High-entropy oxides (HEOs) have attracted considerable attention as promising anode materials for lithium-ion batteries (LIBs) owing to their high-entropy effect, multicomponent synergistic effect, and highly tunable compositions. However, spinel-structured HEOs still suffer from sluggish electron/ion transport kinetics during lithiation and delithiation, which limits their further electrochemical performance enhancement. In this work, a metalloid phosphorus (P) doping strategy was employed to synthesize spinel-structured [P_x(Co_0.2Fe_0.2Mn_0.2Ni_0.2Zn_0.2)_1-x]₃O₄ (x = 0, 0.05, 0.10, 0.15, 0.2, Px-HEO) via a solution combustion synthesis (SCS) method, and the effects of P doping on the crystal structure, defect characteristics, and lithium-storage properties were systematically investigated. The results demonstrate that the formation of covalent P-O and P-O-M bonds promotes the generation of oxygen vacancies and induces the partial conversion of Mn³⁺ to Mn⁴⁺ through charge compensation, thereby effectively suppressing the Jahn-Teller effect and enhancing the structural stability of the spinel framework. Among all samples, P0.1-HEO exhibits a relatively high specific surface area (60.85 m²·g^-1) and abundant surface oxygen vacancies (50.1%), which significantly improve electron/ion transport kinetics. As a result, the P0.1-HEO electrode delivers a high reversible capacity of 1711 mAh·g^-1 after 250 cycles at 200 mA·g^-1 and retains a reversible capacity of 385 mAh·g^-1 even at a high current density of 3000 mA·g^-1. This study provides an experimental basis for synergistically optimizing the structural stability and lithium-storage performance of high-entropy oxide anodes through metalloid P doping.

Key words: High-entropy oxides, Phosphorus doping, Oxygen vacancies, Structural stability, Reaction kinetics