Accelerated Charge-Discharge Cycling Test and Cycle Life Prediction Model for Supercapacitors in Alternative Battery Applications

Supercapacitors (SCs), which are mainly used in high-power applications, can be potential energy storage sources for alternative battery applications once their outstanding cycle life performance at wide temperature ranges is considered. Because the cycle life of SCs is inherently long, aging acceleration and cycle life prediction are of primary importance for practical usage. In this paper, the feasibility of accelerated cycle life testing is investigated and a cycle life prediction model of SCs for alternative battery applications is established. Charge-discharge cycling tests were performed for SCs at various cycling conditions for 3.8 years. The resultant capacitance retention trends were linearly extrapolated with the square root of the number of cycles as the x-axis. Capacitance degradations were mainly influenced by temperature, thus implying that aging can be accelerated by elevating the temperature. Activation energy values of capacitance degradations were obtained from the Arrhenius equation to determine the acceleration factor. By combining the extrapolation and the acceleration factor, the cycle life prediction model was established. Experimental and predicted cycle life trends agreed well, indicating that the established cycle life prediction model is appropriate for SCs in alternative battery applications.