Validation of the methodology for lithium-ion batteries lifetime prognosis

Battery lifetime prognosis is a key requirement for successful market introduction of rechargeable Energy Storage Systems (ESS) based on lithium-ion (Li-ion) technology. In order to make decisions at the system design stage, a procedure for making efficient predictions of battery performance over time is necessary to be developed. In this paper, a general methodology for the evaluation of lifetime prediction is presented, covering the semi-empirical aging model precision and validity. Both calendar-life and cycle-life performance were investigated. Moreover, standing time and working operation were examined jointly using realistic operating profiles. The aim was the predictive model to be suitable for any application, including electric vehicle (EV), within the considered operating range. The efforts were especially focused on model ratification procedures and predictions goodness evaluation. The validation processes not only dealt with static impact factors evaluation but also with dynamic operation schemes. Besides, integration of ageing monitoring algorithm into Battery Management System (BMS) was evaluated. Battery pack design and operation strategies definition criteria were also discussed based on the stress factors influence on cell performance. The presented results correspond to a lithium iron phosphate (LFP) cathode 26650-size Li-ion cell.