(Invited) Analyzing Effect of Battery Design Characteristics and Thermal Dynamics on Battery Performance in Electric Aircraft
Authors: Kiesewetter Lukas , Shah Krishna 
Published: December 2024

One the biggest challenges in achieving net-zero in the aviation sector through electrification of electric aircraft is the limitation of current battery systems in terms of simultaneously providing high gravimetric energy density and power density combined with suboptimal performance and safety issues at extreme temperatures. Much of the current literature related to electric aircraft focuses on aircraft design and optimization with overly simplified battery analysis such as linear voltage profile approximation or the use of equivalent circuit models which do not help understand and quantify material limitations of battery systems in electric aircraft application1-3. This is particularly relevant due to the fact that battery cells used in both fixed-wing electric aircraft and eVTOLs (electric vertical take-off and landing aircraft) see unique operating requirements that are often significantly more demanding than those seen in electric vehicles (EVs)4. Recently, there have been a few studies analyzing battery performance in more detail 5-7. However, there is a lack of investigations on the effect of battery design parameters and material properties on battery performance under real-world operating conditions, such as dynamically varying power demand, and the resulting effect on electric aircraft performance characterized by range, speed, and endurance. This type of study is necessary in guiding design of batteries and battery materials tailored to electric aircraft applications, particularly in dealing with the highly dynamic nature of such an application.

In the present work, we perform coupled simulation studies of longitudinal flight dynamics and battery dynamics using high fidelity electrochemical battery models. First, we study the effect of model fidelity on the prediction of battery dynamics and key battery states, particularly in the context of studying the effect of battery design parameters. This results in the identification of an appropriate battery model for an in-depth analysis on the effect of battery design parameters and material properties on battery dynamics and the resulting effect on aircraft performance. Additionally, we consider the effect of dynamically changing battery temperature obtained from experimental testing under simulated flight conditions. This is particularly important due to the significant battery temperature variation expected during a typical flight and its implications on battery performance and safety. Overall, this work provides detailed analysis on the effect of battery design on its electrochemical performance and the overall system level performance considering real-world operating conditions.

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