Self-activated ‘green’ carbon nanoparticles for symmetric solid-state supercapacitors

• Published in: Journal of materials science 2021-08, Vol.56 (23), p.13271-13290
• Main Authors: Bhat, Vinay S., Krishnan, Syam G., Jayeoye, Titilope John, Rujiralai, Thitima, Sirimahachai, Uraiwan, Viswanatha, R., Khalid, Mohammad, Hegde, Gurumurthy
• Format: Article
• Language: English
• Subjects: Activated carbon; Capacitors; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Electrolytes; Energy Materials; Flux density; Materials Science; Nanomaterials; Nanoparticles; Polymer Sciences; Pore size; Porosity; Sawdust; Solid Mechanics; Solid state; Supercapacitors; Surface properties; Synthesis
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-021-06154-z

Tuning of porosity and surface properties of nanoparticles especially on carbon-based nanomaterials, adopting a ‘greener’ or self-activation synthesis technique for electrical charge storage, is progressing. Herein, we report the self-activation of Teak wood sawdust in a nitrogen atmosphere at different activation temperatures to synthesize carbon nanoparticles. The activated carbon nanoparticles synthesized at 900 °C exhibits a maximum ~ 360 m 2  g −1 surface area with ~ 2 nm average pore size diameter. Five electrolytes viz. KOH, KCl, Na 2 SO 4 , NaCl, and H 3 PO 4 are used for studying the supercapacitance nature of the activated carbon nanoparticles in a 3-electrode configuration. A maximum specific capacitance of ~ 208 F g −1 @ 0.25 A g −1 is obtained in 1 M KOH as the electrolyte. Two symmetric supercapacitors, aqueous (1 M KOH) and solid-state (PVA/KOH), are fabricated, and their performance difference is compiled. The solid-state symmetric supercapacitor performs in a wider voltage window (1.7 V) with a superior energy density of 27.1 Wh kg −1 at a power density of 178 W kg −1 . Graphical abstract