There is news on the Internet that my country's first domestically produced aircraft carrier, the Fujian Ship, used electromagnetic catapult to take off, and the power supply method used by my country's electromagnetic catapult is to power supercapacitors. I briefly explained the

There is news on the Internet that my country's first domestically produced aircraft carrier, the Fujian Ship, uses electromagnetic catapult to take off, and the power supply method used by my country's electromagnetic catapult is the supercapacitor . I briefly explained the principle of electromagnetic ejection in my previous article, but what is a supercapacitor? Is it reliable for the capacitor to power the catapult ? Let’s find out together.

Supercapacitor is a new popular energy storage device between traditional capacitor and rechargeable battery (the table below shows the performance comparison between supercapacitor, capacitor and battery) to meet the needs of the 21st century Growing demand for energy storage systems. Currently, supercapacitors are widely used in electronic products, memory backup systems, industrial power supplies, and energy management.

Supercapacitor is a new component that stores energy through the double-layer interface formed between electrode and electrolyte. When the electrode is in contact with the electrolyte , due to the Coulomb force , intermolecular force and atom force, a stable double-layer charge with opposite sign appears at the solid-liquid interface, which is called interface double-layer . To put it simply, the double-layer supercapacitor is regarded as two inactive porous plates suspended in the electrolyte, and the voltage is loaded on the two plates. The potential added to the positive plate attracts the negative ions in the electrolyte, and the negative plate attracts the positive ions , thus forming a electric double layer capacitor on the surfaces of the two electrodes.

The supercapacitor discharge process is a process in which the positive and negative electrodes of the capacitor are short-circuited or a load is added, so that the ions adsorbed on the electrode surface are detached from the electrode. During this process, the speed of ion desorption determines the discharge rate of the capacitor. Therefore, in theory, the electrode plate If it is large enough and the conductivity of the electrolyte is high enough, the current during discharge can be large enough. According to the principle, we can know that supercapacitors have the characteristics of ultra-large capacity and fast charging and discharging. However, in actual use, it is also necessary to consider whether the voltage between the two electrode plates can reach the use voltage of the load current, and the capacitor The maximum voltage that can be applied at both ends has a great relationship with the supercapacitor electrolyte.

Supercapacitors can be divided into two categories according to different electrolytes: organic type and aqueous type . At present, organic electrolyte capacitors have been commercialized. Compared with aqueous electrolytes, organic electrolytes have a wider potential window , which is about 2~4V. Therefore, the operating voltage and energy density of the capacitor can be increased. However, the electrochemical conductivity of organic electrolyte is relatively low, it will cause certain pollution to the environment, and it is easy to volatilize. In the process of preparing capacitors, the surrounding working environment is required to be oxygen-free and water-free.

The decomposition voltage of water is only about 1.23 V, which makes the potential window of water-based supercapacitors relatively low . The voltage of water electrolysis is 1.23V. In actual situations, considering the polarization voltage of the two electrodes and the voltage drop of the electrolyte and wire circuits, the actual applied voltage of water electrolysis may exceed 1.23V. There are also studies showing that by adding some additives that inhibit water electrolysis to the aqueous electrolyte, the withstand voltage can be increased to above 2V.

However, the single voltage of both organic supercapacitors and aqueous supercapacitors is relatively small, so in actual use, they need to be connected in series and in parallel with to form a larger supercapacitor module, such as a foreign supercapacitor. Manufacturers use 6 layers of water-based supercapacitors in series to launch 5.5V series supercapacitor products, and Maxwell manufacturers have even launched 160V single supercapacitor modules that can be used in electric vehicles.

Unlike batteries that use chemical reactions, the charging and discharging process of supercapacitors is always a physical process, and its performance is very stable. It has many advantages such as high power density, light weight, small size, short charging time, high safety factor, long service life, excellent low-temperature performance, maintenance-free, energy saving and green environmental protection.Therefore, it has a wide range of uses and very good development prospects. Countries around the world are rapidly increasing their attention and R&D investment in this area.

Supercapacitors are used on aircraft carriers as the power source for electromagnetic ejections. Supercapacitors use the excellent characteristics of fast charge and discharge, large capacity, high safety factor, and high environmental adaptability, allowing them to release a huge current in a very short time, thus propelling nearly 30 Tons of fighter jets leapt onto the aircraft carrier. At the same time, in conjunction with the comprehensive power technology for ships launched by Academician Ma Weiming, my country's third aircraft carrier successfully ranked among the first echelons of aircraft carriers in the world.