Amorphous Zirconium‐Based Halide Superionic Conductors with Exceptional Rate Capability and Low‐Temperature Performance

Solid electrolytes (SEs) are the key components for all‐solid‐state lithium batteries (ASSLBs). High‐rate and low‐temperature performance are still large challenges for the ASSLBs with present solid electrolytes. Here, amorphous Zr‐based superionic SEs (Li 2.92 Zr 0.3 Ta 0.7 Cl 4.7 O 1.46 , LZTCO) are reported with an exceptional ionic conductivity of 6.37 mS cm −1 at 30 °C and 1.25 mS cm −1 at −20 °C, synthesized by oxygen‐tantalum co‐incorporation strategy. It is found that fast Li + transport is facilitated by the synergistic interaction of oxygen‐tantalum co‐incorporation with amorphous phase formation, Li + carrier concentration, and local chemical structure variations. Importantly, the full cell with the LZTCO SEs and uncoated scNCM811 cathode shows a capacity retention of 91.1% at 5C after 3700 cycles. In particular, the ASSLB employing the amorphous SEs demonstrates stable operation with 90.2% capacity retention after 600 cycles at 0.3C and −20 °C. This work will pave the way for ASSLBs operating under high‐rate and low‐temperature freezing environments.