A paper-supported inorganic composite separator for high-safety lithium-ion batteries

A paper-supported inorganic composite (PIC) separator is prepared by spraying Al2O3 particles onto both surfaces of a commercial paper substrate. The as-prepared PIC separator shows excellent thermal stability without any shrinkage at 130 °C for 30 min, superior wettability towards the electrolyte, with a contact angle of 0°, and high ionic conductivity compared with that of the conventional polyethylene (PE) separator. The graphite|LiCoO2 full-cells with the PIC separator exhibit good cycling and rate performance. In the nail penetration tests, the pouch cell assembled with the PIC separator shows high safety characteristics. Given the advantages of the PIC separator, it is a good potential replacement for the polyolefin separators used in high-safety lithium-ion batteries.