High-energy nickel-carbon supercapacitors and precautions for their use

High-energy nickel-carbon supercapacitors and precautions for their use
  1. Precautions for the use of supercapacitors

①Supercapacitors have a fixed polarity. Polarity should be confirmed before use.
②Super capacitors should be used at the nominal voltage. When the capacitor voltage exceeds the nominal voltage, the electrolyte will decompose, the capacitor will heat up, the capacity will decrease, the internal resistance will increase, and the life will be shortened. lead to the collapse of capacitor performance.

③Supercapacitors cannot be used in high-frequency charging and discharging circuits. High-frequency rapid charging and discharging will cause internal heating of the capacitor, capacity attenuation, and increase in internal resistance. In some cases, the performance of the capacitor will collapse.

④ After installing the supercapacitor, do not forcibly tilt or twist the capacitor, which will cause the lead wire of the capacitor to loosen and cause performance deterioration.

⑤ Avoid overheating the capacitor during the welding process: If the capacitor is overheated during welding, the service life of the capacitor will be reduced. For example: if a printed circuit board with a thickness of 1.6mm is used, the welding process should be 260 °C, and the time will not be longer. more than 5s.
When supercapacitors are used in series, there is a problem of voltage balance between cells. Simple series connection will lead to overvoltage of one or several cell capacitors, which will damage these capacitors and affect the overall performance.

  1. High-energy nickel-carbon supercapacitors
High-energy nickel-carbon supercapacitors on display
High-energy nickel-carbon supercapacitors on display

In September 2011, China successfully developed high-energy nickel-carbon supercapacitors. Tests and trials showed that high-energy nickel-carbon supercapacitors have high energy density, high power density, high charge and discharge efficiency, good high and low temperature performance, long cycle life, and safety (super After the capacitor is fully charged, hit it with a nail gun to make it short-circuited, and there is no reaction; if it is burned on the fire, even if the stainless steel casing burns red, it will not explode), environmental protection, and high cost performance. The following two measures were taken.

(1) Integrate ordinary supercapacitors with batteries. Activated carbon materials are introduced into the negative electrode of nickel-hydrogen batteries, that is, activated carbon electrodes are used for one electrode, and capacitor electrode materials or battery electrodes are used for the other electrode, realizing the combination of ordinary supercapacitors and batteries. , so as to have both the excellent performance of general supercapacitors and batteries, and achieve high current fast charging and long cycle life.

(2) Increase the specific surface area of ​​the material. Traditional capacitors rely on the specific surface area to store charges. The advantage is that it can be charged and discharged countless times without generating heat. The size of the stored electricity is determined by the size of its internal specific surface area. Supercapacitors are based on the development of new materials to expand the specific surface area as much as possible to greatly increase the power storage.

  1. Design of battery capacity

The capacity of the battery is equal to the set current A multiplied by the time it takes to discharge the battery to the set voltage V (terminal voltage), that is, A·h. Since the input energy of the solar photovoltaic power generation system is extremely unstable, it is generally necessary to configure the battery system to work. Generally, there are lead-acid batteries, Ni-Cr batteries, and Ni-H batteries. Their capacity selection directly affects the reliability of the system and the price of the system.

The selection of battery capacity generally follows the following principles: first, on the premise that it can meet the night lighting, the energy of the solar cell module during the day should be stored as much as possible, and at the same time, it should be able to store the electric energy that meets the continuous cloudy and rainy night lighting needs. The battery capacity is too small to meet the needs of night lighting, and the battery capacity is too large. On the one hand, the battery is always in a state of power deficit, which affects the life of the battery. Although lead-acid battery capacity is affected by many factors, and solar photovoltaic systems have strict requirements on lead-acid battery performance (charge rate, discharge rate, deep discharge capacity, operating temperature, etc.) Lead-acid batteries are more suitable for solar power generation systems. In the absence of photovoltaic array power supply, the lead-acid battery completely supplies the load with the electricity stored in its own battery.

Read more: Sealing silicone for solar modules

Related Posts