Mitsubishi's electrical vehicles charge ahead
MITSUBISHI is continuing to strive towards producing more environmentally compatible vehicles by furthering its research into new battery technology and lightweight chassis.
According to the Business Wire news service, Mitsubishi in Japan, in collaboration with Japan Storage Battery Co, has developed a new low-cost, high-powered lithium ion battery for use in electric vehicles.
Compared to conventional lead-acid accumulator batteries, the new battery offers a significant increase in energy-storage capacity and power.
As a result, the battery enables an electric vehicle to travel over 250km without recharging.
The new lithium ion battery uses cheaper and more abundant manganese electrodes, rather than cobalt, which are found in conventional batteries.
The use of manganese enables mass-production of a high-power battery at a cost close to 40 percent less than the production of cobalt electrode batteries.
Starting late last year, the two companies began collaborating on the development of two types of lithium ion batteries: one for use in electric vehicles (EV) and the other for use in hybrid electric vehicles (HEV).
The lithium ion battery for the EV is more compact and has a higher energy storage capacity, compared to conventional EV batteries.
The Mitsubishi lithium ion battery has an energy capacity of 100 ampere-hours and weighs 15kg, compared to a regular lead-acid battery, which only has 60 ampere-hours and weighs 20kg.
The lithium ion battery designed for HEV produces more power while being significantly smaller.
HEV utilize both an electric motor and gasoline engine.
Therefore, a smaller battery is desired in order to reduce the total weight.
The HEV lithium battery can generate about 700 watts per kilogram compared to a regular lead-acid battery, which generates about 250 watts per kilogram.
To further improve the efficiency of EV, Mitsubishi has developed an aluminum frame chassis for electric cars that reduces the overall weight of the vehicle by about 35 percent over conventional steel monocoque construction.
Since the frame actually forms part of the outer chassis, the amount of material required to construct the vehicle body is reduced by 60 percent, lowering production costs.
The new frame also doubles the rigidity of the chassis and maximizes impact absorption, making the vehicle safer in the event of an accident.
Mitsubishi developed the frame jointly with a Mitsubishi Aluminum Co. subsidiary and is aiming to commercialize it for use in electric vehicles by 2000.
The company is also considering producing the frames for standard passenger cars.
Mitsubishi Motors has been a trailblazer in the EV/HEV field.
While the new batteries are ready to be applied in production models, the electric motors, generators and batteries required for EV and HEV result in substantial increases in vehicle weight, cost and demand for natural resources.
For this reason, Mitsubishi intends to limit manufacturing of these vehicles for use in specific areas such as factories, hospitals and some commercial purposes.
The Japanese carmaker plans to sell 2,000 vehicles equipped with the new batteries annually by 2000.
Emphasizing another major part of its pro-environment strategy, Mitsubishi Motors announced at the end of August that it produced over 100,000 passenger models powered by its revolutionary, environmentally friendly Gasoline Direct Injection (GDI) engine.
Mitsubishi believes that the GDI engine, with its superior resource conservation, economy and performance, will become the benchmark power engine for the 21st Century.