Lithium-ion batteries have developed into a popular energy storage choice for a wide range of
applications because of their superior characteristics in comparison to other energy storage
technologies. Besides modelling the performance behaviour of lithium-ion batteries, it has
become of huge interest to accurately estimate their degradation because of both economic
and technical considerations.
The presentation will introduce a lifetime model for Lithium-ion batteries, based on lithium
iron phosphate and graphite as active materials, which is able to predict both the capacity
fade and power capability decrease; the model was developed based on accelerated ageing
tests performed in laboratory. The obtained model is used to analyse the degradation of a
battery system, which provides primary frequency regulation on the Danish energy market;
for this analysis a real mission profile obtained from field measurements is used.