Lithium-ion batteries for electric vehicles: A review on aging models for vehicle-to-grid services

In the growing market of electric vehicles (EVs), the lithium-ion (Li-ion) battery technology has a main role due to its characteristics in terms of power and energy density. However, the aging of the batteries and their expected lifetime, which are other two key parameters for their utilization, are still under investigation. Battery aging is influenced by many factors like temperature, state of charge (SOC) and current rates (C-rates), whether the batteries are used or not. This paper presents an overview of the aging mechanisms and current models to describe them, going from the electrochemical approach to the empirical one. In the end, the possibility of vehicle-to-grid (V2G) services is discussed according to the aging models of the batteries.