Flexible lignin-derived carbon nanofiber substrates functionalized with iron (III) oxide nanoparticles as lithium-ion battery anodes

To develop high-performance flexible anodes has become an emerging technological demand for the next generation of lithium-ion batteries (LIBs). In this study, flexible substrates consisting of randomly overlaid electrospun carbon nanofibers (ECNFs) with fiber diameters of similar to 200 nm and BET specific surface area of similar to 583m(2).g(-1) were made from lignin and polyvinyl alcohol by electrospinning followed by stabilization in air and carbonization in argon. After surface-functionalization with Fe2O3 nanoparticles, the resulting flexible ECNF/Fe2O3 nanostructures/electrodes exhibited enhanced lithiation/delithiation performance. Specifically, in lithium-ion half-cells with similar to 35 wt% Fe2O3 nanoparticles deposited on ECNF surfaces, the discharge capacities of similar to 951 mA.h.g(-1) in the first cycle and similar to 715 mA.h.g(-1) after 80 cycles were observed. This study presents a new approach for the fabrication of flexible LIB anodes by eliminating commonly used organic binders, metal substrates, and electrode slurries; furthermore, lignin that is a waste byproduct of cellulose industry has been successfully utilized in this approach.