Facile Synthesis of Peapod-Like Cu3Ge/Ge@C as a High-Capacity and Long-Life Anode for Li-Ion Batteries

Graphical Nanocomposite anodes : Uniform peapod-like Cu 3 Ge/Ge@C composites are fabricated successfully through a facile dopamine-coating and annealing route (see figure). Owing to the homogeneous carbon encapsulation and the addition of the inactive alloying phase Cu 3 Ge, this Ge-based anode exhibits an excellent high specific capacity, outstanding cycle stability, and excellent rate performance for LIBs. As anode materials for high-performance Li-ion batteries, peapod-like Ge-based composites, including Ge, a Li-inactive conducting Cu 3 Ge, and a porous carbon matrix are synthesized simply by annealing CuGeO 3 @dopamine in a H 2 /Ar atmosphere. The introduction of the carbon layer and inactive alloying phase Cu 3 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 Cu 3 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.