Carbon-Coated High-Entropy Oxide (AlMnCoNiZn) ₃ O ₄ @C as Anode Materials for Lithium-Ion Batteries

High-entropy oxides (HEOs) with diverse functional properties are considered promising candidates for electrode materials in lithium-ion batteries (LIBs). However, HEO-based anode materials suffer from issues such as interfacial side reactions and insufficient electrical conductivity. In this paper, glucose was used as a biomass carbon source to modify the (AlMnCoNiZn) 3 O 4 HEO through a combination of wet grinding and sintering processes, yielding carbon-coated HEO composites with three different carbon contents (denoted as HEO@C(10%), HEO@C(20%) and HEO@C(30%)). X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations reveal that the carbon coating process retains the spinel cubic crystal structure of the HEO, while refining its grain size and regulating its pore structure. Electrochemical tests demonstrate that HEO@C(20%) exhibits the optimal performance. Its capacity remains at 515.2[Formula: see text]mAh/g after 300 cycles at a current density of 200[Formula: see text]mA/g. Rate performance tests indicate that the discharge specific capacity of HEO@C(20%) is superior to that of the other electrodes. When the current density is restored to 100[Formula: see text]mA/g, its capacity rebounds to 620.0[Formula: see text]mAh/g. The enhanced performance originates from the conductive network formed by the carbon coating layer. This work provides a novel strategy and theoretical basis for the low-cost modification of HEO anodes and for investigating the structure–performance relationship of multicomponent HEOs.