Inductor energy storage
The inductor itself is an energy storage element, and the stored electrical energy is proportional to its inductance and the square of the current flowing through it: E = L*I*I/2. Since inductors have resistance at room temperature, and the resistance consumes energy, many energy storage technologies use superconductors. Inductive energy storage is not yet mature, but there are also examples of applications in the paper.
Capacitor energy storage
Capacitor is also a kind of energy storage element, and its stored electric energy is proportional to its own capacitance and the square of terminal voltage: E = C*U*U/2. Capacitive energy storage is easy to maintain and does not require superconductors. Another important point of capacitive energy storage is that it can provide instantaneous high power, which is very suitable for lasers, flash lamps and other applications.
Supercapacitor, also known as electrochemical capacitor, is a new type of energy storage device between traditional capacitors and rechargeable batteries. Its structure is similar to that of batteries. It mainly includes four parts: double electrodes, electrolytes, current collectors and separators. , has the advantages of high power density, long cycle life, good low temperature performance, safety, reliability and environmental friendliness. However, due to the low dielectric withstand voltage, leakage current exists, and the stored energy and retention time are limited. Currently, supercapacitors are mainly based on the electric double-layer capacitance at the porous carbon electrode/electrolyte interface, or the quasi-capacitance generated by metal oxides or conductive polymers to achieve energy storage. [9] 
In addition, there are other energy storage methods: such as mechanical energy storage.