纳米Si粉分散对硅碳负极性能的影响

Effect of dispersion of Si nano-powders to properties of silicon carbon anodes

通过高频感应等离子蒸发凝聚法制备得到的纳米Si粉结晶性好,球形度高,表面光滑,比表面积为40.03 m^2/g,平均粒径为64.05 nm。以乙二醇和去离子水为分散介质,制备了质量分数10%的纳米Si粉分散液,在乙二醇体系中纳米Si粉颗粒的分散稳定性更好,分散粒径更小,粒度分布为94.17~152.88 nm。以纳米Si粉乙二醇分散液与石墨(G)复合调浆制备的m(G):m(Si)=9:1的复合负极材料电化学性能更优,首次放电比容量为812.5 mA·h/g,可逆充电比容量可达631.0 mA·h/g,30次循环后的容量保持率为73.74%。

Si nano-powders were prepared by radio frequency inductively coupled plasma evaporation method, which were good crystalline and smooth surface spherical powders. Specific surface area and average grain diameter were 40.03 m2/g and 64.05 nm respectively. 10% Si nano-powders dispersion liquid with ethylene glycol and deionized water wsa prepared. It can be found that Si nano-powders in ethylene glycol has better dispersion and smaller particle size than in deionized water, particle size distribution is 94.17-152.88 nm. Silicon carbon composite cathode materials at m （G） ： m （Si） ratio have better electrochemical performance, which are prepared through pulping with 10% Si nano-powers ethylene glycol dispersion and graphite. First discharge capacity is 812.5mA .h/g, charge capacity is 631.0 mA .h/g, and capacity remain is 73.74% after 30 cycles.