Application of supercapacitors in automobiles

The battery is the key electrical component in the car, and its function directly affects the starting of the car. In the process of starting, especially at the moment of starting, because the speed of the starting motor is zero and no induced potential occurs, the starting current is very large, and such a high rate of discharge is harmful to the battery. The damage is also very significant. The drastic change in the voltage during the starting process is also a strong electromagnetic disturbance, which can cause the electrical equipment to lose power, forcing the electrical equipment to be re-energized after the generator starting process, and the computer is very easy to crash during this process. Therefore, from the perspective of improving the electromagnetic environment of the car's electrical equipment, improving the car's starting function and battery function, or extending the battery life, the car power supply should be improved.

In the field of new power cars, supercapacitors can be used in cooperation with secondary batteries to achieve energy storage and maintain the role of batteries. Generally , supercapacitors and lithium-ion batteries are used in cooperation, and the perfect combination of the two forms a power car power supply with stable functions, energy saving and environmental protection, which can be used in hybrid cars and pure electric cars. Lithium-ion batteries solve the problem of charging and storing cars and providing lasting power for cars . The mission of supercapacitors is to provide high-power auxiliary power for cars to start and accelerate, and to collect and store energy when cars are braking or idling. The supercapacitor can quickly recover and store energy when the car decelerates, descends, and brakes, and converts the remaining irregular power safety that occurs when the car is running into the charging power of the battery to maintain the safe and stable operation of the battery; when starting or accelerating , the battery first transfers the energy into the supercapacitor, and the supercapacitor can supply the required peak energy in a short time.

Although the energy density of supercapacitors is 5% or less of that of batteries, this energy storage method can be used where conventional batteries fall short and short-term high peak currents. Compared with batteries, this supercapacitor has the following advantages:

1. Large capacity. At present, the maximum capacitance of a single supercapacitor can reach 3000?F;

2. The charging and discharging life is very long. Up to 500,000 times, and the battery's charge and discharge life is difficult to exceed 1,000 times.

3. It can supply high discharge current. For example, the extra discharge current of the 3000?F supercapacitor is not less than 950?A, and the peak discharge current can reach 1?680?A. Generally, the battery cannot have such a high discharge current. Under the discharge current, the service life is greatly shortened.

4. It can be quickly charged to 95% of the extra capacity in tens of seconds to minutes, and it would be extremely dangerous or almost impossible to fully charge the battery in such a short time.

5. It can work normally in a wide temperature range (-40℃～+85℃), but the battery is difficult to work at high temperature, especially in low temperature environment.

6. The materials of supercapacitors are safe and non-toxic, while lead-acid batteries and nickel-chromium batteries are toxic. Moreover, supercapacitors can be used in parallel to increase the capacitance, and can also be used in series if voltage equalization measures are adopted.