Abstract

Efficient thermal management of prismatic lithium-ion batteries is critical for electric vehicle (EV) performance, safety, and longevity. The thermal conductivity of conventional water-based cooling systems is restricted, which raises battery temperature and increases energy consumption. This study examines AQUENE, a distinctive mixture of graphene-based nanofluid as an advanced coolant for prismatic battery packs. This graphene-based nanofluid offers improved thermal conductivity, stability, and minimal increase in viscosity compared to water. It consists of 1% functionalized graphene dissolved in deionized water. A 1.5-RT water-cooled chiller connected with a 4S1P prismatic battery pack under controlled charge-discharge cycles was implemented for experimental evaluation. Battery surface temperature, chiller energy consumption, pumping power, and energy efficiency ratio were the key performance indicators. AQUENE decreases the peak battery temperature by 1.01% compared to water. Energy efficiency improved by 23.43%, while chiller compressor energy consumption decreased by 22.46%. The results demonstrate that AQUENE enhances convective heat transfer, reduces thermal stress, and improves system energy efficiency without significant retrofitting. Implementation in EV battery thermal management systems can extend battery lifespan, enable more compact cooling designs, and reduce operational energy demand, contributing to sustainable mobility and decarbonization goals.