Preparation method of membrane for lithium battery

Abstract

The invention discloses a preparation method of a membrane for a lithium battery. The preparation method comprises the following steps: preparing a beaker, mixing 30g of polyvinyl chloride and 100g ofacetonitrile solution in the beaker, adding 30 to 40 weight percent of nano silicon dioxide, and heating and stirring for 7 to 9 hours at 80 to 120 DEG C until forming a uniform solution; transferring the mixed solution to a vacuum environment, soaking a basement membrane in the solution for 2 to 5 hours, taking out the basement membrane, drying the basement membrane in a vacuum drying oven for 10 to 20 hours, and completely volatizing acetonitrile, thus forming the membrane for the lithium battery. The preparation method disclosed by the invention is simple in operation and can be easily andrepeatedly applied to industry; the liquid absorption rate on electrolyte is doubled than that of an unmodified membrane, and the electrolyte immersed in a composite membrane can be prevented from running off, so that the situation of preventing the problems of electrolyte leakage, environment pollution and the like is technologically realized, and a new generation of a green battery is further optimized and formed; the electrical conductivity of the membrane is improved, the electric quantity loss is just 5 percent after 20 times of charging, and the charge cycling performance of the lithiumbattery is verified to be obviously improved.

Description

technical field [0001] The invention relates to a preparation method of a diaphragm for lithium batteries, belonging to the field of lithium batteries. Background technique [0002] The lithium battery separator itself is not only a poor conductor of electrons, but also allows electrolyte ions to pass through. Usually, separator materials must have good chemical and electrochemical stability and mechanical properties, and maintain high wettability to the electrolyte during repeated charge and discharge. The interfacial compatibility between the separator material and the electrode, and the retention of the electrolyte by the separator have a great influence on the charge-discharge performance and cycle performance of the lithium-ion battery. In order to improve the performance of the diaphragm, there have been many studies on the modification of the diaphragm so far. However, the wettability of the materials prepared by these materials is not good, and the electrolyte canno...

AI Technical Summary

Problems solved by technology

In order to improve the performance of the diaphragm, there have been many studies on the modification of the diaphragm so far. However, the wettability of the materials prepared by these materials is not good, and the electrolyte cannot be absorbed, causing the electrolyte to leak and pollute the environment; and the preparation method is repeatable. Not good, complicated operation, not conducive to industrial application