Influences of ions and temperature on performance of carbon nano-particulates in supercapacitors with neutral aqueous electrolytes

- A commercial pigment composed of carbon nanospheres can be used for energy storage.
- The carbon nanospheres exhibit high capacitance in neutral aqueous electrolytes.
- Hydrous radius of the cation determines the measured capacitance.
- Semicircles on AC impedance plots are due to ion transfer crossing the carbon/electrolyte interface.
- Capacitance changes with temperature disagree with classic theory of electrical double layer.