Assembly Rooms, Bath (now the Museum of Costume)

This year, IPSS migrated from its traditional home in Brighton to the historic city of Bath, where the meeting was held in the Assembly Rooms built in the Georgian period in the typical stone of the region.

This meeting was the 25th IPSS and celebrated 50 years of the symposium. A wide range of subjects on power sources was covered: batteries (lead-acid, primary and secondary lithium and lithium thermal), fuel cells, solar cells, super-capacitors and applications (national power supplies, supplies for small islands, hybrid systems, military).

Lead-acid Batteries

Sessions covered battery design, chemistry, redox batteries and battery modelling. Thin plate batteries using high purity lead obtained high power, reduced weight, long cycle life, long storage life, good low temperature performance and good deep discharge recovery (Kurian, Enersys, Newport, South Wales). Chemical studies included the effect of surfactant additives (Ghavemi, Niru Battery, Teheran) and use of selenium as an additive to the plates (Tizpar, Niru Battery, Teheran). A new redox flow battery (Wills, Southampton University) used similar plates to the standard lead-acid battery but used an electrolyte of methane sulphonic acid in which lead is soluble. With this system there are no separate anode and cathode compartments and no separator is needed, which saves cost. A fundamental model of lead-acid batteries (Esfahanian, University of Teheran) used numerical analytical techniques to model lead-acid batteries. Catherino (U.S. Army) described his theory that thermal runaway of lead-acid batteries can be caused when overcharging has caused the electrolyte to dry out, increasing the internal resistance of the battery. Pulse charging of lead-acid batteries improved cycle life, which can be important when these batteries are used with photo-voltaic power sources (Karoui, Laboratoire Systems Solaire, INES, France).

Lithium Batteries

Primary, secondary and thermal batteries were covered. Both British (Eweka, QinetiQ, Haslar) and American (Nagasubramanian, Sandia, Albuquerque) researchers had made batteries using the lithium/carbon monofluoride (Li/CFx) technology. Eweka had made a battery in the BA5590 format and Nagasubramanian had investigated electrolytes for low temperature batteries. Wang (Ultralife, Newark, U.S.) described improvements to a D-size lithium/manganese dioxide (Li/MnO2) cell, which increased its capacity to 14Ah. A new cathode material, nano-sized lithium nickel manganese oxide, had been synthesised by Markovsky (Bar-Ilan University, Ramat-Gan, Israel) for lithium-ion batteries. Ritchie (IPSS) described new applications for lithium-ion batteries, such as for power tools and hybrid vehicles. The lithium iron phosphate cathode material, described in previous symposia, now seems to be finding applications. A new type of lithium thermal battery was described by Dekel (Rafael, Haifa, Israel) which has no cathode but, instead uses iron oxide (FeO) from the burnt heat pellet (Fe/KClO4) as a cathode material. Fast activation and reduced battery size were achieved.

Battery Standards and Regulations

Cloke described new European Union regulations concerning labelling and recycling of nickel-cadmium batteries.

Large Scale Power Supplies

Sharman (U.K. Department of Trade and Industry) presented the Bourner lecture on power supplies for this century. Climatic changes (global warming), security of supply, ageing infrastructure and declining supplies of oil were all important considerations. Local energy generation and renewable energy are developing but lack of efficient large scale storage of energy remains a problem. Benton discussed power supplies for small islands, without mains electricity. Renewable sources included biomass, wind, photovoltaic and tidal. Pumped storage could be a means of energy storage.

Other Power Sources and Integration of Hybrid Systems

Salkind described asymmetric electrodes for super-capacitors. Photo-voltaics are a power source but batteries and/or super-capacitors are needed (Kan, Delft University of Technology, Netherlands). A solar-powered computer mouse was also described by Kan, but this too needed a battery. Human power can generate small amounts of electricity (Jansen, Delft University of Technology, Netherlands). Flipsen (Delft University of Technology, Netherlands) had tried to replace the battery in an MP3 player, but this resulted in an increase in size. Conte (Arsenal Research, Vienna) had modelled a hybrid electric vehicle using nickel - metal hydride batteries, as he considered lithium - ion to be insufficiently advanced. A new type of solar cell used polymer electrolytes (Bong Wong, Chonbuk University, Jeonju, South Korea).

Fuel Cells

Various types of fuel cells were described. Nabae (St Andrews, Scotland) had developed a carbon-air fuel cell which used both molten carbonate and solid oxide electrolytes. Borohydride fuel cells (Coowar, QinetiQ, Haslar) produce hydrogen by reaction with water and operate at a higher voltage than ordinary hydrogen fuel cells. New metal electrodes, to replace bulky carbon ones in fuel cells, were described in Northwood’s paper (University of Windsor, Ontario, Canada). Conrad (CMR Fuel Cells, Harston, England) had developed a new type of methanol fuel cell in which different catalysts were used on each electrode, avoiding the need to separate the anode and cathode gas flows, thus reducing the size of the cell.

Military

British, American and Canadian presenters described the power needs of their respective armed forces. British forces were heavy users of rechargeable batteries but this leads to logistic problems of charging batteries in the field. High temperatures were a problem for lithium-ion batteries. Primary batteries also suffered this problem (Browning, DSTL Porton Down, England). Possible future developments include: lithium /carbon monofluoride, lithium/ iron disulphide (to replace zinc alkaline) and carbon/air fuel cells. The U.S. Army is finding power to be a significant problem (Patil, U.S. Army, CERDEC) with bat-tery charging being difficult on active service. They are interested in the same improved primary batteries as the U.K., including methanol and borohydride fuel cells.

Solar cells may be useful for battery charging. Other power sources are: fuel cells, photocells, hybrid vehicles (Lakeman, DSTL Porton Down, England). Andrukaitis (Defence R & D, Ottawa) was interested in a power harness for the Canadian forces, to avoid soldiers having to carry large numbers of battery packs to power each item of equipment individually. Erbacher (U.S. Air Force, Wright Patterson Air Force Base) evaluated the economics of different chemistries for aircraft main batteries (lead-acid, nickel-cadmium, nickel-metal hydride and lithium-ion). All were now considered to be technically viable, so cost was an issue.

Symposium DVD

The proceedings of the symposium are being issued on a DVD, rather than in a book, as on previous occasions. This includes texts of the papers, slides of the presentations and audio versions of the presentations. It is available from the IPSS (www.ipss.org.uk).

Booth Awards were presented by Michael Booth, son of Frank Booth, the founder of the IPSS, to Michel Broussely (SAFT, France) for a lifetime of research on lithium batteries, posthumously to the late Alex Gilmour for distinguished work in battery research and development and to Bob Bailey, for long service to the IPSS.

Michel Broussely had a long career in batteries. After graduating from the University of Poitiers, he moved to the SAFT research laboratories in the appropriately named Rue Leclanché where he spent his working life on research and development of lithium primary and secondary batteries. He is now scientific director of SAFT’s speciality battery division. He has published numerous papers, including publications at IPSS, over a long period.

Alex Gilmour had a working life of over 40 years in batteries, both in the U.K. and the U.S. His interests included all aspects of batteries, from the chemistry of battery materials to battery design and construction. He was highly innovative chemically and he patented new cathode materials for lithium-ion batteries (metal oxide/ sulphite cathodes), new polymer electrolytes and new electrode materials for super-capacitors (pyrolysed nitrogen-containing polymers with sulphites). His engineering skills enabled him to develop the rectangular PP3 battery and to make prototype lithium-ion and lithium primary cells in envelope (‘pouch’) cell construction. Much of his work has been reported at the IPSS.

Bob Bailey took over as secretary of the IPSS in 1993, to succeed the late Sheila Bourner. He brought financial expertise to the symposium and successfully oversaw the transition of the IPSS to become an educational charity. He developed the symposium by adding an exhibition and introduced a theme for each symposium. He also arranged global watch missions for the IPSS on behalf of the Ministry of Trade and Industry to the USA. He is now retiring from the symposium after 14 years.

Various battery companies, several pictured here, had stands to exhibit their products at IPSS.