硅铜复合物电化学储锂性能分析

以Cu_3Si/Si复合物为锂离子电池负极材料,研究Cu_3Si组分对活性物质Si的电化学储锂性能的影响。结果表明,Cu_3Si并无储锂能力,但能够提升活性物质Si的循环和倍率性能。在200mA/g充放电流密度下,负极首次嵌锂比容量为1 345mAh/g,首次库伦效率为88.37%,经过100次循环后,材料的可逆比容量为698.7mAh/g。Cu_3Si/Si负极在200、500、1 000mA/g电流密度下比容量分别为1 346.22、754.33和564.78mAh/g。当电流密度重新回到200mA/g时,可逆比容量仍高达1 030.58mAh/g,体现出了良好的倍率性能。

Study on Electrochemical Lithium-storage Performance of Si-Cu Composite

Effect of Cu3Si component on electrochemical lithium-storage performance of active silicon was studied with Cu3Si/Si composite as lithium-ion battery anode. The results suggest that Cu3Si component is inactive to lithium insertion, but can improve cycling and rate capacities of active silicon material. The first lithiation specific capacity of anode is 1 345 mAh/g with initial columbic efficiency of 88.37% under charging/discharging current density of 200 mA/g. After cycling for 100 times, reversible specific capacity of anode is as high as 698.7 mAh/g. Cu3Si/Si anode exhibits excellent rate capacities with specific capacity of 1 346.22, 754.33 and 564.78 mAh/g at current density of 200, 500 and 1 000 mA/g, respectively. As current returns to 200 mA/g, reversible specific capacity is 1 030.58 mAh/g.