The Anode Challenge for Lithium-Ion Batteries: A Mechanochemically Synthesized Sn-Fe-C Composite Anode Surpasses Graphitic Carbon

Carbon-based anodes are the key limiting factor in increasing the volumetric capacity of lithium-ion batteries. Tin-based composites are one alternative approach. Nanosized Sn-Fe-C anode materials are mechanochemically synthesized by reducing SnO with Ti in the presence of carbon. The optimum synthesis conditions are found to be 1:0.25:10 for initial ratio of SnO, Ti, and graphite with a total grinding time of 8 h. This optimized composite shows excellent extended cycling at the C/10 rate, delivering a first charge capacity as high as 740 mAh g(-1) and 60% of which still remained after 170 cycles. The calculated volumetric capacity significantly exceeds that of carbon. It also exhibits excellent rate capability, delivering volumetric capacity higher than 1.6 Ah cc(-1) over 140 cycles at the 1 C rate.