Session: 09-01-04: Electrochemical Energy Storage and Conversion Systems IV

Paper Number: 165164

Unraveling the Thermo-Electrochemical Behavior of Lithium-Ion Batteries Under Operational Extremes 

As the energy sector transitions toward sustainable solutions, electrification has emerged as a driving force, with lithium-ion batteries (LIBs) at the forefront. Fast charging is critical for enhancing the practicality and user adoption of LIBs in electric vehicles and consumer electronics to significantly reduce charging times. However, rapid charging induces substantial internal thermal gradients, which intensify due to complex thermo-electrochemical interactions, including Joule heating, entropy-driven reversible heating, and heat generated from side reactions such as solid-electrolyte interphase (SEI) growth and electrolyte decomposition. Such thermal challenges tend to exacerbate further under extreme operating temperatures. At low temperatures, elevated charge transfer resistance and lithium plating contribute to heat accumulation, while at high temperatures, SEI degradation and electrolyte decomposition accelerate thermal inhomogeneities, posing significant thermal management challenges. If not effectively controlled, excessive heat buildup and non-uniform temperature distribution accelerate capacity degradation, shorten cycle life, and elevate the risk of thermal runaway or catastrophic failure. As LIBs become indispensable across diverse applications, precise internal temperature monitoring is crucial for optimizing battery reliability and safety. Conventional thermal management systems rely on external sensors to estimate core temperatures, often failing to capture real-time internal thermal variations under fast charging conditions. This study integrates advanced thermal sensing with a physics-based modeling framework grounded in thermodynamics and heat transfer principles to delineate the thermal dynamics under fast charging operations. Experiments are conducted using instrumented pouch cells, with thermal sensors embedded internally between electrode layers and externally at multiple surface locations to capture spatial and temporal thermal distributions. The internal sensors are strategically positioned to minimize electrochemical interference while accurately monitoring core temperature evolution. Simultaneously, external sensors monitor surface temperature, enabling a comparative analysis of core-to-surface temperature disparities, thermal gradients, and asymmetries during charge-discharge operation. The instrumented pouch cells will undergo cycling at ultrafast charging rates across a range of operating temperatures to capture heat accumulation trends and dynamic thermal variations. The modeling framework, informed by experimental data, quantifies in-plane and through-plane internal temperature variations by incorporating irreversible resistive heating, entropy effects, and electrochemical degradation reactions coupled with anisotropic heat diffusion modeling. Furthermore, it provides a detailed assessment of degradation mechanisms driven by thermal variations and links localized heat generation to key degradation processes such as lithium plating and SEI growth. This methodology facilitates high-fidelity mapping of internal and external temperature distributions, providing insights into localized heating effects and heat transport mechanisms. By correlating these thermal measurements with electrochemical degradation mechanisms, this study establishes a direct relationship between internal temperature evolution and capacity degradation under fast charging. By advancing the fundamental understanding of internal heat generation and dissipation, this work informs strategies to optimize fast-charging protocols and thermal management, ultimately enhancing battery safety, longevity, and performance under extreme operating conditions.

Presenting Author: Anuththara Alujjage Purdue University

Presenting Author Biography: Anuththara Alujjage is a third-year PhD student under the mentorship of Dr. Partha Mukherjee at Purdue University. She earned her Bachelor's degree in Mechanical Engineering from Northern Arizona University (NAU) before joining Dr. Mukherjee's lab as a direct Ph.D. student. Anuththara's research focuses on thermo-electrochemical analytics of Li-ion cells. She is dedicated to developing both invasive and non-invasive sensing techniques to elucidate intrinsic thermal dynamics. By coupling electrochemical mechanisms, her work aims to uncover the impact of true core temperatures and thermal gradients on cell degradation, safety, and performance, contributing to the advancement of battery technology.
She was the first recipient of the Udea Collaborative Research Grant, awarded to encourage interdisciplinary projects between undergraduate students at NAU. She also won the First Place Award for this collaborative work in the University Virtual Symposium. Anuththara recently presented her work at the 245th Electrochemical Society conference, where she was awarded a travel grant. She also presented her work at NSF poster competition IMECE 2024 and received the Graduate Student Travel Grant Award from ASME. She has several research publications and hopes her work will advance the field of battery thermal management systems (BTMS).

Authors:

Anuththara Alujjage Purdue University
Avijit Karmakar Purdue University
Bairav Vishnugopi Purdue University
Yevgen Barsukov Texas Instruments
David Magee Texas Instruments
Partha Mukherjee Purdue University