High-power lithium-ion batteries place high demands on
the fast
charging ability of electrode materials, while for the current graphite
anode, it suffers from anisotropic and sluggish Li+ transport
due to its small interlayer spacing. In addition, the large polarization
at low lithiation potential at a high rate leads to Li+ deposition and side reactions of Li with the electrolyte. In this
work, α-Al2O3 nanodots incorporated into
aggregates of thin-layer graphite have been developed by facile high-energy
ball milling of graphite and layer-structured pseudo-boehmite. By
optimization, the ball-milled graphite/Al2O3 (BG/Al2O3) manifests a high reversible capacity
of 344 mAh g–1 higher than the 98.7 mAh g–1 of graphite after 500 cycles at 1 A g–1 (∼2.7C)
and 200 mAh g–1 higher than the 59.6 mAh g–1 of raw graphite at 3 A g–1 after 500 cycles. The
wrinkled edges and expanded interlayer spacing generated by high-energy
ball milling optimize the Li+ transport and accelerate
reaction kinetics, contributing high pseudocapacitance and enabling
fast charging ability. The α-Al2O3 nanodots
can decrease the side reactions between the electrolyte and graphite
electrode, contributing high cyclic stability. This study lays a foundation
for the one-step mechanical force chemistry method to prepare highly
stable fast-charging graphite anode materials for lithium-ion batteries.