The positive and negative materials of the super capacitor are activated carbon and aluminum, the electrolyte system with barren liquid form inside cell is is acetonitrile and salt. The main factors that affect the life are voltage and temperature. When the supercapacitor is in the condition of sustained overvoltage or overtemperature, the gas gradually generates inside, that will cause the internal pressure to increase gradually. So all cell can are equiped with vent(pressure relief valve). For 3000F, it is shown as following:
When gas evolves inside, the vent will open to avoid the danger of explosion duing to the gradual increasing of pressure. Because the form of internal electrolyte is barren liquid, deposited substances usually are crystallization or a small amount of liquid rather than a large number of splashing or flowing electrolyte.
Therefore, the voltage of the supercapacitor should be guaranteed not to exceed its rated voltage, and the temperature should not exceed the operating temperature range.
Ultracapacitor module usually consists of a number of cells in series with the balance board, which balances each cell’s voltage. The mechanism is when the cell voltage exceeds a default value, the circuit will discharge to avoid the overvoltage.
In terms of temperature, modules can be equipped with monitoring devices, which can monitor the real time temperature of modules, upload data and send out alarm signals when exceed the working temperature range.
The supercapacitor system usually refers to the product with total voltage more than 200V. It is equipped with CMS(supercapacitor management system) and can monitor the voltage, temperature, current and other parameters of each unit (cell or module). When a parameter exceeds the default value, the system will send out the alarm signal and upload it to the upper computer. If no effective measures are carried out, and the voltage or temperature continue to exceed the safety value to reach the threshold, the system will be automatically disconnected to ensure safety.
Take voltage for example, a system is composed of 48V modules in series: when one module voltage exceeds 48V, the system will firstly send out the alarm signal, upload to the upper computer for warning; if the voltage rise to a certain value, the system will cut off the power by air switch or circuit breaker and make the voltage no longer continuely rise to ensure the safety. (specific implementation is related to electrical devices and default value, etc.)
4. Abnormal Response
When the vent of cell open, keep away from the deposited substances, isolate faulty products and leave them to the professionals.
If a module or system has alarms, firstly cut off the loop (with power and load), isolate the supercapacitors, and then take it to the professionals to find the cause or carry on the related operation.
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.