Yolk-shell-structured (CrMnFeCoNi)3O4 high-entropy oxide anode for high-performance lithium-ion batteries

High-entropy oxides (HEOs), composed of multiple cations, have emerged as potential anode materials for lithium-ion batteries (LIBs) owing to their excellent capacity, outstanding cycling stability, and tunable charge-discharge properties. This study systematically investigates the effects of morphology on the electrochemical performance of HEO anodes. Combining the high-entropy strategy with morphological tuning can effectively improve the electrochemical performance. Herein, (CrFeMnNiCo)₃O₄ HEOs with well-defined nanoparticle (HEO-NP) and yolk-shell (HEO-YS) structures are successfully synthesized. The influence of morphology on the electrochemical performance of HEO-NP and HEO-YS electrodes are systematically examined. HEO-YS with a yolk-shell morphology outperforms HEO-NP, delivering superior capacities of 954 and 650 mAh g^–1 at lithiation-delithiation rates of 50 and 2000 mA g^–1, respectively, along with an impressive capacity retention of 94 % after 250 cycles. The superior rate capability and cycling stability of HEO-YS can be ascribed to its unique yolk-shell structure, which accommodates volume change, mitigates structural strain, and enhances lithium-ion diffusion. These findings provide valuable insights into morphology engineering as a strategy for optimizing the electrochemical performance of HEO anodes for next-generation LIBs.