Rare Earths-Silicide/Silicon Composite Electrodes with Excellent Anode Performance for Lithium-Ion Battery

摘要

Silicon (Si) has attracted much attention as anode material due to its huge theoretical capacity, while there are critical disadvantages: a low electronic conductivity and significant volume changes during Li-insertion/extraction. We have revealed that Si's anode performance can be improved by being composite electrodes consisting of elemental Si and transition metal silicides [1-4]. In particular, we found that lanthanum silicide (La-Si) is very effective for improvement in the performance [1,2]. In contrast, the effect of other rare-earth metal silicides on the performance has never explored yet. In this study, we chose samarium (Sm), gadolinium (Gd), and dysprosium (Dy) as rare-earth elements to be rare-earth metal silicides (Ln-Si), and investigated the anode performance of Ln-Si composite electrodes prepared by a gas-deposition method. In addition to this, the effect of nickel substitution on the electrochemical performance of a lanthanum silicide (LaSi2)/silicon (Si) composite electrode was studied.