In our real life, we often see the shadow of the capacitor, but the supercapacitor battery is not so much known. The supercapacitor battery is a kind of battery developed on the basis of supercapacitor. This battery has very significant The characteristic is that it is a kind of battery that is more powerful than the traditional battery. The advantage is very much. It is used in many aspects. For example, in the new energy car, the tram, etc., you can see the shadow of the super capacitor battery. It is said that the emergence and development of supercapacitor batteries will surely bring about another industrial revolution and greatly improve the operational capabilities of certain aspects.
Super capacitor battery concept
Supercapacitor battery (Electrical Double-Layer Capacitor) is a new type of energy storage device, which has the characteristics of short charging time, long service life, good temperature characteristics, energy saving and environmental protection. Supercapacitors are widely used. It is used as a power balance power supply for lifting equipment to provide super-current power. It is used as a starting power source for vehicles. It has higher starting efficiency and reliability than conventional batteries. It can replace traditional batteries in whole or in part. It is used as traction energy for vehicles. It can produce electric vehicles, replace traditional internal combustion engines, and transform existing trolley buses; it can be used in military to ensure the smooth start of tanks, armored vehicles and other vehicles (especially in the cold winter), as a pulse energy source for laser weapons. It can also be used for energy storage energy of other electromechanical equipment.
Super capacitor battery works
The capacity of a supercapacitor is much larger than a typical capacitor. Because of its large capacity and the same external performance as the battery, it is also called "capacitive battery" or "golden battery". Supercapacitor batteries are also electric double layer capacitors. They are the largest capacity among the electric double layer capacitors that have been put into mass production in the world. The basic principle is the same as other types of electric double layer capacitors. The electric double layer structure composed of the electrolyte obtains an extremely large capacity.
The electrical energy stored in the traditional physical capacitor is derived from the separation of the charge on the two plates. The vacuum between the two plates (relative dielectric constant is 1) or a dielectric material (relative dielectric constant ε) For isolation, the capacitance value is: C = ε·A / 3.6 πd ·10-6 (μF) where A is the plate area and d is the dielectric thickness.
The stored energy is: E = C (ΔV) 2/2, where C is the capacitance value and ΔV is the voltage drop across the plates.
It can be seen that if you want to obtain a larger capacity and store more energy, you must increase the area A or reduce the thickness d of the medium. However, this expansion space is limited, resulting in less storage and storage energy. The supercapacitor is made of activated carbon material to form a porous electrode, and at the same time, an electrolyte solution is filled between the opposite carbon porous electrodes. When a voltage is applied at both ends, the positive and negative electrons are respectively accumulated on the opposite porous electrodes, and the positive and negative ions in the electrolyte solution will be Since the electric field is respectively concentrated on the interface opposite to the positive and negative plates, two collector layers are formed, which are equivalent to two capacitors connected in series, since the activated carbon material has an ultra-high specific surface area of ≥1200 m 2 /g (ie, the pole is obtained) Large electrode area A), and the interface distance between the electrolyte and the porous electrode is less than 1 nm (that is, a very small dielectric thickness d is obtained). According to the previous calculation formula, it can be seen that the electric double layer capacitor is more conventional than the conventional one. The capacitance of the physical capacitor is much larger, and the specific capacity can be increased by more than 100 times, so that the capacitance per unit weight can reach 100 F/g, and the internal resistance of the capacitor can be kept at a low level, and the carbon material has a low cost. , the technology is mature and so on. This makes it possible to use a capacitor for large-capacity energy storage, and in actual use, it is possible to increase the output voltage or current by connecting in series or in parallel.
Supercapacitors are upgrades to traditional capacitors
The plate capacitor is composed of two metal electrode plates insulated from each other, and the capacitance is proportional to the area of the electrode plate, and inversely proportional to the gap size between the electrode plates. The structure of the supercapacitor is similar to that of a flat-plate capacitor. The electrode is a porous carbon-based material. The porous structure of the material allows it to have a surface area of several thousand square meters per gram of weight, and the distance between the capacitance and charge is determined by the size of the ions in the electrolyte. The huge surface area plus the extremely small distance between the charges makes the supercapacitor have a large capacity, and the capacity of the supercapacitor can vary from 1 Farad to several thousand Farads.
Compared with the traditional battery, the super capacitor has many advantages: the charging speed is fast, it can be charged to more than 95% of its rated capacity in 10 seconds to 10 minutes; the power density is up to (102~104) W/kg, which is the lithium battery 10 Double times; high current discharge capacity; cycle usage up to 100,000 to 500,000 times, long life; high safety factor, long-term use maintenance-free. However, compared with mainstream sulfur batteries, it still faces the disadvantages of high cost and low energy density.