Germanium Nanowires via Molten-Salt Electrolysis for Lithium Battery Anode

Germanium (Ge)-based materials can serve as promising
anode candidates
for high-energy lithium-ion batteries (LIBs). However, the rapid capacity
decay caused by huge volume expansion severely retards their application.
Herein, we report a facile and controllable synthesis of Ge nanowire
anode materials through molten-salt electrolysis. The optimal Ge nanowires
can deliver a capacity of 1058.9 mAh g–1 at 300
mA g–1 and a capacity above 602.5 mAh g–1 at 3000 mA g–1 for 900 cycles. By in situ transmission electron microscopy and in situ X-ray
diffraction, the multiple-step phase transformation and good structural
reversibility of the Ge nanowires during charge/discharge are elucidated.
When coupled with a lithium-rich Li1.2Mn0.567Ni0.167Co0.067O2 cathode in a full
battery, the Ge nanowire anode leads to a relatively stable capacity
with a retention of 84.5% over 100 cycles. This research highlights
the significance of molten-salt electrolysis for the synthesis of
alloy-type anode materials toward high-energy LIBs.