Abstract:

A supercapacitor will generate a lot of heat quickly in the large current charge and discharge process, which may cause security incidents. This article use thermal analysis with finite element method, firstly assumes and simplifies the structure through the analysis of a supercapacitor structure composition and analyze the unsteady heat conduction differential equation to establish the three-dimensional finite element thermal analysis model. To charge and discharge the supercapacitor with 20 A at 25 ℃[and get the temperature distribution inside the super capacitor, the temperature of the core region is the highest and the temperature is higher at the negative column area than that at the positive column area. To select the positive column, the cathode column and supercapacitor’s internal core region as the observation point, we change the current and observed temperature change over time. With increase of the charging current, the time required of internal core heat up every 100 ℃ is gradually reduced when the current is certain. As the charging current increases, the inner core of the super capacitor heat up faster. When the super capacitor use instantaneous large current to work, the internal core can reach several hundred degree centigrade in a short time, so cooling measures should be taken to avoid safety accident.

Key words: super capacitor, high current charge and discharge, finite element thermal analysis, the conduction differential equation, temperature field