<scp>Low‐Enthalpy</scp> and <scp>High‐Entropy</scp> Polymer Electrolytes for <scp>Li‐Metal</scp> Battery

Ionic‐conductive solid‐state polymer electrolytes are promising for the development of advanced lithium batteries yet a deeper understanding their underlying ion‐transfer mechanism is needed to improve performance. Here we demonstrate low‐enthalpy and high‐entropy (LEHE) can intrinsically generate remarkably free ions high mobility, enabling them efficiently drive lithium‐ion storage. The LEHE constructed on basis introducing CsPbI 3 perovskite quantum dots (PQDs) strengthen PEO@LiTFSI complexes. An extremely stable cycling &gt;1000 h at 0.3 mA cm −2 be delivered by electrolytes. Also, as‐developed Li ¦ LiFePO 4 cell retains 92.3% initial capacity (160.7 mAh g −1 ) after 200 cycles. This stability ascribed suppressed charge concentration gradient leading dendrites. It realized dramatic increment in transference number (0.57 vs 0.19) significant decline activation energy (0.14 eV 0.22 eV) comparing with counterpart. PQDs promote highly structural disorder inhibiting crystallization hence endow low melting enthalpy entropy, which turn facilitate long‐term excellent rate‐capability lithium‐metal batteries.