Phase Change Materials for Passive Cooling of EV Batteries

Abstract To address the limitations of conventional energy systems and optimize conversion pathways efficiency, a type “five-in-one” multifunctional phase-change composite with magnetothermal, electrothermal, solar-thermal, thermoelectric electromagnetic shielding functions is developed for multipurpose applications. Such novel fabricated by an innovative combination paraffin wax (PW) as material carbonized polyimide/Kevlar/graphene oxide@ZIF-67 complex aerogel supporting material. The exhibits unique bidirectional porous structure high porosity robust skeleton to support loading PW. reduced graphene oxide CoNC resulting from high-temperature carbonization are anchored on generate thermal conduction magnetic effect, enhancing phonon electron transfer improving its efficiency. not only excellent thermoelectric, magnetothermal performance, but also achieves interference effectiveness 66.2 dB in X -band. introduction PW significantly improves energy-storage capacity during multi-energy conversion. great application potential efficient solar utilization, sustainable power generation,... Read More

Source

A tool and method for connecting electronic components to cooling surfaces like heat sinks without the need for fragile thermal interface material (TIM) foils. The tool has a base with a cavity shaped to match the contour of the cooling surface. A flexible pad is attached inside the cavity. When the component is placed on the tool, the flexible pad conforms to the component's shape and provides a gap-free thermal contact between the component and the cooling surface. The tool can be used in any orientation, vertical or horizontal, without needing to align delicate TIM foils. The flexible pad replaces the need for fragile TIM foils, simplifying component installation and maintenance.

Source

Power supply device with improved heat dissipation and size reduction for applications like electric vehicles. The device uses a case filled with insulating heat dissipation resin to surround and contact heat generating components like semiconductors. This allows direct thermal conduction between the components and the resin, improving dissipation compared to insulated components. The components can also be arranged with different volumes and in contact with the case wall. This leverages the resin and case as additional heat sinks. The compact design enables efficient dissipation of heat from components while reducing overall device size compared to separate heat sinks.

Source

Manufacturing a composite material with improved thermal conductivity by planarizing the surface of the metal foam component before forming the composite. The process involves planarizing the metal foam (step b) before or during mixing with the curable polymer (step c) to create a smoother surface. This increases the bonding area between the composite and the material it contacts, improving heat transfer efficiency. Planarization can be done on the metal foam precursor, the metal foam, the polymer-foam mixture, or the cured composite.

Source

Battery module with enhanced thermal management through strategically integrated phase change materials (PCMs) that absorb heat generated in critical battery connections. The module features a bus bar with integrated phase change members that distribute heat from connecting areas between the cell tab and bus bar, while a secondary phase change member is positioned on the top surface of the cell. This dual-phase design enables targeted cooling of high-temperature areas, particularly the connecting region between the cell tab and bus bar, while maintaining overall system thermal balance. The phase change materials are designed to absorb and release heat efficiently, preventing thermal runaway and fire hazards.

Source

Inside a closed, thin-walled hollow cylinder, there is solid state of phase change material (NePCM) that has been nano-enhanced. This NePCM heated at its bottom, with nanoparticles (Al2O3) inserted and homogenized within the PCM (sodium acetate trihydrate, C2H3O2Na) to create NePCM. The cylinder thermally insulated from outside ambient temperature, while heat supplied sufficient cause change. Once entire converted liquid due heating, it then cooled, thermal insulation removed. cylindrical liquefied bar cooled in this manner. Thermal entropy, entransy dissipation rate, efficiency during heating cooling were analyzed by changing variables. volume fraction ratio nanoparticles, inlet flux, height variables considered. results indicate significant impact on liquefaction convective when values these are altered. For instance, an increase 3% 9%, constant flux 104 Wm−2 0.02 m, decreases 99%. entropy conduction through significantly lower compared air surface. increases average 110% without any cooling. With 6%, 80% as m.

Source

Bonding metal filaments directly to the surface of an electronic substrate to form a heat sink without using a separate thermal interface material. The filaments are formed by processes like ball bonding, wedge bonding, ribbon bonding, and chain bonding. The filaments are heated and placed on the substrate surface to weld them in place. This creates a tailorable, high-density network of filaments that dissipate heat from the substrate. The filaments can be extended away from the substrate or joined back to form an individual heat sink. Repeating the process creates a plurality of filaments that cool the substrate. This eliminates the need for a separate thermal interface material to attach a separate heat sink.

Source

Agglomerated boron nitride powder for heat dissipation sheets with improved thermal conductivity and electrical insulation properties. The agglomerated BN powder has a specific tap density range of 0.6-0.8 g/mL and interparticle void volume of 0.5 mL/g. This density range allows the BN particles to pack closely without excess voids while still allowing interparticle movement for thermal conductivity. The optimized BN powder enables heat dissipation sheets with high thermal conductivity and good electrical insulation properties compared to standard BN powders.

Source

Batteries with improved performance, durability, and safety for electric vehicles and other applications. The batteries have features like phase change materials, thermally conductive articles, and housing designs that mitigate heat generation and cell expansion during charging/discharging. The phase change materials absorb excess heat from cells, cooling them. Thermally conductive articles align cells and facilitate heat transfer. Uniform pressure distribution is achieved by housing components. These features allow high energy density batteries with reduced deleterious effects of lithium metal cells.

Source

High thermal conductivity heat conductive silicone composition with improved slide resistance for use in heat dissipation applications like electronics. The composition contains a crosslinked silicone gel, a specific silicone oil, a heat conductive filler, and gallium or a gallium alloy. The gallium or gallium alloy with a melting point between -20°C and 100°C provides high thermal conductivity. The gallium also improves slide resistance compared to compositions without gallium.

Source

Cooling apparatus for lithium-ion batteries that allows expansion without degrading heat transfer. The cooling apparatus has a heatsink that contacts the battery on three sides to absorb heat. It also has a clearance portion that allows the battery to expand. Additionally, the heatsink has a metal plate with a spring arm to secure the battery. The clearance prevents pressure buildup and swelling, while the metal plate prevents contact loss during expansion. An elastomer between the heatsink and battery provides thermal conductivity and compression force to maintain contact. This enables efficient cooling and prevents overheating during fast charging and discharging.

Source

Preparing ultra-thin copper foam with small thickness and high water absorption for use in heat dissipation applications in electronic devices. The preparation method involves electroforming copper foam in a specialized electrochemical cell setup. The cell has a cathode electrode with a porous substrate and an anode electrode with a soluble coating. The copper foam is grown on the cathode by electrolysis, with the soluble anode coating dissolving into the electrolyte as the foam grows. This allows the foam thickness to be precisely controlled by adjusting the anode coating dissolution rate. The resulting ultra-thin copper foam has a thickness as low as 50 microns while still retaining excellent water absorption properties.

Source

A lightweight, flexible heat control structure for spacecraft and electronics with high temperature gradients. It uses multiple graphite sheets held at ends by clamping members. The exposed edges of the graphite sheets contact the heat source and dissipation targets. This allows efficient heat transfer with a simple, flexible design that can handle large temperature differences. The graphite sheets can be made from polymer films like polyoxadiazole or polybenzothiazole. The clamping members hold the graphite sheets with parallel basal planes and spaced edge planes.

Source

Battery pack design for mobile devices and electric vehicles that enhances heat management through a novel heat transfer system. The pack incorporates a heat sink with strategically positioned windows that match the cell vents, and a leg extending from the heat sink to the bus bar. The heat transfer material is integrated into the bus bar's design, covering both protrusions and concave sections. This multi-directional heat transfer system optimizes heat dissipation from both the bus bar and cell compartments, significantly reducing thermal stress and improving overall pack performance.

Source

Simplifying the assembly of battery submodules for electric vehicles to reduce complexity and costs. The submodule design involves stacking pouch cells and welding electrode tabs between cells without removing them from the stack. This eliminates the need for complex handling of flexible pouch cells. The submodule is then attached to a frame and heat sink, with busbars added prior to welding the electrode tabs to them. This allows joining the cells without damaging the frame. The submodule can be stacked with others to form a battery module.

Source

Battery pack for vehicles with a fluid-filled compartment in the battery holder to improve cooling and prevent uneven temperature distribution. The holder has a base plate with through openings for venting battery cell gases. It also has a closed compartment partially filled with fluid. The fluid spreads heat generated by the cells, reducing risks of hot spots. The compartment can extend across the base plate. Grooves channel gas to the compartment. The compartment surface structures facilitate heat transfer. The fluid can be a phase change material for temperature regulation.

Source

Sandwich structure with high heat dissipation and mechanical properties for applications like electronics cooling. The structure has a thermally conductive sheet sandwiched between fiber-reinforced sheets. The thermally conductive sheet has a high in-plane thermal conductivity of 300 W/mK or more. It is not bonded to the core fiber-reinforced sheets, allowing the core to bear most stress. This prevents destruction of the thermally conductive sheet. The fiber-reinforced sheets have higher modulus than the core to provide strength. The core can be a porous material for lightweight. The sandwich structure is made by sequentially pressing the components. This allows the thermally conductive sheet to be positioned accurately without displacement.

Source

Spiral-shaped heat sink design with internal flow channels that have communicating sections to circulate refrigerant. The spiral channels allow evenly distributed cooling performance through temperature control at the heat sink contact surface with the electronic device. The spiral shape creates turbulence and counter flow for enhanced heat transfer. The communicating sections allow circulating refrigerant flow between channels for improved cooling.

Source

Charging inlet assembly with integrated cooling to prevent overheating of the charging terminals during high current charging. The cooling module has phase change elements enclosed in pockets on a carrier that is thermally connected to the charging terminals. The phase change elements absorb heat from the terminals during charging to lower their operating temperatures.

Source

Battery pack cooling design to improve thermal management and efficiency of battery cells. It uses a thermal component with channels to capture and move heat away from the cells. The component extends between rows of cells in the pack. Coolant flows through the channels to absorb cell heat and transfer it away. This reduces overall pack temperature, gradient across cells, and improves pack cooling.

Source