Sumitomo Electric has developed what is being called the world's first automobile powered by a superconducting motor. The electric passenger sedan (a modified Toyota Crown Comfort), which is powered by a high-temperature superconducting motor cooled by liquid nitrogen, was unveiled in Osaka on June 12 and will go on display at the Hokkaido Toyako G8 Summit on June 19.

Superconductors -- energy-efficient materials that can carry electrical current without resistance -- are used in applications ranging from medical devices to linear motors for trains. Until now, however, they have never been used to power an automobile, says Sumitomo, who developed an ultra-powerful 365-kw superconducting motor last year.

Sumitomo's motor uses high-temperature superconducting wires instead of the copper wire typically used in the coils in electric vehicle motors. When cooled to -200 degrees Celsius, electrical resistance and current loss are reduced to nearly zero, so the motor can operate with greater energy efficiency and torque -- in other words, the motor uses less electricity to do the same amount of work. The company says the prototype vehicle can travel more than 10% farther than conventional electric vehicles running on the same type of battery.

The development comes as demand for electric vehicles grows, and as manufacturers step up efforts to improve battery and motor performance to increase the distance that vehicles can travel on a single charge.

Sumitomo intends to further improve the motor with the aim of putting a vehicle on the market in the not-too-distant future. The company is looking to develop superconductor motors for buses and trucks as well.

[Sources: Nikkei, Yomiuri]