Nitrogen-doped lignin-derived electrode materials for supercapacitors were prepared using the domain-limited effect

Abstract

Supercapacitors, pivotal in mitigating the energy crisis stemming from dwindling fossil fuel reservoirs, necessitate meticulous consideration of electrode material preparation. While lignin-derived carbon materials sourced sustainably exhibit commendable potential as electrode materials, their intrinsic low capacitance limits widespread utilization. Herein, nitrogen atom doping of lignin (CNL) was accomplished employing a chemical modification technique employing cyanuric chloride as a dopant. The resultant nitrogen content measured at 2.85 %. Subsequent to CNL carbonation, the generated C3N4 was selectively confined to the internal surface of the CNLMS-800 through a domain-limited activation method, thereby rendering it suitable for deployment as a supercapacitor electrode material. CNLMS-800 manifests a substantial specific surface area of 1778.0 m2 g−1 and a concomitantly diminutive pore size of 2.6 nm. Noteworthy, the specific capacitance of CNLMS-800 attains 473.0 F g−1 at a current density of 0.5 A g−1 in a 6 M KOH electrolyte. The resultant energy density reaches 39.0 Wh kg−1 at a power density of 338.0 W kg−1. Crucially, even after 20,000 charge/discharge cycles at a current density of 10 A g−1, the capacitance retention attains an impressive 87.5 % in the KOH electrolyte. This innovative utilization of sustainable resources for electrode fabrication epitomizes a seminal advancement in the field of energy technology.