Misinterpreted in literature, Trasatti method cannot be used to differentiate double-layer capacitance and pseudocapacitance. The misinterpretation was caused from the confusion that pseudocapacitance is diffusion-controlled while double-layer capacitance is surface-controlled. Both double-layer capacitance and pseudocapacitance can either be surface-controlled or diffusioncontrolled. Pseudocapacitance involves chemical changes during charging/discharging and can be distinguished from double-layer capacitance by combining electrochemical methods with in-situ spectroscopic technique capable of monitoring the variation of element valence or chemical bonding.