Experimental and numerical investigation of nanoparticle assisted<sc> PCM-</sc>based battery thermal management system

Li-ion batteries generate a large amount of heat in the electric vehicles. The poor heat dissipation from the battery causes temperature rise and affects its performance and life. If the battery temperature is not controlled, it may lead to serious damage to the battery cells; in extreme scenario, it may lead to fire hazards. A properly designed battery thermal management system (BTMS) controls the battery temperature ensuring its safe and efficient operation. In the present work, a nanoparticle assisted phase change material (PCM) and active cooling based BTMS technique has been investigated. The study employs both experimental and numerical approaches in the development of a water-composite PCM-based hybrid BTMS (combination of active and passive cooling techniques). Firstly, the investigation is performed to optimize the amount of PCM in the BTMS as it affects the thermal performance and mass of the system. It is found that an excess amount of PCM results in heat accumulation at the heating surface, which leads to rise in the cell temperature. The reduction in thickness of PCM from 40 to 5 mm results in 26.98% reduction in the maximum temperature. Moreover, it is found that introduction of nanoparticles between 1 and 20% (by volume) in PCM results in improved thermal conductivity. The melting fraction of PCM is improved by 29.33% and 28.0% with 20% concentration of CuO and Al2O3 in the PCM, respectively. It further helps in 70.79% improvement in the thermal non-uniformity in PCM-based hybrid BTMS.