Hierarchically structural Ge encapsulated with nitrogen-doped carbon for high performance lithium storage

The anode of Ge has attracted extensive attention due to its high theoretical capacity and energy density. A composite of hierarchically structural Ge encapsulated with nitrogen-doped carbon has been successfully synthesized by using a scalable method. Such a composite properly combines the two superiorities of hierarchically structural Ge and nitrogen-doped carbon, showing a superior electrochemical performance. Designed as an anode for lithium ion batteries, a high reversible capacity of 1067 mA h g(-1) after 300 cycles at 1 A g(-1), an outstanding rate capabilities of 1270 mA h g(-1) at 0.1 A g(-1) and 605 mA h g(-1) at 20 A g(-1) and a stably long-term capacity of 912 mA h g(-1) after 600 cycles at 2 A g(-1) were achieved. The hierarchically structural electrode could promote the diffusion of electrolyte into anode of Ge particles, and the nitrogen-doped carbon could strengthen the stability of structure and enhance electrical conductivity of the composite. This work could pave a new route for developing Ge-based anodes in next-generation lithium ion batteries and high-energy-storage devices.