There are several typical failure modes of supercapacitor:
Some typical failures, such as leakage and short circuit, appear rapidly in initial operation. In general, these initial failures are usually inspected in the routine inspection of manufacturers, and they are not considered in Weibull distribution model.
High voltage and temperature will result in increased internal pressure of the product, even evolve gas, and the amount of gas increases with the working time. When the internal pressure reaches the certain value, the vent（usually are the groove of shell or the pressure outlet on the cover）will open to avoid the danger of explosion. The function of EDLC are not invalid, but the speed of capacity attenuation will be accelerated.
When the capacity decrease to 80% of initial measured value or ESR increases to 200% of the specified value, the failure of the EDLC function is defined by the industry. That means EDLC reaches the end of the life.
Simple life equation
The working voltage and ambient temperature have a great influence on the performance of the EDLC supercapacitor. Generally speaking, EDLC follows the principle of 10 degrees, that is the temperature is reduced by 10 Centigrade and the life is doubled. The principle is very suitable for approaching the highest working temperature and working voltage. For the organic system symmetric EDLC, the voltage principle is like this: the voltage is reduced by 0.1V, the life is increased by 1.3 times. Therefore, the simple life equation of EDLC can be in the following form:
Notes: The life (T0, V0) is the time at a known temperature T0 and known voltage V0 .
Supreme Power Solutions Co., Ltd. (SPS) is a leading manufacturer of ultracapacitors, as well as a provider of ultracapacitor energy storage systems and technological solutions. Our products have wide industry applications, such as new energy vehicles, wind turbines pitching control systems, trams and subways, smart grid, micro grid, heavy duty machineries, intelligent instrument, etc. We support more than 200 customers, and our products are exported to 26 countries and territories.
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