London: Scientists are developing high-performance energy storage units for more effective and powerful hybrid vehicles that combine the best of combustion engines and electric motors.

Hybrid vehicles are powered by petroleum on the highway and by electricity in town, saving considerably energy. A hybrid propulsion system stores energy released by braking in a battery.

The electric motor uses this current during the start-up, yielding tremendous savings, particularly in urban traffic. But hybrid technology has always been plagued by the energy storage problem.

Scientists from three Fraunhofer institutes are developing new storage modules in a project called Electromobility Fleet Test. The pilot project was launched by Volkswagen and Germany's federal ministry for environment BMU with seven other partners.

Fraunhofer institutes will be pooling their expertise for the next three years. The researchers are developing an energy storage module based on lithium-polymer accumulator technology that is suitable for use in vehicles.

"This module has to be able to withstand the harsh environmental conditions it will encounter in a hybrid vehicle, and above all it must guarantee high operational reliability and a long service life," stated Gerold Neumann, who coordinates Fraunhofer activities.

The researchers hope to reach this goal with new electrode materials that are kinder to the environment. A specially developed battery management system makes the energy storage device more durable and reliable.

The experts are also researching new concepts that will enable large amounts of energy to be stored in a small space. To do this, they integrate mechanical and electrical components in a single module, devising systems for temperature control, performance data registration and high-voltage safety. IANS