Strategic Atomic Interaction Modification for Highly Durable Inorganic Solid Electrolytes in Advanced All-Solid-State Li-Metal Batteries

Abstract

All-solid-state Li-metal battery (ASSLB) represents advantageous energy storage system for automotive applications. For ASSLB, inorganic solid electrolyte is essential in determining safety and cycling performance. However, significant challenges persist in practical construction of ASSLB with optimized electrolyte. Specifically, electrolyte's structural instability influencing its electrochemical performance remains critical issue within typical operating temperatures for ASSLB in electric vehicles. Herein, this challenge is fundamentally addressed by substituting trace amount of lithium with cadmium, which lacks crystal field stabilization energy. This strategy of atomic interaction modification has induced electrolyte's structural distortion and electronic alteration by deliberately introducing disorder at local lithium sites. Li symmetric cell with cadmium-substituted antiperovskite solid electrolyte exhibits outstanding critical current density of 11.5 mA cm⁻² (5.75 mAh cm⁻²) and excellent stability for 3000 h at 10.0 mA cm⁻² (5.0 mAh cm⁻²). This study highlights explicit research direction for breakthrough of ASSLB, focusing on understanding how local distortion affects complex inorganic materials.