Improved Electrochemical Performance for High-Voltage Spinel LiNi_0.5Mn_1.5O₄ Modified by Supercritical Fluid Chemical Deposition

Abstract

Among candidates at the positive electrode of the next generation of Liion technology and even beyond post Li-ion technology as all-solid-state batteries, spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is one of the favorites. Nevertheless, before its integration into commercial systems, challenges still remain to be tackled, especially the stabilization of interfaces with the electrolyte (liquid or solid) at high voltage. In this work, a simple, fast, and cheap process is used to prepare a homogeneous coating of Al 2 O 3 type to modify the surface of the spinel LNMO: the supercritical fluid chemical deposition (SFCD) route. This process is, to the best of our knowledge, used for the first time in the battery field. Significantly improved performance was demonstrated vs those of bare LNMO, especially at high rates and for highly loaded electrodes.