Cool runnings – immersion cooled battery technology

Immersion Cooled Battery technology offers a future approach to enabling a multitude of benefits including: faster charging, extended battery life, safer operation and smaller, lighter weight, lower cost batteries in EV and hybrid vehicles. Andy Ennever, Head of Electrification at Ricardo, reveals the potential importance of the technology.

What is immersion cooling?

Put simply, immersion cooling is exactly as it sounds: the battery cells and components are cooled more effectively by immersion in a dielectric coolant fluid. The resulting benefits of this innovative thermal management approach include faster charging, extended battery life, safer operations and smaller, lighter weight, lower cost batteries in EV and hybrid vehicles.

The immersion cooling enables cells to be packaged more closely, increasing energy density, whilst removing the requirement for extensive coolant channels and cold plates. The casing is then designed to be leak-tight with pressure relief features, preventing moisture or air from entering the cell and compromising performance of the battery system. Immersion cooling can be applied to all battery cell types.

Ricardo engineers worked alongside TotalEnergies to develop one of the world’s first road cars fitted with immersion technology. The project saw the application of the technology in a road-going car, replacing the battery cooling system in a Volvo XC90 plug-in hybrid with an immersion alternative. In performance terms, the results were immediate. Information harvested during various tests revealed that cooling capability was seven times more effective. It also found that in this vehicle application there was potential to reduce mass by 4% and cost by 5.6%. The immersion cooled modified Volvo pack was tested for thermal runaway and the dielectric fluid prevented the vented gas from the triggered cell from affecting the neighbouring cells, successfully preventing the thermal propagation through the pack.  

What are the key advantages of Ricardo’s immersion cooling battery technology?

Excessive temperature variations between cells in battery packs presents significant challenges for vehicle manufacturers. Not only does this lead to batteries aging more quickly, but it also results in diminished vehicles range, power and overall efficiency.

Ricardo’s immersion cooling technology leads to 40% faster peak charge rate, (meaning the battery could go from 10% charged to 80% charged in eight minutes), 48% higher peak power density, up to 22% longer battery lifetime and up to 8% lower cost battery packs.

Ricardo’s innovative immersion cooling battery design has been developed with the complete lifecycle of the vehicle in mind. Battery packs are customised to customer requirements to achieve optimal packaging to maximise energy density.

Are there any challenges?

The immersion cooling battery design is still a relatively new technology with the potential to provide significant benefits for applications across multiple sectors including passenger cars, commercial vehicles, motorsport, aerospace and maritime industries to name just a few. The primary challenge is design of the optimised battery thermal system, and that is where Ricardo’s tools, processes and depth of expertise deliver bespoke, cutting edge, industry leading solutions.

How can Ricardo support your business to understand the benefits of immersion cooling?

Immersion cooling battery technology can confidently address the challenges of the next generation of higher performance electric batteries and the need to charge more quickly, last longer and be lower cost, more powerful, safer, smaller and lighter.

Through its research work and commercial projects, Ricardo has already delivered immersion cooled battery projects for aerospace, passenger car and commercial vehicle applications. In each case achieving step change benefits.

Whether you are a vehicle OEM or fleet user, a battery pack Tier 1, a battery cell manufacturer or a dielectric coolant supplier, Ricardo is ready to support you on your immersion cooled battery journey. We are at the forefront of immersion cooling technology, please do get in touch to find out more.