Anchoring an Artificial Solid–Electrolyte Interphase Layer on a 3D Current Collector for High‐Performance Lithium Anodes

Abstract

The application of Li anodes is hindered by dendrite growth and side reactions between Li and electrolyte, despite its high capacity and low potential. A simple approach for this challenge is now demonstrated. In our strategy, the garnet-type Li_6.4 La₃ Zr_1.4 Ta_0.6 O₁₂ (LLZTO)-based artificial solid-electrolyte interphase (SEI) is anchored on Cu foam by sintering the Cu foam coated with LLZTO particles. The heat treatment leads to the interdiffusion of Cu and Ta₂ O₅ at the Cu/LLZTO interface, through which LLZTO layer is fixed on Cu foam. 3D structure lowers the current density, and meanwhile the SEI reduces the contact of Li and electrolyte. Furthermore, the anchoring construction can endure Li-deposition-induced volume change. Therefore, LLZTO-modified Cu foam shows much improved Li plating/stripping performance, including long lifespan (2400 h), high rate (maximum current density of 20 mA cm^-2 ), high areal capacity (8 mA h cm^-2 for 100 cycles), and high efficiency (over 98 %).