Design of cuboidal FeNi₂S₄-rGO-MWCNTs composite for lithium-ion battery anode showing excellent half and full cell performances

Ternary metal sulfides are projected as advanced lithium-ion battery (LIB) anodes due to their superior electronic conductivity and specific capacity compared to their respective oxide counterparts. Herein, a porous composite of cuboidal FeNi₂S₄ (FNS) with 2D reduced graphene oxide (rGO) and 1D multi-walled carbon nanotubes (MWCNTs) (composite name: FNS@GC) synthesised by an in-situ single-step hydrothermal process. The 1D/2D combined thin carbon coatings on the FeNi₂S₄ prevent aggregation during battery performance by increasing conductivity and resisting the volume changes at lithiation/de-lithiation processes. Consequently, the FNS@GC composite exhibits a commending electrochemical performance with a charge capacity of 797 mAh g^-1 and a first cycle coulombic efficiency of ~67% with reversible capacity restoration property and excellent longterm cycling stability. Furthermore, FNS@GC//LiFePO₄ full cell reveals its practical applicability as a LIB anode with a reversible capacity of 77 mAh g^-1 at 50 mA g^-1 current density.