The aim of the RED-LION project – which was part-funded by the Department for Transport under the Energy Saving Trust’s Low Carbon R&D program – was to develop an alternative Li-ion cell chemistry that could be integrated within an HEV using a bespoke battery management system.
Following project completion, the partners have announced that a battery pack using the innovative QinetiQ iron sulfide-based cell chemistry and an advanced battery management system from Ricardo, has demonstrated significant cost and weight reductions compared with the reference Efficient-C full hybrid vehicle.
The RED-LION project set out to replace the battery pack used in the Efficient-C prototype HEV with one using new cells demonstrating suitable material cycle life, capacity, specific energy, rate capability, and safety. Custom cells were manufactured and packaged within a bespoke battery pack incorporating many novel features. Ricardo designed the overall battery pack to directly replace the existing unit, developing a new battery management system to manage the iron sulfide chemistry.
The prototype cells, designed and manufactured by QinetiQ, have been shown to deliver a cycle life of over 1000 cycles at a limited depth of discharge. The high charge/discharge rate capability shown by the particular cell design would make it suited to both HEVs and plug-in hybrid electric vehicles (PHEVs). Comparing the performance of the prototype high-rate cells with the original cells from the Efficient-C HEV, a 20% weight reduction (on a Wh/kg basis) was achieved.
QinetiQ believes that significant cost savings are possible in comparison with current commercial production Li-Ion chemistries, through cheaper raw materials and a more energy efficient, patented manufacturing process.
Another key innovation of the RED-LION project is the new battery management system, developed by Ricardo based on a bespoke architecture, which is fully adaptable to a range of cell chemistries and battery architectures. Ricardo has fully integrated its system into a battery pack containing the QinetiQ cells.
‘One of the most exciting aspects of this new lithium-ion cell chemistry is its flexibility, being customizable for both high-power and high-capacity applications,’ says Mark Roberts, Strategic Market Team Director for Energy & Environment at QinetiQ.
‘Not only could this improve performance in existing HEVs through reduced cell size and weight, but also make all-electric vehicles a more credible proposition, by increasing range,' continues Roberts. 'And because iron sulfide-based cell chemistry is cheaper to produce than traditional cobalt cells, lower production costs could make hybrid and all-electric vehicles more affordable in the future.’