Discharge of electrochemical energy storage devices at elevated rates for driving pulsed power applications

Abstract

Over the last several decades a number of electrochemical energy storage devices have been developed for use in portable applications. Traditionally devices such as lithium-ion batteries are very energy dense but only modestly power dense limiting their use in pulsed power applications. Recently however, new specialty lithium-ion battery technologies have been developed, such as those used in the Saft VL5U cell, with power densities as high as 28.5 kW/kg [1]. With these power densities, they are much more suitable for driving pulsed power applications than ever before. Additionally, advanced hybrid capacitors such as electric double layer capacitors and lithium-ion capacitors have been developed with high energy and power densities making them also suitable for use in pulsed power experiments. Previously, research using these types of devices in applications other than as storage in hybrid electric vehicles and renewable energy platforms has been limited. The University of Texas at Arlington is currently engaged in research to understand the limitations of these types of devices for use in pulsed high current experiments. A test stand, similar to that of Chen et. al [2], has been developed and used to further characterize the performance of these types of devices when they are discharged at rates several hundred times their rated C values. This paper describes the rationale behind the experiments, the experimental setup developed, and the research progress made thus far.