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43 

 

 

 

Perspective 

Advanced thermal management strategies for 

electric vehicles: enhancing efficiency, reliability, 

and performance 
Jamshid Moradi1, Amin Mahmoudzadeh Andwari1*, Ayat Gharehghani2, Juho Könnö1 

1Machine and Vehicle Design (MVD), Materials and Mechanical Engineering, University of Oulu, P.O. Box 4200, FI90014 

Oulu, Finland 
2School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran  

A R T I C L E   I N F O 
 

Article history: 
Received 20 December 2024  
Received in revised form 
26 January 2025 
Accepted 09 February 2025 
 
Keywords: 
Thermal management, Electric vehicles (EVs), 
Power electronic components (PECs), Battery 
thermal management system (BTMS),  
Cooling technologies, Heat dissipation 
 
*Corresponding author 
Email address:  
amin.m.andwari@oulu.fi 
  
 
DOI: 10.55670/fpll.fuen.4.1.5 

A B S T R A C T 
 

Thermal management plays a crucial role in enhancing electric vehicles' 
performance, reliability, and lifespan (EVs) by effectively dissipating heat from 
key components, including electric traction motors, power electronic 
components (PECs), and batteries. This paper explores various thermal 
management strategies tailored for these systems, highlighting their 
advantages, limitations, and technological advancements. In electric traction 
motors, heat dissipation is primarily addressed through active and passive 
cooling techniques such as forced convection, heat pipes, and phase change 
materials (PCMs), with recent advancements like direct slot cooling (DSC) 
improving efficiency. Similarly, PECs and electronic chips face thermal 
challenges due to electrical resistance, requiring innovative solid-state, air, 
liquid, and two-phase cooling methods to prevent performance degradation 
and component failure. Battery thermal management systems (BTMS) are 
equally critical, as temperature variations directly impact efficiency, safety, and 
cycle life. Active, passive, and hybrid BTMS technologies—including liquid 
cooling, thermoelectric systems, PCMs, and heat pipes—are evaluated based on 
their effectiveness in maintaining optimal operating temperatures. This paper 
comprehensively analyzes emerging cooling solutions, addressing key trade-
offs between efficiency, cost, and design complexity. By integrating advanced 
thermal management techniques, the EV industry can achieve improved energy 
efficiency, enhanced safety, and prolonged component durability, paving the 
way for more reliable and sustainable electric mobility. 
 

 
1. Introduction  

The global transition to electric vehicles (EVs) and 

hybrid electric vehicles (HEVs) is accelerating due to 

increasing environmental concerns and the demand for 

sustainable transportation solutions. However, one of the 

most critical challenges in EV and HEV development is 

thermal management, which directly impacts efficiency, 

reliability, and safety. Key components such as electric 

traction motors, power electronic components (PECs), and 

batteries generate significant heat during operation, which, if 

not managed effectively, can lead to performance 

degradation, energy loss, and potential safety hazards such as 

thermal runaway. Efficient thermal management is essential 

to dissipate excess heat, maintain optimal operating 

conditions, and extend the lifespan of these components [1,2]. 

Electric traction motors, which convert electrical energy into 

mechanical motion, experience heat generation primarily due 

to copper and iron losses, as well as mechanical friction. 

Overheating can lead to insulation degradation, efficiency 

loss, and irreversible demagnetization of permanent magnets. 

To counteract these issues, various cooling strategies have 

been developed, categorized into active and passive methods. 

Active cooling techniques, including forced air convection, 

liquid cooling via water jackets or microchannels, and 

advanced methods like direct oil spray cooling, enhance heat 

dissipation but require additional energy. In contrast, passive 

cooling solutions such as phase change materials (PCMs), heat 

pipes, and finned heat sinks offer efficient thermal 

management without external power consumption. Recent 

advancements, such as direct slot cooling (DSC), have further 

improved thermal regulation in modern permanent magnet 

synchronous motors (PMSMs), enabling higher efficiency and 

 

 

Future Energy 

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February 2025| Volume 04 | Issue 01 | Pages 43-49 

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mailto:amin.m.andwari@oulu.fi
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J. Moradi et al. /Future Energy                                                                                                 February 2025| Volume 04 | Issue 01| Pages 43-49 

44 

 

torque density [3,4]. Similarly, power electronic components, 

including inverters, converters, and semiconductor chips, 

face significant thermal stress due to electrical resistance, 

switching losses, and parasitic effects. Excessive 

temperatures in PECs can lead to reduced performance, 

shorter lifespan, and potential component failure. Various 

cooling techniques are employed to address this issue, 

including solid-state methods such as thermoelectric cooling, 

thermotunneling, and heat sinks with thermal interface 

materials. Air-based cooling, through either natural or forced 

convection, remains a common solution, while more 

advanced technologies such as piezoelectric fans, synthetic jet 

cooling, and electrohydrodynamic cooling offer innovative 

approaches to heat dissipation. Liquid-based cooling 

methods, including cold plates, microchannels, 

electrowetting, immersion cooling, and jet impingement, 

provide superior heat transfer efficiency. Additionally, two-

phase cooling systems, such as heat pipes and spray cooling, 

leverage phase transition properties to enhance thermal 

performance, ensuring that power electronics operate within 

safe temperature limits [5]. 

Battery thermal management is equally crucial in EVs 

and HEVs, as battery performance is highly sensitive to 

temperature fluctuations. The optimal operating temperature 

range for lithium-ion batteries is typically between 15°C and 

35°C; deviations beyond this range can lead to increased 

internal resistance, capacity loss, and severe safety risks such 

as thermal runaway. Battery thermal management systems 

(BTMS) are classified into active, passive, and hybrid 

methods. Active BTMS technologies, such as forced air 

cooling, liquid cooling, and immersion cooling, provide 

effective temperature control, with some manufacturers, like 

Tesla and Audi, adopting direct dielectric coolant immersion 

for enhanced thermal regulation. Thermoelectric cooling 

(TEC) and thermoelectric generators (TEGs) are also gaining 

attention for their ability to convert excess heat into usable 

power. Passive BTMS techniques, including phase change 

materials (PCMs) and heat pipes, offer energy-efficient 

solutions by leveraging latent heat storage and efficient heat 

transport. Hybrid BTMS approaches combine active and 

passive methods, such as liquid-PCM or air-PCM hybrid 

systems, to optimize heat dissipation while minimizing 

energy consumption and design complexity [6]. 

Given the rapid advancements in EV technology, the 

development of effective thermal management systems is 

paramount to ensuring higher efficiency, prolonged 

component durability, and improved safety. This paper 

provides a comprehensive review of thermal management 

strategies across electric traction motors, PECs, and batteries, 

evaluating the strengths, limitations, and emerging trends in 

cooling technologies. The integration of innovative thermal 

solutions, such as immersion cooling, direct slot cooling, and 

hybrid cooling techniques, represents a critical step toward 

optimizing EV and HEV performance. By addressing thermal 

challenges, manufacturers can enhance energy efficiency, 

extend vehicle lifespan, and contribute to the broader 

adoption of sustainable electric mobility. 

2. Thermal management in EVs 

Thermal management methods are as essential as 

control strategies in PCU. Temperature has a great impact on 

the performance and durability of electronic components, and 

it also determines the magnetic flux of electric motors. 

Thermal management aims to dissipate heat from EVs’ 

components to limit failure, optimize energy consumption, 

improve reliability, enhance power and flux density, and 

extenuate device quantity. In EVs, there are various systems, 

such as batteries, electric traction motors, and PCUs with 

subcategories, including electronic boards and PECs, each of 

which has different thermal management methods. In EVs 

that are equipped with engines (HEVs), using the term 

thermal management for the engine is not correct, and WHR 

is more appropriate instead, while applying WHR systems in 

other components of EVs is not justified, since they do not 

generate much heat [7]. 

3. Thermal management in electric traction motor 

The main source of heat in high-torque traction motors 

in EVs is stator windings resistance, which brings copper loss 

as the most heated unit and major energy loss, respectively, 

although there is iron loss due to hysteresis in magnetic field 

and mechanical loss from the bearing’s friction. High-

temperature regions emerge in the winding copper core, air 

gaps between the stator and rotor, around the axial center of 

the rotor bar, and stator section. The high temperature must 

be managed seriously since a 10 C increase in temperature 

halves the lifetime of the insulation across the conductors and 

demagnetizes the permanent magnets irreversibly. Active 

and passive cooling are two main categories of EV electric 

traction motor cooling methods. Active methods refer to 

forced convection using fans or pumps to circulate the coolant 

with more capability to dissipate heat, although they consume 

extra energy, while passive cooling methods are based on 

natural convection such as fins and heat pipes, which limit the 

absorbing heat while they do not need energy and much 

maintenance cost. Solid-liquid phase change material (PCM) 

is one of the passive cooling methods applied around the 

stator coil and does not affect the reluctance much. PCM with 

high melting heat capacity can absorb the large heat 

generated from the coil by changing its phase from solid to 

liquid and back again to the previous state by transferring 

heat to the environment when the motor turns off.  

The heat pipe, as a passive cooling, does not use any 

moving parts and is able to transfer large amounts of heat 

over long distances at a constant temperature. Generally, 

water is used as a cooling fluid in electric traction motors. 

Heat pipes could be installed in different locations, including 

motor housing, winding, stator shaft, rotor shaft, and stator 

core. There are so many methods to dissipate heat from EV 

electric traction motors, such as air-cooling, water jacket 

cooling, liquid/oil-based cooling, oil spray cooling, cooling 

tubes and microchannels, and potting silicon gelatin (PSG) 

cooling. In modern PMSMs, a direct spray of dielectric oil to 

cool the stator and windings with water jacket cooling has 

shown the highest torque achievement of electric motors 

compared to all other methods. Recent alternative optimal 

methods remove heat more accurately. Direct slot cooling 

(DSC) uses heat pipes applying a cooling channel to cool 

motor windings directly in the open slot of a motor stator as 

the cooling channel [8].  

 

 



J. Moradi et al. /Future Energy                                                                                                 February 2025| Volume 04 | Issue 01| Pages 43-49 

45 

 

4. Thermal management in PECs and electronic chips 

Electrical resistance in semiconductors is the main heat 

source in electronic devices. The heat generation from 

switching losses, conduction losses, and parasitic effects 

degrade the performance, durability, and reliability of PECs. 

The essentials of innovative cooling technologies should be 

achieved by both high absorbing heat capacity and small 

module size. Thermal stress is the main reason for capacitor 

and semiconductor failures. Developing wide bandgap 

devices (WBG) with high heat generation in power electronic 

topologies requires more effective cooling techniques [9]. An 

appropriate cooling system must contain three proficiencies 

in absorbing, transferring, and removing heat out of the 

module. As indicated in Table 1, the cooling of power 

electronics is classified according to different heat transfer 

mechanisms or coolant agents. The cooling technologies are 

as follows [10]: 

A) Solid-state cooling is employed in the technologies of solid 

materials with high thermal conductivity or thermoelectric 

effects. 

1. Heat sinks, thermal interface materials, and 

conduction plates: Based on the amount of heat generation, 

different materials could be applied with various thermal 

conductivities, from conventional cheap devices like 

aluminum with limited ability in terms of heat dissipation and 

density to high-performance devices like pyrolytic graphite. 

They are used to eliminate the gap between a semiconductor 

and a heat sink instead of air. Their main restriction is 

uncontrollable heat spread that requires thin plates. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Magnetic cooling: In this method, integrating 

magnetocaloric devices and a temporary magnetic field leads 

to a drop in the temperature of the electronic components. 

This method is performed according to a four-stage cycle of 

increasing the temperature of the device, magnetizing it, 

releasing heat, decreasing the temperature, and finally, 

demagnetizing. The importance of this method is determined 

when volume and weight are constrained and high efficiency 

is considered. 

3. Thermoelectric cooling: This method works exactly the 

opposite of the TEGs. DC low voltage current flows through 

the device to enable heat transfer based on the Peltier effect. 

This method, despite its low efficiency, low heat transfer 

capability and high cost, is used in applications where there is 

volume and weight limitation, and temperature changes are 

extremely transient and require precise control. 

4. Thermotunnelling and thermionic cooling: The 

operation of this method is inverse of a battery and uses two 

electrodes, one to absorb heat as an emitter and the other to 

repel as a collector, then transmission the front of electrons, 

and finally to drive an electric current and generate 

electricity. No mechanical moving parts like other solid-state 

methods, high power density, high reliability, good stability, 

and high efficiency are the main advantages of this method. 

Its main restrictions are only supporting localized cooling and 

low cooling power from ambient temperature. 

B) Air cooling technologies: This method does not have 

complications of liquid heat transfer, and it is done in two 

ways: natural and forced convection. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                Table 1. Thermal management strategies in power electronics 

Heat Transfer 

Mechanisms \ Coolant 

Agent 

Solid Gas (Air) Liquid Two-Phases 

Conduction Conduction plates and 

heat sinks, Thermal 

interface materials, 

Advanced conduction 

plates 

Not applicable Not applicable Not applicable 

Natural Convection Not applicable Air cooling Immersion cooling Immersion cooling 

Forced Convection Not applicable Standard fans, 

Piezoelectric devices, 

Synthetic jet 

impingement, 

Electrohydrodynamics, 

Thermoacoustic cooling 

Cold plates, 

Microchannel cooling, 

Electrowetting, 

Immersion cooling, Jet 

impingement cooling 

Cold plates, 

Microchannel cooling, 

Electrowetting, 

Immersion cooling, Jet 

impingement cooling, 

Heat pipes, Spray 

cooling, Phase change 

materials 

Magnetocaloric Effect Magnetic cooling Not applicable Not applicable Not applicable 

Peltier Effect Thermoelectric cooling Not applicable Not applicable Not applicable 

Tunnel and Thermionic 

Effects 

Thermotunnelling and 

thermionic cooling 

Not applicable Not applicable Not applicable 

 



J. Moradi et al. /Future Energy                                                                                                 February 2025| Volume 04 | Issue 01| Pages 43-49 

46 

 

1. Natural air convection: This heat transfer mechanism is 

the simplest way to cool electronic boards, and it is done due 

to the bouncy force and the density difference between the 

hot device and the cool surrounding air. Limiting the amount 

of heat transferred is the main challenge of this method. 

2. Forced air convection: The combination of fan and 

thermal heat sinks causes more heat transfer than natural 

convection. This method is the most common way to cool 

PECs. The main limitations of this method are fan energy 

consumption, high volume-to-weight ratio, and lower 

capability than other novel methods based on energy 

efficiency. 

3. Piezoelectric devices: Piezoelectric fans use vibrating 

cantilevers instead of rotating fans to generate cooling 

flowing air. This method has higher preferences than 

conventional fans in positional accuracy, reliability, and flow 

direction, although limiting heat dissipation is its main 

obstacle. 

4. Synthetic jet impingement: A pump with a controlled 

diaphragm is equipped to jet turbulent airflow to dissipate 

heat from the electric device. This method is restricted by a 

low heat dissipation capability, while high reliability, low 

energy consumption, and noise are its main benefits. 

5. Electrohydrodynamic: By increasing the voltage 

difference between two electrodes with different thicknesses 

until the electric arc does not occur, the electric field around 

the anode electrode is enhanced. As a result, the gases around 

the anode are ionized, leading to the phenomenon of corona 

discharge. The collision of ions with neutral molecules causes 

the transfer of momentum and cooling of the power device. 

Silent operation, high cooling power density, and low energy 

consumption are the best options, although degradation of 

the electrodes, high operating voltage, and complex 

equipment are its main disadvantages. 

6. Thermoacoustic: This property refers to producing sound 

waves and, consequently, pressure fluctuations from heat for 

a cooling mechanism. No moving parts, silent operation, and 

simplicity are the charms of this method, and the low 

capability to dissipate heat is its major restriction. 

C) Liquid cooling technologies: The conductivity coefficient in 

liquids is significantly more than in air, and as a result, their 

cooling capacity is higher. Although air cooling causes 

additional weight and volume to be imposed on the system 

due to the fan and heat sink, the main challenges of liquids are 

leakage, corrosion, electrical conductivity, and flammability. 

1. Cold plates: Cold plates are the main alternative to air 

cooling with heatsinks. In this method, a pump replaces the 

fan to circulate the liquid in a heat exchanger. Although it has 

more ability to dissipate heat, it increases weight and reduces 

reliability. 

2. Microchannel: Microchannel is a much more efficient 

method than cold plates because they are more capable of 

dissipating heat from the power device with less volume and 

weight. Different types of fluids and even nanofluids are used 

in them, but their main challenge is high-pressure drop. 

3. Electrowetting: Applying an electric field to the fluid 

causes its surface tension to change, and a droplet is sprayed 

on the power device. This spray can be applied directly on the 

part board (wetted surface) or at a distance from it (dry 

surface). The fluid must be dielectric, such as de-ionized 

water, liquid electrolytes, or ethanol. This method has a very 

high ability to absorb heat with low pump energy 

consumption. 

4. Immersion: In this method, the whole power device is 

submerged in the dielectric coolant fluid through natural 

convection or forced with a pump. The coolant fluid can even 

reach the boiling point, which is called nucleate boiling. This 

method has a great ability to dissipate heat due to its high-

power density and high efficiency. This method is mostly used 

in microelectronics. 

5. Jet impingement: In this method, liquid jet spraying in the 

form of regular matrices on the electric board with a high flow 

rate as a free surface or immersed with a dielectric fluid that 

causes significant heat transfer. The arrangement and 

number of nozzles, spray flow velocity, and properties of the 

coolant fluid are among the most important factors that 

determine the amount of heat dissipated in this method. 

D) Two-phase cooling technologies: Two-phase cooling 

methods can absorb considerable heat from the high latent 

heat capacity of phase change, also due to their low volume-

to-weight ratio, they have a higher power density and 

efficiency than other methods, but their most important 

challenge is the selection of coolant fluid and complexity of 

their control and design. 

1. Heat pipes: A heat pipe uses evaporative cooling to 

transfer thermal energy from one point to another. The 

operation is based on evaporation and condensation, relies on 

the temperature difference between the two ends of the pipe, 

and cannot reduce the temperature on both sides. The heated 

side of the heat pipe evaporates the coolant and increases the 

vapor pressure inside the heat pipe. The latent heat of 

vaporization absorbed by the fluid causes the temperature to 

drop on the tube's hot side. High thermal convection, 

isothermal operation, durability, and low costs are the most 

important strengths of the heat pipe, despite the control of the 

temperature range that depends on the material and fluid of 

the coolant since the liquid in hot temperature evaporates 

completely, and in low temperature there is no evaporation, 

to create a two-phase flow. 

2. Spray: Spray cooling is defined as the passage of a high-

pressure liquid through a nozzle and its atomization. Liquid 

droplets have a great ability to absorb heat and consume low 

power but choosing the right fluid that has the right chemical 

properties, dielectric constant, and adequate non-conduction 

thermal due to direct contact with the power device is its 

main challenge. The performance of this method depends on 

the number and arrangement of nozzles, flow rate, and many 

other parameters. 

3. Phase change materials: Phase change materials (PCMs) 

store energy in the form of latent heat of fusion. PCM absorbs 

heat as part of a continuous cycle, which has high heat 

dissipation density and does not need a heat sink. High 

melting point, high volumetric storage density, uniform 

melting ability, stable chemical properties, high fusion 

temperature, and reliability are its strengths, but low thermal 

conductivity in the solid state is its main weakness. 

4. Thermal management in batteries: The electricity 

produced in the battery is created during the electrochemical 

process, which is accompanied by heat generation. Therefore, 

the temperature of the battery increases and affects its 

performance. The ideal temperature for battery operation is 

between 15 and 35 degrees Celsius; providing this condition, 



J. Moradi et al. /Future Energy                                                                                                 February 2025| Volume 04 | Issue 01| Pages 43-49 

47 

 

along with creating a uniform temperature distribution in 

cells, is the responsibility of the battery thermal management 

system (BTMS). Temperatures below 15 degrees increase 

resistance and charge failure, and temperatures above 35 

degrees intensify side reactions and cause thermal runway 

[11]. A conventional classification of BTMS is presented in 

Figure 1. 

 
Figure 1. Classification of BTMS technologies 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Active BTMS: Forced heat transfer of air or liquid coolant, 

as an active method, is the most common BTMS technology in 

EVs. Toyota and Lexus use a fan to circulate air over the 

battery cells, but Tesla and Audi use direct contact immersion 

with dielectric coolant. Indirect cooling technology causes the 

loss of an important part of the cooling power due to the 

conduction resistance in the pipe.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                Table 2. The advantages and disadvantages of BTMS technologies 

BTMS Technologies Advantages Disadvantages 

Air  
1-simple design, low cost and maintenance, 
2-low volume occupation 
3- compatible with different batteries 

1-Low efficiency and heat transfer rate 
2-high energy consumption 
3- Non-uniform temperature distribution 

Liquid  
1-High efficiency and heat transfer rate 
2- uniform temperature distribution 

1- Leakage risk 
2- high occupied volume 
3- complexity  
4- Short system lifespan 

Thermoelectric 
System  

1-Switching capability between cooling and heating 
mode 
2-no coolant nor mechanical component 
3- light-weighted 

1-high cost 
2-low conversion efficiency 

PCM  

1-Simple design 
2-Light weight 
3-low volume occupation 
4- low maintenance 
5-no power consumption 

1-low thermal conductivity 
2- continuous operation difficulty 
3- Leakage risk 
4- Risk of supercooling 
5- Limited thermal storage capacity. 

Heat pipe  

1-High thermal conductivity 
2- no power consumption 
3-reliable 
4- low maintenance 
5-compact and light 

1-low efficiency and capacity due to the limited 
contact area 
2-High initial costs 
3- Leakage risk 

Hybrid BTMS  
1-light weight  
2-high cooling performance 

1-complex structure 
2-expensive 

 



J. Moradi et al. /Future Energy                                                                                                 February 2025| Volume 04 | Issue 01| Pages 43-49 

48 

 

Immersion technology is at the cutting edge of science, and 

there is a long way to go in its development. Usually, a mixture 

of water and ethylene glycol, besides acetone and oil, is used 

as a dielectric fluid in this method. On the other hand, the 

design of the system using coolants that experience phase 

change conditions in the operating temperature range of the 

battery can enhance the heat transfer rate up to 10 times. 

Thermoelectric cooling (TEC) and thermoelectric generator 

(TEG) are the other approaches in active BTMS, which require 

electrical power to cool the battery. TEC application had been 

considered before when it could be integrated with TEG. TEG 

converts the lost heat from the battery to power TEC to 

improve heat absorption capability. They need no coolant 

fluid or moving components, which gives them high heat 

absorption density and low weight. 

2. Passive BTMS: These methods are not very popular, but 

they have advantages that can cover the challenges of active 

technologies. Its most famous subcategories are phase change 

materials (PCMs) and heat pipes (HPs). PCM has two 

attractive features: one is to create a uniform temperature 

through the battery, and the other is to operate at the melting 

temperature, which causes suitable heat absorption. 

Paraffins, fatty acids, or hydrated salts are the most important 

materials that can work in the operating temperature range 

of batteries between 30-50 degrees Celsius. Low thermal 

conductivity is the most important challenge for the 

advancement of PCMs, which restricts heat transfer since 

researchers have been trying to solve it with different 

approaches, including porous structures combined with 

nanoparticles, fibers, and graphite. Heat pipes are an 

alternative option in the passive approach, whose main 

application is in PECs and electronic chips and not in BTMS. 

HPs are vacuum tubes consisting of three sections of an 

evaporator, an adiabatic fragment, and a condenser. HPs have 

a great ability to absorb heat, do not need external energy, are 

adaptable and flexible, and do not have maintenance costs, 

but their design is complex and expensive. 

3. Hybrid BTMS: Hybrid methods are a combination of active 

and passive technologies that enhance strengths and 

eliminate weaknesses of them alone. In this approach, PCM is 

central to creating a uniform temperature distribution 

throughout the battery, while the integrated method could be 

air or liquid to improve the heat transfer rate or HPs to 

increase natural heat transfer. Although the results of this 

approach meet expectations, their main problem is the 

expensive design and their complexity. In short, the 

advantages and disadvantages of these technologies are 

mentioned in Table 2. 

5. Conclusion 

Effective thermal management is essential for ensuring 

the efficiency, reliability, and safety of electric and hybrid 

electric vehicles (EVs and HEVs). As these vehicles continue 

to evolve, advanced cooling strategies are required to address 

the heat dissipation challenges in key components, including 

electric traction motors, power electronic components 

(PECs), and batteries. Each of these systems generates 

significant heat during operation, which, if not properly 

controlled, can lead to performance degradation, reduced 

lifespan, and critical failures. Electric traction motors face 

thermal challenges due to copper and iron losses, which 

impact efficiency and durability. A range of cooling methods, 

from conventional air cooling to advanced liquid cooling 

techniques such as direct oil spray cooling and microchannel 

cooling, have been developed to enhance thermal regulation. 

Additionally, passive methods like phase change materials 

(PCMs) and heat pipes offer energy-efficient solutions 

without the need for additional power consumption. 

Similarly, power electronic components experience 

substantial heat generation due to electrical resistance and 

switching losses. Innovative cooling solutions, including 

solid-state methods like thermoelectric cooling, air-based 

convection techniques, and liquid immersion cooling, have 

significantly improved heat dissipation, increasing the 

efficiency and lifespan of PECs. Battery thermal management 

remains one of the most critical aspects of EV and HEV 

performance, as temperature fluctuations directly affect 

battery capacity, charging efficiency, and safety. Active 

cooling techniques such as liquid immersion and forced air 

circulation provide effective temperature regulation, while 

passive methods like PCMs and heat pipes contribute to 

improved heat distribution. Hybrid approaches, combining 

both active and passive cooling, have emerged as optimal 

solutions to maximize efficiency while minimizing energy 

consumption and design complexity. The continuous 

development of innovative thermal management 

technologies is crucial for advancing EV and HEV 

performance. Emerging trends, such as direct slot cooling, 

advanced two-phase cooling systems, and immersion-based 

cooling, are pushing the boundaries of heat dissipation 

efficiency. By integrating these advanced solutions, 

automakers can achieve higher energy efficiency, extend the 

operational lifespan of components, and enhance overall 

vehicle safety. As the demand for sustainable transportation 

grows, refining thermal management strategies will play a 

pivotal role in the future of electric mobility, ensuring that 

EVs and HEVs continue to provide a reliable and efficient 

alternative to internal combustion engine vehicles. 

Ethical issue 
The authors are aware of and comply with best practices in 
publication ethics, specifically concerning authorship 
(avoidance of guest authorship), dual submission, 
manipulation of figures, competing interests, and compliance 
with policies on research ethics. The authors adhere to 
publication requirements that the submitted work is original 
and has not been published elsewhere in any language. 

Data availability statement 
The manuscript contains all the data. However, more data will 

be available upon request from the corresponding author. 

Conflict of interest 

The authors declare no potential conflict of interest. 

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