石墨烯-碳化海绵/石蜡复合相变材料:热特性及其在电池热管理中的应用OA

To address the issues of low thermal conductivity,leakage during melting,and the lack of active temperature regulation under low-temperature conditions in conventional phase change materials(PCMs),a novel graphene-carbonized sponge/paraffin(CF-rGO/PW)composite phase change material was developed.Its key thermophysical properties,including thermal conductivity and latent heat of phase change,were experimentally measured and analyzed.Based on these results,a three-dimensional coupled thermal model of a battery module incorporating the composite material was established.The simulated maximum battery temperature under different discharge rates agreed well with experimental results,with an error of less than 2%,verifying the reliability of the model.Using this model,the thermal management performance of the composite material was further investigated under constant-rate discharge,frequent charge-discharge,and thermal abuse triggering conditions.Results show that under 2 C and 3 C discharge conditions,the incorporation of the composite phase change material reduces the maximum cell temperature by approximately 5-15℃and limits the maximum temperature difference to within 1.5℃.Under frequent charge-discharge conditions,the average transient temperature fluctuation amplitude decreases by about 23%compared with air cooling,and the reduction increases to 36%within the phase change temperature range.Under thermal abuse conditions,compared with the battery module without a barrier structure,the high-temperature region in the composite phase change material-battery module is confined to the triggered cell and its immediate neighbor.The peak temperature of the neighboring cell is delayed by about 300 s,and the rear cells exhibit only a slight temperature rise as well.These results demonstrate that the developed composite phase change material significantly enhances the thermal stability and safety of battery modules.