Economic implications of lithium ion battery degradation for Vehicle-to-Grid (V2X) services

Electric and Plug-in Hybrid Electric Vehicles are a promising sustainable mobility alternative due to their low emissions impact and the rapidly falling production costs of Li-ion batteries. To lower total vehicle ownership costs, Vehicle-to-Grid/Building/Home (V2X) services aim to derive additional value from the battery asset through dynamic or bi-directional charge control to provide benefits to the electric grid or to reduce/flatten/shift peak energy consumption of buildings. Battery State of Health (SOH) is impacted through reduction of total capacity and/or increase in internal impedance due to various degradation mechanisms which collectively result in Calendar Aging and Cycling Aging behaviors. At moderate temperatures, Calendar Aging is the dominant factor and this understanding paired with the fact that most vehicles are immobile more than 90% of the time, implies that the battery management strategy while at rest will bound lifetime. Evidence suggests that V2X could prolong battery life through integration with optimized management algorithms and that cost effective V2X services may be dependent on battery chemistry. Therefore economic analyses of battery assets should contain sufficient electrochemical detail to account for chemistry specific degradation behavior.