Towards a Smarter Battery Management System for Electric Vehicle Applications: A Critical Review of Lithium-Ion Battery State of Charge Estimation

Muhammad Umair Ali,Muhammad Junaid Alvi,Sadam Hussain,Hee-Je Kim,Sarvar Hussain Nengroo,Amad Zafar

doi:10.3390/en12030446

Muhammad Umair Ali, Muhammad Junaid Alvi + Show 4 more

Open Access

https://doi.org/10.3390/en12030446

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Abstract

Energy storage system (ESS) technology is still the logjam for the electric vehicle (EV) industry. Lithium-ion (Li-ion) batteries have attracted considerable attention in the EV industry owing to their high energy density, lifespan, nominal voltage, power density, and cost. In EVs, a smart battery management system (BMS) is one of the essential components; it not only measures the states of battery accurately, but also ensures safe operation and prolongs the battery life. The accurate estimation of the state of charge (SOC) of a Li-ion battery is a very challenging task because the Li-ion battery is a highly time variant, non-linear, and complex electrochemical system. This paper explains the workings of a Li-ion battery, provides the main features of a smart BMS, and comprehensively reviews its SOC estimation methods. These SOC estimation methods have been classified into four main categories depending on their nature. A critical explanation, including their merits, limitations, and their estimation errors from other studies, is provided. Some recommendations depending on the development of technology are suggested to improve the online estimation.

Highlights

The global reserves of diesel, petrol, and other fossil fuels are decreasing rapidly due to their extensive use in transportation operation
The results showed that the Sigma Point Kalman Filter (SPKF) has high accuracy than the Extended Kalman Filter (EKF)
The Li-ion battery has been strongly recommended for electric vehicle (EV) because of its high-power density, long lifespan, high energy density, nominal voltage, and relatively low cost

Summary

Introduction

The global reserves of diesel, petrol, and other fossil fuels are decreasing rapidly due to their extensive use in transportation operation. The far-flung use of the traditional fuels produces tons of CO2 yearly, which have harmful implications for the environment, such as greenhouse gas emissions (GHGE) and global warming [1]. The costs of these fuels are increasing exponentially, so there is a need for a secondary energy source for transportation, such as electric vehicles (EVs), new energy vehicles (NEVs), plug-in hybrid electric vehicle (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehicles (FCEVs) [2,3]. Rechargeable batteries (RBs) have attracted considerable attention owing to their high demand in EVs, HEVs, and PHEVs [4,5,6,7]. The alternative energy sources, such as wave, wind, tidal, and solar, are episodical, so these energy resources require an energy storage system (ESS) to maintain a smooth and reliable supply to the consumer [9]

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