Table 20.
Composite supercapacitor electrodes based on biochar derived from biomass
| Composite materials | Biomass material | Current density (A g−1) | Number of cycles | Capacitance (F g−1) | Stability (%) | Electrolyte used | References |
|---|---|---|---|---|---|---|---|
| Hierarchically porous carbon/nitrogen | Houttuynia | 1 | 10,000 | 473.5 | 95.74 | 6 M potassium hydroxide | Shang et al. (2020) |
| Nanofibers/nickel–cobalt oxides | Typha domingensis | 1 | 5000 | 142 | 92.1 | 6 M potassium hydroxide | Golmohammadi and Amiri (2020) |
| Porous carbon/phosphorus | Elaeocarpus tectorius | 0.2 | 1000 | 385 | 96 | 1 M sulphuric acid | Nirosha et al. (2020) |
| Porous carbon/ iron (III) oxide | Hemp straw | 1 | 5000 | 256 | 77.71 | 6 M potassium hydroxide | Jiang et al. (2020) |
| Carbon nanosheet/ nickel (II) hydroxide | Peach gum | 1 | 5000 | 350 | 83.9 | 6 M potassium hydroxide | Yu et al. (2019b) |
| Activated mesoporous carbon/nitrogen/sulphur | Datura metel seed pod | 1 | 3000 | 340 | 95.24 | 1 M sulphuric acid | Raj et al. (2020) |
| Hierarchically porous carbon/N/N | Carboxymethyl cellulose ammonium | 1 | 10,000 | 465 | 86.3 | 3 M potassium hydroxide | Meng et al. (2020) |
| Activated carbon/ copper (II) chloride | Lotus pollen | 1 | 10,000 | 496 | 90.8 | 1 M sodium sulphate | Wan et al. (2021) |
| Hierarchically porous carbon/nitrogen/sulphur | Rape pollen | 1 | 20,000 | 361 | 94.5 | 6 M potassium hydroxide | Wang et al. (2019d) |
| Porous carbon/nitrogen | Ginkgo leaves | 0.5 | 12,000 | 323.2 | 99 | 6 M potassium hydroxide | Wang et al. (2019e) |
| Porous Carbon three-dimensional honeycomb structure | Cotton Seed Husk | 0.5 | 5000 | 238 | 91 | 6 M potassium hydroxide | Chen et al. (2018c) |
| Hierarchical porous carbon/copper(I) oxide/copper(II) oxide | Bamboo leaves | 1 | 10,000 | 147 | 93 | 3 M potassium hydroxide | Wang et al. (2019e) |
| Bio- carbon xerogel/graphene | Bamboo | 1 | 10,000 | 189 | 100 | 6 M potassium hydroxide | Yang et al. (2018) |
| Biochar/nitrogen | Peanut shells | 0.2 | 10,000 | 447 | 91.4 | 1 M sulphuric acid | Gandla et al. (2021) |
| Porous carbon hollow-sphere/nitrogen/sulphur | Puffball spores | 0.5 | 5000 | 285 | 80.3 | 2 M potassium hydroxide | Shang et al. (2021) |
| Three-dimensional porous carbon/ manganese dioxide | Banana peel | 10 | 3000 | 170 | 98 | 1 M sodium sulphate | Yang and Park (2018) |
The composite materials and underlying biomass feedstocks utilised are reported. Furthermore, the operating conditions, such as the current density (A g−1), capacitance (F g−1) and the percentage stability, are presented