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

• Published in: Journal of colloid and interface science 2019-03, Vol.539, p.665-671
• Main Authors: Hao, Qin, Liu, Qiang, Zhang, Yuanyuan, Xu, Caixia, Hou, Jiagang
• Format: Article
• Language: English
• Subjects: Anode; Dealloying; Germanium; Lithium ion batteries; Nanoporous
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2018.12.104

Nanoporous Ge/Cu3Ge composite is easily prepared through etching GeCuAl alloy in NaOH solution, which exhibits satisfactory electrochemical performance as an advanced anode material for Li-ion batteries in terms of high specific capacity, excellent rate capability, as well as outstanding cycling stability compared with pure porous Ge. [Display omitted] 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.