a direction perpendicular to the main plate.

5. The lithium ion battery of claim 4, wherein the first swelling layer is sprayed on an inside of the main plate of the side spacer and the second swelling layer is sprayed on an outside of the main plate of the side spacer.

6. The lithium ion battery according to claim 4, wherein the first swelling layer is sprayed on an inner side of the main plate, and the second swelling layer is sprayed or stuck on an inner wall of the case on a side parallel to an end side of the main plate.

7. The lithium ion battery of claim 1, wherein the casing is an aluminum casing.

8. The lithium ion battery of claim 2, wherein the insulator is an insulating sleeve, the swelling member is a third swelling layer, the insulating sleeve is sleeved on the periphery of the pole core, the third swelling layer is located between the insulating sleeve and the casing, and the third swelling layer is adhered to the inner wall of the casing in a direction parallel to the end side surface of the pole core.