Experimental investigation on thermal performance of battery using composite phase change material

This study introduces a novel alternate stirring and sonication technique for synthesis of composite phase change material composed of paraffin wax and Graphene. With this novel technique, six different composite phase change material samples were prepared with varying proportions of Graphene (1–10%). The thermal conductivity of sample was notably enhanced with addition of Graphene. The thermal performance of the battery was experimentally evaluated under discharge rates of 1C, 2C and 3C for three different cases: without thermal management, with phase change material and with various composite phase change material samples. At 1C discharge rate, the maximum cell surface temperature was 37.5 ℃ without thermal management, which reduced to 34.5 ℃ with phase change material, and then dropped to 33 ℃ with 1% graphene addition. These temperature drops correspond to reductions of 24.57% and 36.44% in temperature rise, respectively. Significant temperature reduction is observed with increased graphene fractions up to 3%; however, above 3%, graphene lump formation occurs and effectiveness is reduced. Throughout all tests, the surface temperature variation with composite phase change material stays within 5 ℃. Furthermore, the battery with delivers 4.80% more power after 100 cycles as compared to the bare cell, proving the effectiveness of passive thermal management strategies.