Lignin-based multi-channels carbon nanofibers @ SnO2 nanocomposites for high-performance supercapacitors

Abstract The lignin-based multi-channels carbon nanofibers (MCNFs) @ SnO2 nanocomposites with various microstructures are synthesized via co-electrospinning by regarding Poly (vinyl pyrrolidone) (PVP)–SnCl2·2H2O as shell materials and lignin-Poly (methyl methacrylate) (PMMA) at different mass ratios as core materials, followed by heat treatment and acid treatment. The experimental results show that when the mass ration of lignin to PMMA in the core region is 5:5, the obtained nanocomposites possess hierarchical internal channels, porous surface, and high specific surface area. This optimized nanocomposites as supercapacitor electrode show high specific capacitance of 406 F g−1 at current density of 0.5 A g−1. In addition, the electrode exhibits unexceptionable cycling stability with only 5% capacitance decay over 10 000 cycles at 10 A g−1. Furthermore, the symmetric supercapacitor using the optimized nanocomposites as electrodes possesses remarkable power and energy densities. The superior electrochemical performance of nanocomposites is benefited from the hierarchical structures of MCNFs, faradaic pseudocapacitance of SnO2, and pore-forming effect of SnCl2·2H2O. The unique hierarchical nanocomposites show great potential in future development of lignin-based low-cost, non-toxic and eco-friendly carbon materials for high-performance energy storage devices.