Controllable fabrication of FeCoS4 nanoparticles/S-doped bowl-shaped hollow carbon as efficient lithium storage anode

To address the low conductivity and easy agglomeration of transition metal sulfide nanoparticles, FeCoS4 nanoparticles embedded in S-doped hollow carbon (FeCoS4@S-HC) composites were successfully fabricated through a combination of hydrothermal processes and sulfidation treatment. The unique bowl-shaped FeCoS4/S-HC composites exhibit excellent structural stability with a high specific surface area of 303.7 m2·g−1 and a pore volume of 0.93 cm3·g−1. When applied as anode material for lithium-ion batteries, the FeCoS4@S-HC anode exhibits efficient lithium storage with high reversible specific capacity (970.2 mA·h·g−1 at 100 mA·g−1) and enhanced cycling stability (574 mA·h·g−1 at 0.2 A·g−1 after 350 cycles, a capacity retention of 84%). The excellent lithium storage is attributed to the fact that the bimetallic FeCoS4 nanoparticles with abundant active sites can accelerate the electrochemical reaction kinetics, and the bowl-shaped S-HC structure can provide a stable mechanical structure to suppress volume expansion.