CN211150656U

CN211150656U - High-effect environment-friendly battery diaphragm

Info

Publication number: CN211150656U
Application number: CN201921900015.8U
Authority: CN
Inventors: 李军
Original assignee: Shishi Shentai New Material Technology Co ltd
Current assignee: Shishi Shentai New Material Technology Co ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-07-31
Anticipated expiration: 2029-11-06

Abstract

The utility model relates to the technical field of lithium batteries, and provides a high-efficiency environment-friendly battery diaphragm, which solves the problems of large internal resistance of a battery and influence on the charging and discharging efficiency and the cycle performance of the battery caused by the structural design defects of the diaphragm in the prior art, and comprises a diaphragm main body, wherein the diaphragm main body is provided with a longitudinal direction along the length direction and a transverse direction along the thickness direction, the longitudinal two ends of the diaphragm main body are provided with fixing seats, each fixing seat comprises a first connecting part, a second connecting part and a third connecting part which are integrally formed, a first lug is arranged on one side of the first connecting part close to the third connecting part, a second lug is arranged on one side of the third connecting part close to the first connecting part, the diaphragm main body comprises a base material layer and nylon layers arranged on the two transverse sides of the base material layer, a heat conduction layer is arranged on one side, the upper surface and the lower surface of the diaphragm main body are provided with clamping grooves, and the clamping grooves are clamped with the first protruding blocks and the second protruding blocks.

Description

High-effect environment-friendly battery diaphragm

Technical Field

The utility model relates to a lithium cell technical field especially relates to a high-effect environmental protection battery diaphragm.

Background

The battery diaphragm is widely applied to various types of lithium batteries, such as mobile phone batteries, new energy automobile batteries and the like. The performance of the diaphragm determines the interface structure, internal resistance and the like of the battery, directly influences the capacity, circulation, safety performance and other characteristics of the battery, and the diaphragm with excellent performance plays an important role in improving the comprehensive performance of the battery. The diaphragm has the main function of separating the positive and negative plates in the battery and preventing the positive and negative plates from being in direct contact with each other to generate short circuit, and meanwhile, as the diaphragm is provided with a large number of through micropores, positive and negative ions in the battery can freely pass through the micropores, and migrate between the positive and negative plates to form a conductive loop inside the battery, while electrons migrate between the positive and negative electrodes through an external loop to form current for utilization by electric equipment.

Chinese patent No.: 201020541429.9 discloses a composite diaphragm for lithium ion battery, which comprises a diaphragm formed by an upper polypropylene microporous membrane and a lower polypropylene microporous membrane or an upper polyethylene microporous membrane and a lower polyethylene microporous membrane, wherein a polytetrafluoroethylene microporous membrane is arranged between the upper polypropylene microporous membrane and the lower polypropylene microporous membrane or between the upper polyethylene microporous membrane and the lower polyethylene microporous membrane. The composite diaphragm for the lithium ion battery not only has the low closed pore temperature of the lithium battery diaphragm, but also has the performance of high diaphragm breaking temperature, and the safe reliability of the lithium battery in the use process is practically ensured. But the wettability of the electrolyte on the composite diaphragm is poor, the wettability refers to the wetting degree of the electrolyte on the diaphragm, when the wettability is good, the diaphragm can quickly absorb the electrolyte as much as possible, the good liquid retention capacity is achieved, the swelling of the diaphragm and the size change of the diaphragm are not caused, the normal passing of ions is ensured, and the ionic conductivity is high; on the contrary, poor wettability increases interfacial resistance between the separator and the electrode, which affects charge and discharge efficiency and cycle performance of the battery.

SUMMERY OF THE UTILITY MODEL

Therefore, to the above, the utility model provides a high-effect environmental protection battery diaphragm solves the problem that prior art diaphragm structural design defect leads to the battery internal resistance big and influence battery charge-discharge efficiency and cycle performance.

In order to achieve the purpose, the utility model is realized by the following technical proposal:

a high-efficiency environment-friendly battery diaphragm comprises a diaphragm main body, wherein the diaphragm main body is provided with a longitudinal direction along the length direction and a transverse direction along the thickness direction, fixing seats are arranged at two longitudinal ends of the diaphragm main body and comprise a first connecting part, a second connecting part and a third connecting part which are integrally formed, a first convex block is arranged at one side, close to the third connecting part, of the first connecting part, a second convex block is arranged at one side, close to the first connecting part, of the third connecting part, the diaphragm main body comprises a base material layer and nylon layers arranged at two transverse sides of the base material layer, a heat conduction layer is arranged at one side, far away from the base material layer, of each nylon layer is provided with a polyimide layer, clamping grooves are arranged on the upper surface and the lower surface of the diaphragm main body, the clamping grooves are clamped with the first convex blocks and the second convex blocks on the fixing seats, and, each groove is arranged between the clamping grooves, the diaphragm main body is defined to be vertical to the longitudinal direction and the transverse direction, the grooves vertically extend to the other side from one side of the same surface of the diaphragm main body, and wear-resistant protrusions are uniformly arranged between the adjacent grooves.

Further improvement: the substrate layer is a biaxially oriented polyethylene film.

Further improvement: the wear-resistant protrusions are in a circular truncated cone shape.

Further improvement: the heat conduction layer is a polyether-ether-ketone film, and high-heat-conduction carbon powder is added into the heat conduction layer.

Further improvement: the grooves do not extend through the polyimide layer.

By adopting the technical scheme, the beneficial effects of the utility model are that:

the nylon layers are arranged on the two sides of the base material layer, so that the puncture resistance strength of the diaphragm is improved, and the diaphragm can be prevented from being punctured by sharp objects, so that local short circuit is caused; when the temperature inside the battery is raised due to an accident, a large amount of heat is generated, the heat conducting layer can disperse and conduct the heat, the heat is prevented from being excessively concentrated at local parts, and potential safety hazards such as ignition or explosion are prevented. The polyamide layer has the characteristics of excellent thermal stability, high temperature resistance, corrosion resistance and the like, and according to the similarity and intermiscibility principle, the electrolyte has good wettability to the polyamide layer with strong polarity, the diaphragm shows good liquid absorption and retention capacity, the internal resistance of the battery is small, and the charge-discharge efficiency and the cycle performance of the battery are excellent. Furthermore, the upper surface and the lower surface of the diaphragm main body are respectively provided with the plurality of grooves, so that the contact area of the electrolyte and the diaphragm is increased, the liquid absorption and retention capacity of the diaphragm is improved, and better liquid absorption and retention capacity is shown. The wear-resistant bulges arranged between the adjacent grooves do not need to consume a large amount of materials while improving the wear-resistant performance of the diaphragm, the air permeability of the diaphragm is increased, the wear-resistant bulges are in a circular truncated cone shape, the contact surfaces of the wear-resistant bulges and the positive and negative plates are larger, and the wear-resistant bulges are firmly contacted and are not easy to shift. The substrate layer is a biaxially oriented polyethylene film, and the biaxially oriented polyethylene film has high orientation, molecular weight orientation and crystallization orientation, so that compared with the conventional polyethylene film, the biaxially oriented polyethylene film has excellent impact resistance and puncture resistance, and the puncture resistance of the diaphragm is improved. The clamping groove arranged on the diaphragm main body is clamped with the first lug and the second lug on the fixing seat to fix the position of the diaphragm. Each layer of the diaphragm main body is made of low-toxicity and environment-friendly materials, so that the environment is not harmed.

Drawings

Fig. 1 is a schematic exploded view of the present invention;

fig. 2 is a schematic structural view of the main body of the middle diaphragm of the present invention;

FIG. 3 is a schematic view of the three-dimensional structure of the membrane body of the present invention

Detailed Description

The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

The embodiment of the utility model provides a do:

referring to fig. 1 to 3, a high-performance environment-friendly battery separator comprises a separator main body 1, wherein the separator main body 1 has a longitudinal direction along a length direction and a transverse direction along a thickness direction, fixing bases 2 are arranged at two longitudinal ends of the separator main body, each fixing base 2 comprises a first connecting portion 21, a second connecting portion 22 and a third connecting portion 23 which are integrally formed, a first bump 3 is arranged on one side, close to the third connecting portion 23, of the first connecting portion 21, a second bump 4 is arranged on one side, close to the first connecting portion 21, of the third connecting portion 23, the separator main body 1 comprises a substrate layer 5 and nylon layers 6 arranged on two transverse sides of the substrate layer 5, the substrate layer 5 is a biaxially oriented polyethylene film, the substrate layer 5 and the nylon layers 6 are bonded through a hot melt adhesive, a heat conducting layer 7 is arranged on one side, far away from the substrate layer 5, of the nylon layer 6, and the, carbon powder with high thermal conductivity is added in the heat conduction layer, the heat conduction layer 7 is connected with the nylon layer in a coating mode, a polyimide layer 8 is arranged on one side of the heat conduction layer 7 far away from the nylon layer 6, the heat conducting layer 7 and the polyimide layer 8 are bonded through hot melt adhesive, the upper surface and the lower surface of the diaphragm main body 1 are both provided with clamping grooves 9, the clamping grooves 9 are clamped with the first convex blocks 3 and the second convex blocks 4 on the fixed seat 2, four grooves 10 are respectively arranged on the surfaces of the two transverse ends of the diaphragm main body 1, each groove 10 is arranged between the clamping grooves 9, the diaphragm main body 1 is defined to be vertical to the longitudinal direction and the transverse direction, the recess 10 is followed one side of 1 coplanar of diaphragm main part and is followed vertical extension to the opposite side, polyimide layer 8 is not run through to recess 10, lies in evenly to be equipped with the wear-resisting arch 11 of round platform form between the adjacent recess 10 of vertical side, wear-resisting arch 11 is by silica and epoxy 1: 5, and compounding the components in proportion.

The fixing seats are arranged at the longitudinal two ends of the diaphragm main body, and the clamping grooves formed in the diaphragm main body are clamped with the first convex blocks and the second convex blocks on the fixing seats, so that the diaphragm is fixed. The polyamide layer at the outermost layer of the diaphragm main body has the characteristics of excellent thermal stability, high temperature resistance, corrosion resistance and the like, and the polarity is strong, so that the wettability of electrolyte on the polyamide layer is good, the diaphragm shows good liquid absorption and retention capacity, the internal resistance of the battery is small, and the charge-discharge efficiency and the cycle performance of the battery are excellent. The upper surface and the lower surface of the diaphragm main body are respectively provided with the plurality of grooves, so that the contact area of electrolyte and the diaphragm is increased, the liquid absorption and retention capacity of the diaphragm is improved, and better liquid absorption and retention capacity is represented. The wear-resistant bulges arranged between the grooves do not need to consume a large amount of materials while improving the wear-resistant performance of the diaphragm, the air permeability of the diaphragm is increased, the wear-resistant bulges are in a circular truncated cone shape, the contact surfaces of the wear-resistant bulges and the positive and negative plates are larger, and the wear-resistant bulges are firmly contacted and are not easy to shift. The heat conducting layer connected with the polyamide layer can disperse and conduct heat, and potential safety hazards such as ignition or explosion caused by the fact that the heat is excessively concentrated at local parts when the temperature of the battery is raised due to accidents are avoided. The nylon layer connected with the heat conduction layer improves the puncture resistance of the diaphragm, and can prevent the diaphragm from being punctured by sharp objects, thereby causing local short circuit. The substrate layer connected with the nylon layer is a biaxially oriented polyethylene film, and the biaxially oriented polyethylene film has high orientation, molecular weight orientation and crystallization orientation, so that compared with the conventional polyethylene film, the biaxially oriented polyethylene film has excellent impact resistance and puncture resistance, and the puncture resistance of the diaphragm is improved.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A high-performance environment-friendly battery diaphragm is characterized in that: the heat-conducting membrane comprises a membrane main body, wherein the membrane main body is provided with a longitudinal direction along the length direction and a transverse direction along the thickness direction, fixing seats are arranged at two longitudinal ends of the membrane main body, each fixing seat comprises a first connecting part, a second connecting part and a third connecting part which are integrally formed, a first lug is arranged on one side, close to the third connecting part, of each first connecting part, a second lug is arranged on one side, close to the first connecting part, of each third connecting part, each membrane main body comprises a base material layer and nylon layers arranged on two transverse sides of the base material layer, a heat-conducting layer is arranged on one side, far away from the base material layer, of each nylon layer, a polyimide layer is arranged on one side, far away from the nylon layers, clamping grooves are formed in the upper surface and the lower surface of the membrane main body, the clamping grooves are clamped with, each groove is arranged between the clamping grooves, the diaphragm main body is defined to be vertical to the longitudinal direction and the transverse direction, the grooves vertically extend to the other side from one side of the same surface of the diaphragm main body, and wear-resistant protrusions are uniformly arranged between the adjacent grooves.

2. The high performance environmentally friendly battery separator according to claim 1, wherein: the substrate layer is a biaxially oriented polyethylene film.

3. The high performance environmentally friendly battery separator according to claim 1, wherein: the wear-resistant protrusions are in a circular truncated cone shape.

4. The high performance environmentally friendly battery separator according to claim 1, wherein: the grooves do not extend through the polyimide layer.