Elevated Recharge Of Electrochemical Cells

Abstract

Electrochemical cells are energy dense storage devices used to power everything from small portable electronics such as cell phones, to larger systems including electric and hybrid-electric vehicles or even electric utility backup supplies. In recent years, the electrochemical community has analyzed many aspects of cell performance with papers covering the influence of temperature, humidity, pressure, and various other factors on the aging of different types of cells. Despite the abundance of information on various issues, very little work has been presented in the area of high rate elevated charge and even less work regarding high rate pulsed elevated charge. This thesis starts by giving a basic overview of batteries and pulsed power systems, a specific type of load used in a variety of defense and civilian applications, before moving on to a more detailed technical background on a number of different types of cells with a focus on lithium-ion batteries. Prior work investigating the aging mechanisms of lithium-ion batteries will also be presented and examined. The aim of the work performed here is to further demonstrate how high-rate pulsed and continuous recharge impacts the aging of lithium-ion batteries. The development of the experiments performed and the results obtained will be discussed along with the results of a cell modeling exercise. Conclusions are then drawn in the final chapter.