Silicon nanoparticle self-incorporated in hollow nitrogen-doped carbon microspheres for lithium-ion battery anodes

In this study, Silicon nanoparticles (Si NPs) were homogeneously self-incorporated into melamine-formaldehyde resin microspheres using a facile hydrothermal technique, followed by annealing the precursors to form hollow nitrogen-doped carbon microspheres (hNC MSs) containing approximately 10.8 wt.% Si NPs (Si@hNC MSs). Melamine was directly polymerized with formaldehyde, providing N and C sources for Li-ion battery anodes. Electrochemical tests demonstrated that the Si@hNC MS anode delivered a high reversible capacity of 872 mAh g(-1) at a current density of 200 mA g(-1) after 360 cycles. The hNC MSs largely limited the Si volumetric changes caused by repeated charging and discharging, resulting in the high electrochemical stability of the Si anode. This work demonstrates that melamine-formaldehyde resins can be used directly as C and N sources and can effectively mitigate the Si volumetric expansion. Moreover, we believe that this unique resin, an effective C source, has promising potential for improving the electrochemical performance of other metal or metal-oxide anodes. (C) 2020 Elsevier Ltd. All rights reserved.