Analysis on the Distinguishability of Ageing Mechanisms within a Doyle-Fuller-Newman Framework

Battery models allow battery management systems to make the most out of Li-ion cells. Electrochemistry-based models can provide detailed information about internal states. However, toolboxes and implementations of electrochemistry-based models rarely consider ageing phenomena. Furthermore, those that do model ageing mechanisms in their implemen-tation, do not address issues with identifiability of model parameters and the distinguishability of different ageing mechanisms. In this work, the most-studied ageing phenomena are implemented into the Doyle-Fuller-Newman model and their distinguishability is studied. It will be shown that Solid-Electrolyte-Interphase (SEI) formation and lithium plating are indistinguishable at a constant temperature and some of their model parameters are unidentifiable. We further show that operating conditions such as C-rate and upper cut-off voltage (U CV) can be used to distinguish loss of active material and cathode degradation, respectively.