Semi-empirical ageing model for LFP and NMC Li-ion battery chemistries

• Published in: Journal of energy storage 2023-11, Vol.72, p.108016, Article 108016
• Main Authors: Nájera, J., Arribas, J.R., de Castro, R.M., Núñez, C.S.
• Format: Article
• Language: English
• Subjects: Ageing; Capacity fade; Experimental validation; Lithium batteries; Semi-empirical model; Theoretical validation
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2023.108016

LFP and NMC chemistries are currently, among the Li-ion family, the most relevant and with higher prospects technologies. This paper analyses the modelling process of the capacity decay in a Li-ion battery caused by calendar and cycling ageing. An on-line ageing estimation model valid for both LFP and NMC is developed considering the variation of the main parameters used to define the model: temperature, State of Charge and rate of charge and discharge. This model is validated from a theoretical point of view for both chemistries by comparing its performance with the data provided by manufacturers and previous ageing models. The proposed battery ageing model attains a maximum relative error of 3%, which varies depending on the battery chemistry and the specified working conditions. A further analysis regarding the model accuracy at the battery end-of-life is developed. Moreover, the model performance is validated from an experimental point of view with an NMC battery tested in the laboratory, reaching errors below 5%. In addition, a methodology for parameterizing the ageing model is proposed aiming to facilitate the application of this model into a specific battery. •Semi-empirical expression for both LFP and NMC chemistries is developed.•Model validated theoretically with average error lower than 4%.•Model deviation below 3% for Li-ion working conditions.•Model partially validated experimentally for NMC.