The aim is to demonstrate the performance of, and develop manufacturing processes for, an advanced sodium-nickel chloride battery cell with a capacity 200 Wh/kg and power rating 200-300 W/kg, capable of mass production at a cost of $550/kWh by 2015, and ultimately at a cost of $130/kWh. This represents an increase of more than 50% in capacity and power over the state-of-the-art 'Zebra' battery cell that has a good safety record in EVs but is complex and costly to manufacture; the tubular solid electrolyte results in performance limitations due to the high cathode resistance especially at low state of charge, and is operated vertically which is inconvenient for EVs due to the 28 cm height requirement.
We propose a novel slim-line battery cell concept incorporating a thin layer cathode, a flat solid electrolyte manufactured by plastic forming, and a novel hermetic sealing method. The number of cell components + weld operations is thereby reduced from 20 to 10. A composite glass-ceramic-metal seal replaces the Zebra cell's complex and costly header cap. Long cell life is promoted by the use of 2 different glass seals which are corrosion-resistant to the respective electrode materials. The slim-line cell is flexible for battery stacking and can result in an EV battery height of less than 12 cm. Enhanced performance projections have been verified by cathode modelling studies. Raw materials are abundant and low-cost, except for nickel for which the cell requires only 1.5 g/Wh (cf. 6.8 g/Wh in nickel metall hydride cells). No handling of liquid sodium is required since cells are manufactured in the discharged state.
85,264
2008-10-01 to 2011-12-31
Collaborative R&D
The goal of the NASTRAC project is to manufacture bulk advanced ceramic components with significantly enhanced properties delivered via a retained nanostructure. This will be demonstrated during the project at a pilot-scale level. Uniquely, the goal will be achieved using largely conventional processing routes (for example, powder suspension optimisation, atomisation to form a granulate and then pressing / sintering). The partners aim to realise a combined increase in sales of £5-10M over 5 years from project end. Advanced ceramic components, currently worth £17B worldwide, play an enabling role across many sectors. The NASTRAC project will focus on 2 case studies (zirconia inserts for valves and barium titanate capacitors), with inputs along the supply chain. Work will involve applying patented technology to create high solids content suspensions. Following conventional shaping, novel firing schedules (including microwave-assisted firing) will be used to ensure the nanostructure is retained. The final components will be assessed using in-field testing and / or appropriate in-service tests.