Upgrading of pine tannin biochars as electrochemical capacitor electrodes

CO2 outperforms KOH as an activator for high-rate supercapacitors in aqueous electrolyte

“…Wh kg -1 at the same power. These values of E and P are within the range reported for similar materials and testing conditions in H 2 SO 4 , as shown in Table S4 [18,37,47,[55][56][57][58][59][60][61][62][63][64][65][66][67][68].…”

Functional utilization of biochar derived from Tenebrio molitor feces for CO2 capture and supercapacitor applications

“…Even when the energy density was 27.22 W h kg −1 , the power density was as high as 10 kW kg −1 . When compared with other reported biochar capacitors such as AC-700//AC-700 (19.9 W h kg −1 , 700 W kg −1 ), 58 MnO 2 /NBC/PEDOT (7.8 W h kg −1 , 706.3 W kg −1 ), 59 WBMs-800//WBMs-800 (9.4 W h kg −1 , 227 W kg −1 ), 60 TBC-K 3.6 //TBC-K 3.6 (6.7 W h kg −1 , 110 W kg −1 ), 61 HBFC-1//HBFC-1 (13.1 W h kg −1 , 225 W kg −1 ), 62 and NFAC-c//NFAC-c (22 W h kg −1 , 80 W kg −1 ) 63 our results were superior. Meanwhile, our results were closed to other reported capacitors based on modified biochar, including FBC//FCBC (45.1 W h kg −1 , 900 W kg −1 ), 64 FBC//MBC (30.8 W h kg −1 , 900 W kg −1 ), 64 BMIMBF 4 /AN (46.38 W h kg −1 , 300 W kg −1 ), 65 and Ni(OH) 2 -MnO 2 -RGO//NBKBC (39.5 W h kg −1 , 264 W kg −1 ) 66 (Table S5†).…”

Progress in the Use of Biosourced Phenolic Molecules for Electrode Manufacturing

“…Chemical activations involve the use of chemical activating agents, such as KOH, NaOH, and H 3 PO 4 (Marsh and Rodríguez-Reinoso, 2006;Pérez-Mayoral et al, 2021;Pérez-Rodríguez et al, 2021). These activating agents are mixed with the carbon precursors, followed by thermal treatment at temperatures of 350-900 °C.…”

“…In addition to the carbonization of renewable phenolic resins, the direct thermal treatment of lignin and tannin has also been evaluated for the production of advanced carbon electrodes for electrochemical capacitors. A recent work (Pérez-Rodríguez et al, 2021) used biochars obtained as a byproduct of bio-oil production from the fast pyrolysis of pine bark tannin as green and abundant precursors for the fabrication of SC electrodes (Figure 7A). After activation of the tannin-derived biochars with KOH at 650 °C at different activation ratios (ARs), the resultant microporous activated carbons exhibited highly developed surface areas (up to 2,200 m 2 g −1 ) and high oxygen content (10-15 wt%).…”