Proline-derived in situ synthesis of nitrogen-doped porous carbon nanosheets with encaged Fe2O3@Fe3C nanoparticles for lithium-ion battery anodes
proline, N-doped C nanosheet, porous, encaged Fe2O3@Fe3C, Li-ion battery
ABSTRACT The homogeneous incorporation of heteroatoms into two-dimensional C nanostructures, which leads to an increased chemical reactivity and electrical conductivity as well as enhanced synergistic catalysis as a conductive matrix to disperse and encapsulate active nanocatalysts, is highly attractive and quite challenging. In this study, by using the natural and cheap hydrotropic amino acid proline—which has remarkably high solubility in water and a desirable N content of 12.2 wt.%—as a C precursor pyrolyzed in the presence of a cubic KCl template, we developed a facile protocol for the large-scale production of N-doped C nanosheets with a hierarchically porous structure in a homogeneous dispersion. With concomitantly encapsulated and evenly spread Fe2O3 nanoparticles surrounded by two protective ultrathin layers of inner Fe3C and outer onion-like C, the resulting N-doped graphitic C nanosheet hybrids (Fe2O3@Fe3CNGCNs) exhibited a very high Li-storage capacity and excellent rate capability with a reliable and prolonged cycle life. A reversible capacity as high as 857 mAhg–1 at a current density of 100 mAg–1 was observed even after 100 cycles. The capacity retention at a current density 10 times higher—1,000 mAg–1—reached 680 mAhg–1, which is 79% of that at 100 mAg–1, indicating that the hybrids are promising as anodes for advanced Li-ion batteries. The results highlight the importance of the heteroatomic dopant modification of the NGCNs host with tailored electronic and crystalline structures for competitive Li-storage features.
Tsinghua University Press
Jingfei Zhang,Lijuan Qi,Xiaoshu Zhu,Xiaohong Yan,Yufeng Jia,Lin Xu,Dongmei Sun,Yawen Tang, Proline-derived in situ synthesis of nitrogen-doped porous carbon nanosheets with encaged Fe2O3@Fe3C nanoparticles for lithium-ion battery anodes. NanoRes.2017, 10(9): 3164–3177