Study on the effect of intrinsic electrical resistivity of silicon materials on its performance for Li-ion batteries

Abstract

In this work, broken silicon (Si) wafers with electrical resistivity of 1Ωcm, 0.1Ωcm and 0.01Ωcm and 0.001Ωcm were ball-milled to form Si powders for being used as anode materials for Lithium ion batteries (LIBs). As a result, in relation to other three Si wafers, 0.001Ωcm-Si-wafer presents the highest first discharge and charge capacity, which is 543.4mAhg−1and 457.7mAhg−1 (Si: Carbon=5: 95, weight ratio), respectively. Besides, Si wafer with lower electrical resistivity was found to have better electrochemical properties, including higher charge and discharge capacities at different current densities and lower impedance. In addition, 0.001Ωcm-Si-wafer shows 65.5mAhg−1 (1310mAhg−1 from Si materials after calculation) higher in charge capacity than that of 1Ωcm-Si-wafer. Results obtained in this study are good for the selection of Si raw materials for LIBs.