High Entropy Oxide Duplex Yolk–Shell Structure with Isogenic Amorphous/Crystalline Heterophase as a Promising Anode Material for Lithium‐Ion Batteries

Achieving composition and structure regulation on high entropy materials is a big challenge but will give this kind of new materials a huge boost in energy storage. Herein, a novel high entropy oxide ((CrMnFeCoNi)₃O₄) duplex yolk-shell structure (DYSHEO) with isogenic amorphous/crystalline heterophase are designed and successfully prepared through a simple microthermal solvothermal reaction followed by mesothermal calcination. The microthermal solvothermal reaction results in high entropy precursor with duplex yolk-shell structure, while the mesothermal calcination (annealing temperature at 450 °C) realizes the precursor transformation to (CrMnFeCoNi)₃O₄ (DYSHEO-450) with isogenic amorphous/crystalline heterophase structure. The high entropy effect, the duplex yolk-shell structure, and the isogenic amorphous/crystalline heterophase endow DYSHEO-450 great advantages as lithium-ion battery anode including reducing ion migration obstruction, accommodating volume expansion, and alleviating the stress. Accordingly, DYSHEO-450 exhibits high capacities of 1721 mAh g^-1@0.5 A g^-1, and 1356 mAh g^-1@1 A g^-1 after 500 cycles with a capacity retention rate of 90.3%. It also shows excellent performances in practical application as anode of a coin-type full cell. This work provides new ideas and directions for the structural regulation of high-entropy materials.