3. Modeling aging

Aging models can be empirical, semi-empirical, physical or multiphysical. Physics-based models require a thorough understanding of the phenomena at work in lithium-ion batteries (see [D 7 001] ).

Despite numerous experimental techniques for physicochemical and electrochemical characterization of aging, degradation phenomena are so complex and interdependent that the development of a comprehensive model still remains a challenge. And even when an ageing mechanism is well understood, it remains to be equated satisfactorily.