Cycle ageing analysis of a LiFePO4/graphite cell with dynamic model validations: towards realistic lifetime predictions
E. Sarasketa-Zabala, I.Gandiaga, E. Martínez-Laserna, L.M Rodríguez-Martínez, I. Villarreal
ELSEVIER: Journal of Power Sources Volume 275, 1 February 2015, Pages 573–587
The present investigation work compares cycling ageing behaviour upon constant operation conditions (static tests) with degradation under non-constant schemes (dynamic tests), through a novel methodology for ageing model dynamic validation. A LFP-based Li-ion cell performance loss is analysed using a DOD and C-rate stress factors Ah-throughput-domain characterisation method, and represented using a semi-empirical model. The proposed stepwise validation approach enables assessing the static ageing tests acceleration factor and systematically improving the ageing model. The result is a simple but comprehensive model. The predictions root-mean-square error, under dynamic cycling operation conditions, is just 1,75 %.