Ga and Si co-doped Li1.3Al0.3Ti1.7(PO4)3-enhanced poly(ethylene oxide) solid composite electrolyte for high-performance all-solid-state lithium-ion battery

Nasicon-type Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) is a potential electrolyte for lithium-ion batteries due to its appropriate conductivity and good air stability. Herein, LATP was co-doped with Ga and Si to improve its ionic conductivity. The Li 1.325 Al 0.29 Ga 0.01 Ti 1.7 Si 0.025 P 2.975 O 12 (LAGTSP025) electrolyte exhibits an ionic conductivity of 8.92 × 10 −4  S/cm at 30 °C, which is mainly ascribed to its enlarged crystal lattice and high densification. This electrolyte material was incorporated into poly(ethylene oxide) (PEO) polymer to form a polymer-based PEO-LITFSI-LAGTSP025 solid composite electrolyte (SCE). The optimized SCE shows a high ionic conductivity of 5.33 × 10 −4  S/cm and excellent interfacial stability at 60 °C. Consequently, a Li/SCE/Li symmetric battery can stably cycle for 1600 cycles at a current density of 0.1 mA/cm 2 . Moreover, an LFP/SCE/Li all-solid-state lithium-ion battery (ASSLIB) maintains a discharge capacity of 143.56 mAh/g and exhibits 95.21% capacity retention after 300 cycles at 0.5C. This work demonstrates PEO-LITFSI-7.5LAGTSP025 SCE is a potential solid electrolyte for ASSLIBs.