Electrochemical performance of biomass carbon-silicon composite anode materials
Biomass carbon has a unique pore structure and large interlayer space,which can accelerate the diffusion of Li+in amorphous carbon.Nano-silicon,pitch and biomass carbon are used to prepare biomass carbon-silicon composite anode materials by spray granulation and high-temperature pyrolysis.The surface morphology of materials is studied by XRD,SEM and surface analysis.The electrochemical performance is investigated by galvanostatic charge-discharge experiments.The initial specific charge capacity of the button cell prepared by this material is 1 692.5 mAh/g and the initial Coulombic efficiency is 90.7%.The prepared 18650 type battery cycles in 2.75-4.20 V,the capacity retention rate of 616 cycles at 1.00 C is 91.44%,447 cycles at 0.50 C charge and 1.00 C discharge is 94.48%,which are higher than 84.90%and 91.98%of asphalt carbon-silicon composite,indicating that the rate capability of the material is better.