Hamburg - Researchers have recently made rapid progress in battery drive systems fuelling hopes that clean-drive, electric vehicles will soon be an everyday reality. Several car makers have presented electrically-driven concept cars at this year's big car shows, offering a range thought impossible only a few years ago.
Conventional combustion engines produce mainly heat and use only a small part of their energy to actually move the vehicle, emitting pollutants such as carbon dioxide which has led eco-activists to lambast the motor car as a "climate killer".
Electric drive as used in trains with overhead cables has an energy efficiency of almost 100 per cent, transferring energy directly.
But all attempts in the past at using electric-drive technology in cars failed because of poor battery capacity and weight which produced a range of hardly 50 kilometres.
Volkswagen has now claimed "a clean drive revolution" by presenting the four-seater Space Up! blue concept car at the Los Angeles Motor Show fitted with the world's first, new high- temperature fuel cell (HT-FC) together with an array of 12 lithium- ion batteries.
When driven exclusively by battery the vehicle has a range of 100 kilometres. The range is extended by another 350 kilometres when energy is "refuelled" via an electric outlet or by the high temperature cell.
Honda also unveiled in Los Angeles its zero-emission FCX Clarity which is to be delivered to a limited number of people in southern California in 2008.
Hydrogen in a tank combines with atmospheric oxygen in the fuel cell stack where energy is converted into electric power to propel the vehicle.
Honda puts the top speed at 160 km/h with a range of 430 kilometres with the lithium-ion battery pack some 40 per cent lighter and 50 per cent smaller than the current generation available. Each car costs hundreds of thousands of dollars and will be leased only to individual clients.
The high cost remains one of the big obstacles to the lithium-ion battery technology, currently estimated at around 1,500 dollars per kilowatt hour. Toyota also postponed the market launch of the lithium-ion battery driven Prius hybrid to a period after 2010 because of overheating and safety concerns.
But lithium-ion batteries are already widely used in laptops and cell phones. However, using them in vehicles requires more power and the elimination of all safety concerns such as overheating.
Volkswagen's Dr Juergen Leohold, head of the company's research department, however believes that the high performance lithium-ion battery "is a key technology" to clean energy drive of the future.
Volkswagen is part of an alliance of German companies that is racing against their Japanese competitors to perfect lithium-ion batteries. The companies including BASF, Bosch, Li-Tec and the Federal Ministry of Education and Development are investing 360 million euros (529 million dollars) in the project aimed at accelerating the lithium-ion for mass production.
Mass production would lower costs substantially. At current electricity prices, a distance of 100 kilometres would only cost a fraction of a comparable petrol or diesel-driven car.
Researchers are also confident of solving the overheating problem. The eastern German battery manufacturer Li-Tec says it is working on flexible ceramic "separator" membranes that can withstand heat of 450 degrees Celsius, replacing the aluminium foils currently used that are prone to melting at temperatures of around 140 degrees Celsius.
