Naturally nitrogen-doped self-encapsulated biochar materials based on mouldy wheat flour for silicon anode in lithium-ion batteries

Researchers are interested in the porous structure and high specific surface area properties of biochar. Si/C composites are an effective method for enhancing the performance of silicon anodes in lithium-ion batteries (LIBs). Meanwhile, the protein contained in the large amount of wheat that moulds each year can be used as a premium source of nitrogen-doped carbon and is urgently needed of being recycled. Here, we demonstrate the first use of biochar from mouldy wheat in silicon anode components for LIBs and performed morphological, structural, and electrochemical analyses. After annealing, the mouldy wheat flour is capable of encapsulating the silicon nanoparticles in a homogeneous manner and delivering sufficient nitrogen to the porous carbon skeleton. Due to the presence of this nitrogen-containing carbon layer, the produced Si@Self-encapsulated N-doped biochar from mouldy wheat composites can deliver a reversible capacity of 712.6 mAh g-1 and 478.0 mAh g-1 after 500 and 1000 cycles at high currents of 1A g-1. During manufacture, the carbon material can be prepared in a solitary annealing step, which is energy-efficient and environmentally benign. This study presents a novel method for the clean and sustainable growth of LIBs.