Anode Properties of Cr V_1- Si₂/Si Composite Electrodes for Lithium-Ion Batteries

We have reported the effects of substituting a transition metal in silicide on the electrochemical performance of the silicide/Si composite anode for lithium-ion batteries (LIBs); the Cr_0.5V_0.5Si₂/Si electrode exhibited much better cyclability compared with CrSi₂/Si and VSi₂/Si electrodes. Herein, we investigated the electrochemical performance of a Cr V_1- Si₂/Si slurry electrode for its application in LIBs, and the results obtained were compared to those of a gas deposition (GD) electrode, which was comprised of only active materials. The slurry electrode exhibited a superior cycling life as with the GD electrode. After charge-discharge cycles, the expansion of the electrode thickness of CrSi₂/Si and Cr_0.5V_0.5Si₂/Si was smaller than that of VSi₂/Si, and VSi₂ was significantly pulverized compared with the other silicides. It is considered that VSi₂ deformed easily by the stress from Si expansion and pulverized because the hardness of VSi₂ was the smallest among the silicides used in this study. These results reveal that Cr_0.5V_0.5Si₂/Si has great potential as an anode material for next-generation LIBs and hardness is an important property for compositing silicide with Si.