Using its annual Advanced Technology Week in Japan as a high-tech show-and-tell session, Nissan provided several new insights about its plans for a greener and more efficient future. Highlights of the meeting involved presentations on prototype versions of the firm's upcoming hybrid and electric vehicle packages plus an inside look at the latest advances in its fuel cell program.
Nissan demonstrated its upcoming parallel hybrid system on an Infiniti G35, marking the firm's first application of a parallel gas/electric setup on a rear-drive platform. It employs two separate clutches -- one between the engine and the electric motor and a second between the motor and the rear drive wheels -- to optimize overall operating efficiency, depending on driving conditions. The motor is powered by a new lithium-ion (Li-ion) battery package that uses input from regenerative braking to supply on-the-fly recharging. Nissan's claims that its system, which eliminates the need for a conventional torque converter, improves overall responsiveness and provides for more linear acceleration. Like many other hybrid systems, it also incorporates a stop/start feature to deliver further improve mileage of the gasoline engine.
On the electric vehicle (EV) front, the automaker showed a prototype based on the Japan-market Nissan Cube, although it definitively noted the production EV that's headed to the U.S. starting in 2010 will be an all-new design that's not based on any existing Nissan platform. The lightweight, compact plug-in system fitted in the Cube matches a new 80kW (107-hp) electric motor and inverter with a variant of the space-efficient laminated Li-ion battery used in the hybrid system. Here, the batteries are installed under the vehicle's rear floor area to help optimize both passenger and cargo room. Nissan was equally quick to point out that this new laminated Li-ion battery design, which was developed as part of a joint venture with NEC, delivers twice the output of a conventional nickel metal-hydride cell but is safer, more reliable, more versatile and less expensive to produce.
Although still undergoing development, Nissan also displayed a new, next-generation fuel cell stack that's smaller and cheaper to manufacture but delivers double the power density and has a longer projected service life. One of the keys to the stack's reduced cost is a new electrode catalyst that requires only half as much platinum as previous designs. That alone is a huge advance, as platinum currently accounts for over half of the materials cost in today's average fuel cell. Improvements to the internal configuration headed by a better polymer electrolyte membrane helps boost output of this enhanced cell from 90kW to 130kW (121-hp to 174-hp) compared to the existing 2005-era stack. That extra capability will allow for potential applications on larger and heavier vehicles while offering enhanced range and more spirited performance when fitted in smaller, lighter ones.