Inorganic Layer Coated Polyolefin Separator with High Performances for Lithium-ion Batteries

Inorganic layer-coated separator was prepared by coating the sides of a porous polyolefin membrane with ZrO2 powder and polyvinylidene fluoride binder. The composite separator exhibits improved thermal stability at high temperatures without significant thermal shrinkage. Moreover, the separator has higher melt temperature. It is expected that the ZrO2-coated separator in this study can be potential candidate as a separator for rechargeable lithium-ion batteries that require thermal safety. Due to the high hydrophilicity of the ZrO2 powder and large surface area of the small particles, the separator shows good wettability in non-aqueous liquid electrolytes. Meanwhile, a higher amount of electrolyte solution is expected to be retained by the separator. By using the ZrO2-coated separator, lithium-ion cell was assembled and its cycling performance is evaluated. The cells are proven to be having better capacity retention than the cells prepared with polyolefin membrane.