Natural polymers as sustainable precursors for scalable production of N/SO_x doped carbon material enabling high‐performance supercapacitors

Abstract

Natural polymers‐based carbon electrodes have gained significant research attention for next‐generation portable supercapacitors. Herein, present an environmentally benign and novel approach for the synthesis of N/S‐Ox carbon material derived from natural polymers on gram scale. By capitalizing the synergistic effect of sulfonated lignin and amino‐containing chitosan, this methodology produces a straightforward, low‐budget, and scalable process. The incorporation of sulfonate motifs from lignin contributes to the formation of C‐SOx moieties and multi‐porous architecture with a high surface area. Simultaneously, amino groups in chitosan induce nitrogen doping, enhancing conductivity, and wettability. The resulting N/SOx carbon material exhibits a micro/meso‐porous architecture, facilitating electrolyte diffusion, and demonstrating improved rate capability and pseudocapacitance via Faradaic redox reactions. The N/SOx carbon material showcases notable capacitance (392 F g−1 at 1 Ag−1) as compared with the reported carbon materials form biomass and outstanding cyclic stability (94.8% retention after 5000 cycles). By optimizing various chitosan mass ratios, the most effective N/SOx carbon material SNACM = S/N‐doped activated carbon material (SNACM‐2) was produced using a lignin: chitosan sample ratio of 1:2 for symmetric supercapacitors. Furthermore, the quasi‐solid‐state symmetric supercapacitors based on SNACM‐2 exhibit an excellent specific capacitance of 142 F g−1 at 1 A g−1, coupled with outstanding flexibility. The SNACM‐2 demonstrates a high‐energy density of 9.8 W h kg−1 at a power density of 0.5 kW kg−1. This study presents a successful strategy for transforming low‐valued, eco‐friendly natural polymers into renewable, high‐performance carbon materials for supercapacitors.image

Mn Cluster-Embedded N/F Co-Doped Carbon toward Mild Aqueous Supercapacitors

“…The obtained heteroatom-doped porous carbon materials exhibited a specific capacitance of 455.3 F g −1 at 1 A g −1 [ 16 ]. Although heteroatom-doped carbon materials exhibit excellent electrochemical performance, challenges still persist in the following aspects: firstly, there is still an absence of studies in the literature investigating the fundamental mechanism of doping metal ions on the electrochemical performance improvement of carbon materials [ 17 , 18 , 19 , 20 ]; secondly, carbon-based electrodes realize the discharging/charging process within acidic or alkaline electrolytes, which aggravate equipment corrosiveness and pose a risk to environmental safety.…”

Heteroatom-Rich Hierarchical Porous Biomass Carbon for Vanadium Redox Flow Batteries

“…A number of research studies have applied biomass carbon to various electrochemical energy storage systems. − For example, the combination of lignin and cellulose- or hemicellulose-derived hard carbon can serve as an anode for sodium-ion batteries, exhibiting better performance than pure lignin-derived hard carbon . Furthermore, biomass-derived carbon is also suitable for VRFBs owing to low cost, tunable structure in hierarchical pores, and heteroatom doping, which helps reduce diffusion resistance and accelerate electrolyte circulation. − In order to further increase the catalytic sites toward the redox of vanadium ions in VRFBs, it is necessary to develop a functionalized strategy for biomass carbon-modified electrodes with excellent electrocatalytic performance by structure designing, including biomass pretreatment and post-treatment methods. In addition, it is crucial to reveal the relationship of the biomass carbon structure and improvement in catalytic activity.…”