Kulr introduces thermal management technology for aerospace applications into the field of electric vehicles
According to foreign media reports, thermal management technology developer Kulr uses phase change materials with vertically aligned carbon fibers for electronic products and lithium-ion batteries to serve the field of electric transportation.
(Image source: eetasia)
When the battery reaches its limit state, it may overheat, causing great damage to the entire system. Due to the lack of space and sufficient ventilation area in electric vehicles, new solutions need to be developed in terms of thermal management design. The thermal management solution used by Kulr Technology Group in the Mars mission may promote the development of the next generation of electric luxury sports cars.
Kulr CEO Michael Mo said that Drako Motors will apply its carbon fiber technology in the new electric supercar. The technology was jointly designed by Kulr and the National Aeronautics and Space Administration (NASA) to regulate the extreme temperatures of sensitive components in space to keep them in long-term operation. The Drako GTE electric vehicle platform is a 1200 horsepower architecture, highlighting the importance of new high-performance thermal management solutions.
Thermal Management
As the automotive industry shifts to electrification and the emergence of 5G communication technology, the world of power electronics is changing, and these applications require more power. For batteries and other powertrain systems, thermal management solutions or cooling technologies are also needed.
When electrons pass through conductors and semiconductors, they generate a lot of heat, which affects the final performance of the circuit. Now, with the increase in power density of electronic devices, the size of the devices is gradually reduced, and the problem of heat dissipation has become increasingly prominent. Therefore, in power equipment, temperature management is still a key factor.
The interface between high-power components generates heat, and the heat sink itself also generates heat. The tiny contact area between the interfaces may affect the heat conduction, and the uneven surface is the main reason for the contact thermal resistance. Mo pointed out: 'Kulr's solution aims to increase the contact between the two surfaces and reduce the thermal resistance of the interface.'
The first preventive measure is to choose a strategy to dissipate heat from electrical and electronic circuits. The heat transfer efficiency of the radiator is related to the thermal resistance between the radiator and the surrounding space. The ideal heat sink material must have high thermal conductivity, low thermal expansion coefficient, low density and low cost.
Thermal interface material
Kulr uses phase change materials with vertically aligned carbon fibers (carbon fiber thermal interface, or FTI) for electronics and lithium-ion batteries to serve electric transportation, energy storage, battery safety, 5G infrastructure, and cloud computing As well as aerospace and defense applications.
Carbon fiber not only dissipates heat, but also helps reduce size, weight and manufacturing complexity. Kulr has developed a proprietary manufacturing technology that integrates 5 to 10 micron carbon fiber bundles onto the substrate to make it look and feel like black velvet.
Drako GTE’s battery can produce 1,800 continuous amperes and 2,200 peak amperes. It is designed to provide megawatt-level power output and cooling capacity to withstand various track-level sports performance.
The production of electric supercars involves a lot of power. In order to maintain the limited radiator space, the thermal interface is very important. Introducing technologies used in high-temperature space environments into electric vehicles can provide more power to ensure proper heat dissipation and avoid overheating. Mo pointed out: 'We need to solve some challenges, that is, consumers want to find products with high thermal conductivity and cost-effective prices.'
The FTI solution series includes Alcor and Mizar FTI materials. Mo said: 'The density of Alcor is less than 0.7g/cm^3, because the contact pressure is very low, and low thermal resistance can be achieved. MIZAR FTI can increase the power density of the circuit board layout, relieve mechanical stress, and thus comprehensively improve thermal stability and reliability. .
As another solution, Hydra can be used as a radiator for lithium-ion batteries to prevent thermal runaway propagation (TRP), which is an important parameter in electric vehicles. A short circuit in the battery pack may cause thermal runaway, causing fires and burning of materials, such as increasing the temperature of adjacent cells. The rise in temperature increases the possibility of short circuits in adjacent cells. Mo said: 'Hydra aims to prevent the temperature of adjacent cells from rising above 100 °C to avoid thermal runaway.'
As part of the battery test, Kulr developed the LYRA internal short circuit (ISC) trigger cell to identify the fault conditions of the cell and explore the possible failure modes and safety issues in the battery pack.
With the gradual promotion of electric vehicles, the real challenge lies in fast charging stations. This will shorten the battery charging time, but it will also result in a significant increase in the heat generated by the powertrain system. Therefore, it is necessary to optimize the heat flow and develop a controlled thermal management scheme.
