Project I-CoBat Case Study

Project Overview

As part of the Government’s Industrial Strategy Challenge Fund (ISCF), the Faraday Battery Challenge is investing up to £330 million in research and innovation projects and facilities to drive the growth of a strong battery business in the UK. Led by M&I Materials, Project I-CoBat was funded by the ISCF Faraday Battery Challenge to test an immersion cooled battery pack concept designed by Ricardo and tested by WMG, using MIVOLT as the dielectric cooling liquid.

The Challenges

1- Cost Effective

The Faraday Battery Challenge aims to develop battery technologies that are cost effective. Project I-CoBat had to demonstrate that liquid cooling battery packs with MIVOLT would prove to be more cost effective than cold plate cooling.

2- Performance

High performance, longer range and long-lasting battery technology were high on the Faraday Battery Challenge’s requirements list. The consortium had to ensure that their immersion cooling module and dielectric liquid could meet these demands.

3- Faster Charging

With EV charging stations lacking the convenience of petrol pumps, faster charging has to be made available to encourage the uptake of EVs. The possibility of faster charging would need to be validated by Project I-CoBat.

4- Safety and the Environment

The Faraday Battery Challenge is seeking battery technology that will be safe and environmentally friendly throughout its lifecycle, from cradle to the grave.

The MIVOLT Solution

MIVOLT can come into direct contact with components, removing heat from the source more effectively than indirect cooling systems such as cold plates and heat sinks. Though the concept of immersion cooling for EV batteries has been explored before, manufacturers often express concerns over the weight and volume of the required levels of liquid.

To help solve this problem, Ricardo designed a novel immersion cooled battery module with cylindrical cells, smaller and more powerful than the leading cold plate design. Rather than flooding the entire case, the coolant was only directed where it was needed through an innovative coolant jacket design, which also minimised the sealing requirements.

As well as cooling the battery cells in the module, the design utilised MIVOLT for busbar cooling, further reducing weight in the system.

The system delivered major increases in both power density and charge rate compared to an equivalent cold plate cooled module:

Reduced Costs

The battery pack took 1/3 of the space of a typical module, meaning that less cells were necessary - yet the same amount of power was still delivered. This lowered costs and reduced module weight. Busbars were also reduced in size by 85%, adding to the cost and weight savings.

Faster Charging

The battery system offered major increases in both power density and charge rate compared to an equivalent cold plate cooled module. Twice as fast charge rates were achieved, an increase of 43% compared to cold plate cooling. The battery module designed by Ricardo also delivered significantly higher power output.

Battery Life

In order to prevent premature battery ageing or even failure, heat has to be removed to maintain a constant cell temperature. The immersion cooled battery module could increase battery life in automotive applications by 2+ years.

Safety and the Environment

Battery abuse testing demonstrated that MIVOLT has the potential to mitigate thermal runaway and prevent battery fires. As a fully biodegradable and non-toxic liquid, MIVOLT makes recycling batteries easy, unlike the thermal pastes used in plate or pipe cooling systems.