Integrating morphology modulation and high entropy engineering to unlock excellent lithium storage performance

High-entropy oxides (HEOs), comprised of multiple cations, are emerging as innovative materials with remarkable potential across diverse applications, owing to their unique structural and functional properties. However, regulating the structure and morphology precisely of HEOs remains a considerable challenge. Leveraging the high-entropy strategy along with morphological modulation not only exposes more active sites but also enhances structural stability, thereby improving electrochemical performance. In this paper, (Fe0.2Co0.2Ni0.2Cu0.2Zn0.2)3O4 HEOs (FCNCZO-HEO) with distinct morphologies of nanoparticles, core-shell spheres, and nanosheets were successfully prepared by a solvothermal strategy. Among them, the core-shell structure exhibited superior electrochemical performance, with its robust shell providing mechanical support, alleviating volume changes and mitigating particle pulverization during cycling. Post-cycling analyses revealed a gradual transition of the core-shell structure into hollow microspheres accompanied by shell thickening as the core partially dissolved and integrated with the shell. Intermediate phases adhered to the shell, stabilizing the structure and preventing aggregation. This morphological evolution maintained the integrity of the core-shell architecture, significantly enhancing the cycling stability of the electrode material. These features contribute to its prominent electrochemical performance, including a notable rate performance of 314 mAh g-1 at 2 A g-1 and outstanding cycling stability with 977 mAh g-1 after 500 cycles at 500 mA g-1. This study illustrates that integration of the high-entropy strategy with morphology control is an effective approach for strengthening the electrochemical performance of materials, which provides valuable insights for the design of high-entropy materials as anode materials for lithium-ion batteries.