What is the difference between a super capacitor and a lithium battery?

Super capacitors are divided into electric double layer capacitors and tantalum capacitors. It is a new energy storage device with high power density, short charging time, long service life, good temperature characteristics, energy saving and environmental protection. Super capacitors are widely used.

Lithium batteries pollute the environment, the system is complex, and the cost is high. The super capacitors can use their excellent characteristics to avoid weaknesses. They can partially or completely replace traditional chemical batteries for traction power and starting energy of vehicles, and have more than traditional chemical batteries widely used.

The super capacitor has a 50% leakage current for 2 days, and the equal volume capacity is only 10% of the lithium battery. It can only be used in applications where instantaneous impact power is required.

An example can also be given:

If the electric car is the super capacitor, 10 ampere 48 volt lithium battery is only 6 kg, about 1200 Yuan, you can run 25 km, if you switch to super capacitor, you need 60 kg, need 500 Farah 1000, the price is 10,000 Yuan the above. So the capacitor is the capacitor, which is an order of magnitude worse than the battery. Capacitance is destined to be a temporary storage of electricity. However, the explosive power is super strong. Therefore, the bus can run for 2 kilometers, and each gram of Farah capacitor can release 3 watts of instantaneous power, so a small volume can explode powerful power. It just can't last. Electromagnetic guns and electromagnetic catapults are said to be good for this stuff. Maybe this will be used when launchingspecials.

The super capacitor battery is also called a gold capacitor and a farad capacitor. It stores energy by polarizing an electrolyte, and is a type of electric double layer capacitor. Since the process of energy storage does not undergo a chemical reaction, this energy storage process is reversible because the super capacitor can be repeatedly charged and discharged hundreds of thousands of times. Super capacitors generally use activated carbon electrode materials, which have the characteristics of large adsorption area and high electrostatic storage, and are widely used in new energy vehicles.

Super capacitor battery, also known as electric double layer capacitor (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. Super capacitors 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 traditional 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 to ensure the smooth start of tanks, armored vehicles and other vehicles (especially in the cold winter) and as a pulse energy source for laser weapons. It can also be used for energy storage energy of other electromechanical equipment.

Due to the shortage of petroleum resources in super capacitors and the environmental pollution caused by the exhaust of diesel-burning internal combustion engines (especially in large and medium-sized cities), people are studying new energy devices that replace internal combustion engines. Research and development of hybrid power, fuel cells, chemical battery products and applications have been carried out, and some results have been achieved. However, due to their inherent shortevity, poor temperature characteristics, chemical battery pollution, complex systems, high cost and other fatal weaknesses, there has been no good solution. Super capacitors, with their excellent characteristics, can replace some of the traditional chemical batteries for traction power and starting energy of vehicles, and have a wider range of applications than traditional chemical batteries. Because of this, countries around the world (especially developed countries in the West) spare no effort to research and develop super capacitors. Among them, the United States, Japan and Russia are not only in the front of R & D and production, but also established a special national regulatory agency (such as: USABC in the United States, Sun in Japan, REVA in Russia, etc.) to formulate a national development plan. We invested heavily and manpower and actively promoted it. As far as the level of super capacitor technology is concerned, Russia is currently in the forefront of the world, its products have been commercialized and applied, and it has been rated as the most advanced product by the 17th International Electric Vehicle Annual Conference (EVS-17), Japan, Germany, France, the United Kingdom, Australia and other countries are also catching up. At present, the field of promoting the application of super capacitors in various countries has been quite extensive. The promotion of the use of super capacitors in China can reduce oil consumption, reduce dependence on oil imports, and is conducive to national oil safety; effectively solve urban exhaust pollution and lead-acid battery pollution problems; and help solve the problem of low-temperature start of vehicles. At present, there are more than 10 companies in China that are conducting research and development of super capacitors.

The super capacitor is a brand new capacitor based on the interface electric double layer theory proposed by the German physicist Helmholtz. It is known that an excessive charge having a sign opposite to the surface of the metal electrode inserted into the electrolyte solution and the liquid surface causes a potential difference between the phases. Then, if two electrodes are simultaneously inserted in the electrolyte, and a voltage smaller than the decomposition voltage of the electrolyte solution is applied there between, the positive and negative ions in the electrolyte will rapidly move toward the two poles under the action of the electric field, and respectively in two The surface of the upper electrode forms a tight charge layer, ie, an electric double layer, and the electric double layer formed by the electric double layer and the dielectric in the conventional capacitor are similar in polarization charge generated by the electric field, thereby generating a capacitive effect and a close electric double layer approximation. In the case of a plate capacitor, however, since the tight charge layer spacing is much smaller than the distance between the charge layers of a conventional capacitor, it has a larger capacity than a conventional capacitor.

The electric double layer capacitor has a larger internal resistance than the aluminum electrolytic capacitor. Therefore, it can be directly charged without load resistance. In the case of overvoltage charging, the electric double layer capacitor will open without damaging the device. The overvoltage breakdown of aluminum electrolytic capacitors is different. At the same time, the electric double layer capacitor can be charged in an unrestricted manner compared with the rechargeable battery, and the number of times of charging can reach 10E6 times or more. Therefore, the electric double layer capacitor not only has the characteristics of capacitance but also has battery characteristics, and is a kind of A new special component between the battery and the capacitor.

The capacity of a super capacitor is much larger than a typical capacitor. Because of its large capacity and its external performance and battery, it is also called "capacitor battery" or "golden battery". The super capacitor battery is also an electric double layer capacitor. It is the largest one 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. And the electric double layer structure composed of electrolytes obtains a 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) Isolation, capacitance value: C = ε · A / 3.6πd · 10-6 (μF) where A is the plate area, d is the thickness of the medium. The stored energy is: E=C(ΔV)2/2, where C is the capacitance value and ΔV is the voltage drop between the plates. It can be seen that if you want to obtain a larger capacitance and store more energy, you must increase it. Large area A or reduced media thickness d, but this expansion space is limited, resulting in less storage and storage energy. The super capacitor 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 to both ends, 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 is 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, the specific capacity can be increased by more than 100 times, so that the capacitance per unit weight can reach 100F/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.

(1) The charging speed is fast, as long as it is charged for more than 95% of its rated capacity by charging for several tens of seconds to several minutes; now it takes several hours to charge the lead-acid battery with the largest area.

(2) The cycle life is long, and the number of deep charge and discharge cycles can reach 500,000 times. If the super capacitor is charged and discharged 20 times a day, it can be used continuously for 68 years. If compared to lead-acid batteries, it has a service life of 68 years and has no "memory effect".

(3) The high current discharge capacity is super strong, the energy conversion efficiency is high, the process loss is small, and the high current energy cycle efficiency is ≥90%;

(4) The power density is high, up to 300W/kg~5000W/kg, which is equivalent to dozens of times of ordinary batteries; the specific energy is greatly improved, the lead-acid battery can only reach 200W/kg, and the super capacitor battery is currently developed. Up to 10KW/kg,

(5) The raw material composition, production, use, storage and dismantling process of the product are not polluted, and it is an ideal green environmental protection power source;

(6) The charging and discharging circuit is simple, no charging circuit like rechargeable battery is needed, and the safety factor is high, and the maintenance is long-term maintenance-free;

(7) Good ultra-low temperature characteristics, the ambient temperature range is as wide as -40 ° C ~ +70 ° C;

(8) Easy to detect, the remaining power can be read directly;

(9) The monomer capacity is usually in the range of 0.1F to -3400F.

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