The capacitance of the liquid electrolyte is mainly a trace amount of water in the electrolyte. This moisture is used to be electrolyzed to hydrogen and oxygen when the aluminum electrode has insufficient pressure, and then the alumina electrode increases the compressive strength. There is still a very small gap around the sealed rubber ring to release excess hydrogen. In fact, the amount of hydrogen is small, but it still needs to be released.

And this water is very small. So after a long time, he will volatilize. However, the aluminum electrode is thinned by the corrosion of the electrolyte, so that the leakage will increase when it is operated again and the original insulation strength cannot be restored due to the loss of moisture. And the drying of the electrolyte also causes the capacity to be lost.

Generally, capacitors that have been stored by the manufacturer for more than one year should be aged or treated as expired products before being sold again.

But in fact, my 8x years of electrolytic capacitor capacity and withstand voltage are very normal and there is no problem.

According to the calculation of the service life of the display in a 10-year cycle, the design life of the internal electrolytic capacitor should also exceed this life limit.