Energy storage technology for power automation equipment: progress and prospects of supercapacitor

The development of a new electricity system is vital for the efficient use of renewable energy sources such as solar and wind power. Electronic automation equipment plays a crucial role in ensuring the safety and reliability of the power grid, while energy storage devices as primary or backup power are the key to ensuring the long-term working of electronic automation equipment. Among these, electrochemical energy storage technologies are widely used due to their high energy and power densities, rapid response times, and environmental adaptability. However, current lithium-ion and lead-acid batteries face challenges like short lifespan, high maintenance costs, and safety risks. Therefore, there is a need to develop advanced storage technologies with high security, energy density, cycle life, and low maintenance. Supercapacitors, including symmetric and asymmetric types, offer excellent performance. Double-layer capacitors, for example, provide high power density and long lifespan, however they have limited energy density. Lithium-ion capacitors combine the benefits of activated carbon cathodes and lithium-ion battery anodes, offering higher energy density and safety. Battery-type capacitors combine battery and capacitor materials to achieve high energy density, power density, and long cycle life. This paper reviews the strengths and challenges of these three storage technologies, and discusses future directions for energy storage in power automation systems.