Effect of a thin ceramic-coating layer on thermal and electrochemical properties of polyethylene separator for lithium-ion batteries

In this paper, a new kind of ceramic-coating separator for lithium-ion batteries is successfully prepared by forming a ceramic layer consisted of Al2O3 powder, carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) mix binder onto one side of pristine PE separator. During the preparation of the separator, water is used as solvent and a very small amount of SBR-CMC mixture is applied as binder to obtain better thermal stability. The effect of thickness of the ceramic-coating layer on its thermal stability, physical properties and electrochemical performance is also investigated. The results clearly showed that the ceramic-coating separator with SBR-CMC binder has wonderful thermal stability, good wettability and high uptake of liquid electrolyte. Pouch cell tests with the ceramic-coating separator also show excellent stable cycle performance.