Optimum Charging Rate for a Lithium-ion Battery using COMSOL LiveLink for Matlab Model

Abstract

Electric Vehicles (EVs) are considered to be one of the most promising advancements to decarbonise the road transport. However, the realisation and sustainability of this technology demand the availability of public electrical chargers and fast charging techniques to substantially reduce the long charging time of conventional charging techniques. The work in this research presents an effort to determine the optimum Charge rate (C-rate), for a Li-ion cell, as a function of the State of Charge (SoC), in a 30 minutes charging time and, a Cut off Voltage (CoV) of 4.1 V. Firstly, a two-level modelling method is used to analyse the effect of charging performance of three different C-rates as a function of SoC with a typical CoV of 4.2 V. Secondly, the study is furthered by applying a period of 30 minutes charging time and a CoV of 4.1 V as the two constraints to obtain the boundary condition for the SoC. Thirdly, an integrated modelling approach deploying COMSOL LiveLink for Matlab toolbox is proposed to determine the optimum C-rate as a function of the SoC. The results show a 14 % rise in the SoC, at the determined optimum C-rate than that possible at a typical 1 C-rate.