In Situ Coupling of Colloidal Silica and Li Salt Anion toward Stable Li Anode for Long-Cycle-Life Li-O2 Batteries

Lithium-oxygen (Li-O-2) batteries are promising next-generation batteries owing to their ultrahigh theoretical energy density. However, Li metal anodes in Li-O-2 batteries are still plagued by uncontrollable dendrite growth and serious parasitic reactions. Herein, we report an electrolyte regulation strategy via in situ coupling of CF3SO3- and hydrophobic silica colloidal nanoparticle through electrostatic interaction. With the assistance of the seed crystal effect and the solid-like rheological properties, 10 wt % hydrophobic silica colloid electrolyte (HSCE) enables the dendrite-free morphology of Li deposition and helps form a stable solid-electrolyte interface, which can reduce the impedance by about 45-fold after long-term cycling. Moreover, 10 wt % HSCE with a lower diffusion coefficient can achieve a 980-fold better anticorrosion effect than 0 wt % HSCE. Consequently, the 10 wt % HSCE batteries exhibit a stable plating/stripping process (30 mV in overpotential up to 700 h) and a good anodic cycle life in Li-O-2 batteries (550 cycles).