Novel Lignin-Cellulose-Based Carbon Nanofibers as High-Performance Supercapacitors

Abstract

In this work, a simple phosphating process was proposed to modify cellulose-acetate (CA) and lignin for a novel energy storage precursor material. The prepared precursor fibers exhibited good thermal stability of lignin and flexibility of CA. Subsequently, the precursor fibers undergo a short preoxidation and carbonization treatment process to obtain the biomass-based carbon fibers (CFs) with complete fibrous morphology, uniform fiber diameter, high surface areas, good flexibility, and excellent power storage capacity. The specific capacitance of 346.6 F/g was obtained by using CFs-5 (prepared with 40% H3PO4 content) as a supercapacitor. Simultaneously, the biomass-based CF supercapacitor device delivers a high-energy density of 31.5 Wh/kg at the power density of 400 W/kg. These results indicate that the introduction of H3PO4 can effectively reduce the energy consumption of the preoxidation treatment process for the preparation of the biomass-based CFs, while increasing the energy storage properties significantly. This novel strategy showed a successful route for the preparation of high-quality and low-consumption biomass-based CFs.

State of the Art and New Directions on Electrospun Lignin/Cellulose Nanofibers for Supercapacitor Application: A Systematic Literature Review

“…By adding phosphoric acid (H 3 PO 4 ) into lignin/CA precursor solution, stable phospholipid bonds were reported to blend poplar lignin and cellulose acetate [9]. Prepared nanofibers from this blend exhibited the flexibility of CA and the thermal stability of lignin.…”

“…This supercapacitor recorded a high capacitance of 87 Fg −1 and a high energy density of 37 Whkg −1 . Alternatively, a homogenous slurry containing lignin/CA (active material), carbon black (conductive additive), and PTFE (binder) were coated onto nickel foam (current collector) to form the electrode [9,15,83].…”

“…Using ECH as a covalent bond source, stable and beads free CNF from lignin/CA were synthesized. Similarly, phospholipid bonds (via H 3 PO 4 ) were used to prepare CNFs from lignin/CA precursor [9]. Interestingly, prepared nanofibers not only retain their morphological properties after carbonization but also exhibit the thermal stability of lignin and mechanical flexibility of CA.…”

“…Biomass cellulose (mostly from cellulose acetate, ethyl cellulose, methyl cellulose, etc. ), being the most abundant biological macromolecules in nature, is a good precursor material for electrospinning CNFs due to its good flexibility and essential properties [9]. In the last few decades, CNFs has been fascinating, due to its abundance and low cost, while at the same time having special characteristics such as large surface area and high carbon content [10].…”

“…However, cellulose is a macromolecular polysaccharide, a large number of oxygen atoms in cellulose structure are highly autoxidized at high temperatures, thereby causing thermal instability. This thermal instability leads to morphology collapse during carbonization [9]. The second most abundant bio-based polymer is lignin.…”