Bio-derived carbon nanofibers from lignin as high performance Li-ion anode materials

Development of cost effective and increasingly efficient sustainable materials for energy storage devices, such Li ion batteries, is of crucial future importance. Herein, the preparation of carbon nanofibers from biopolymer blends of lignin (by-product from the paper and pulp industry), with polylactic acid (PLA) and a thermoplastic elastomeric polyurethane (TPU) are described. Scanning electron microscopy (SEM) analysis shows the evolving microstructural morphology after each processing step, (electrospinning, stabilization and carbonization). Importantly, it is possible to tailor nanofiber porosity utilising miscibility/immiscibility rules between lignin and the polymer additive (PLA/TPU). PLA blends (immiscible) generate porous structures while miscible lignin/TPU blends are solid when carbonised. Electrodes produced from 50 % of PLA blends have capacity values of 611 mAhg-1 after 500 charge/discharge cycles; the highest reported to date for sustainable electrodes for Li-ion batteries. Thus, this work will promote the development of lignocelluose waste materials as high performace energy storage materials