Due to material and capacity reasons, ordinary electrolytic capacitors cannot be used for large energy storage applications due to their low energy storage capacity. The storage capacity of supercapacitors can reach more than 103 times that of ordinary capacitors. Due to the dual layer and large internal resistance of supercapacitors, they have high power density and long cycle life. Compared with batteries and ordinary capacitors, the characteristics of supercapacitors are mainly reflected in:

1) High power density: up to 102~105W/kg, far exceeding the power density level of existing batteries;

2) Long cycle life: After tens of thousands of very short high-speed deep cycles, the performance of supercapacitors still changes very little, with only a 10% to 20% reduction in capacity and internal resistance;

3) Working temperature range: Due to the small change in ion adsorption and desorption speed in supercapacitors at low temperatures, the working temperature range of commercial supercapacitors on the market can reach -30~60 ℃;

4) Green and environmentally friendly: In the production process of supercapacitors, harmful chemicals such as heavy metals are prevented from being used, making them a new type of green and environmentally friendly energy storage device.

At present, supercapacitors are widely used, but there is still room for improvement in terms of safety and stability in use.