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The function of lithium battery diaphragm material

- Jan 17, 2019 -

Diaphragm is one of the key inner components in the structure of lithium ion battery. The performance of the diaphragm determines the interface structure and internal resistance of the battery, which directly affects the capacity, circulation and safety performance of the battery. Excellent performance of the diaphragm to improve the overall performance of the battery has an important role.

The difficulty of diaphragm technology lies in the engineering technology of hole making and the preparation of matrix material. The engineering technology of hole making includes diaphragm hole making process, production equipment and product stability. The preparation of matrix materials includes the preparation and modification techniques of polypropylene, polyethylene materials and additives. The difficulties of hole making technology are mainly reflected in such aspects as insufficient porosity, uneven thickness and poor strength.


The function of diaphragm in ion battery is mainly reflected in two aspects:

One is to provide security for the battery. Diaphragm material must first have good insulation, in order to prevent the anode contact is short circuit or particle, dendritic spines by burr, wear and short circuit, thus, the diaphragm requires a certain tensile, puncture strength, not easy to tear, and the sudden high temperature under the condition of basic maintain the stability of size and will not melt condensation lead to large area of short circuit and thermal runaway of the battery.

The second is to provide ion battery charging and discharging function, rate performance of the microporous channel. Therefore, the diaphragm must be a film with high porosity and evenly distributed micropores. The characteristics of the material itself and the pore characteristics after film formation restrict the migration of lithium ions in the battery, which is reflected in the ionic conductivity in the performance parameters.

With the increasing abundance of diaphragm materials, equipment and consummation of consumable parts technology, the high requirements of cutting blade will vigorously promote the demand of carbide cutting blade with high technical content and high quality stability, and also provide good development opportunities for the tool industry.