(625g) Long Lasting Li-S Batteries Via Suppressing Lithium Dendrites
Due to high theoretical capacity, low negative potential and prospective for next-generation Li-S batteries, Lithium (Li) metal has received huge attention as a promising anode, where stable Li metal electrode is crucial. However, Li dendritic growth and unstable solid electrolyte interphase (SEI) layer result in poor electrochemical performances and safety problems (e.g. short-circuit). Distinctive design of nanoporous SiO2 nanosheet layer is coated on separator in order to uniformly control Li-ion flux and minimize the lithium dendrite formation. The propagation of Li dendrites against the separator was dramatically restrained and suppressed via porous SiO2 nanosheets, thus leading to significant enhancement of electrochemical performances of Li metal and in Li-S batteries. Li-S prototype cell coupled with designed SiO2 nanosheet membrane delivered stable cycle retention (over 400 cycles) with high Coulombic efficiency by selectively allowing Li ions to pass through functional separator and preventing the migration of polysulfides.