Supercapacitors Energy Storage Technology and Its Applications

Supercapacitors are a new type of energy storage component developed in recent years, characterized by high power density, long lifespan, no maintenance required, and rapid charging and discharging. This article describes the classification, energy storage principles, and performance characteristics of supercapacitors, and introduces the current application fields and issues that need attention in the application of supercapacitors.

The energy storage principle of supercapacitors

Supercapacitors can be divided into double-layer capacitors and Faraday quasi capacitors based on energy storage principles.

(1) Basic principles of double-layer capacitors

The basic principle of double layer capacitors is a new type of electronic component that uses the interface double layer formed between electricity and electrolyte to store energy. When electricity comes into contact with the electrolyte, due to the Coulomb force, intermolecular force, or interatomic force, two stable and opposite sign charges appear at the solid-liquid interface, known as the interface double layer. The energy storage of this capacitor is achieved by electrochemically transforming the electrolyte solution without generating any electrochemical reactions, and this energy storage process is reversible.

(2) The basic principle of Faraday quasi capacitors

After double-layer capacitors, Faraday quasi capacitors, also known as quasi capacitors, have been developed. This capacitor is formed by the underpotential deposition of electroactive substances on the two-dimensional or quasi two-dimensional space of the electric surface or bulk phase, resulting in highly chemical adsorption desorption or redox reactions, and generating a capacitor related to the electric charging potential. For Faraday quasi capacitors, the process of storing charge includes not only the storage on the double layer, but also the storage of charge by ions in the electrolyte in the electroactive material due to redox reactions.

Characteristics of supercapacitors

Supercapacitors are a superior energy storage component that falls between traditional physical capacitors and batteries, with significant advantages such as high power density. The internal resistance of supercapacitors is very small, and they can achieve rapid storage and release of charges at both the electrical/solution interface and within the electrical material body Long charge discharge cycle life. Supercapacitors do not undergo electrochemical reactions during the charging and discharging process, and their cycle life can reach over ten thousand times Short charging time. Fully charging only takes a few minutes Realize high specific power and energy output. ⑤ Long storage life. ⑥ High reliability. Supercapacitors have no moving parts during operation, resulting in minimal maintenance work The ambient temperature has little effect on normal use. The normal operating temperature range for supercapacitors is -25 ℃ to 75 ℃ Can be used in parallel at will to increase capacitance; If voltage equalization is adopted, it can also be used in series to increase the voltage level.

Application of supercapacitor energy storage technology

Supercapacitors, as high-power physical secondary power sources, have a wide range of applications in various fields of the national economy. Developed countries have listed the research on supercapacitors as a strategic research project.

Tram power supply

Due to their high power density, supercapacitors can effectively meet the power requirements of electric vehicles during start-up, acceleration, and hill climbing, and can serve as acceleration or starting power sources for hybrid electric vehicles. The use of supercapacitors in parallel with batteries as a power source can reduce the size and weight of batteries and extend their service life.

Electronic power supply

Supercapacitors can not only be used as power sources for small devices such as optoelectronic electronic watches and computer memory, but also for satellites. The power source used on satellites is mostly a hybrid power source composed of solar energy and batteries. Once supercapacitors are installed, the pulse communication capability of satellites will definitely be improved. Due to the fast charging characteristics of supercapacitors, they are undoubtedly an ideal power source for devices such as power tools and toys that require fast charging. In the field of mobile communication power supply, electrochemical double-layer capacitors are mainly used to mix with other power sources to form power supplies due to their high power density and low energy density characteristics. They can also be used for short-term power backup to protect memory data.

Application in power system

The vast majority of high-voltage substations and switch stations use electromagnetic operated switch mechanisms, specifically equipped with capacitive energy storage silicon rectifier opening and closing devices as DC power sources for opening and closing operations, control, and protection. However, the electrolytic capacitors of capacitive energy storage devices have limited capacity and poor reliability.