Entropy Stabilized Oxide Nanocrystals as Reaction Promoters in Lithium‐O2 Batteries

Abstract

AbstractCharge transport limitations at the Li2O2 discharge product‐electrode interfaces hinder the rechargeability of Li−O2 batteries. Herein, we introduce entropy stabilized oxides (ESO) as reaction ′promoters′ in positive electrodes that can facilitate charge transport by reducing the binding energy of the intermediates. In this work, we developed a rock‐salt type entropy stabilized oxide. We show that the rock salt phase transforms into a pure, equimolar, quinary spinel on heat treatment. A Li−O2 battery with the developed ESOs at the positive electrode is cycled with an areal capacity of 1 mAh cm−2 at a current rate of 0.25 mA cm−2 to study its role as a reaction promoter. The surface, bulk, and morphological characterization are carried out for both materials. The presence of multiple cations and defects on the surface of the ESO is found to benefit the discharge product oxidation and improve the cyclic stability.