基于电池老化效应的电池热管理系统性能分析与优化OA

Novel model considering electrochemistry,battery aging,and heat transfer is developed for the design and optimization of battery thermal management systems(BTMS)to ensure efficient and durable battery operation.The multiphysics behaviors of BTMSs under different working cycles are analyzed and compared.Results show that solid electrolyte interphase(SEI)formation in aged battery packs leads to high heat generation rates.The reversible heat generation rate gradually decreases during cycling owing to SEI formation and Li+reduction inside the battery.By contrast,the irreversible heat generation rate increases with cycling.Meanwhile,the increase in irreversible heat generation was much higher than the decrease in reversible heat generation,causing the total heat generation rate to rise continuously during cycling.Consequently,the maximum temperature and maximum temperature difference after 1000 cycles of BTMS are higher than the initial case by 2.54,2.15,1.93 K and 2.34,2.04,1.85 K,respectively.Such significant deviations in maximum temperature and maximum temperature difference caused by capacity fade will definitely affect BTMS design.Without considering battery aging,an airflow velocity of 0.05 m/s is sufficient for BTMSs to meet the requirements for maximum temperature and maximum temperature difference.However,when capacity fade is considered,BTMSs cannot maintain battery pack temperature within the required limits after 1000 cycles under the investigated inlet velocity.Thus,optimization schemes are proposed for BTMSs to ensure effective thermal management for battery packs during long-term cycling.The addition of Al2O3 nanoparticles at different volume fractions consistently enhances the cooling performance of BTMSs.Furthermore,increasing nanoparticle volume fraction made the nanofluid-based BTMS more effective in controlling thermal behaviors of the battery pack.After 1000 cycles,the maximum temperature and maximum temperature difference decrease by 1.24,0.98,0.86 K and 1.09,0.88,0.79 K for water-1%Al2O3;1.92,1.56,1.36 K and 1.63,1.52,1.27 K for water-3%Al2O3;2.64,2.20,1.94 K and 2.29,2.02,1.83 K for water-5%Al2O3,respectively.For the optimized BTMS operation strategy based on battery heat generation,this method more effectively controls thermal behavior and mitigates battery capacity fade in all working cycles while significantly reducing pressure loss and increasing battery discharge potential.For the aged battery pack after 1000 cycles,the maximum temperature and maximum temperature difference decrease by 5.98,4.17,3.04 K and 4.27,2.79,1.81 K,respectively,using the optimized strategy.