Fig. 4: Feasibility of the reactivating strategy under different conditions.

a Stability test of graphite reacting in an electrolyte containing 2 M NaAc (pH= 8.50 ± 0.25) with or without the addition of NaClO₄ at 0.3 A cm⁻². The solution resistance (R) is around 15.6 Ω and 16.7 Ω for the measurement with and without NaClO₄, respectively. b Stability test of graphite reacting in an electrolyte containing 2 M NaAc and 0.1 M NaOH (pH= 12.9 ± 0.20) with or without the addition of NaClO₄ at 0.5 A cm⁻². The solution resistance (R) is around 9.71 Ω and 9.5 Ω for the measurement with and without NaClO₄, respectively. c Stability test of graphite in an electrolyte containing 1 M propionic acid (HPr) and 1 M sodium propionate (NaPr) (pH= 4.88 ± 0.10) with or without the addition of NaClO₄ at 0.3 A cm⁻². The solution resistance (R) is around 24.9 Ω and 31.0 Ω for the measurement with and without NaClO₄, respectively. d Stability test of graphite in electrolyte containing 1 M butyric acid (HBu) and 1 M sodium butyrate (NaBu) (pH= 4.82 ± 0.25) with or without the addition of NaClO₄ at 0.2 A cm⁻². The solution resistance (R) is around 30.9 Ω and 38.5 Ω for the measurement with and without NaClO₄, respectively. e Stability test of graphite in an electrolyte containing 0.5 M monosodium succinate (NaSA) (pH= 6.50 ± 0.33) with or without the addition of NaClO₄ at 0.1 A cm⁻². The solution resistance (R) is around 36 Ω and 40.4 Ω for the measurement with and without NaClO₄, respectively. f Stability test of graphite in an electrolyte containing 1 M levulinic acid (HLA) and 1 M sodium levulinate (NaLA) (pH= 4.65 ± 0.13) with or without the addition of NaClO₄ at 0.1 A cm⁻². The solution resistance (R) is around 25.9 Ω and 28.1 Ω for the measurement with and without NaClO₄, respectively. The concentration ratio of carboxylate to NaClO₄ was maintained at 20:1 for all the tests.