Table 1.
Biomass derived electrodes (NOT hydrothermally pre-treated).
| Electrode Material | Synthesis Method | Electrolyte | Stability | Microporosity (%) |
BET Area (m2/g) | Cap (F/g) 1 |
|---|---|---|---|---|---|---|
| AC from paulownia flower [177] | Pyrolysis at 600 °C, mix with KOH (3:1 KOH: carbon ratio) and carbonization at 800 °C | 1 M H2SO4 | 93% retention after 1000 cycles | 81% | 1159 | 297 |
| AC from wheat straw [178] | Pyrolysis at 800 °C, KOH (5:1) activ. ** at 800 °C | PVA/KOH | 97.6% after 5000 cycles | 62% | 2115 | 294/296 * |
| Ginger straw-based AC [175] | Carbonization at 700 °C | 6 M KOH | 88% after 6000 cycles | 65% | 720 | 243 |
| AC from rice husk [179] | Mix with ZnCl2 (4:1) followed by microwave heating (600 W). | 6 M KOH | 28% at 20 A/g | 15% | 1565 | 240 |
| Carbon nanosheets derived from silk [176] |
Mix with ZnCl2 (2.5:1) followed by annealing at 900 °C | EMIMBF4 | 92% after 10,000 cycles | 18% | 2494 | 213 |
| Porous carbon from tissue papers [180] | KOH (2.5:1) activ. at 700 °C | 6 M KOH | 58 F/g at 100 mV/s | Mainly microporous | 1320 | 200 (at 1 mV/s) |
| AC from biomass waste [181] | Pyrolysis at 500 °C and KOH (3:1) activ. at 700 °C |
6 M KOH | 75% at 10 A/g | 85% | 1831 | 197/289 * |
| AC from peanut shell [179] | Mix with ZnCl2 (4:1) followed by microwave (MW) heating (600 W). | 6 M KOH | 52% at 20 A/g | 1% | 1552 | 188 |
| Glucose-derived graphene-based AC [174] |
NH4Cl mix (1:1), heating at 400 °C, heating at 1100 °C, KOH (13:1) activ. at 800 °C. | EMIM-TFSI/AN | 90% after 10,000 cycles | Large micro and mesopore presence | 3657 | 175 |
| AC from bacterial cellulose 2 [182] | Freezing (liquid N2), heat at 900 °C, and KOH (1:1) activ. at 900 °C | 6 M KOH | Over 90% after 10,000 cycles | 32% | 491 | 167 |
| Porous carbon from starch 4 [39] | Graphite addition (20% w/w), MW heating (140 °C) and pyrolysis at 800 °C | 2 M H2SO4 | 85% after 10,000 cycles | 38% | 337 | 157 |
| Porous carbon from bamboo 3 [183] | Mix with KHCO3 (4:1) and carbonization at 400 °C | 6 M KOH | 98.4 after 10,000 cycles at 10 A/g | 56% | 1425 | 143 |
| Cashew nut husk derived AC [184] |
Heating at 600 °C and KOH (4:1) activ. at 850 °C | 6 M KOH | Close to 100% after 4000 cycles |
Mainly micro and small mesopores | 2742 | 125/305 * |
1 Specific capacitance measured at 1 A/g (unless specified otherwise) on a two-electrode system. 2 Prepared as a freeze-dried aerogel. 3 Using leaving method with KHCO3 activation. 4 Following a gelation method. * Values in a 3-electrode setup. ** Activ. = Activation.