Electrochemical performances of lithium-ion cells prepared with polyethylene oxide-coated separators

Poly(ethylene oxide) (PEO)-coated separators were prepared by coating PEO onto a microporous polyethylene (PE) separators. Highly conductive electrolytes were prepared by soaking them in an electrolyte solution. The uptake of the electrolyte solution and the ionic conductivity of the PEO-coated separator (PCS) after soaking in LiBF4¯ethylene carbonate (EC)/dimethyl carbonate (DMC) were measured to be 76% and 1.0×10-3 S/cm, respectively. With these PCSs, lithium-ion cells composed of mesocarbon microbead (MCMB) anode and LiCoO2 cathode were assembled, and their electrochemical performances were evaluated.