双金属(Sn/Ni)掺杂多孔硅微球的液相合成与电化学储锂性能

Solution-phase synthesis of bimetallic(Sn/Ni)doped porous silicon microspheres with electrochemical lithium storage

使用廉价的硅铝合金前驱体,通过简单的化学沉积方法制备了新型双金属(Sn/Ni)掺杂多孔硅微球(pSi@SnNi)。pSi@SnNi复合材料的三维多孔结构可以缓冲硅在锂化过程中的巨大体积膨胀,增加储锂活性位点。双金属(Sn/Ni)的掺杂可以提高硅的电子导电性,改进pSi的结构稳定性。由于其独特的组成和微观结构,具有适当Sn/Ni含量的pSi@SnNi复合材料显示了较大的可逆储锂容量(0.1 A·g^(-1)下为2651.7 mAh·g^(-1))、较高的电化学循环稳定性(1 A·g^(-1)下400次循环后为1139 mAh·g^(-1))和优异的倍率性能(2.5 A·g^(-1)下为1235.8 mAh·g^(-1))。

Novel bimetallic(Sn/Ni)doped porous silicon microspheres(pSi@SnNi)were prepared by a simple chemical deposition method,using an inexpensive silicon-aluminum alloy precursor.The three-dimensional porous structure of pSi@SnNi composites can buffer the huge volume expansion of silicon in the lithiation process and increase lithium storage active sites.The deposition and doping of bimetallic(Sn/Ni)may improve the electronic conductivity of Si as well as enhance the structural stability of pSi.Profiting from the unique composition and microstructure,the pSi@SnNi composite with moderate Sn/Ni content showed large reversible lithium storage capacity(2651.7 mAh·g^(-1)at 0.1 A·g^(-1)),high electrochemical cycling stability(1139 mAh·g^(-1)after 400 cycles at 1 A·g^(-1)),and excellent rate capability(1235.8 mAh·g^(-1)at 2.5 A·g^(-1)).