Fig. 3.

Experimentally derived scaling relations: (A) Rate-independent capacitance of eight different carbon-cement electrode materials showing the intensive nature of the energy storage capacity of our electrode systems. (B) Rate-dependent capacitance scaled along the horizontal axis by means of the classical dimensionless diffusion variable ξ = d²/(D t₀). All measured capacitance values for eight different electrodes and 5 different scan rates collapse onto a master curve.