Preparation of NiSe₂/CoSe₂/C composites and their lithium storage properties

Abstract

As an effective energy storage device, lithium-ion batteries (LIBs) have attracted great attention in the past 40 years because of their advantages of high energy density, long cycle life, light weight, and less environmental pollution, and people have put forward higher requirements for the performance of LIBs. The performance of LIBs depends largely on the choice of cathode and anode materials, while the anode materials are limited by their lithium intercalation mechanism, so they are difficult to greatly improve their specific capacity. In this work, NiSe₂/CoSe₂/C composites were prepared by calcining Ni–Co PBA and selenium powders in inert atmosphere at high temperature. The as-prepared samples are granular with a thin carbon layer on the surface. The average crystallite size of NiSe₂/CoSe₂/C₃₅₀ is 14.03 nm. The NiSe₂/CoSe₂/C₃₅₀ composites exhibit a high initial discharge specific capacity of 1381.5 mAh g⁻¹ at a current density of 0.1 A g⁻¹, and a reversible capacity of 695.3 mAh g⁻¹ after 200 cycles and remains at 425.3 mAh g⁻¹ after 800 cycles at a high current density of 1 A g⁻¹. Therefore, NiSe₂/CoSe₂/C₃₅₀ composites have a good development prospect as a new generation of anode materials for LIBs.