Impact of Current Waveforms on Battery Behaviour

With increasing emphasis on renewable energy sources and efficient energy use, energy storage devices, and in particular electrochemical storage devices, are becoming more prevalent. In order to interface batteries to systems, converters are used to maintain the desired voltage, current or power. In this thesis, we explore the response of the battery to commonly seen current waveforms to understand the impact of the converter on the battery. An electrochemical model of the electrode-electrolyte is studied to first understand its operating principles and then to pinpoint the causes of the observed battery response. A circuit was built to test the response of the battery to current waveforms. Experiments consisting of constant current, triangular and sinusoidal currents of varying frequency and ripple currents, and pulsed currents were conducted. Using electrochemical principles, an explanation of the results is presented along with the impact of the experimental results on converter design specifications.MAS