Boosting wide-temperature solid-state lithium metal batteries by polyether–carbonate hybridization

The development of temperature-resilient solid-state lithium metal batteries is hindered by multiple interrelated factors, including the intrinsically low ionic conductivity of solid-state electrolytes, the propensity for lithium dendrite formation due to non-uniform Li⁺ flux distribution, and interfacial degradation mechanisms that collectively deteriorate electrochemical performance and raise safety concerns at elevated or sub-ambient temperatures. Herein, a polyether-co-carbonate solid polymer electrolyte (PDPC) adaptable for a wide temperature range has been developed through an electronic cloud modulation strategy. The synergistic combination of electron-donating ether groups and electron-withdrawing carbonate groups in PDPC effectively regulates the coordination structure and transport characteristics to optimize ionic transport and interfacial stability. The resulting electrolyte, composed of poly(1,3-dioxolane), poly(propylene carbonate), and poly(vinylene carbonate) segments, exhibits a high ionic conductivity of 1.8 × 10^-4 S cm^-1 at 25 °C, a low activation energy of 0.16 eV, an expanded electrochemical stability window of 4.5 V vs. Li⁺/Li, and an improved Li⁺ transference number of 0.84. Owing to these outstanding properties, the PDPC-based lithium-metal batteries overcome the challenges in both low- and high-temperature operation, delivering superior electrochemical performance and high Coulombic efficiency across a wide temperature range (-10 to 60 °C).