Thermal behavior analysis of stacked-type supercapacitors with different cell structures

As a new energy storage element, supercapacitors have characteristics such as high power density, fast charge and discharge rates, green environmental protection, and long cycle life. Temperature is an important parameter of supercapacitors which significantly influences the stability of the supercapacitors. In this study, the finite element method is used to realize a coupling between a one-dimensional electrochemical model and a three-dimensional thermal model. Then, based on this model, the concept of limited cycle numbers is defined, and different unit quantities, unit size, and the effect of temperature under different temperature environments such as low temperature, room temperature, and high temperature on stacked-type supercapacitors is studied. Finally, stacked-type supercapacitors are compared with rolled-type supercapacitors considering the same cell size, density, and volume approximations. The simulation results show that the higher the number of packaging units, the lower is the limit cycle number. This phenomenon is more pronounced under high current than under low current conditions. Increasing the package size of the porous electrode or separator decreases the limiting cycles. Under the same unit volume scenario, improving the separator size proportion can accurately control the temperature rise at small current values. Under the same material, volume, and density approximations, the temperature rises slowly for stacked-type supercapacitors as compared to rolled-type supercapacitors. This phenomenon is more pronounced with an increase in current.