An Investigation of the Fe-Mn-Si System for Li-Ion Battery Negative Electrodes

Abstract

Fe-Mn-Si alloys prepared by ball milling were investigated as negative electrodes for Li-ion batteries. X-ray diffraction and room temperature 57 Fe Mössbauer measurements were used to characterize alloy structure, which revealed the formation of ternary (Fe,Mn,) 11 Si 19 solid solutions. During cycling in Li cells, the formation of crystalline Li 15 Si 4 was effectively suppressed by inactive transition metal silicide phases, resulting in good cycling performance. In addition, Fe was found to be superior to Mn in avoiding excessive side reactions with electrolyte during cycling.