Facile Synthesis of Peapod-Like Cu3 Ge/Ge@C as a High-Capacity and Long-Life Anode for Li-Ion Batteries

Abstract

As anode materials for high-performance Li-ion batteries, peapod-like Ge-based composites, including Ge, a Li-inactive conducting Cu₃ Ge, and a porous carbon matrix are synthesized simply by annealing CuGeO₃ @dopamine in a H₂ /Ar atmosphere. The introduction of the carbon layer and inactive alloying phase Cu₃ Ge not only enhances the electrical conductivity of the Ge anode, but also reduces the volume change of Ge during the cell cycle as a buffer. In particular, the anode of this peapod-like Cu₃ Ge/Ge@C shows an excellent long cycle life as well as outstanding capacity performance, with a discharge specific capacity up to 934 mA h g^-1 after 500 cycles.

Keywords: Li-ion batteries; alloys; anodes; germanium; nanocomposites; nanorods; nanostructures.