Abstract
Inactive silicon-metal phase as addition agent of silicon-based anode materials for lithium ion batteries can effectively improve the battery electrochemical performance. Si-Mn/C composites composed of Si, Mn4Si7 alloy and amorphous carbon, were synthesized by a liquid solidification method with subsequent heating treatment. The obtained 90%Si10%Mn/C composite as the electrode displays a good cyclabiltiy with a capacity retention of 82.3% after 100 cycles and an excellent rate capability with a high capacity of 880.6 mAh g-1 even at a high rate of 13 A g-1. The outstanding performance of 90%Si10%Mn/C electrode is attributed to the inactive Mn4Si7 alloy in the composites, which mainly distribute in between nano-silicon particles or on the surface of nano-silicon, to build up a connection between nano-silicon particles and enhance the stability of both electrode material structure and electrode/electrolyte interface. We believe that integrating inactive Mn4Si7 alloy may open a sacred door for the large-scale production silicon-based anode materials.