Ionic liquid electrodeposition of Ge nano-film on Cu wire mesh as stable anodes for lithium-ion batteries

Abstract

Germanium-based materials as anode can improve the capacity of lithium-ion battery because of its excellent lithium-ion storage ability. But the application of Ge anode is hampered by the huge volume variation during de/lithiation processes. Herein, a Ge/Cu wire mesh (Ge/Cu-WM) electrode is prepared by ionic liquid electrodeposition, where the Ge nano-film is deposited on Cu wire mesh. The unique structure of Ge/Cu-WM electrode not only buffers the volume expansion but also enhances electron migration and electron transport during lithiation. The Cu3Ge is observed by XRD, which confirms that the Ge nano-film tightly attach to the Cu wires. All structural properties give the electrode excellent electrochemical performance, where a capacity of 633 mAh/g after 100 cycles at 0.1 C is obtained. The reasonable structure and improved cycling stability make Ge-based anodes highly attractive for lithium-ion battery applications.