An in situ element permeation constructed high endurance Li–LLZO interface at high current densities

Abstract

The construction of a solid/solid SEI is proposed to improve the endurance of LLZO solid electrolytes. Al will spontaneously permeate into LLZO and construct a robust Al enriched SEI by the reaction between Al₄Li₉ and LLZO, realizing a low interfacial impedance of <1 Ω cm², high endurance for 3000 h and a high critical current density of more than 0.9 and 2.3 mA cm⁻² at 25 °C and 60 °C, respectively.