title: Synthesis of Olive-Like Nitrogen-Doped Carbon with Embedded Ge Nanoparticles for Ultrahigh Stable Lithium Battery Anodes.
abstract: The development of environment-friendly and high-performance carbon materials for energy applications has remained a great challenge. Here, a novel and facile method for synthesis of olive-like nitrogen-doped carbon embedded with germanium (Ge) nanoparticles using widespread and nontoxic dopamine as carbon and nitrogen precursors is demonstrated, especially by understanding the tendency of pure GeO2nanoparticles forming ellipsoidal aggregation, and the chelating reaction of the catechol structure in dopamine with metal ions. The as-synthesized Ge/N-C composites show an olive-like porous carbon structure with a loading weight of as high as 68.5% Ge nanoparticles. A lithium ion battery using Ge/N-C as the anode shows 1042 mAh g-1charge capacity after 2000 cycles (125 d) charge/discharge at C/2 (1C = 1600 mA g-1) with a capacity maintaining efficiency of 99.6%, significantly exceeding those of the previously reported Ge/C-based anode materials. This prominent cyclic charge/discharge performance of the Ge/N-C anode is attributed to the well-dispersed Ge nanoparticles in graphitic N-doped carbon matrix, which facilitates high rates (0.5-15 C) of charge/discharge and increases the anode structure integrity. The synthesis strategy presented here may be a very promising approach to prepare a series of active nanoparticle-carbon hybrid materials with nitrogen doping for more and important applications.
authors.affiliation: Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China.
authors.forename: Yongning
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China.
authors.forename: Limin
authors.initials: L
authors.lastname: Wu
keywords: carbon; electrodes; germanium; nitrogen-doped; olive-like