Excellent high-temperature resistance performance of one-dimensional sepiolite coated membrane based on an organic-inorganic composite binder for lithium ionic batteries

Abstract

A one-dimensional sepiolite (SNRs) coated membrane based on organic-inorganic composite binder (polyvinyl alcohol-phosphate inorganic binder, PVA-PIB) is constructed to solve the problems of poor high-temperature resistance and blockage pore of particle-coated membrane based on organic binders. Results show that the thermal shrinkage of SNRs-coated membrane based on PVA-PIB binder are low of 2.44% at high temperature of 200 °C, which is much lower than that of the membrane based on PVA binder (69.90%). The SNRs coating presents a porous structure with interlaced fibers which makes the porosity, the electrolyte uptake and the lithium ionic conductivity of the membrane much better than that of the Al2O3 particle-coated membrane. The wetting angle and Brunauer Emmett Teller results show that SNRs coating have good wettability and strong adsorbability to liquid electrolyte. The open circuit voltage-temperature and current-time curves show that the battery has excellent safety at high temperature of 180 °C and after 50 h constant-voltage charging. In addition, the battery based on the SNRs-coated membrane with PVA-PIB binder has good cycle and rate performance. The excellent high-temperature resistance and good electrochemical performance of SNRs-coated membranes is of great significance to the application of lithium ionic battery.