A novel high entropy perovskite fluoride anode with 3D cubic framework for advanced lithium-ion battery

Abstract

High-entropy materials are recently attracted significant attention due to their variability of composition and entropy stabilizing phase structure. However, the current mainstream synthesis methods of high-entropy materials require high-energy ball milling and calcination, which limits their further generalization. In this work, a new class of high-entropy perovskite fluorides (HEPFs) as an anode material using for LIBs is reported. In particular, a high-entropy fluoride of KMgMnFeCoNiF3 (TM5) and a series of medium-entropy fluorides (TM4) including KMnFeCoNiF3 (TM4-Mg), KMgFeCoNiF3 (TM4-Mn), KMgMnCoNiF3 (TM4-Fe), KMgMnFeNiF3 (TM4-Co), and KMgMnFeCoF3 (TM4-Ni) are prepared by a facile ball milling with hydrothermal method. Interestingly, the TM5 electrode shows better cycling performance (120 mAh g−1 at 2 A g−1 over 1000 cycles with ∼99% coulombic efficiency) and rate performance (472–57 mAh g−1 at 0.1–3.2 A g−1 current densities) than TM4. The key to such improvement depends on the high-entropy effect together with the synergistic effects of multiple electroactive redox centers. It is believed that this work can provide a new idea for the design and synthesis of high-entropy perovskite materials in the future.