A correlation of surface/textural properties of carbon derived from Musa acuminata stem and its high supercapacitance performance with superior cycle stability

• Published in: Journal of energy storage 2021-12, Vol.44, p.103424, Article 103424
• Main Authors: Byatarayappa, Gopalakrishna, M G, Radhika, Bhatta, Umananda M., Ingale, Deepak V., Venkatesh, Krishna, N, Nagaraju, Nagaraju, Kathyayini
• Format: Article
• Language: English
• Subjects: High cycle stability; Micro porosity; Musa acuminata stem; Porogens; Specific energy; Specific power
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2021.103424

•KOH activated carbon (C-1) from banana stem with high surface properties showed low Cs.•KCl activated (C-3) with average surface properties exhibited high Cs of 339 F g−1.•Symmetric coin cell using C-3 exhibited SE 34.4 Wh kg−1 SP 25.6 kW kg−1 & 75,000 cycles.•Two-coin cells connected in series were used to power 1-watt LED operated at 100 mA. Carbonization of variety of biomass materials and activation using metal salts, oxides carbonates etc., aids in increasing its specific surface area (SSA) and activation site density utilized in many applications. Here, Musa acuminata (banana) stem has been carbonized at 450 °C and activated using five different porogens like KOH (C-1), ZnCl2 (C-2), KCl (C-3), NaHCO3 (C-4) & K2HPO4 (C-5) at 750 °C. The physico-chemical properties of these carbon materials have been analysed using P-XRD, SEM, EDS, TEM, SAED, BET and Raman techniques. Apart from usual amorphous graphitic peak in carbon materials, inorganic metal oxides/carbonate/silicate peaks are present due to interaction among biomass derived elements like C, O, K, Mg, Si & P etc., at high temperatures. Among ACs, C-1 shows superior surface properties with very high SSA of 3351 m2 g−1 but gave only specific capacitance (Cs) of 75 F g−1 at 5 A g−1. But C-3 with moderate surface properties exhibited a high Cs of 339 F g−1 at 5 A g−1. C-3 was subjected to continuous charge-discharge cycles at 15 A g−1 indicated 80% Cs retention & 100% coulombic efficiency at 25,000th cycle. A symmetric coin cell (CR2032) fabricated using C-3 in 1 M KOH solution, exhibited a high Cs, specific energy (SE) & specific power (SP) of 88 F g−1 at 2 mV s−1, 62 F g−1 at 1 A g−1 remarkably 34.4 Wh kg−1 and 25.6 kW kg−1 respectively. The coin cell was subjected to enormous number (75,000) of cycles at 25 A g−1 showed Cs retention of 75% with 100% coulombic efficiency. Two-coin cells, each cell operating in the potential range from 0–2 V connected in series are used to power 1-watt LED for 3 minutes. Agricultural biowaste Musa acuminata stem derived carbon was activated with various porogens and proved that moderate surface properties would lead to high supercapacitance performance and the same exhibits 75,000 cycle stability in coin cell (CR2032). [Display omitted]