The Universal Super Cation‐Conductivity in Multiple‐cation Mixed Chloride Solid‐State Electrolytes

Abstract As exciting candidates for next‐generation energy storage, all‐solid‐state lithium batteries (ASSLBs) are highly dependent on advanced solid‐state electrolytes (SSEs). Here, using cost‐effective LaCl 3 and CeCl 3 lattice (UCl 3 ‐type structure) as the host and further combined with a multiple‐cation mixed strategy, we report a series of UCl 3 ‐type SSEs with high room‐temperature ionic conductivities over 10 −3 S cm −1 and good compatibility with high‐voltage oxide cathodes. The intrinsic large‐size hexagonal one‐dimensional channels and highly disordered amorphous phase induced by multi‐metal cation species are believed to trigger fast multiple ionic conductions of Li + , Na + , K + , Cu + , and Ag + . The UCl 3 ‐type SSEs enable a stable prototype ASSLB capable of over 3000 cycles and high reversibility at −30 °C. Further exploration of the brand‐new multiple‐cation mixed chlorides is likely to lead to the development of advanced halide SSEs suitable for ASSLBs with high energy density.