Lignin-based electrospun carbon nanofibrous webs as free-standing and binder-free electrodes for sodium ion batteries

Low-cost and bio-based carbon nanofibrous webs (PL-CNFs) are fabricated from polyacrylonitrile (PAN) - refined lignin (RL) which is extracted from hardwood lignosulfonate via simple eletrospinning followed by stabilization and carbonization. The effects of the PAN/RL mass ratios varying from 9/1,7/3 to 5/5 and heat-treatment temperatures (HTTs) in the range from 800, 1000 to 1300 degrees C on morphology and structure of PL-CNFs are systematically studied. Due to unique morphology and weakly ordered turbostratic microstructure of the 3-D conductive composite networks, the PL-CNFs anode obtained at 1300 C with a mass ratio of 5/5 exhibits a high reversible capacity of 292.6 mA h g(-1) with an initial efficiency of 70.5% at a constant current density of 0.02 A g(-1) when used as free-standing and binder-free anodes for sodium ion batteries (SIBs). The anode also presents high rate capability (210 and 80 mA h g(-1) at 0.4 and 1 A g(-1), respectively) and excellent cycle stability (247 mA h g(-1) reversible capacity with 90.2% capacity retention ratio at 0.1 A g(-1) over 200 cycles). It is demonstrated that biomass waste lignin can be applied as a promising precursor to fabricate low-cost-high performance carbon electrode materials for SIBs. (C) 2014 Elsevier B.V. All rights reserved.