High-entropy (NiFeMnCuZn)Co2Se4@C as an anode material for lithium-ion batteries

Abstract

A dopamine-derived carbon-coated selenide composite (NiFeMnCuZn)Co₂Se₄@C (HESe@C) was synthesized by a solvothermal method followed by carbonisation and evaluated as an anode material for lithium-ion batteries (LIBs). Structural characterization shows that HESe@C possesses a dominant crystalline selenide phase, a thin carbon coating layer, and a porous nanocluster morphology. Electrochemical measurements indicate that HESe@C delivers an initial discharge capacity of 880 mAh g⁻¹ at 0.1 A g⁻¹ and retains 966 mAh g⁻¹ after 100 cycles. In addition, a reversible capacity of 380 mAh g⁻¹ is maintained at 5.0 A g⁻¹, which is higher than that of NiCo₂Se₄@C under the same conditions. Electrochemical impedance spectroscopy reveals a lower charge-transfer resistance for HESe@C. Kinetic analysis based on scan-rate-dependent cyclic voltammetry shows that the pseudocapacitance contribution reaches 94.2% at 1.0 mV s⁻¹. The improved electrochemical performance is likely related to the combined effects of multicomponent composition, carbon coating, and porous structure, which may facilitate charge transfer and ion transport. These results indicate that HESe@C is a promising selenide and carbon composite anode for LIBs.