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This work presents a follow up of previous case studies from the authors on the estimation of the in-vehicle battery capacity fade with performance-based models of Lithium-ion batteries applied to real-world vehicles’ activity data. The mobility pattern database is significantly enlarged compared to previous works from the authors, encompassing now six European regions, including 508,609 private vehicles which corresponds to 1.78 billion GPS records, 9.1 million trips and parking events and a total driven distance of 106.1 million kilometres. The capacity fade is derived at given years and mileage thresholds under different driving and recharging scenarios, supporting the concept of setting minimum performance requirements for traction batteries in future road transport policies. The vast majority of the considered scenarios do not lead to a battery capacity drop below 80% of its nominal value in less than five calendar years or 100,000 driven kilometres and below 70% in less than 8 years or 160,000 driven kilometres. The results of this work contributed to inform the new UN ECE Global Technical Regulation No. 22 on in-vehicle battery durability.

Battery capacity fade analysis was conducted to enhance both battery life and safety for different battery thermal managements based on natural convection, forced convection, finned-natural convection, PCM, and liquid cooling channels combined with PCM. The numerical model was developed according to Newman's pseudo two-dimensional (P2D) model, which included the generation of electrochemical heat. The capacity fade analysis showed that the temperature limit of 45 °C had the least negative impact on the battery life during charge/discharge cycles. In addition, the capacity fade was considerable as the battery temperature rose, showing 70% capacity loss after 500 cycles at 55 °C. The PCM provided a more uniform temperature distribution across the battery pack, however required extra heat dissipation mechanism. PCM cooling with liquid cooling channels could satisfy the temperature limits and significantly enhance the performance of battery heat management system.

Lithium-ion batteries are extensively used in electric vehicles, however, their significant degradation over discharge and charge cycles results in severe capacity fade, limiting driving ranges of electric vehicles over time and useful lifetime of batteries. In this study, capacity fade for lithium-ion battery has been investigated through modeling and experiment. A predictive model is developed based on first principles incorporating degradation mechanisms. The mechanisms of degradation considered include solid-electrolyte interface (SEI) growth and active material loss at both negative and positive electrodes. Battery performance including capacity is measured experimentally under discharge and charge cycling with battery operation temperature controlled. It is shown that battery capacity is reduced over battery discharge/charge cycling at a given battery operation temperature, and the model predicted battery performance, including capacity fade, agrees well with the experimental results. As the number of discharge/charge cycles are increased, battery capacity is reduced significantly; battery capacity fade is increased substantially when battery operation temperature is increased, indicating significantly accelerated aging of the battery at elevated operation temperatures and hence the importance of battery thermal management in the control of battery operation temperature for practical applications such as electric vehicles. Battery capacity fade is mainly caused by SEI film growth at the negative electrode, which is the largest contributing factor to the capacity fade, and the active material isolation at the negative electrode, which is the second largest influencing aging factor.