Thermal stable poly-dioxolane based electrolytes via a robust crosslinked network for dendrite-free solid-state li-metal batteries

Rechargeable batteries paired with polyether-based solid-state electrolytes is a promising system to solve the safety problem of lithium metal (Li-metal) batteries, and stable solid electrolyte interface (SEI) layer between electrolyte and anode is highly required for their long-term stability. Here we propose a novel thermal-stable polymerized 1,3-dioxolane electrolyte (PSiDOL), which is in situ formed via a multifunctional 1,3-bis(3-glycidoxypropyl) tetramethyl disiloxane crosslinker. This network structural PSiDOL not only achieves good flame retardancy, significantly increased operating temperature and improved oxidative stability, but also induces the formation of stable and robust SEI layer with rich LixSiOy/LiF on the surface of Li-metal anode. Moreover, the three-dimensional polymer skeleton with abundant polar groups is beneficial to improve the ionic conductance and cationic transference number. As a result, the PSiDOL electrolyte enable ultralong-term (over 4000 h) reversible and stable lithium plating/stripping in Li symmetrical cell for lithium anode. In addition, the assembled full cells based on such electrolyte display desirable cycling stability at high temperature and high voltage with suppressed electrolyte degradation. This work affords a facile and practical approach to develop advanced electrolytes for solid-state Li-metal batteries with high safety and durability.