Method for producing battery diaphragm

Abstract

The invention discloses a method for producing a battery diaphragm. The method comprises the following steps: preparing a polymer fiber blend into a 5-8 um non-woven fabric layer by using a melt blowing method; fusing and spray coating a resin blend onto one side face of the non-woven fabric layer A to form a 3-5um surface film layer A; coating ceramic slurry on the other side face of the non-woven fabric layer A, and drying the ceramic slurry to form a 6-10um ceramic slurry layer; fusing and spry coating the polymer fiber blend onto an exposed surface of the ceramic slurry layer to form a 5-8um non-woven fabric layer B; and fusing and spry coating the resin blend onto the exposed surface of the non-woven fabric layer B to form a 3-5um surface film layer B, and performing rolling and sizing to prepare the battery diaphragm. In the scheme, the generation of dendritic crystals is prevented by changing the components of the materials and changing the stratified structure of the diaphragm, and the ceramic slurry layer will not drop from the base film; and the porosity, the high temperature resistance, the thermal stability and other performance of the diaphragm are significantly improved as well.

Description

technical field [0001] The invention relates to the field of lithium battery production, in particular to a production process of a battery diaphragm. Background technique [0002] Lithium batteries are widely used, especially in mobile devices, due to their excellent properties such as high energy density, long life, and high operating voltage. The diaphragm is an important part of the lithium battery, which has an important impact on the capacity, charge and discharge density, cycle performance and battery safety of the battery. Lithium battery separators currently used in the market are mainly ceramic membranes coated with a ceramic material layer on the base membrane, but most of this type of ceramic membranes have some defects, such as the problem of dendrites puncturing the separator and causing a short circuit; The problem that the material layer is easy to fall off from the base film; and the mobility of lithium ions on the battery separator is poor, the ion conduct...

AI Technical Summary

Problems solved by technology

Lithium battery separators currently used in the market are mainly ceramic membranes coated with a ceramic material layer on the base membrane, but most of this type of ceramic membranes have some defects, such as the problem of dendrites puncturing the separator and causing a short circuit; The problem that the material layer is easy to fall off from the base film; and the poor mobility of lithium ions on the battery separator, poor ion conductivity, etc.