Enhanced Performance of Electric Double Layer Capacitor as Peak Power Buffer in the Hybrid Power Source Under Low Temperature

The performance of the hybrid power source at low temperature is experimentally analyzed. The parallel connected electric double layer capacitor (EDLC) enhances the power of Li-ion battery as it acts as a buffer in charge and discharge processes, especially at low ambient temperature. The behaviors of current and voltage of both the battery and EDLC are studied by experiments and described by a mathematical model. The EDLC can share a great part of total current load at low temperature, which effectively release the battery stress in pulse charge/discharge processes. Moreover, adding an EDLC in parallel with the battery also exhibits a considerable increase in capacity as compared to the Li-ion battery standalone in pulsed and continuous discharge processes. The performance of the hybrid power source under practical drive cycle is also studied in this article.