What are the characteristics of ultracapacitors compared with secondary batteries and ordinary electrolytic capacitors?

Supercapacitors, also known as electrochemical capacitors, are a new type of energy storage device between traditional capacitors and secondary batteries. It mainly relies on the double layer and redox pseudocapacitors to store electricity, and has the characteristics of high-capacity storage and high-power discharge. Compared with traditional capacitors, supercapacitors have higher specific capacity and energy density; while supercapacitors and secondary batteries performance comparison, 1) secondary batteries energy density is higher than the supercapacitor (the two charging energy and the potential difference between the relationship between the two are Q * E and 1/2 * Q * E, E is the potential difference, Q is the charge, Q is the potential difference, E is the charge. potential difference, Q is the charge, based on the above principle, it is obvious that when the two have the same mass or volume, the energy of the secondary battery is twice as much as that of the capacitor under the same conditions), 2) the power density of the secondary battery is less than that of the supercapacitor, 3) the life span of the supercapacitor is better than that of the secondary battery (mainly relative to the cycling stability), and 4) the secondary battery has a wider charging and discharging voltage platform (i.e., in the process of charging and discharging, there exists A stage, the battery potential difference does not change with the charge and discharge capacity), supercapacitors do not have this platform U = Q * (1 / C).