Self-Templating Synthesis of Hollow Co<sub>3</sub>O<sub>4</sub> Nanoparticles Embedded in N,S-Dual-Doped Reduced Graphene Oxide for Lithium Ion Batteries
Junke Zhu, Wenmao Tu, Hongfei Pan, Heng Zhang, Bin Liu, Yapeng Cheng, Zhao Deng, Haining Zhang, Haining Zhang, Haining Zhang
Abstract
The design and synthesis of hollow-nanostructured transition metal oxide-based anodes is of great importance for long-term operation of lithium ion batteries. Herein, we report a two-step calcination strategy to fabricate hollow Co 3 O 4 nanoparticles embedded in a N,S-co-doped reduced graphene oxide framework. In the first step, core–shell-like Co@Co 3 O 4 embedded in N,S-co-doped reduced graphene oxide is synthesized by pyrolysis of a Co-based metal organic framework/graphene oxide precursor in an inert atmosphere at 800 °C. The designed hollow Co 3 O 4 nanoparticles with an average particle size of 25 nm and wall thickness of about 4–5 nm are formed by a further calcination process in air at 250 °C via the nanoscale Kirkendall effect. Both micropores and mesopores are generated in the HoCo 3 O 4 /NS-RGO framework. Benefiting from the hierarchical porous structure of the hollow Co 3 O 4 and the co-doping of nitrogen and sulfur atoms in reduced graphene oxide, the thus-assembled battery exhibits a high specific capacity of 1590 mAh g –1 after 600 charge–discharge cycles at 1 A g –1 and a promising rate performance from 0.2 to 10 A g –1 .