Originally, work on sodium (salt) battery technology was focused on sodium sulphur only.
All started with Sodium Sulphur
In the early 1970s four British organisations were each involved in advanced battery development, British Rail, the Research Establishment (AERE) of the UK Atomic Energy Authority, Chloride (then one of the world’s top three battery manufacturers) and the U.K. Electricity Council.
In 1975, with UK Government encouragement, these pooled resources to establish Chloride Silent Power Ltd., a joint venture between Chloride and the Electricity Council (which, together with the Central Electricity Generating Board, co-ordinated all British electric power supply).
Progress was promising, including a 5-year development contract with the US Department of Energy.
But, with the privatisation of British electric power generation and the consequent disbandment of the national Electricity Council, UK official support was withdrawn and in 1992 the company, renamed Silent Power, was sold to the German electric utilities company RWE.
In May 1996 RWE closed Silent Power and auctioned most of the assets.
However, core members of the team in a management buyout acquired some key assets and established a new British company, Ionotec Ltd., which survives as an independent specialist in aspects of the technology, especially ceramics. This and an earlier Beta R&D Ltd. buyout (see below) maintained the development momentum which had built up and ensured that today’s batteries contain a significant British element.
Sodium Metal Chloride
A separate salt battery development – with a sodium metal chloride cell instead of sodium sulphur as hitherto – had its roots in South Africa in the mid-1970s, with the emergence of the ZEBRA battery by the ZEolite Battery Research Africa group (hence the name ZEBRA, later Zero Emission Battery Research Activity), led by Dr. Johan Coetzer at the South African Council for Scientific and Industrial Research (CSIR) in Pretoria.
This team working with AERE (Harwell) in the UK discreetly procured some of British Rail’s (BR) beta alumina tubes and sodium sulphur cell components and used them to research the ZEBRA technology.
In 1981 when BR closed down its battery operation, key members of the BR team bought this out and established a new company, Beta R&D Ltd.
On 4th January 1982, 4 days after Beta R&D started operating, they hosted a meeting with Johan Coetzer and the ZEBRA team together with their financial sponsors, Anglo American Corp. (AAC). The visitors convinced the Beta team, who believed firmly in the sulphur technology, to accept that there was virtue in the new ZEBRA type of battery.
It was the beginning of close collaboration, which soon led to Beta R&D being incorporated into AAC’s rapidly developing new ZEBRA Power Systems firm.
In 1989 the battery was ready for industrialisation and AAC formed AEG Anglo Batteries (AABG), a joint venture company with the German AEG; the later company was soon absorbed into Daimler Benz, but retained the name. Production lines were set up in Berlin, Ulm and Derby, UK with research continuing in separate facilities at Beta, AERE Harwell and Daimler Benz. The joint venture company went on to put pilot vehicles on the road – by 1997 the 80 ZEBRA-powered test vehicles had completed 1.6 million km (Daimlers and BMWs) – both intended for the Californian market, where in 1990 the Californian Air Resources Board had adopted a zero emission vehicle regulation which required that by 1998 2% of vehicles produced by large auto manufacturers for sale in California would have to be zero-emission-vehicles (ZEVs), progressing to 10% in 2003.
But then, in 1998, came a body blow: in a dramatic development which sucked the life out of the AEG Anglo Batteries (AABG) joint venture company, California stepped back from this mandate and withdrew the 2% ZEV immediate requirement. This released Daimler and BMW from the need to introduce their electric vehicles at once. Both redirected their focus away from electric vehicles.
Deprived of the expected Daimler and BMW production orders, AABG failed to find a company to rescue it and was facing the end of the road, when a deus ex machina in the form of the industrialist Carlo Bianco appeared from nowhere and took over the entire AABG company assets and Beta R & D Ltd., transferring them in a grand gesture to his facility in Stabio, Canton Ticino, Southern Switzerland.
This company, MES-DEA, built up a considerable ZEBRA battery production capability but concentrated on small series and individual conversions of vehicles.
It was sold in 2010 to the Italian FIAMM, whose subsidiary FZSoNick continues to produce and market a modified ZEBRA.
By then, a new Salt Battery era had dawned: the Production Director at MES-DEA,
Dr. C.-H. Dustmann, had left in 2007 and in 2008 established his own company, Battery Consult, to build on the experience he had gained over his many years of close involvement with the development and industrialisation of the ZEBRA technology, and to bring it also to embrace stationary applications, not only automotive, as until then.
During the first two years Battery Consult performed consulting tasks such as the layout and planning of a SaltBattery production project, application studies for an electric ferry boat, an EV charging station, an elevator system and battery cooling.
End of 2010 a technology transfer agreement with FPTI (Itaipu Technological Park Foundation, part of the hydropower generating company Itaipu Binacional) in Brazil was signed and enabled the installation of the laboratory in Meiringen, Canton Berne, Switzerland.
During the following years several SaltBattery cell types were developed and tested. Special attention was always paid to the cost-effectiveness of the production processes and the required equipment. This led to the development and testing of different cells such as the 50 Ah cell for a 30 kWh bus battery or a 23 Ah Flat Plate Cell for high voltage solar powered home battery installations. Recently a High Energy Cell and a High Power Cell were designed and are in the prototype stage.
These activities enable BC to select the best suited cell type for any application as long as it has stored energy of more than 5 kWh.
The above text is a condensed outline of the complex series of developments that led to the sodium metal battery of today.
More detailed information on aspects of the story can be found in the Literature Section of this website, especially in the following articles:
Out of Africa, the Story of the Zebra Battery, article by Johan Coetzer and Jim Sudworth, 2000, Courtesy of Johan Coetzer and Jim Sudworth