Cycling performance of lithium-ion polymer cells assembled with a cross-linked composite polymer electrolyte using a fibrous polyacrylonitrile membrane and vinyl-functionalized SiO2 nanoparticles

Abstract

Vinyl-functionalized SiO₂ nanoparticles were synthesized and uniformly dispersed on the surface of a fibrous polyacrylonitrile (PAN) membrane for use as cross-linking sites. A composite polymer electrolyte was prepared by in situ cross-linking between vinyl-functionalized SiO₂ particles on the PAN membrane and the electrolyte precursor containing tri(ethylene glycol) diacrylate. The cross-linked composite polymer electrolyte effectively encapsulated the electrolyte solution without leakage. It exhibited good thermal stability as well as favorable interfacial characteristics toward electrodes. Lithium-ion polymer cells composed of a graphite negative electrode and a LiNi_0.8Co_0.15Al_0.05O₂ positive electrode were assembled with the in situ cross-linked composite polymer electrolyte. The cells with cross-linked composite polymer electrolytes using the fibrous PAN membrane and vinyl-functionalized SiO₂ particles exhibited high discharge capacity and good capacity retention at both ambient temperature and elevated temperature.