A basic study on power storage capacitor systems

Abstract Storage batteries or pumped hydraulic power stations have been used to store electric energy. However, there are problems with storage batteries, e.g., long charging time, limited cycle life, low Coulomb efficiency, and inaccurate residual power meters. Because of these problems, practical power applications have not been achieved. To solve these problems, a complex system of capacitors and electronic circuits called the ECS (Energy Capacitor System) is proposed. The capacitor part of the ECS is a group of electric double‐layer capacitors of increased energy density. The circuits part is built around switching regulators. Although the capacitors alone are not capable of delivering stable output, the accompanying circuits compensate for various characteristics throughout the charge and discharge cycle. This combination of capacitors and electronic circuits increases the energy density by about 16 times that of the conventional electric double‐layer capacitors, close to the level of lead‐acid batteries but with lower output resistance and better voltage stability. The ECS inherently features short charging time, very long cycle life, and good Coulomb efficiency. The cells are completely sealed and made from materials which are not harmful to the environment.