Scientists of two leading Indian labs have jointly developed lightweight car batteries by replacing the lead with plastic. These storage batteries for which a patent has been filed in the United States will be a boon to electric cars of the future, the developers claim.
Currently used lead-acid car batteries - that make use of metallic lead or lead alloys - typically weigh about 20 kilograms. The new battery, delivering the same energy, will weigh only about 12 kg.
"Its development is the result of materials scientists at the Indian Institute of Science in Bangalore joining hands with electrochemists at the Central Electrochemical Research Institute in Karaikudi," says A K Shukla who led the research team. Shukla is director of CECRI and also does research at IISc.
The other team members are S.K. Martha and B. Hariprakash of IISc, D.C. Trivedi of CECRI, and S.A. Gafoor of NED Energy Limited, a Hyderabad-based company that will commercialise the new battery.
The scientists reduced the battery weight by using a special plastic and coating it with lead instead of fabricating the battery entirely using solid lead.
The "acrylonitrile butadiene styrene" polymer plastic used to make the battery "grids" is 75 per cent lighter than metallic lead, the scientists report.
Similar lightweight lead-acid batteries have also been developed abroad but Shukla says they have a problem. Their grids are not protected from corrosion in the acid medium and so their life is cut short.
In contrast, Shukla claims his battery grids are protected from corrosion by a layer of "polyaniline," that is electro-deposited on to the grids by using "a novel room-temperature process." This technology is covered by a US patent.
Prototype 6-volt batteries delivering 3.5-ampere current developed using this technology have been tested in laboratory. The scientists say they "meet the service requirements for fast charge-discharge duty cycles."
"The study is a major step forward in realising a low-cost lead acid battery with high specific energy," Shukla told PTI adding that electric carmakers are looking around for light weight batteries that are also cheap.
The nickel-metal hydride batteries currently used in electric cars are very expensive while plastic is cheap.
