The study and identification of the thermo-electric behaviour of lithium-ion batteries for electric vehicles

Presented in this paper is a summary of a lithium-ion battery cell, the study and the modelling of it.

1834 Marked the year of the very first Electric Vehicle (EV) invention, the Electric Vehicle soon became a thing of the past when Internal Combustion Engine Vehicles (ICEVs) were developed. Recently the interest in EVs and Hybrid Electric Vehicles (HEVs) has started to blossom again, this is due to their lower contaminant emissions. There’s only one major difference between the three vehicles namely; EV, ICEV and HEV and that is the existence of a battery pack that is used to power the vehicle. A system of single battery cells that are connected both in series and parallel are used to increase the voltage, as well as increase the capacity is called the battery pack.

The Battery Management System (BMS) is an electronic unit that is used to assure the first class working conditions, voltage, current as well as temperature of these single cells. Qualities such as high energy density and power density is what traction batteries needs, lithium-ion and lithium-polymer cells satisfy these necessities the greatest. Lithium-ion batteries have other advantages as well these include; they are high in cell potential and they have a high charge/discharge rate. There are however some disadvantages which include the cost, safety, lithium reliability and cycle life.

Lithium-ion batteries are then further classified. The first categorisation is done according to the shape and size of the battery cell. The second categorisation on the other hand is done according to the materials that are found inside the battery cell. The major known materials that are found in a battery cell are none other than the anode and cathode of course but the separator between the electrodes and the electrolytes are also major materials found in the battery cell. For anodes generally, graphite but recently more Lithium Titanate (LTO) is used. For the cathodes Lithium Cobalt Oxide (LCO), Lithium Manganese Oxide (LMO), Nickel Manganese Cobalt Oxide (NMC), Nickel Cobalt Aluminium Oxide (NCA) and Lithium Iron Phosphate (LFP) can be used. Usually the Lithium Iron Phosphate-graphite battery is the battery of choice because it guarantees the best results in both safety and the duration.