OTHERS

Battery hybrid electric vehicle

CENTRE FOR Energy Research, SPIC Science Foundation, Chennai has developed and demonstrated a prototype fuel cell - battery hybrid electric vehicle, for the first time in India. This electric vehicle (ev) employs a hybrid power source, consisting of polymer electrolyte membrane (PEM) fuel cell stacks developed at this Centre and lead-acid batteries.

Electric vehicles generally employ different types of batteries as the power source. The battery powered electric vehicles have certain disadvantages, such as limited range and long refuelling/recharging time, due to the limitations of the currently available batteries. In order to over come these limitations, efforts are being made throughout the world to develop fuel cells for electrical vehicles propulsion.

Centre for Energy Research at SPIC Science Foundation has been working on development of PEM fuel cell stacks since 1989. Several multi kilowatt stacks have been developed and demonstrated. Some of the stacks developed at this Centre are also undergoing trials.

PEM fuel cell mainly consists of an anode and a cathode (electrodes) separated by an electrolyte. The electrodes contain noble metal catalysts in small quantities and the electrolyte is a proton conducting membrane such as NafionR. The reactant gases fed to the electrodes (hydrogen to the anode and oxygen/ air to cathode) combine electrochemically at the interface between the electrode and electrolyte producing electricity and water. Unlike a battery which has limiting charge - discharge cycle, fuel cells produce electricity as long as the reactant gases are supplied.

Scientists at the Centre have developed a hybrid power source integrating the fuel cell stacks and battery bank which have been installed in a four wheeler van. The electric motor's power requirement to run the vehicle is shared by the battery bank and the fuel cell stacks. A controller that has been developed enables sharing of the power between the two power sources and also has the facility to charge the battery from fuel cell power whenever the vehicle is stopped. Several safety features have also been incorporated. The fuel cell-battery hybrid van can seat 6 people. The hybrid vechile has recorded an increase of 40 per cent in the distance traveled on a single charge compared to the battery powered ev. Further improvements in fuel cell stack performance, reduction in weight, volume and cost of the stack are being carried out. These improvements are expected to enhance the ev performance further.

Joseph Thomas

Director,

Spic Science Foundation

Chennai-600032