Integrating antimony-based compounds and hard carbon spheres for enhanced Na-ion storage

High-capacity electrode materials with good electrochemical stability are essential for developing sodium-ion batteries (SIBs). This work uses a hydrothermal reaction to dewater glucose and synthesize antimony-hard carbon-based composite materials as high-capacity anodes for SIBs. The microscopic image demonstrates that antimony-based rod-shaped materials are decorated on the interconnected hard carbon spheres. The impact of different weight compositions of antimony compounds and hard carbon on Na-ion storage behavior is analyzed. Further, the increase in hard carbon content in the composite results in better stability with reduced specific capacity. The composite with 50 wt% of both the materials (i.e., Sb: HC-1:1) delivers an initial reversible capacity of 348 mAh g−1 with a retention of 96 % after 100 cycles. The C-rate performance of the composite materials shows a 1.93 times improvement in absolute capacity value compared to the pristine hard carbons anode at a current density of 200 mA g−1. This preliminary work dictates that hybridizing hard carbon with an appropriate electrochemical active material might be an effective strategy to improve the electrochemical performance of the Na-ion battery anode in terms of specific capacity and C-rate performance.