Easy preparation of nanoporous Ge/Cu₃Ge composite and its high performances towards lithium storage

Nanoporous Ge/Cu₃Ge composite is fabricated simply through selective dealloying of GeCuAl precursor alloy in dilute alkaline solution. The as-made Ge/Cu₃Ge is characterized by three dimensional (3D) bicontinuous network nanostructure which comprises of substantial nanoscale pore voids and ligaments. Owing to the 3D porous architecture and the introduction of well-conductive Cu₃Ge, the lithium storage performances of Ge are dramatically enhanced in terms of higher cycling stability and superior rate performance. Nanoporous Ge/Cu₃Ge anode delivers steady capacities above 1000 mA h g^-1 upon cycling for 70 loops at 400 mA g^-1. In particular, after 300 cycles at the high rate of 3200 mA g^-1 the capacity retention for Ge/Cu₃Ge is able to reach a maximum of 99.3%. On the contrary, the pure nanoporous Ge encounters severe capacity decay. In view of the outstanding energy storage performances and easy preparation, nanoporous Ge/Cu₃Ge exhibits great application potential as an advanced anode in lithium storage related technologies.