NiSb-Al2O3-C Nanocomposite Anodes with Long Cycle Life for Li-Ion Batteries

A NiSb-Al2O3-C nanocomposite alloy anode has been synthesized by high-energy mechanical milling, involving the mechanochemical reduction of Sb2O3 by metallic Al and Ni in the presence of acetylene black carbon. X-ray diffraction and X-ray photoelectron spectroscopy confirm the presence of crystalline NiSb and amorphous Al2O3 in the final nanocomposite. Transmission electron microscopy analysis shows the distribution of nanoscale crystalline NiSb particles in the matrix of Al2O3 and carbon. The presence of reinforcing Al2O3 and nanoscale active particles give this nanocomposite excellent cycle life with demonstrated capacity of 280 mAh g(-1) to 1000 cycles. While the as-synthesized sample suffers from low coulombic efficiency of 55% in the first cycle and a large irreversible loss of roughly 350 mAh g(-1), post-heat-treatment processes dramatically reduce the irreversible loss to 150 mAh g(-1) with a coulombic efficiency of 73%. Combined with good rate capability and a tap density of 1.3 g cm(-3), NiSb-Al2O3-C has significant potential as an alternative to graphite anodes in Li-ion batteries.