Composite diaphragm for semi-solid lithium battery and preparation method of composite diaphragm

• Main Authors: ZHANG XIAOLEI, WANG CHAOJUN, YIN QIAOBO, HAO FURUI, WANG ZHONGWEI, KONG XIANGHAI, YANG LICAN
• Format: Patent
• Language: Chinese; English
• Published: 08.03.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention discloses a composite diaphragm for a semi-solid lithium battery and a preparation method of the composite diaphragm. The composite diaphragm is prepared by the following steps of: dispersing and modifying a ceramic nano material by using polyvinyl alcohol with different polymerization degrees and alcoholysis degrees, and performing heat treatment in a vacuum reaction kettle to obtain polyvinyl alcohol coated ceramic nanowire slurry; pMMA and PVDF are uniformly dissolved in a mixed solvent through heat treatment in a vacuum reaction kettle to prepare a membrane casting solution, and a substrate or a polyolefin membrane substrate is directly coated with the membrane casting solution to form a membrane; and finally, coating the polyvinyl alcohol coated ceramic nanowire slurry on a polymer base membrane to obtain the composite diaphragm for the semi-solid lithium battery. The composite diaphragm has high liquid retention property, high ionic conductivity, high flexibility and high mechanical streng