Enhanced Capacity and Cycle Stability of a Pomegranate-Like Si/rGO Composite Anode by Electrostatic Self-Assembly and Spray-Drying Processes

Si is considered one of the most promising anodes for lithium-ion batteries due to its ultrahigh theoretical capacity and abundant resource reserves. However, the poor conductivity and large volume expansion of silicon-based anode materials seriously affect their charge-discharge efficiency and cycling stability. In this study, the dispersion of Si nanoparticles and graphene oxide (GO) is atomized into small droplets, followed by electrostatic self-assembly, spray-drying, and high-temperature annealing to obtain the pomegranate-like Si/rGO composite (ES-Si/rGO) with a concentrated size of ∼2 μm. It is noteworthy that the preparation is under mild conditions and easy to scale up. As a result, ES-Si/rGO shows a high rate performance at wide current densities and maintains a reversible capacity of 969.3 mAh g^-1after 200 cycles at 500 mA g^-1. The compact rGO improves the electrical conductivity and slows down the structure deterioration. This work is of great potential toward the scalable preparation of silicon-based anodes.