Electron Insulative Interface Based on Schottky Contact Enabling Dendrite-free Solid-state Lithium Metal Batteries

Abstract

A novel approach is proposed to address the lithium dendrite penetration issue in solid-state lithium metal batteries based on the garnet-type electrolyte Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO). Se and Te nanofilms are deposited on LLZTO using a chemical vapor deposition process and subsequently reacted with molten lithium in situ to form a tightly-bonded Li-LLZTO interface, facilitating the interfacial lithium-ion conduction. Most importantly, the constructed Li₂Se/Li₂Te semiconductor interlayers form a p-type Schottky contact with lithium metal, impeding the electron injection from Li to LLZTO electrolyte, resulting in a dramatical decrease in leakage electronic current. Benefiting from the effective blocking of electrons and the facilitated interfacial lithium conduction, the constructed Li|Se-LLZTO-Se|Li symmetric cell achieves a high critical current density of 2.3 mA cm⁻² and can be stably cycled for over 2000 h at 0.2 mA cm⁻².