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_6.4La₃Zr_1.4Ta_0.6O₁₂ (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_0.8Co_0.1Mn_0.1O₂ (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.