As the global initiatives strive to cut down emissions, electric vehicles (EV) will soon become the dominant transportation on our roads. The key technology in EVs is of course the battery, with the electric vehicle battery market projected to be in excess of $150 billion USD by 2028.
With this rising demand for batteries (namely lithium-ion) as well as for increasing their capabilities such as improved energy density, one of the key challenges which needs to be addressed is thermal management.
Effective thermal management not only improves the performance of the battery and system, but also ensures that the technology is operating safely without the risk of thermal propagation.
New developments in thermal management of batteries are a hot topic in the industry, with manufacturers exploring a number of new techniques and technologies.
Does liquid cooling provide the answer?
Liquid cooling is currently the thermal management solution being developed by some of the industry’s top players, including TESLA, BMW, Ford and Jaguar. The benefits of this type of cooling system are that it has a compact structure, high heat capacity and high operating efficiency. It can come in two forms; indirect and direct.
Indirect cooling
In this type of cooling, a coolant is circulated through a system of pipes. The system architecture can vary for each manufacturer. For example, Tesla has patented it’s own system whereby each battery cell is against a coolant pipe, whilst BMW uses a system whereby the entire battery has coolant pipes which are directly against it. With variations in how this system is designed, it is an exciting area currently being developed.
Direct (immersion) cooling
A slightly more novel approach to liquid cooling is direct or immersion cooling. Here, the battery is submerged directly into the coolant (which must have little to no conductivity). Although direct cooling has the potential to reduce battery pack temperatures better than indirect cooling, selecting a liquid with the optimal characteristics as well as mitigating leakage which can cause damage to the system is still ongoing, and as such the technology has not yet hit the mass market.
Two-phase cooling
Two-phase cooling is similar to immersion cooling in that the pack is immersed in a liquid, however here some or all of the working fluid is evaporated to remove the heat and then condensates to continue the cycle. Although this technology is largely still in the research phase, once commercialized it has the potential to provide the ideal solution for battery thermal management.
Approaches to battery thermal management are varying, and continued innovation means that development can take many technological forms. However, with end-users sharing the common goals of increasing the range, lifespan, and safety of a vehicle, it is a rapidly developing area which will have a big impact on the progression on the market.
The conference at Thermal Management Expo 2022 will be exploring and addressing the latest developments in battery cooling, with speakers from leaders at companies including Romeo Power, AllCell Technologies and KULR Technologies. To register for the free-to-attend event, taking place in Cleveland OH from August 30-31, please click here.
