Nissan has unveiled its latest all-electric car prototype, a model based on a new lithium ion battery manufactured by a joint venture it formed with NEC.
Automotive Energy Supply Corp. (AESC) began operations in May this year and plans to invest ¥12 billion (US$110.8 million) over the next three years to build a lithium ion battery manufacturing plant in Japan. Nissan holds a 51 percent stake in the company with the remainder held by NEC and its affiliated company, NEC Tokin.
Better known as the energy source of choice for most laptop computers, cell phones and other portable electronic gadgets, lithium ion batteries are now being eyed by the automotive industry for use in vehicles.
AESC will produce batteries for electric vehicles including Nissan’s planned models. Nissan has committed to launch its first all-electric car in the U.S. and Japan in 2010 and to mass market the vehicle globally by 2012.
The latest electric vehicle prototype is a version of the “Cube” model that Nissan sells in Japan modified to carry three lithium ion batteries under the floor and an 80kW motor and inverter.
In a test drive at Nissan’s research and development center in Yokosuka near Tokyo, the car’s motor exhibited a high torque that gave a kick when I pressed hard down on the accelerator. On the test track it easily got up to a speed of 100 kilometers per hour.
Nissan said the acceleration is roughly that of a 3.5-liter gasoline engine and cruising performance is around that of a 1.8 liter engine.
Nissan has been developing lithium ion battery technology since 1992 and its latest models are based on a laminated design, said Hideaki Horie, leader of Nissan’s next generation battery group. Batteries used in Nissan prototypes between around 1995 and 2002 were cylindrical, but that meant the entire cell would sometimes need to be redesigned if engineers needed to make the batteries just a few millimeters thinner.
Now Nissan is experimenting with laminated cells that are stacked on top of each other inside batteries. If the dimensions of the battery need to be changed its easy to add or remove a few of the cells, which are just a few millimeters thick. The laminated batteries also run cooler so they are much less likely to overheat.
The latest battery, which uses the laminated cells and is employed in the test car, delivers about twice the capacity of Nissan’s previous model and has been slimmed down by one quarter.