Lithium-ion batteries are the most commonly used battery type in commercial electric vehicles due to their high energy densities and ability to be repeatedly charged and discharged over many cycles. In order to maximize the efficiency of a li-ion battery pack, a stable temperature range between 15 °C to 35 °C must be maintained. As such, a reliable and robust battery thermal management system is needed to dissipate heat and regulate the li-io. Lithium-ion batteries are the most commonly used battery type in commercial electric vehicles due to their high energy densities and ability to be repeatedly charged and discharged over many cycles. In order to maximize the efficiency of a li-ion battery pack, a stable temperature range between 15 °C to 35 °C must be maintained. As such, a reliable and robust battery thermal management system is needed to dissipate heat and regulate the li-ion battery pack's temperature. This paper reviews how heat is generated across a li-ion cell as well as the current research work being done on the four main battery thermal management types which include air-cooled, liquid-cooled, phase change material based and thermo-electric based systems. Additionally, the strengths and weaknesses of each battery thermal management type is reviewed in this study. It was determined that air cooled systems are suited for short-distance travel electric vehicles, liquid cooled are for electric vehicles that require long-distance travel, larger battery packs and for high thermal loads, phase change material based are for electric vehicles with constant thermal loads and stable ambient temperatures and thermo-electric battery thermal management systems are best best suited in conjunction with the other types for better control.••••Present simplified heat generation model for li-Ion batteries.••Review of upcoming PCM Cooling BMS models.••Analysis of strengths and weaknesses of air, liquid, PCM, and thermoelectric BMS.••Recommendation on appropriate BTMS type for different EV models.••Identified main attributes required for an effective BMS for EV systems.Battery thermal managementAir coolingLiquid coolingPCM coolingAbbreviationsBTMS Battery Thermal Management SystemCFD Computational Fluid DynamicsCPCM Combined PCM with EGEV Electric VehicleEG Expanded GraphiteHP Heat Pipeli-ion Lithium-IonPCM Phase Change MaterialTEC Thermo-Electric CoolerTEG Thermo-Electric GeneratorNotationsbat BatteryCaO3 Calcium carbonateCO2 Carbon dioxideH2O Dihydrogen oxideMgCl2 Magnesium dichlorideMg(NO3)2 Magnesium nitratemax MaximumSiO2 SilicaTiO2 Titanium dioxideTmax Maximum battery temperature (°C)Tbat Battery operating temperatureZnO Zinc oxideUnitsA AmperesAh Ampere hourC Discharging rate°C CelciusI Nominal current (A)K KelvinPa Pascalm meterm3/s Cubic meter per secondm/s Meter per secondmm MillimetermAh Milli ampere hourOCV Open circuit voltage (V)Q Heat generation rate (W)s SecondsV Nominal voltageW Wattswt% Weight percentageWith the increasing demand to lower the carbon footprint of the transport sector, automobile manufacturers are rapidly developing electric vehicle (EV) technologies and increasing EV production. In 2021 alone, the global sales of EVs reached 6.6 million which tripled the 2019 sales figures. Despite the growth in demand, there are still several factors that hinder the widespread adoption of EVs in the general automotive market. Among the issues faced by consumers are the EV's lack of reliability for long-distance travel and the EV's short vehicular lifespan, particularly with regard to the longevity of the EV's battery pack.There are several factors that affect the performance of an EV battery pack but the main factor is its susceptibility to thermal effects. A conventional EV li-ion battery pack operates optimally between 15 °C to 35 °C. If the li-ion battery pack operates below 15 °C, the overall capacity drops and the battery's internal resistance increases. Conversely, temperatures above 35 °C could potentially lead to an irreversible reaction occurring across the li-ion battery pack and an increased risk of thermal runaway. Additionally, it can also accelerate the capacity drop of the li-ion battery. Given the critical impact of thermal effects on an EV battery pack's performance, continuous advancements in efficient cooling systems will benefit the overall longevity and safety of the p.
