A Multi-physics Coupling Estimation Approach for the State of Charge of Lithium Batteries in All-Electric Aircraft

Lithium-ion batteries are the sole energy supply for all-electric aircraft (AEA), their State of Charge (SOC) estimation is challenged by extreme temperature fluctuations, varying power loads, and mechanical stresses during flight. Inaccurate SOC estimation can lead to battery depletion and safety risks. This paper proposes an electro-thermal-mechanical multi-physics coupling approach for SOC estimation in aviation lithium batteries, developing a Differential Evolution (DE) algorithm for model parameter optimization and an Adaptive Extended Kalman Filter for improved accuracy. Experimental results show the proposed method achieves a SOC estimation error of less than 2.7% under extreme conditions.