Supercapacitor batteries, also known as golden capacitors and fara capacitors, store energy through polarized electrolytes and are a kind of double-layer capacitors. Because the process of storing energy does not involve chemical reactions, it is reversible, and because supercapacitors can be recharged and discharged hundreds of thousands of times. Supercapacitors generally use activated carbon electrode materials, which have the characteristics of large adsorption area and more static electricity storage, and are widely used in new energy vehicles.
The supercapacitor battery, also known as the electric double-layer capacitor, is a new type of energy storage device, which has the characteristics of short charging time, long service life, good temperature characteristic, energy saving and green environment protection. Supercapacitors have many uses. Used as the power balance power supply of the lifting device, which can provide super-large current power; Used as vehicle starting power supply, starting efficiency and reliability are higher than the traditional battery, can completely or partially replace the traditional battery; The traction energy used for vehicles could be used to produce electric cars, replace traditional internal-combustion engines and retrofit existing trolley buses. It can be used in the military to ensure the smooth start of tanks and armored vehicles (especially in the cold winter) and as the pulse energy of laser weapons. In addition, it can also be used for energy storage of other electromechanical equipment
Due to the increasing shortage of petroleum resources and the increasingly serious environmental pollution caused by the exhaust emissions from the internal combustion engine burning petroleum (especially in large and medium cities), people are studying the new energy devices to replace the internal combustion engine. The research and development of hybrid power, fuel cell, chemical battery products and their applications have been carried out, and certain results have been obtained. However, due to their inherent short service life, poor temperature characteristics, chemical battery pollution of the environment, complex system, high cost and other fatal weaknesses, there has been no good solution. With its excellent characteristics, supercapacitors can partially or completely replace the traditional chemical batteries for the traction power supply and starting energy of vehicles, and they are more widely used than the traditional chemical batteries. Because of this, all countries in the world (especially western developed countries) have spared no effort in the research and development of supercapacitor. Among them, the United States, Japan and Russia not only take the lead in R&D and production, but also set up special national management organizations (such as: USABC in the United States, SUN in Japan, REVA in Russia, etc.) to formulate national development plans, which are actively promoted by the state with huge investment and manpower. In terms of the super capacitor technology, Russia walk in front of the world at present, its products have been commercially production and application, and by the 17th annual international electric vehicles (EVS - 17) rated as the most advanced products, Japan, Germany, France, Britain, Australia and other countries are also catch-up, at present the application of super capacitor has been quite widely. The application of supercapacitors in China can reduce the consumption of oil and reduce the dependence on oil imports, which is beneficial to the national oil security. Effectively solve the problem of urban exhaust pollution and lead-acid battery pollution; It is helpful to solve the low temperature start problem of the vehicle. At present, there are more than 10 domestic enterprises in the research and development of supercapacitor
Supercapacitor is a new kind of capacitor based on the theory of interfacial double electric layer proposed by German physicist Helmholtz. It is well known that a metal electrode inserted into an electrolyte solution will have an opposite sign of excess charge on both sides of the surface and the surface, resulting in a potential difference between the two phases. Then, if two electrodes are inserted into the electrolyte at the same time, and a voltage less than the decomposition voltage of the electrolyte solution is applied between them, the positive and negative ions in the electrolyte will quickly move towards the poles under the action of the electric field, and form a close charge layer on the surface of the two upper electrodes, namely the double electric layer. It formed by the electric double layer and traditional capacitor of the dielectric in electric field under the action of the polarization charge similar, resulting in a capacitance effect, closely similar to electric double layer plate condenser, however, due to the tight than ordinary capacitor charge layer between the charge layer spacing distance is much smaller, thus has greater capacity than the general capacitor.
Dual-layer electrolytic capacitors have higher internal resistance than aluminum electrolytic capacitors, so they can be charged directly without load resistance. In case of overvoltage charging, dual-layer electrolytic capacitors will open the circuit without damaging the device, which is different from the overvoltage breakdown of aluminum electrolytic capacitors. At the same time, compared with the rechargeable battery, the double-layer capacitor can carry out unlimited current charging, and the charging times can reach more than 10E6 times. Therefore, the double-layer capacitor not only has the characteristics of capacitor, but also has the characteristics of battery. It is a new type of special components between the battery and capacitor.
The capacity of an ultracapacitor is much larger than that of a normal capacitor. Because of its large capacity, the external performance is the same as the battery, so it is also called "capacitive battery" or "gold battery". Supercapacitor batteries also belong to double-layer electric capacitors, which have the largest capacity among the double-layer electric capacitors that have been put into mass production in the world at present. The basic principle is the same as other kinds of double-layer electric capacitors, which use the double-layer electric structure composed of porous activated carbon electrode and electrolyte to obtain the super-large capacity.
The electric energy stored in the traditional physical capacitor comes from the separation of the charge on two plates, which are separated by A vacuum (relative dielectric constant 1) or A layer of dielectric material (relative dielectric constant ε). The capacitance value is :C=ε·A/3.6π D ·10-6(μF), where A is the plate area and D is the thickness of the medium. The stored energy is :E=C(ΔV)2/2, where C is the capacitance value and a V is the voltage drop between the plates. It can be seen that in order to obtain A larger electric capacity and store more energy, it is necessary to increase the area A or reduce the thickness D of the medium. However, this telescopic space is limited, leading to its small storage of electricity and energy. Supercapacitors using activated carbon materials made of porous electrodes, at the same time, in a relatively between porous carbon electrode filling the electrolyte solution, when the applied voltage at both ends, relatively gathered electron-positron respectively, and the porous electrode and the positive and negative ions in the electrolyte solution due to electric field respectively gathered in contrast with positive and negative plates of interface, thus forming two collector layer, the equivalent of two capacitors Machine series, due to the activated carbon material with high specific surface area of 1200 m2 / g or higher (A) electrode area of the great, and the electrolyte and the interface between the porous electrode distance less than 1 nm (i.e., the minimal medium thickness d), according to the previous calculation formula can be seen that the electric double layer capacitor is bigger than the traditional physical capacitance of the capacitor value A lot, specific volume The quantity can be increased by more than 100 times, so that the electric capacity per unit weight can reach 100F/g, and the internal resistance of the capacitor can also be kept at a very low level, carbon materials also have the advantages of low cost, mature technology and so on. Thus, it is possible to use capacitors to store large quantities of energy, and in practice, the output voltage or current can be increased by series or parallel connection. [1]
(1) the charging speed is fast, as long as the charging tens of seconds to a few minutes can reach more than 95% of its rated capacity; Today's largest lead-acid batteries typically take several hours to charge.
(2) Long cycle service life, deep charge and discharge cycles can be up to 500,000 times, if the supercapacitor is charged and discharged 20 times a day, the continuous use can be up to 68 years. If compared to lead-acid batteries, it has a lifespan of 68 years, with no "memory effect".
(3) Super high current discharge capacity, high energy conversion efficiency, small process loss, high current energy cycle efficiency ≥90%;
(4) high power density, up to 300W/kg~5000W/kg, equivalent to dozens of ordinary battery; The specific energy of lead-acid batteries can only reach 200W/kg, while the supercapacitor batteries can reach 10KW/kg.
(5) The composition, production, use, storage and disassembly process of the raw materials of the products are free from pollution, and it is an ideal green environmental protection power supply;
(6) Charge and discharge circuit is simple, no need to charge the battery as charging circuit, high safety factor, long-term use of maintenance-free;
(7) good ultra-low temperature characteristics, the use of ambient temperature range wide up to -40℃ ~ +70℃;
(8) Convenient detection, the remaining electric quantity can be read directly;
(9) The monomer capacity range is usually 0.1F--3400F.