将电阻率为1Ω·cm、0.1Ω·cm、0.01Ω·cm、0.001Ω·cm的n型掺杂硅片以及电阻率为1Ω·cm、0.001Ω ·cm的p型掺杂硅片球磨制成6种硅粉,并分别将其与石墨按照5:95的质量比进行混合,用作锂离子电池负极材料并制成扣式电池,通过电化学阻抗谱和倍率性能测试来研究硅材料体电阻率和掺杂类型对锂离子电池电化学性能的影响规律.结果表明,硅材料体电阻率越低,其储锂容量越高,倍率性能越好.电阻率相同时,n型掺杂硅始终比p型掺杂硅具有更大的储锂容量和更好的倍率性能.但是,当p型掺杂硅的电阻率远低于n型掺杂硅时,p型掺杂硅电化学性能更佳.另外,0.001Ω ·cm的n型掺杂硅样品具有最佳的充放电比容量和倍率性能,其首次充放电比容量分别为457.7 m A h·g-1和543.4 m A h·g-1.%n-Type silicon wafers with bulk electrical resistivity of 1 Ω· cm ,0 .1 Ω· cm ,0 .01 Ω· cm and 0 .001 Ω · cm and p-type silicon wafers with bulk electrical resistivity of 1 Ω · cm and 0 .001 Ω · cm were separately ball-milled to form six different types of silicon powders ,which were subsequently mixed with graphite powders at a weight ratio of 5:95 respectively in order for serving as anode materials in lithium-ion batteries (LIBs) .The effects of bulk electrical resistivity and doping types of silicon materials on the anodes' electrochemical performances in LIBs were investigated through the electrochemical impedance spectra and rate tests .The results showed that silicon with lower bulk electrical resistivity exhibits higher capacity and better rate performance . Besides ,n-type doped silicon has higher capacity and better rate performance than those of p-type doped silicon with the same bulk electrical resistivity .In addition ,if the bulk electrical resistivity of p-type doped silicon is much lower than that of n-type doped silicon ,p-type doped silicon can perform better in electrochemical properties .The sample prepared from 0 .001 Ω · cm n-type-Si wafer achieves the highest discharge and charge capacities (543 .4 mAh · g -1 and 457 .7 mAh · g -1 ,respectively ) during the first cycle .
展开▼
