Elevated Rate Cycling of High-Power Electrochemical Energy Storage Devices for Use as the Prime Power Source of an EM Launcher

In recent years, energy storage manufacturers such as GAIA Advanced Lithium Battery Systems, Saft America, JM Energy, and Maxwell Corporation, among others, have greatly increased the power density of their respective electrochemical energy storage cells. Among the many types of high-power cells produced by the manufactures just listed are lithium-ion batteries, lithium-ion capacitors, and electric double-layer capacitors, respectively. The increased power density has made these types of portable energy storage devices more appealing and feasible for use as the prime power source of pulsed-power supplies that are used to drive systems such as electromagnetic launchers (EMLs). It has been previously shown by both Sitzman at the Institute for Advanced Technology, The University of Texas, Austin, and Allen and Neri at the U.S. Naval Research Laboratories that the prime power for small EMLs is derived from different types of batteries. In these types of pulsed-power systems, the batteries must be able to source pulsed currents at rates much higher than their continuous C rating. While this mode of operation has been shown to be possible, the elevated rate limitations of these types of devices are not well published, and it is unclear how the fundamental aging phenomena that occur inside these types of devices will be affected. Researchers at the University of Texas, Arlington, have ongoing experiments which are testing the limitations of these types of electrochemical cells for use in pulsed high-current applications. Experiments are also being performed to understand the aging characteristics when they are operated at elevated rates that are tens to hundreds of their rated C values. This paper describes the rationale behind the experiments, the experimental setup, and the research progress made thus far.