At the early stage of the development of new energy vehicles, manufacturers continued the design principles of fuel vehicles for the manufacturing of electric vehicles. During this time, the motor, battery, and charging systems made little heat. So, passive methods such as airflow and heat sinks were enough for battery cooling. However, these passive cooling methods had significant limitations. Airflow cooling relies on natural convection or simple fans, which can only dissipate a limited amount of heat. Heat sinks spread heat across a large area. But, they rely on the air around them to absorb and remove the heat.
Electric vehicle technology advanced. This was thanks to more powerful motors, supercharging, and fast charging. But, these advances put a lot more heat stress on batteries. This increase highlighted the insufficiency of passive cooling methods. The industry needed a more effective solution to handle the new thermal management demands.
Motors, supercharging, fast charging, and other related tech are rapidly innovating. They bring big challenges for battery thermal management. Passive methods, like air cooling, can’t meet the new demands for battery heat dissipation. This need led to the adoption of liquid cooling. It is a better way to get rid of heat.
Liquid cooling technology provides several advantages over passive cooling methods. It has better heat dissipation. It ensures even temperatures with liquid cooling. This system helps maintain the battery’s performance and longevity by effectively managing the heat generated during operation and charging. Trumonytechs is a thermal management specialist. We have lots of design and manufacturing experience. We offer a wide range of products and designs. We are not just for cooling batteries. We are also for energy storage, high heat flow, and new liquid cooling tech. This expertise ensures that modern electric vehicles’ thermal needs are met well. It fixes the limits of earlier passive cooling.
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Battery Liquid Cooling System Overview
Electric motors, supercharging, fast charging, and related tech are innovating rapidly. This is creating big challenges for battery thermal management. Air cooling is a passive method. It can’t meet the new demand for battery cooling. So, liquid cooling, a more effective active method, replaces it.
Liquid cooling technology provides better heat dissipation. It also provides uniform temperature through a liquid cooling system. This ensures battery performance and cycle life. Specific technical advantages include high cooling efficiency, uniform temperature distribution, flexible design, and low noise. Liquid-cooled systems provide even temperatures in the whole battery pack. They avoid local overheating. This extends battery life and stabilizes performance. Liquid cooling systems are quieter than fans in air-cooled systems. They add to the comfort of electric vehicles.
Liquid cooling systems have demonstrated significant results and benefits in real-world applications. Tesla Model S utilizes an advanced liquid-cooling system to manage battery heat. In the liquid-cooling cycle, Model S can control battery temperature well. It does so during high-performance driving and fast charging. This keeps the vehicle safe and performing well. This enables the Model S to perform well during long periods of high-speed driving and extreme weather conditions. As the world’s leading battery manufacturer, NDT provides liquid-cooled battery packs for several EV brands. NDT uses liquid cooling to keep its battery packs at a low temperature. This works even in high-power and fast-charging modes. It improves the batteries’ service life and charging efficiency.
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Application Of Liquid Cooling System In The Industry
The system is mainly used in four fields: power batteries, energy storage, high heat density, and new liquid cooling components.
In the field of electric vehicles, thermal design is more complex than for fuel vehicles. This is because electric vehicles have more motors, batteries, and control systems. These make the heat of the power batteries the core of thermal design. The thermal performance of the power battery will directly affect the efficiency and performance of new energy vehicles. Commonly used lithium batteries are used as the power source of the vehicle and are connected in series and parallel to form a battery module. Lithium batteries are very sensitive to temperature changes during their electrochemical reaction. They usually need to be kept between 15℃ and 35℃. A temperature that is too high or too low will affect their safety and performance.
Liquid cooling has unique advantages. It meets the power battery’s temperature requirement. It has two circuits for cooling and heating. Liquid cooling systems have greater heat capacity than air cooling. They also have low flow resistance and high heat transfer efficiency. Energy density is rising. Charging and discharging are getting faster. So, liquid cooling is becoming the top choice for most new energy vehicle makers.
In the field of energy storage, liquid cooling systems are equally important. Large energy storage systems often need to handle large amounts of heat, especially during high power output and charge/discharge cycles. Liquid cooling systems can control the battery temperature well. They prevent overheating and ensure the system runs stably for a long time. They also improve the life and safety of the energy storage system.
High heat flow density applications, like data centers and high-performance computing, are seeing rapid growth in the use of liquid cooling. Traditional air cooling methods can no longer meet the increasing heat dissipation needs of these devices. Liquid-cooled systems can handle lots of heat in a small space. They do this through efficient heat transfer and dissipation. This greatly improves the efficiency and reliability of equipment.
The new components transfer heat using liquid cooling. They have broadened the technology’s uses. These parts use advanced materials and designs to improve heat exchange. They can be used in many industries and businesses. For example, electric airplanes and fast electric motorcycles are also starting to use liquid-cooling technology. It boosts their thermal performance.
Liquid-cooled systems offer many technical advantages. They beat other heat dissipation methods, like air cooling. First, liquid-cooled systems have better heat transfer. They can quickly remove large amounts of heat. Second, liquid cooling systems can achieve more uniform temperature distribution, avoiding localized overheating and improving overall system reliability. Also, liquid cooling systems are more flexible. They can be customized to meet specific needs. In contrast, fans and air paths limit the cooling of air-cooled systems.
Components Of The Battery Liquid Cooling System
The battery liquid cooling system is composed of the following components:
Liquid Cooling Plate: The liquid cooling plate is the core component of thermal management. It is usually made of materials with excellent thermal conductivity, such as aluminum and copper. The heat dissipation parts are on the surface of the cooling plate. The coolant passing through the plate’s internal channels absorbs the heat there. This design maximizes heat transfer. It ensures even temperatures. This is crucial for keeping battery stability and performance in many conditions.
Liquid Cooling Circulation System: This system includes cooling channels and electric pumps. It also includes the path of the coolant and other related parts. The cooling channels are designed to efficiently transfer and dissipate heat. The electric pumps propel the coolant. They ensure continuous and effective heat removal from the battery.
Cooling Fluid: Also known as heat transfer fluid, the cooling fluid is used to conduct the heat from the components that need to be cooled to other parts of the system. The best cooling fluids have high heat capacity. They also have low viscosity and are non-toxic, chemically inert, and electrically insulating. Common cooling fluids include water, water/glycol mixtures, mineral oil, and fluorinated fluids. Each is suitable for different applications, depending on its specific properties.
Control System: The control system typically consists of temperature sensors, control units, and actuators. It monitors and regulates the battery temperature to ensure it remains within a safe range. Temperature sensors provide real-time data, which the control unit uses to adjust the flow and temperature of the coolant. Actuators then execute the necessary operations based on the control unit’s instructions.
Cooling Fan: The cooling fan helps to remove the remaining residual heat by expelling it to the outside environment. The coolant carries away most of the heat. But, the fan provides extra cooling when needed. This is crucial under high loads or extreme conditions. It makes sure the system works reliably.
Cooling Fluid Selection
Coolant generally refers to the fluid that surrounds or flows through a system used for heat transfer. The best coolant has a high heat capacity. It also has low viscosity, is affordable, non-toxic, chemically inert, non-corrosive, and electrically insulating. Below is a comparison of various coolants, detailing their properties and use cases.
| Coolant Type | Thermal Conductivity | Viscosity | Cost | Toxicity | Insulation | Key Characteristics |
| Water | High | Low | Very Low | Non-toxic | Non-insulating | Excellent thermal conductivity and heat capacity; not insulating |
| Water/Glycol Mixture | Moderate | Moderate | Low | Non-toxic | Non-insulating | High boiling point, anti-freeze properties; improves coolant performance |
| Mineral Oil | Moderate | Low | Moderate | Low toxicity | Insulating | Good thermal conductivity, lubricating performance, stability; risk of combustion |
| Fluorinated Fluids | Moderate | Low | High | Low toxicity | High insulating | Low toxicity, high electrical insulation, excellent thermal stability and chemical inertness |
Water: Water has high thermal conductivity and capacity. It is often used in systems that don’t need direct electrical insulation. For example, in HVAC systems and some industries, water cools well but is usually kept away from electrical parts.
Water/Glycol Mixture: This coolant is widely used in automotive applications, including electric vehicles. The mixture has a high boiling point. It also has anti-freeze properties. This makes it ideal for places with extreme temperatures. For instance, many electric vehicle manufacturers use water/glycol mixtures. They use them to manage battery temperatures well during rapid charging and high-performance driving.
Mineral Oil: Mineral oil is known for its insulating properties. It is often used in electrical transformers to cool and insulate. It offers good thermal conductivity and stability, though it poses a combustion risk at high temperatures. Some data centers also utilize mineral oil in immersion cooling systems to manage the heat generated by servers.
Fluorinated Fluids: They were first used for cleaning circuit boards. But, they have spread to high-end cooling. This is because they are not very toxic and insulate well. And, they are very stable at high temperatures. They are now common in large submerged cooling systems. These are used in data centers for server cooling. They provide an efficient and safe way to manage heat.
Principle Of Liquid Cooling System
A liquid cooling system for new energy vehicles has a basic principle. It is to keep each component working well and reliably. It does this by circulating coolant to soak up heat from the heat-dissipation components. The system keeps the components in the right temperature range.
The system has parts such as expansion kettles, condensers, cooling fans, water pumps, three-way solenoid valves, and battery cooling tubes. Here is a step-by-step breakdown of the working principle:
Heat Absorption: The coolant flows through the liquid cooling plates, which are attached to the battery cells. As the battery operates, it generates heat. The coolant absorbs this heat from the battery cells.
Heat Transfer: The heated coolant then flows into the condenser. In the condenser, the coolant releases the absorbed heat to the surrounding air, aided by the cooling fans. This process cools down the coolant.
Pressurization: After cooling down in the condenser, the coolant enters the electronic water pump. The pump pressurizes the coolant to ensure it circulates efficiently through the system.
Heat Exchange: The coolant is pressurized. It flows through the electric control and drive systems. It absorbs extra heat from these parts. This keeps the temperature of these systems within optimal ranges.
Temperature Regulation: The flow of coolant is regulated by a three-way solenoid valve. Depending on the cooling needs, the valve directs the coolant back to the battery pack or an auxiliary cooling system.
Coolant Circulation: The cooled coolant is then recirculated back to the liquid cooling plates to absorb more heat from the battery cells, and the cycle repeats.
Compared with air-cooled systems, the technical advantages of liquid-cooled systems are more apparent. Liquid cooling provides higher cooling efficiency and better temperature balance. This is due to the higher heat capacity and thermal conductivity of the coolant compared to air. Liquid cooling systems also hold more heat, have less flow resistance, and transfer heat better. Energy density is increasing. Charging speeds are too. As this happens, liquid cooling is becoming the top choice for new energy vehicle makers.
Conclusion
Liquid cooling systems are crucial in battery thermal management, ensuring battery stability and performance under various operating conditions through efficient heat transfer and uniform temperature distribution. Compared with traditional air cooling methods, liquid cooling systems have higher heat dissipation efficiency and lower flow resistance, and have become the preferred choice for mainstream new energy vehicle manufacturers such as Tesla, Ningde Times and General Motors. In the future, as battery energy density and charging/discharging speeds continue to increase, liquid cooling technology will show even greater potential in electric vehicles, energy storage systems and high heat flow density applications. If you would like to learn more or are looking for a professional thermal management solution, please feel free to contact Trumonytechs and our team of experts will provide you with comprehensive support and services.
FAQ
A battery liquid cooling system uses coolant that circulates. It manages battery temperature. This ensures safe and efficient operation.
Liquid cooling has better heat transfer. It gives even temperatures and stops hotspots. This improves performance.
The key components include cooling plates, coolant, a circulation system, a control system, and cooling fans. They all work together for efficient heat management.
Common coolants include water, water/glycol mixtures, mineral oil, and fluorinated fluids. Each is chosen for specific thermal and environmental needs.
It improves thermal management. This extends battery life and boosts performance. It is ideal for high-power applications, like fast charging and intense driving.
