fig7

Figure 7. (A) Illustration of the typical synthesis process of HC using liquid phenol-formaldehyde (PF) resin as the precursor and EtOH as the pore-forming agent^[145] (Copyright 2019, American Chemical Society). (B) Electrochemical performance: (i) Galvanostatic initial discharge-charge profiles. (ii) Specific capacity of HCs contributed from the slope and plateau region. (iii) Relationship among the plateau capacity (0.1-0 V), true density, and EtOH content^[145] (Copyright 2019, American Chemical Society). (C) Schematic of the material synthesis for PNDCs-500CDs-1,200 °C^[146] (Copyright 2023, Wiley-VCH). (D) Electrochemical performance: (i) Specific capacity of all samples from the plateau and slope contribution (discharge capacity at the 50th cycle). Cycling curves of samples with (ii) CD content and (iii) annealing temperature as variables. (iv) First galvanostatic discharge/charge curves of PNDCs, PNDCs-500CDs, and PNDCs-500CDs-1,200 °C at 0.1 A g^-1; (v) Galvanostatic discharge/charge curves of PNDCs-500CDs-1,200 °C at different current densities from 0.05 to 5 A g^-1[146] (Copyright 2023, Wiley-VCH).