Non-woven fabric high-molecular material composite diaphragm

Abstract

The invention discloses a non-woven fabric high-molecular material composite diaphragm, and mainly relates to the technical field of non-woven fabric applications. The composite diaphragm comprises abase material and high-molecular material layers, and is characterized in that the base material is divided into two layers which are adhered together by an adhesive polymer, the high-molecular material layers are arranged on the two outer surface of the base material, the base material is non-woven fabric, and the high-molecular material layer includes inorganic particles, a surfactant and a porous active layer. The composite diaphragm is good in high temperature resistance and can maintain stability at a temperature of 200 DEG C. The high-molecular microporous membrane is good in liquid absorbing performance and can absorb sufficient electrolyte in the full-life stage of a battery, thereby improving the cycle performance of the battery. The composite diaphragm is uniform in pore distribution, low in self-discharge rate of the battery, good in puncture strength, high in tensile strength and not easy to have pore deformation under high tension, and reduces potential safety hazards.

Description

technical field [0001] The invention mainly relates to the technical field of non-woven fabric application, in particular to a non-woven polymer material composite membrane. Background technique [0002] Lithium-ion batteries have become one of the most important chemical power sources in contemporary times due to their advantages such as high energy density, high output voltage, long cycle life, and environmental friendliness. At present, in addition to being widely used in mobile communications, digital products and other fields, lithium-ion batteries are gradually becoming an important power supply system in the fields of energy storage and electric vehicles. [0003] In lithium-ion batteries, the separator mainly plays the role of isolating positive and negative electrode materials and conducting lithium ions. The performance of the separator directly determines the cycle performance and safety performance of lithium-ion batteries. Because lithium-ion batteries, especia...

AI Technical Summary

Problems solved by technology

Because lithium-ion batteries, especially power lithium-ion batteries, will release a lot of heat during the process of charging and discharging at a high rate, causing the battery to heat up.

Under such conditions, if the melting point of the separator is low or the softening temperature is very low, the separator will shrink significantly at high temperature, which will lead to a short circuit due to contact between the positive and negative electrodes, or even an explosion.

At present, the separators mainly used in the market are polyolefin separators, and the melting point temperature range of this type of separator is only 130-165°C, which is difficult to ensure the safe operation of high-power lithium batteries.