Stable operation of polymer electrolyte-solid-state batteries via lone-pair electron fillers

Due to the increasing demand and wide applications of lithium-ion batteries, higher requirements have been placed on the energy density and safety. Polymer solid-state electrolytes have gained significant popularity due to their excellent interface compatibility and safety. However, their applications have been greatly restricted by the high crystallinity at room temperature, which hinders the transport of lithium ions. Herein, we utilize inorganic tubular fillers with abundant lone-pair atoms to reduce the crystallinity of the polyethylene oxide (PEO) solid-state electrolyte membrane and improve its ionic conductivity at room temperature, enabling stable operation of the battery. The tubular lone-pair-rich inorganic fillers play a key role in providing avenues for both internal and external charge transportation. The surface lone-pair electrons facilitate the dissociation and transport of lithium ions, while the internally tubular electron-rich layer attracts ions into the cavities, further enhancing the ion transport. After 100 cycles at room temperature, the lithium battery loaded with this solid-state electrolyte membrane delivers a specific capacity of 141.6 mAh·g⁻¹, which is 51.3% higher compared to the membrane without the fillers.