Ge@C three-dimensional porous particles as high-performance anode materials of lithium-ion batteries

We demonstrate the synthesis of Ge@C three-dimensional porous particles (Ge@C TPP) via the decomposition of magnesium germanide (Mg2Ge) and subsequent deposition of a carbon layer. Briefly, Ge TPP is first synthesized by the annealing of a Mg2Ge precursor in air and a subsequent acid pickling process. Then, the carbon layer is deposited onto the Ge TPP by the pyrolysis of acetylene to form Ge@C TPP. When used as anode materials in lithium-ion batteries, the Ge@C TPP shows higher reversible capacity and better cycling performance than bulk Ge and bare Ge TPP. It is believed that the porous and core-shell structures can accommodate the volume change, give more lithiation sites, and stabilize the structure during the charge/discharge process, which may be responsible for the enhanced performance.