Stable Cycling of a 4 V Class Lithium Polymer Battery Enabled by In Situ Cross-Linked Ethylene Oxide/Propylene Oxide Copolymer Electrolytes with Controlled Molecular Structures.

Commercial lithium-ion batteries are vulnerable to fire accidents, mainly due to volatile and flammable liquid electrolytes. Although solid polymer electrolytes (SPEs) are considered promising alternatives with antiflammability and processability for roll-to-roll mass production, several requirements have not yet been fulfilled for a viable lithium polymer battery. Such requirements include ionic conductivity, electrochemical stability, and interfacial resistance.