page_title: Pseudocapacitance
section_title: Verification
hierarchical_section_title: Pseudocapacitance / Capacitance functionality / Verification
caption_attribution_description: English: Voltagram of a supercapacitor with pseudocapacitance compered with other capacitor voltagrams
context_page_description: Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor. This faradaic charge transfer originates by a very fast sequence of reversible faradaic redox, electrosorption or intercalation processes on the surface of suitable electrodes. Pseudocapacitance is accompanied by an electron charge-transfer between electrolyte and electrode coming from a de-solvated and adsorbed ion. One electron per charge unit is involved. The adsorbed ion has no chemical reaction with the atoms of the electrode since only a charge-transfer takes place.
  Faradaic pseudocapacitance only occurs together with static double-layer capacitance. Pseudocapacitance and double-layer capacitance both contribute inseparably to the total capacitance value.
  The amount of pseudocapacitance depends on the surface area, material and structure of the electrodes. Pseudocapacitance may contribute more capacitance than double-layer capacitance for the same surface area by 100x.
  The amount of electric charge stored in a pseudocapacitance is linearly proportional to the applied voltage. The unit of pseudocapacitance is farad.
context_section_description: Pseudocapacitance properties can be expressed in a cyclic voltammogram. For an ideal double-layer capacitor, the current flow is reversed immediately upon reversing the potential yielding a rectangular-shaped voltammogram, with a current independent of the electrode potential. For double-layer capacitors with resistive losses, the shape changes to a parallelogram. In faradaic electrodes the electrical charge stored in the capacitor is strongly dependent on the potential, therefore, the voltammetry characteristics deviate from the parallelogram due to a delay while reversing the potential, ultimately coming from kinetic charging processes.
caption: A cyclic voltammogram shows the fundamental difference of the current curves between static capacitors and pseudocapacitors
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