EDLC cells consist of active carbon and aluminum as the positive and negative electrode materials, and the electrolyte includes acetonitrile and a salt solution, existing in a poor liquid state within the cell. The main factors affecting their lifespan are voltage and temperature. When the product experiences continuous over-voltage or overheating conditions, gas gradually forms inside, leading to an increase in internal pressure. As a result, all EDLC cell casings are equipped with explosion-proof valves, also known as pressure relief valves. Taking the 3000F cell as an example, the explosion-proof valve is located on the casing wall, as depicted below:
3000F EDLC Cell – Vent
When gas forms inside, the pressure relief valve will open to prevent the risk of explosion due to the gradual increase in internal pressure without a means of release. As the internal electrolyte is in a poor liquid state, there won’t be significant electrolyte spray or flow. Typically, there might be the precipitation of crystals or a small amount of liquid. Therefore, it’s important to ensure that the voltage across the supercapacitor does not exceed its rated voltage and that the temperature remains within its operating temperature range during usage.
EDLC modules are typically composed of multiple individual cells connected primarily in series. These modules include a balancing circuit that ensures voltage equalization among each individual cell. The mechanism involves discharging a cell when its voltage exceeds a certain predetermined threshold, effectively preventing over-voltage.
Modules can be equipped with temperature monitoring components. These components continuously monitor the real-time temperature of the module and transmit the data. If the temperature goes beyond the specified operating range, an alarm signal is generated.
EDLC system typically refers to products with an overall voltage exceeding 200V. These systems are equipped with a Capacitor Management System (CMS) that monitors parameters such as voltage, temperature, and current of individual units (cells or modules). When a parameter exceeds its set value, the system triggers an alarm signal and uploads the information to the central control unit. If effective measures are not taken and the voltage or temperature continues to exceed safe levels, reaching a threshold, the system will automatically disconnect to ensure safety.
Taking voltage as an example, suppose a system is composed of series-connected 48V modules. If the voltage of any module surpasses 48V, the system initially emits an alarm signal and sends an alert to the central control unit. If the voltage of the module keeps rising and reaches a certain predetermined threshold, the system will control a contactor or circuit breaker to disconnect the power source, preventing further voltage increase and ensuring safety. (The actual implementation and the electrical components used, as well as the threshold settings, depend on the specific product and design.)
4.Response to Abnormal Situations
In the event that an individual cell’s explosion-proof valve opens, avoid contact with any discharged materials. Proceed to isolate the problematic product by disconnecting the power, and have it addressed by professionals. For modules or systems triggering alarms, the initial step is to disconnect the circuit (from both the power source and the load), followed by isolating the supercapacitor section. Subsequently, professionals should investigate the cause or perform necessary actions.
We specialize in the field of EDLC and have evolved into a global-quality manufacturer of EDLC components and provider of EDLC system solutions. To date, our EDLC products have found widespread applications in industries such as wind energy, solar energy, new energy vehicles, rail transportation, smart grids, microgrids, engineering machinery, and industrial energy efficiency. Our clientele spans across Asia, Europe, North America, and 26 other countries and regions, making us a prominent representative in the domestic Chinese EDLC market, further driving the rapid expansion of its application scope in China.