Composite polymer electrolytes reinforced by hollow silica nanotubes for lithium metal batteries

Abstract Herein, a series of one-dimensional silica nanotubes (SNts) with hollow nanostructures and high uniformity are synthesized by etching the rod-shaped nickel-hydrazine complex, and composite polymer electrolytes (CPEs) are prepared by introducing SNts and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) into poly(ethylene oxide) (PEO) skeleton. The CPEs obey Vogel-Tamman-Fulcher empirical equation and the ionic conductivity is demonstrated to be maximum of 4.35 × 10−4 S cm−1 with the longest SNts (270 nm) as fillers at 30 °C, which is significantly higher than that of PEO/LiTFSI (6.13 × 10−8 S cm−1) and PEO/LiTFSI/silica nanoparticles (SNps) (1.07 × 10−6 S cm−1). The connection between SNts among the whole composite contributes the efficient transport pathway to lithium ions. Furthermore, the fabricated cell exhibits good cyclability and rate capability. The SNts based CPEs represent a new design idea for solid-state electrolytes and offers opportunities for lithium metal batteries in the future.