Silicon@Natural Nitrogen-Doped Biomass Carbon Composites Derived from “Silicon Tofu” as Green and Efficient Anode Materials for Lithium-Ion Batteries

The use of Si/nitrogen-doped carbon composites is an effective means to improve the performance of silicon anode materials for lithium-ion batteries (LIBs), but the large-scale development of such materials is restricted by their high cost and challenging processes. Tofu, a low-cost food rich in protein, can be used as a natural source of carbon and nitrogen. In addition, it has a developed pore structure. Herein, we report for the first time the ingenious application of the traditional tofu manufacturing technology in the field of silicon materials and the fabrication of unprecedented “silicon tofu.” After simple carbonization, the intertwined protein in silicon tofu is transformed into a natural amorphous carbon conductive network doped with nitrogen atoms, which can effectively maintain the integrity of the electrode structure during the cycle process. Because of the synergistic effect of the natural porous structure and nitrogen doping, the optimized Si@natural nitrogen-doped biomass carbon composite can maintain a reversible capacity of a 731.6 mA h g–1 after 300 cycles, even at a high current density of 1 A g–1. Moreover, the overall preparation process is environmentally friendly and sustainable. This research provides a simple, clean, and scalable solution for green and efficient anode materials for LIBs.