Efficient Coolants for EV Battery Thermal Management

A low-cost heat transfer fluid for cooling high-power density electrical components like batteries and electronics in applications like electric vehicles and servers. The fluid has balanced electrical properties like low electrical conductivity and dielectric constant to avoid issues like shorts, arcing, and static buildup. It also has desirable thermal properties like low pour point, kinematic viscosity, and flash point. The fluid is synthesized from isoparaffinic mineral oil base stock with additives like antioxidants, dispersants, and detergents to optimize performance.

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Cooling composition for batteries in electric vehicles that combines improved cooling with protection against thermal runaway. The composition has a thermal conductivity less than or equal to 125 mW/m·K at 30°C. It contains base oils, antioxidants, and optional additives like anti-corrosion agents. The composition circulates in cooling loops around battery cells to extract heat. By having lower thermal conductivity, it prevents excessive heating that can lead to thermal runaway. The lower conductivity also improves cooling performance compared to conventional oils. The composition can be used in devices like cooling circuits and storage tanks to cool batteries in electric vehicles.

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Thermal management system for heat-generating components like batteries in electric vehicles that uses a working fluid with encapsulated phase change materials (PCMs) to improve cooling performance. The system involves direct contact between the component and the fluid, which contains a base fluid and micro/nano-encapsulated PCMs. The encapsulated PCMs absorb and store heat as they melt, providing additional cooling capacity compared to just the base fluid. This allows more effective thermal management of the component by uniformly distributing the heat away from the component surface.

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Thermal management system for heat-generating components like batteries in electric vehicles that uses a working fluid containing a Fischer-Tropsch derived base oil, antioxidant, and antistatic additives. The components are directly immersed in the fluid to improve heat transfer. The fluid flows cyclically between components and a heat exchanger. The Fischer-Tropsch oil provides better aging properties compared to conventional fluids.

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Integrated phase change cooling and heating structure for battery packs in electric vehicles. The structure uses inflated aluminum plates between the battery cells, vapor chamber plates on top, and a heating film on bottom. This allows phase change cooling with aluminum and vaporization cooling at the top, while also providing heating at the bottom using a film. A control system manages the cooling/heating fluid flow. It enables efficient thermal management of the battery pack across a wide temperature range.

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Coolant for electric vehicle batteries containing a phase change material (PCMs) like paraffin, salt hydrates, carboxylic acids, sugar alcohols, etc. to maintain battery temperature. The PCMs absorb/release heat during charging/discharging to prevent overheating. The coolant also has surfactants like sorbitan sesquioleate to improve PCM dispersion. The PCM, surfactants, and solvent are mixed and stirred to form the coolant.

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Battery cooling plate with improved thermal management for electric vehicle batteries. The cooling plate has a phase change material coated with heat conducting silica gel. The silica gel improves the mechanical strength, thermal consistency, and prevents leaks compared to the phase change material alone. The silica gel is cladded on the phase change material surface and seals it to prevent leakage when the gel liquefies during charging/discharging. This provides a reliable, leak-free cooling solution for battery modules.

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Battery thermal management module for electric vehicle packs with high temperature uniformity using heat pipes and phase change materials. The module has a liquid-cooled plate, battery cells on top, and heat pipes between columns. The heat pipes have vertical sections in the box and flat sections on the plate. Corrugated plates distribute lateral heat. Phase change material fills the box to quickly transfer heat to the pipes and plate. This improves lateral and longitudinal temperature uniformity of large, high-density battery packs.

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Electric vehicle battery cooling system using nanofluid with enhanced heat transfer capability. The system has three loops: a cold start loop, a regular heat dissipation loop, and an enhanced heat dissipation loop. The nanofluid, like ethanol with silicon carbide nanoparticles, is pumped through the loops. The enhanced loop has internal and external circulation paths with a deionizer to reduce conductivity. The external path has cosine-curved microchannels. This system improves battery cooling in high power applications by using the nanofluid for better heat transfer and the enhanced loop for extra dissipation.

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Battery thermal management system for electric vehicles that provides uniform temperature distribution and efficient heat dissipation for battery packs. It uses a composite phase change material inside the battery enclosure, with heat dissipation pipes between cells. A circulating water system takes away heat from the phase change material and cells. Temperature sensors control the water pump to circulate fluid when needed. This balances temperatures, prevents hot spots, and reduces battery degradation.

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Thermal management system for electric vehicle batteries that uses phase change materials (PCMs) and air cooling to improve battery safety and performance without adding external devices. The system has a box with a heat dissipation pipe, a cover with a hole for the pipe, and a battery column filled with a PCM made of lauric acid. The cover also has connectors for the battery and charging. The column, box, and pipe are filled with a second PCM made of sodium acetate trihydrate and urea. This design allows the battery column to change phase and release heat when operating, avoiding overheating. The air cooling through the pipe dissipates the remaining heat. The PCMs provide efficient thermal management without external devices or liquids.

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Thermal management fluid for cooling electric vehicle batteries and other electrical components without using conductive cooling. The fluid has a high dielectric constant and flash point above 120°C to prevent ignition. It contains a low-viscosity dielectric base oil with a flash point below 150°C and a small amount (0.1-20wt%) of halocarbons. The halocarbons reduce viscosity further and provide vaporization to disperse ignition risk. The dielectric fluid absorbs heat from electrical components without conducting electricity.

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Non-aqueous coolant composition for cooling high-temperature devices in electric vehicles that provides better insulating properties and cooling performance compared to water-based coolants. The composition contains at least one non-aqueous base, such as an amine compound, that has excellent insulating properties. The composition can be used in cooling systems for electronic devices in electric vehicles that generate heat, like inverters, converters, and batteries. The non-aqueous coolant prevents secondary disasters like short circuits if it leaks by not conducting electricity well. It allows direct contact cooling of devices without insulating barriers.

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A combined type battery cooling device for electric vehicles that uses phase change material (PCM) and microchannel cooling for efficient and uniform battery temperature control. The device has a battery mounting frame with adjustable grooves, a heat conducting sheet with PCM and cooling channels, and a radial flow pipe for circulating coolant. The PCM absorbs excess heat during low charge/discharge and melts at a fixed temperature. This provides stable cooling when the battery temperature drops. The microchannel cooling provides additional cooling capacity for high charge/discharge. The adjustable grooves allow customizing the PCM volume based on battery size.

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Vehicle-mounted lithium ion battery pack with integrated phase change cooling for thermal management. The battery pack has microcapsules coated on the inner shell surface and thin tubes attached to the diaphragm. Both contain phase change materials that absorb and release heat as the battery temperature changes. This provides localized cooling inside the battery to prevent overheating and thermal runaway. The encapsulated phase change materials avoid affecting battery electrolyte chemistry.

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Two-phase immersion cooling system for batteries that uses phase change material (PCM) to store energy. The system allows electric vehicles to cool batteries without opening the cooling system during short trips. It uses a PCM-filled fin structure around the battery. When the battery heats up, the PCM absorbs the heat instead of the coolant. For short trips, the PCM melts and solidifies without opening the cooling system. This saves energy compared to full coolant cooling. For long trips, the PCM melts and the coolant kicks in.

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Battery coolant for electric vehicles that has low conductivity, low ion elution, low viscosity at low temperatures, and equivalent cooling performance compared to water-based coolants. The coolant contains carbonates like propylene carbonate and butylene carbonate, along with compounds like benzotriazole and tolyltriazole. It has less than 3% of these additives by weight. The carbonate content replaces water to avoid freezing issues. The coolant has viscosity below 250 mPa·s at -30°C and conductivity below 1.0 μS/cm after heating and flux testing.

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Microencapsulated phase change materials (PCMs) for passive thermal management of automotive battery packs, modules, and cells. The microPCMs contain core materials that exhibit latent heat changes in temperature ranges relevant to battery operation. The core is encapsulated in a protective shell to prevent leakage during melting. The microPCMs are placed in thermal communication with battery components to absorb/release heat during phase changes. This reduces the need for active cooling/heating systems. The microPCMs are tailored to specific temperature ranges for low/high temperatures. Composite PCMs with multiple core materials for wider ranges. The microPCMs can be mixed, shaped, and foam-compressed for thermal optimization.

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Thermal management system for automotive battery packs that uses microencapsulated phase change materials (PCMs) suspended in a fluid medium to regulate pack temperatures. The microPCMs are tiny bi-component capsules containing a core material tailored to temperature ranges encountered in batteries. They are placed in thermal communication with the battery cells through fluid conduits. The high latent heat of the PCM cores absorbs or delivers heat to balance cell temps. The fluid medium circulates to move heat between cells and the PCMs.

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Coolant for cooling batteries and capacitors in electric vehicles that provides sufficient cooling performance while avoiding issues like electric shock and flash point safety. The coolant has specific properties like density, kinematic viscosity, and thermal effusivity optimized for the temperature range of secondary batteries and capacitors in vehicles. This balance of properties provides good cooling performance without issues like electric shock or flash point safety concerns. The coolant can be made from base oils like GTL synthesized from natural gas, and contains additives like antioxidants and anticorrosion agents.

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