Towards Low-Voltage and High-Capacity Conversion-Based Oxide Anodes by Configuration Entropy Optimization

Transition metal oxide (TMO)-based anodes attract much attention for lithium storage due to the merits of high theoretical capacity, facile synthesis, and easy scale-up. Moreover, the increased working potential avoids the issue of lithium dendrites formation and thus improves battery safety. Herein, we propose a route to significantly improve the electrochemical performance of TMO anodes through configurational entropy optimization. For example, high-entropy oxide (FeCoNiCrCu)3O4 is synthesized by carefully selecting metal elements. The (FeCoNiCrCu)3O4 electrode ensures not only low potential but also holds high capacity. In the half-cell configuration, the (FeCoNiCrCu)3O4 electrode provides a specific capacity of 575.7 mAh g−1 after 200 cycles at 0.2 A g−1. More importantly, the electrode showed a relatively low discharge voltage of 0.39 V at 0.5 A g−1, which is caused by the configuration entropy optimization. The assembled (FeCoNiCrCu)3O4//LCO coin-type full cell exhibits a high capacity of 266.3 mAh g−1 after 100 cycles at 0.2 A g−1 and an operating voltage up to 3.9 V.