Electro-aging model development of nickel-manganese-cobalt lithium-ion technology validated with light and heavy-duty real-life profiles

The understanding of battery aging has a significant influence on electric vehicle performance with optimized battery usage on the road. This paper presents a comprehensive electrical-aging model which has been developed by the thorough investigation of commercial Nickel-Manganese-Cobalt (NMC) 20Ah lithium-ion pouch cells. During a span of more than three years, detailed characterization and lifetime tests have been conducted on 75+ cells to build an extensive database of battery test results. A total of 39 aging test conditions covering 10 °C-45 °C temperatures, 20%-90% depth of discharge (DoD), 10%-80% storage state of charge (SoC), and 0.5C-3C current rate (C-rate) are performed to construct a robust electro-lifetime model. Within the scope of this research, the precision of the developed model is validated with both light and heavy-duty real-life dynamic profiles for the first time. More than a yearlong worldwide harmonized light vehicles (WLTC) cycling corresponds to very accurate root-mean-square error (RMSE) of 0.83% and 0.78% at 10 °C and 45 °C temperature, respectively. The model is also able to predict two types of inhouse developed heavy-duty profiles with an RMSE of 1.07% and 0.73%. The robust validation enables the developed tool to model complete aging and can be taken as base work towards online implementation.