Exploring the Efficacy of Nanofluids for Thermal Management in Lithium-Ion Battery Systems

Elevated safety and improved cycle-life of lithium ion batteries continue to remain challenges which limit the wide-spread deployment of electric drive vehicles (EDV). Excessive local temperature excursion and nonuniformity in Li-ion cells result in reduction of cycle-life and may lead to catastrophic thermal runaway [1]. Particularly in electric vehicle battery packs, thermal runaway of an individual cell can propagate leading to the failure of the entire pack. Importantly, excessive and uneven temperature rise in a battery module or pack reduces its cycle-life dramatically. To this end, recent years have witnessed phenomenal emphasis in safety and abuse testing in order to provide critical information about the failure mechanisms owing to thermal stability behavior and enabling development of thermal management strategies leading to safe and abuse tolerant batteries.

The current strategies in developing appropriate thermal management techniques involve either active cooling (e.g. air/liquid cooled) systems or passive thermal management techniques based on phase change material composites. The overall system efficiency (e.g. parasitic loss from fan power) and compatibility and/or adequacy to handle the stressful operating conditions for electric vehicles (e.g. high discharge rates, high operating or ambient temperatures) continue to remain a formidable challenge. In this work, we propose to evaluate a nanofluids-based thermal management strategy which will explore the unique characteristics of enhanced heat transfer. Nanofluids are colloids consisting of a base fluid such as water or ethylene glycol with a suspension of nanoparticles [2]. Previous work has shown that nanofluids can significantly enhance heat transfer in heat exchangers at a modest increase in pumping power [3, 4]. The heat transfer enhancement that nanofluids offer allows for smaller and more lightweight management systems, at a small increase in power draw [5]. This work aims to determine the performance efficacy of nanofluids in a typical battery thermal management system by detailed analysis of the heat transfer enhancement using nanofluids in such a system. In particular, the study will focus on system efficiency, heat dissipation capability under vehicular operational constraints (high discharge rates and high temperatures), and design considerations relevant to electric vehicle applications.

References:

[1]  T. M. Bandhauer, S. Garimella, and T. F. Fuller, “A Critical Review of Thermal Issues in Lithium-Ion Batteries,” Journal of the Electrochemical Society, vol. 158, pp. R1-R25, 2011.

[2]  Y. H. Hung, T. P. Teng, T. C. Teng, J. H. Chen, “Assessment of heat dissipation performance for nanofluid,” Applied Thermal Engineering, vol. 32, 2012.

[3]  K. V. Wong, O. De Leon, “Applications of Nanofluids: Current and Future,” Advances in Mechanical Engineering, vol. 2010, 2010.

[4]  I. C. Nelson, D. Banerjee, “Flow Loop Experiements Using Polyalphaolefin Nanofluids,” Journal of Thermophysics and Heat Transfer, vol. 23, 2009.

[5]  Y. H. Hung, J. H. Chen, T. P. Teng, “Feasibility Assessment of Thermal Management System for Green Power Sources Using Nanofluid,” Journal of Nanomaterials, vol. 2013, 2013.