Abstract:

An Electrical Double Layer Capacitor (EDLC), also known as a supercapacitor or ultracapacitor, is an energy storage device. It is unique because it can store much more energy than conventional capacitors and offers much higher power density than batteries. Their low internal resistance and long lifetimes allows EDLCs to supplement batteries and conventional capacitors in applications requiring rapid delivery of power and energy on demand; e.g., back-up power sources for electronic devices, load-leveling, engine start or acceleration for hybrid vehicles, and electricity generated from solar or wind energy. Since these applications could potentially expose EDLCs to harsh environments, knowledge of their possible failure modes and mechanisms will help to ensure safety of operation.

This study focuses on the effect of temperature and voltage on performance and reliability of EDLCs from several manufacturers. A comparison of the construction and packaging of the various samples is made, as well as the specifications and recommended applications. The parts are initially characterized and their capacitances and DC resistances are measured. After exposure to thermal and/or voltage stresses, the electrical performance is reevaluated. The observed failure modes are analyzed and compared in light of the differences in construction and manufacturer.

Complete article available to CALCE Consortium Members.