Facile Synthesis of BiSb/C Composite Anodes for High-Performance and
Long-Life Lithium-Ion Batteries
Abstract
Alloy-type antimony (Sb) is considered as an attractive candidate anode
for high-energy lithium-ion batteries (LIBs) because of its high
theoretical specific capacity and volumetric capacity. However, Sb
suffers from enormous volume variation during cycling, which causes
electrode cracking and pulverization, and hence the fast capacity decay
and poor cyclability, limiting its practical applications as a LIB
anode. Herein, we report a facile, scalable, low-cost and efficient
route to successfully fabricate BiSb/C composites via a two-step
high-energy mechanical milling (HEMM) process. The as-prepared BiSb/C
composites consist of nanosized BiSb totally embedded in a conductive
carbon matrix. As LIB anodes, BiSb/C-73 (with 30 wt % carbon)
electrodes exhibit excellent Li storage properties in terms of stable
high reversible capacities, long-cycle life, and high-rate performance.
Reversible capacities of ∼583, ∼466, ∼433 and ∼425 mAh g–1 at a current
density of 500 mA g–1 after 100, 300, 500 and 1000 cycles,
respectively, were achieved. In addition, a high capacity of ∼380 mAh
g−1 can still be retained at a high rate of 5 A g−1. Such outstanding
cycling stability and rate capability could be mainly attributed to the
synergistic effects between the ability of nanosized BiSb particles to
withstand electrode fracture during Li insertion/extraction and the
buffering effect of the carbon matrix. The as-prepared BiSb/C composites
are based on commercially available and low-cost Bi, Sb and graphite
materials. Interestingly, HEMM is more convenient, efficient, scalable,
green and mass-production route, making as-prepared materials attractive
for high-energy LIBs.