Sb2S3 nanorods encapsulated reduced graphene oxide as an anode material for Na/K-ion batteries

Abstract

Sodium/Potassium-ion batteries (SIBs & PIBs) have received much attention as like lithium-ion batteries (LIBs). In order to commercialize Na/K-ion systems, the developed electrode material must deliver high energy and power density on par with LIBs. Recently, Antimony sulfide (Sb2S3) has drawn widespread attention as a promising anode material for SIBs/PIBs. In this work, Sb2S3 nanorods are selectively encapsulated in rGO network which is synthesized through hydrothermal method and it has been employed as an anode material for SIBs/PIBs. Various structural and electrochemical characterizations are carried out to confirm the structural and electrochemical features of the Sb2S3@rGO composite. FESEM and HRTEM studies confirm that Sb2S3 are crystallized into nanorods in the form of slate pencil-like morphology and reside on the surface of rGO. The Sb2S3 nanorods attached on the surface of rGO through strong C-S bond which effectively inhibit the polysulfide formation during cycling. Such nanoarchitecture not only buffers the volume expansion of Sb2S3 nanorods but enhance the electrochemical kinetics of nanorods during cycling of Na/K-ion batteries. As a result, the composite exhibits superior electrochemical performance in terms of specific capacity, cycling stability and outstanding rate capability for both Na/K-ion batteries. Furthermore, surface enhanced pseudocapacitive ion storage mechanism also contributes to the improvement in specific capacity and cycling stability of Sb2S3@rGO electrode for SIBs. This work opens the door to design the advanced electrode material for SIBs/PIBs.