Session: 09-01: Photovoltaic & Electrochemical Technologies

Paper Number: 131251

131251 - Understanding Li-Ion Battery Degradation Under Realistic Loads 

Abstract: 

Electrochemical systems, including batteries, play a pivotal role in the transition towards a low-carbon economy. The global rise in renewable energy adoption has stimulated a high demand for energy storage technologies. As more energy is derived from fluctuating renewable sources, energy storage systems capable of retaining this energy become increasingly valuable. Electrochemical systems, including batteries, have gained significant attention due to their high energy density, scalability, and flexibility, among other energy storage technologies. Batteries serve to balance the demand for electricity with the supply from green energy sources. However, various degradation mechanisms impact electrochemical systems’ performance and longevity by affecting their different components. Therefore, understanding and mitigating these degradation phenomena is vital to improve the durability, efficiency, and reliability of the electrochemical systems. The stability of electrochemical systems over time, particularly when powered by naturally intermittent renewable sources like Photovoltaic (PV) or wind energy with fluctuating input power profiles, remains a complex issue. The escalating demand for Lithium-Ion Batteries (LIBs) across various sectors, ranging from portable devices to electric vehicles and grid-scale energy storage systems, underscores the importance of investigating battery degradation over time and in realistic loading scenarios. Moreover, achieving a cost-effective decarbonization method for energy grids and transport necessitates a deeper understanding of battery degradation. To investigate these degradation mechanisms, novel in-situ or ex-situ characterization techniques are needed to capture the aging phenomena in batteries.   One of the challenges in studying battery degradation is the lack of effective characterization techniques that can capture the aging phenomena in real time and under realistic loading scenarios. Therefore, in the present study, a Power-Hardware-in-the-Loop (PHIL) system is used to perform aging studies on various chemistries of Lithium-Ion batteries under realistic load profiles.  The PHIL system is an experimental platform that can emulate the electrical behavior of realistic load profiles and apply it to the LIBs cells. To achieve the ultimate aim of a deeper understanding of battery degradation mechanisms and the durability and reliability improvement of electrochemical systems, this research characterizes the effect of differences in operating conditions such that we can develop optimal control methods to minimize degradation rates.  In this paper, we present some preliminary data on the degradation of different Li-ion battery chemistries under various realistic load profiles. The present work includes testing of in-situ state-of-health estimations for Lithium-Ion batteries and post-processing methods to understand the impact of common degradation stressors related to the load shapes applied to the batteries.   

Presenting Author: Efat Mohammadi University of Memphis

Presenting Author Biography: Efat Mohammadi is a Ph.D. student in the Mechanical Engineering department at the University of Memphis (U.S.A.), where she works in the Energy System Control and Optimization (ESCO) Lab under the supervision of Dr. Alexander J. Headley. She holds a bachelor’s and a master’s degree in mechanical engineering– energy conversion from the University of Tafresh (Iran).

Her research focuses on the degradation mechanisms of electrochemical systems, such as li-ion batteries and electrolyzers, and how to control them by designing optimal load profiles. She aims to enhance the performance, reliability and lifespan of these systems by applying advanced control techniques.

Authors:

Efat Mohammadi University of Memphis
Alexander Headley University of Memphis