AbstractHerein, a composite polymer electrolyte with a viscoelastic and nonflammable interface is designed to handle the contact issue and preclude Li dendrite formation. The composite polymer electrolyte (cellulose acetate/polyethylene glycol/Li1.4Al0.4Ti1.6P3O12) exhibits a wide electrochemical window of 5 V (vs Li+/Li), a high Li+ transference number of 0.61, and an excellent ionic conductivity of above 10−4 S cm−1 at 60 °C. In particular, the intimate contact, low interfacial impedance, and fast ion‐transport process between the electro...
