生物质碳-硅复合负极材料的电化学性能

Electrochemical performance of biomass carbon-siliconcomposite anode materials

生物质碳具有独特的孔结构,较大的层间距,可加速Li+在无定形碳中的扩散速度。采用纳米硅、沥青、生物质碳,通过喷雾造粒、高温热解法制备生物质碳-硅复合负极材料。通过XRD、SEM、表面分析研究材料的表面形貌特征;通过恒流充放电等实验研究电化学性能。该材料制备扣式电池的首次充电比容量达到1 692.5 mAh/g,首次库仑效率为90.7%。制备的18650型电池在2.75~4.20 V循环,以1.00 C循环616次的容量保持率为91.44%;以0.50 C充电、1.00 C放电循环447次的容量保持率为94.48%,高于沥青碳-硅复合材料的84.90%和91.98%,说明该材料的倍率性能较好。

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 1692.5 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.