A project led by battery manufacturer Axeon, involving partners Ricardo and Allied Vehicles, and co-funded by the Technology Strategy Board, has successfully demonstrated a new type of lithium-ion battery for use in electric vehicles.
The new battery uses nickel-cobalt-manganese (NCM) cathode electrochemistry and offers a 35 per cent. improvement in range compared to existing technologies, for the same installed battery-pack mass.
Axeon-Ricardo assembled prototype battery-pack.
Nickel-cobalt-manganese (NCM) electrochemistry theoretically requires 50 per cent. less volume and 30 per cent. less mass when compared to the currently-conventional lithium-iron-phosphate chemistry, at cell level. A key goal of the project was to confirm that these cell-level benefits pass through to the battery-pack level when taking into account overall packaging, cell retention, cooling and interconnection, the battery management system (BMS) components and overall system functionality.
The project included subjecting a prototype battery to automotive environmental validation testing. Axeon and its partners, Ricardo and Allied Vehicles, have now built a functioning battery-pack that has been fitted to a test vehicle, and its range, driveability and performance have indeed improved. The project has confirmed that it is feasible to replace lithium-iron-phosphate cathode chemistry with NCM, and that the majority of cell-level benefits translate to improvements at battery-pack level.
The demonstrator pack uses NCM ‘pouch’ (‘coffee-bag’) cells — a relatively new technology for electric vehicles. These have been packaged in modules which support a range of thermal mamagement options, and also allow Axeon to support rapid prototyping into a range of vehicle types with short development lead times.
An added benefit of the new system was better drivability.
The new battery-pack incorporates a battery management system developed by Ricardo. This works with multiple cell chemistries, has active cell-balancing, and delivers diagnostic and prognostic information to the vehicle control system.
The project partners are now in discussions on commercialisation of the new technologies.
In 2009, the Technology Strategy Board awarded over £680,000 of funding to the consortium led by Axeon, bringing the total project funding to over £1.3m, with the aim of developing an innovative high-energy-density battery system for an electric vehicle.