Charge storage capacity (CSC)

Charge storage capacity is the total charge, per unit geometric area, that an electrode can pass reversibly over a slow cyclic-voltammetry sweep within the safe (water-window) potential limits. It is the standard bench metric of how much charge a material can in principle deliver, usually reported as cathodal CSC (CSCc) in units such as mC/cm^2, and it integrates both capacitive and faradaic contributions.

CSC is necessary but not sufficient for stimulation design. It is measured at slow sweep rates, whereas real stimulation uses short, sub-millisecond pulses during which slow faradaic and diffusion-limited processes cannot fully engage. The pulse-relevant metric is charge-injection capacity (or limit), which is typically far smaller than CSC. Quoting CSC alone therefore overstates what a material can safely inject per pulse.