State of charge and health estimation of batteries for electric vehicles applications: key issues and challenges

Abstract

Using electric vehicles (EVs) for transportation is considered as a necessary component for managing sustainable development and environmental issues. The present concerns regarding the environment, such as rapid fossil fuel depletion, increases in air pollution, accelerating energy demands, global warming, and climate change, have paved the way for the electrification of the transport sector. EVs can address all of the aforementioned issues. Portable power supplies have become the lifeline of the EV world, especially lithium-ion (Li-ion) batteries. Li-ion batteries have attracted considerable attention in the EV industry, owing to their high energy density, power density, lifespan, nominal voltage, and cost. One major issue with such batteries concerns providing a quick and accurate estimation of a battery’s state and health; therefore, accurate determinations of the battery’s performance and health, as well as an accurate prediction of its life, are necessary to ensure reliability and efficiency. This study conducts a review of the technological briefs of EVs and their types, as well as the corresponding battery characteristics. Various aspects of recent research and developments in Li- ion battery prognostics and health monitoring are summarized, along with the techniques, algorithms, and models used for current/voltage estimations, state-of-charge (SoC) estimations, capacity estimations, and remaining-useful-life predictions.