A fast-ion conducting interface enabled by aluminum silicate fibers for stable Li metal batteries

Abstract

Lithium (Li) metal anode is attracting more attention because of its ultrahigh theoretical specific capacity and the lowest redox potential. However, the growth of Li dendrites caused by nonuniform Li-ion diffusion and distribution leads to safety hazards and hinders its practical application. Here, a fast-ion conducting interface is constructed on the Li surface to address the above issues by employing aluminum silicate (ASO) fibers. In addition, a stable inorganics-rich solid electrolyte interphase can be formed, which is revealed by cryogenic transmission electron microscopy and X-ray photoelectron spectroscopy. As a result, a stable Li anode with long-term lifespan can be achieved (over 5500 cycles with low overpotential at 3 mA cm−2 in Li/Li symmetric cells). When paired with the LiFePO4 cathode, the cell with ASO can achieve more than 500 cycles with reduced capacity degradation. This work might shed new light on the facile design of fast-ion conducting interface for the Li metal anode and even other alkali-metal anodes.