Optimization of lithium-ion battery pack thermal performance: A study based on electrical, design and discharge parameters

Abstract

Lithium-ion batteries are increasingly preferred for energy storage, particularly in Electric Vehicles (EVs). A comprehensive understanding of the thermal and electrical behavior of these batteries under diverse conditions can enhance their efficacy. This study investigates the impact of electrical configuration (1P6S, 2P3S, 2S3P and 1S6P), tab width (15 mm, 25 mm, 35 mm and 45 mm), tab depth (2.4 mm, 3.4 mm, 4.4 mm and 5.4 mm), busbar height (2 mm, 4 mm, 6 mm and 8 mm), and discharge rate (1C, 3C, 5C and 7C) on the thermal and electrical performance of a commercially available LiMn₂O₄ battery cell. Analysis of voltage and power characteristics reveals that increasing the number of parallel connections reduces overall voltage and power output while significantly extending discharge time. This can be attributed to the reduced discharge current in each individual battery within the parallel configuration, which consequently lowers discharge power and increases longevity. Furthermore, this study introduces a novel perspective on optimizing battery configurations to enhance energy efficiency and discharge duration, highlighting the unique contributions of this research to battery technology. Statistical evaluation using Design of Experiments (DOE) and Analysis of Variance (ANOVA) indicates that the discharge rate has the highest contribution in maximum temperature (44 %) and maximum temperature difference (58.2 %), followed by electrical configuration (42.5 % and 38.6 %, respectively). Other parameters like tab width, tab depth, and busbar height also contribute to the maximum temperature. Therefore, achieving a proper balance in electrical configuration, tab dimensions, busbar height, and discharge rate is crucial for the design and utilization of lithium-ion battery packs.