Coolant

Overview

Charging and operation of the electric vehicle generates heat from the battery pack and the motor. Inappropriate handling of this heat will lead to reduced efficiency, and lifetime of the components, and might even draw safety hazards. Coolants provide for the maintenance of operational temperatures by absorbing heat and releasing this heat through the cooling system. This is different from Internal Combustion Engine (ICE) vehicles, where the basic function of the coolant is to cool the engine. EVs use specially designed coolant systems for cooling both battery packs and electrical components. 

How It Works

Coolant flows through a system of pipes and channels in the EV cooling system. With one end connected to high-temperature components and the other to an air-cooled radiator or a heat exchanger, the coolant absorbs heat and, through convection, then introduces it into the coolant heating mechanism.

In this way, a liquid-cooled battery system circulates a coolant through battery cells to pull the heat away from the cells and maintain an even heat temperature. Some high-performance EVs feature even more powerful thermal management systems with refrigerants, similar to air conditioning systems.

If cooling isn’t provided, the battery of the EV can overheat, leading to performance degradation, slower charge times, and even thermal runaway, whereby as heat builds up, a chain reaction causes battery cells to overheat. 

Key Features

Coolant plays a vital role in maintaining the efficiency, safety, and longevity of an electric vehicle’s critical components. It ensures stable thermal conditions, preventing damage caused by excessive heat.

By keeping EV batteries and motors at safe operating temperatures, coolant prevents overheating and performance degradation. It also helps reduce heat buildup, minimizing unnecessary power loss and ensuring the vehicle operates at peak efficiency. Maintaining a stable thermal environment decreases wear and tear on battery cells, ultimately extending their lifespan and preserving performance over time. 

Additionally, proper cooling lowers the risk of thermal runaway, a dangerous condition that can occur due to overheating. Depending on the design and thermal management needs of the vehicle, different EVs use liquid-based coolants, such as glycol-water mixtures or refrigerant-based cooling systems.

Applications in Electric Vehicles

The coolant plays a very important role in multiple EV systems, allowing them to work well and to work effectively:

• Battery Thermal Management System: This system maintains optimum battery temperature during fast charging and extreme weather.
• Motor and Inverter Cooling: Electric motors and inverters generate heat while functioning, and the coolant prevents an increase in temperature that could be problematic.
• Fast Charging Support: Efficient cooling allows the EVs to charge faster by preventing excessive heating of the battery pack.
• Cabin heating (heat pump systems): Some EVs use the coolant in heat pump systems to provide cabin heating more efficiently by transferring waste heat from the other vehicle components.

Modern EVs, including the Tesla Model Y, BMW i4, and Hyundai Ioniq 5, are equipped with advanced liquid cooling systems to better cool the batteries and motors, ensuring their longevity and steady performances. 

Conclusion

It is a crucial part of the thermal management system in an electric vehicle. This system ensures optimal temperature ranges in the batteries, motors, and electronics. Besides influencing other designs, coolants effectively regulate heat, increase safety, and prolong the operation of such elements. As EV technology advances, state-of-the-art cooling solutions will play an ever-increasing role in improved battery performance, fast charging, and vehicle reliability.