Sb particles embedded in N-doped carbon spheres wrapped by graphene for superior K+−Storing performances

Abstract

Antimony (Sb)-based nanocomposites have emerged as an attractive class of anode materials for potassium ion batteries as they exhibit large theoretical capacity and impressive working voltage. However, the tardy potassium ion diffusion characteristic, unstable Sb/electrolyte interphase, and huge volume variation pose a grand challenge that hinder the practical use of Sb-based anodes for potassium ion batteries. Herein, we develop a simple yet robust strategy to fabricate a three-dimensional N-doped carbon (N–C) porous microspheres and reduced graphene oxides (rGO) dual-encapsulated Sb hierarchical structures (denoted Sb@N–C/rGO), which are pursued for resolving the stubborn issues of Sb-based compounds for PIBs. As expected, such judiciously crafted Sb@N–C/rGO anode renders a set of intriguing electrochemical properties, representing a high reversible specific capacity of 586 mAh g−1 at a current density of 0.2 A g−1 after 200 cycles and excellent long-cycle stability of 358 mAh g−1 at 1.0 A g−1 after 1000 cycles. It is believed that the work can provide deep understanding and new insight to develop the alloying-type electrode materials for rechargeable batteries.