Coordination‐Induced Plastic Ceramic‐Ether Coupling Electrolyte for High‐Voltage Lithium Metal Batteries

Abstract The high‐voltage reactivity and flammability of electrolytes remain critical challenges for high‐safety and high‐energy‐density lithium metal batteries (LMBs). Here, a novel ceramic‐ether coupling electrolyte (CCE) is reported, in which a thin liquid layer of the ether electrolyte is immobilized on the particle surface of Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) matrix through coordination interactions. With an LLZTO content exceeding 82%, it demonstrates high plasticity, non‐flammability, and a high oxidation voltage threshold above 5.0 V. strong coordination interactions between LLZTO and solvent molecules or anions are revealed, which generate cohesive forces that impart high‐plastic rheological behavior to the LLZTO matrix, ensuring conformal contact at solid/solid interfaces. These interactions also lead to a loose Li + solvation sheath in the ether electrolyte, which not only accelerates Li + transport, achieving a high ionic conductivity of 2.7 × 10 −4 S cm −1 , but also promotes anion decomposition to form an inorganic‐rich cathode electrolyte interphase (CEI). This enables the Li/LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cells to operate stably at a cut‐off voltage of 4.5 V. This work can open up new insights into the design of electrolytes for high safety and high‐voltage LMBs.