Flame-retardant composite phase change material with silicone resin and melamine phosphate for battery thermal safety

With the prosperity of electric vehicles (EVs), the thermal management of lithium-ion battery (LIB) is crucial for ensuring the safety of drivers on EVs. Composite phase change material (CPCM) with high latent heat has a great promising prospect in battery thermal management systems (BTMS). However, the thermal management efficiency of CPCM is limited due to the leakage, low thermal conductivity and flammability. Herein, the novel multifunctional CPCM with paraffin (PA), epoxy resin (ER), expanded graphite (EG), methyl MQ silicone resin (MQ) and melamine phosphate (MP) (PEE/MQ/MP3) has been prepared, which can achieve well anti-leakage, high flame-retardant and thermal conductivity, enhancing the thermal safety for battery module. The results reveal that PEE/MQ/MP3 with MQ and MP at a ratio of 1:2 can exhibit optimum flame retardant performance. The total heat release peak, smoke production rate, carbon monoxide production and carbon dioxide production are 169 MJ/m2, 0.05 m2/s, 0.005 g/s and 0.38 g/s, respectively. The battery module with PEE/MQ/MP3 displays excellent thermal management performance, delaying thermal propagation. Even after ten cycles at a 3 C rate, the maximum temperature is controlled below 50 °C and the maximum temperature difference is maintained with 5 °C. Besides, the thermal propagation processes of battery modules reveal that PEE/MQ/MP3 can absorb and transfer heat in the first stage timely and quickly, efficiently suppressing the thermal hazard occurrence. Therefore, this study has proposed a multifunctional flame-retardant CPCM as an effective solution to enhance the thermal safety of battery modules, thus ensuring the safety of EV drivers.