Improved Cycling Performance of Cr x V1−x Si2/Si Composite Electrode for Application to Lithium-Ion Battery Anodes

Abstract

We have evaluated the anode properties of the silicide/Si composite electrodes for lithium-ion batteries and revealed that ternary silicide made by elemental substitution improved the electrochemical performance of the electrodes. In particular, a Cr0.5V0.5Si2/Si composite electrode exhibited a good cycle stability. Herein, we attempted mechanical grinding of the Cr0.5V0.5Si2/Si composite and addition of fluoroethylene carbonate (FEC) into the electrolyte to further improve the performance of the electrode. The electrode showed a superior cycling performance by these attempts as expected. The mechanical grinding should cause the formation of amorphous Si phase and fine dispersion of Cr0.5V0.5Si2 in the Si phase, which suppresses the pulverization of the Cr0.5V0.5Si2/Si composite particle during charge-discharge. It is considered that the addition of FEC suppresses the continuous reductive decomposition of the electrolyte, which contributes to the improvement in the cyclability.