The synergetic effects of a multifunctional citric acid and rice husk derived honeycomb carbon matrix on a silicon anode for high-performance lithium ion batteries

Using silicon/carbon composites is one of the most attractive strategies to improve the anode performance for lithium ion batteries. Nevertheless, the adhesion between silicon and carbon can be hardly maintained. It is critical to enhance the silicon/carbon structure stability. Here, we report a facile procedure to design a stable Si@CA@RH anode. Silicon nanoparticles are encapsulated with citric acid that can buffer the volume change and maintain the connection with the carbon structure via ester bonds. A rice husk derived carbon skeleton is used to facilitate the electronic conductivity network as well as the structural stability of the electrode. The hierarchically porous carbon matrix provides sufficient space to accommodate the volume expansion of Si and shortens the lithium-ion transportation distance. Hence, the Si@CA@RH electrode exhibits a stable capacity of 2126 mA h g−1 and high coulombic efficiency of 99.5% after 250 cycles. This strategy gives a perspective on alternative design of integrated carbon/silicon anode materials for high-performance Li-ion batteries.