The background of supercapacitors and the significance of supercapacitors

Due to the increasing shortage of petroleum resources and the increasing pollution of the environment caused by the exhaust emissions of internal combustion engines burning oil (especially in large and medium-sized cities), people are researching new energy devices to replace internal combustion engines. It has carried out research and development of hybrid, fuel cell, chemical battery products and applications, and has achieved certain results. However, due to their inherent Achilles heel such as short service life, poor temperature characteristics, environmental pollution by chemical batteries, complex systems, and high cost, there has been no good solution.

Supercapacitors, with their excellent characteristics, can partially or completely replace traditional chemical batteries for traction power and starting energy of vehicles, and have a wider range of uses than traditional chemical batteries. Because of this, countries all over the world (especially the developed countries in the West) have spared no effort in the research and development of supercapacitors.

Among them, countries such as the United States, Japan and Russia are not only in the forefront of R&D and production, but also have established special national management agencies (such as: USA USA, Japan's Sun, Russia's REVA, etc.), formulate national development plans, and actively promote them with huge investment and manpower from the state. In terms of the technical level of supercapacitors, Russia is ahead of the world, its products have been commercialized and applied, and were rated as the most advanced products by the 17th International Electric Vehicle Annual Conference (EVS-17), Japan, Germany, France, the United Kingdom, Australia and other countries are also catching up, and the field of promoting the application of supercapacitors in various countries has been quite extensive.

Promoting the use of supercapacitors in China can reduce oil consumption, reduce dependence on oil imports, and contribute to national oil security; Effectively solve the problems of urban exhaust pollution and lead-acid battery pollution; It is beneficial to solve the problem of low temperature start of the combat vehicle. Today, there are more than 10 domestic companies in the research and development of supercapacitors.

Supercapacitor: A new type of energy storage device between a traditional capacitor and a rechargeable battery.

1.Supercapacitors use an electric double-layer structure consisting of activated carbon, porous electrodes, and electrolyte to obtain ultra-large capacitances. Unlike batteries that use chemical reactions, the charging and discharging process of supercapacitors is always a physical process, and the performance is very stable, so the safety factor is high, the low temperature performance is good, the service life is long, and the maintenance is free.

2.The core component of a supercapacitor is the electrode, and the electrode manufacturing process is divided into two technologies: dry electrode and wet electrode. Dry electrode technology processes electrodes using only dry-blended activated carbon powders and binders.

Wet electrode technologyIn addition to activated carbon powder and binders, liquid solvents are added to the electrode manufacturing process. Since liquid solvents can affect the operating performance of supercapacitors, it is necessary to dry them in an oven to remove solvents from the electrodes. This means that wet electrode technology has a longer process and additional production costs compared to dry electrode technology.

In addition, it is difficult to completely remove the solvent by drying. During the operation of supercapacitors, solvent impurities react to form additional substances that affect the performance of the electrode and electrolyte. The gas produced by the reaction accelerates the aging of the supercapacitor.

As a result, supercapacitors with wet electrode technology have a relatively short lifetime, low reliability, and poor stability. In China, the most widely used supercapacitor is the braking energy system of urban hybrid buses. According to statistics, at present, Maxwell ultra-large capacity hybrid buses in China have more than 10,000 Yuzhi reputation, Yutong, King Long, Golden Brigade, Higer, CSR and other more than 10 well-known domestic car companies have successfully applied ultra-large capacity to new energy vehicles, Qingxiao energy saving and emission reduction, fuel saving and environmental protection effect is remarkable.

It can be said that Maxwell supercapacitors have played a positive role in promoting the prosperity and development of China's hybrid bus market.

Millions of car purchase subsidies.

Supercapacitor, also known as 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 characteristics, energy saving and green environmental protection. Supercapacitors are used in a wide range of applications.

Supercapacitor use: stupid.

1. It is used as a power balance power supply for lifting devices, which can provide power with ultra-high current.

2. Used as a starting power source for vehicles, the starting efficiency and reliability are higher than that of traditional batteries, and can replace traditional batteries in whole or in part.

3. The traction energy used as a vehicle can produce electric vehicles, replace traditional internal combustion engines, and transform existing trolleybuses.

4. It can be used in the military to ensure the smooth operation of tanks, armored vehicles and other combat wheeled vehicles, and as a pulse energy source for lasers.

Effect on battery charging.

After the vehicle is started, the alternator generates a DC voltage of about 15V after rectification, which is mainly used to charge the battery in addition to the power supply of the vehicle's lights, air conditioning, audio and other electrical systems. If a group of supercapacitors are connected in parallel on the battery, the charging system needs to charge the supercapacitors at the same time in addition to charging the battery, which is equivalent to increasing the load of the charging power supply, and the charging speed is slower than that when the supercapacitor is not added. However, considering that when the supercapacitor is installed, the capacitor is charged to the same voltage as the battery (under normal circumstances, the terminal voltage of the battery is increased to about after the vehicle is started, because the supercapacitor has a strong ability to absorb voltage, the voltage can be charged to the same as the battery voltage in a short time, so the extension of the charging time after the parallel supercapacitor is very short; At the same time, since the vehicle's power generation system has a certain reserve capacity, the impact on the charging equipment is also minimal.

The characteristics of the supercapacitor are strong ability to absorb charge, and the charging speed is much greater than that of the lead-acid battery, which could have charged the voltage to the output voltage of the generator (about 15V) in a short time, and then continued to charge the battery when the vehicle engine was turned off, so that the battery was easier to be filled, but because the supercapacitor and the battery were in a parallel state, its voltage was always clamped at the same voltage as the battery, so the rapid power storage advantage of the supercapacitor could not be played normally.

Due to the large capacity, the supercapacitor can play a good stabilizing role in the fluctuation of voltage, and the AC component after the alternator rectification can be greatly reduced, so it can improve the noise and sound quality of the car audio system, which has an immediate effect on the vehicle with poor audio system processing ability, but the effect on the vehicle with better processing ability of the audio system will not be obvious. However, the stabilizing effect of supercapacitors on voltage is not conducive to charging batteries: vehicle batteries are lead-acid batteries, lead-acid batteries rely on the electrolysis of plates to produce chemical reactions to store electricity when charging, and the DC voltage containing AC components can not only accelerate the electrolysis of plates and enhance the charging ability because it contains high-frequency positive and negative pulses, but also eliminate the sulfidation phenomenon and reduce the aging of the battery, so the parallel supercapacitor is unfavorable to the charging of lead-acid batteries.

Supercapacitors use an electric double-layer structure composed of activated carbon porous electrodes and electrolytes to obtain ultra-large capacitance. Unlike batteries that use chemical reactions, the charging and discharging process of supercapacitors is always a physical process, and their performance is very stable, so they have a high safety factor, good low temperature performance, long life and maintenance-free. The core element of a supercapacitor is an electrode, and the electrode manufacturing process is currently divided into two technologies: dry electrode and wet electrode.

Dry electrode technology is made into electrodes by simply mixing activated toner and binders. Wet electrode technologyIn addition to activated toner and binder, a liquid solvent is added to the electrode manufacturing process. Since liquid solvents affect the performance of supercapacitors, they are also dried in an oven to remove the solvent from the electrodes.

This means that wet electrode technology has a longer process and higher production costs than dry electrode technology. In addition, it is difficult to completely remove the solvent during the drying process. During the operation of supercapacitors, solvent impurities react to produce additional substances that affect the performance of the electrode and electrolyte.

The gas produced by the reaction will accelerate the aging of the supercapacitor. As a result, supercapacitors with wet-electrode technology have a relatively short lifetime, low reliability, and poor stability. In China, the most widely used over-foot-level capacitors are the braking energy system of urban hybrid buses.

According to statistics, at present, Maxwell has more than 10,000 oversized hybrid buses in China, and more than 10 well-known domestic car companies such as Yutong, King Long, Golden Brigade, Higer, CSR and other well-known domestic car companies have successfully applied overcapacity to new energy vehicles, with outstanding effects on energy saving and emission reduction, fuel saving and environmental protection. It can be said that MAXWELL supercapacitors have played a positive role in promoting the prosperity of China's hybrid bus market.