Polymer electrolytes reinforced by Celgard® membranes

Solid polymer electrolytes have been prepared by encapsulating plasticized polymer electrolytes based on poly(tetraethylene glycol diacrylate) into the pores of Celgard{reg_sign} microporous membranes. Electrolyte membranes with thicknesses of {approximately}40 {mu}m have been prepared. The conductivity of the electrolyte is determined by the porosity of the membrane, and a conductivity of {approximately}2 {times} 10{sup {minus}4} {Omega}{sup {minus}1} {center_dot} cm{sup {minus}1} at room temperature has been demonstrated. These electrolytes showed good compatibility with Li and an electrochemical stability window spanning the range of 0.0 to {approximately}4.5 V vs. Li{sup +}/Li. The excellent chemical and electrochemical stabilities enabling the use of the membranes in rechargeable Li batteries have been confirmed by the discharge/charge cycling of Li/solid polymer electrolyte/LiMn{sub 2}O{sub 4} cells at room temperature.