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There is considerable need for a mobile, reliable, efficient, and compact prime power supply for use in a host of directed energy applications. Recent improvements in the energy and power density of electrochemical lithium-ion batteries have made them a very viable option for these types of applications where fast and rep-rate operation is of interest. Despite the proven ability of lithium-ion batteries to source high currents, it is still unclear how they age when they are used to repeatedly source high-rate currents in a pulsed manner, as they must when used in a repetitive rate prime power supply. Similarly, it is unclear how elevated rate recharge affects the life of the battery. Research has been performed at University of Texas at Arlington in which high-power, 2.6 Ah lithium-ion batteries have been repeatedly discharged and recharged at high pulsed rates. This paper will discuss the potential of lithiumion batteries for use in these applications and will present experimental results performed when two 2.6 Ah cells were both discharged at 28 A (10.8C) and recharged at 9 A (3.5C) to 2.5 and 2.0 V, respectively.

The University of Texas at Arlington (UTA) has performed experiments in which high power 3Ah LiNixCoyAl1-x-yO2 batteries have been studied at high C rates. The first of three identical cells has been discharged using a 10 kHz (50% duty cycle), high C rate (100C/300 A) pulsed discharge procedure and a 1C constant current (CC) - constant voltage (CV) recharge procedure. The second cell has been discharged using a 1C CC procedure and recharged using a 111 mHz (33% duty cycle), high C rate (33C/100 A) pulsed recharge procedure. The third cell, the control cell, has been cycled using a 1C CC discharge procedure and 1C CC-CV recharge procedure. The results of these experiments enable the impact each respective high rate procedure has on cell aging to be better understood. The experimental procedures and methods will be discussed in detail and the results of the experiments will be presented.