Accelerated impedance-based aging modeling for NCA/Gr-SiOx batteries and the impact of reduced test duration

Aging models are essential for evaluating the aging behavior of lithium-ion batteries (LIBs) and guiding industry decisions on warranty commitments. This study presents an open-source impedance-based aging model for a nickel cobalt aluminum/silicon oxide-graphite LIB. The model accurately predicts capacity loss across various stress factors, achieving less than 1% deviation from validation measurements in real-world driving scenarios. Traditional modeling approaches require extensive testing and parameterization, making the assessment of new cell designs time consuming and costly. To address this issue, optimized testing strategies are developed through sensitivity analysis, revealing significant potential to reduce testing efforts by focusing on key stress factors such as temperature for calendar aging and depth of discharge for cyclic aging. Additionally, using fractional portions of available aging data suggests that test durations of 90 days may be sufficient to achieve reliable results.