Monday, 31 December 2012

Building a Greener LEAF

The Japan-market Nissan LEAF
Dec. 11  – Yokohama - Nissan’s zero-emission LEAF electric vehicle just became even greener.
The latest version of the industry leader, introduced in Japan in November, has a new electric motor using 40% less of the rare-earth mineral dysprosium – without affecting performance.
“The driver will not notice any differences. Vehicle performance will remain unchanged,”  said Kiyoshi Takagi, deputy general manager in Nissan’s Materials Technology Planning Group.
“In fact, the overall performance increased, so drivers don’t need to worry.”
The rare-earth element dysprosium
Dysprosium is added to the LEAF’s electric-motor magnets to make them more resistant to heat as they spin at speeds of up to 10,000 rpm.
A new process called “grain boundary diffusion” allows Nissan to drastically cut rare-earth content in use a way that may extend beyond EVs and hybrids to use in other automotive applications.
Nissan's Takagi (left) and Murakami
“Dysprosium is used not only in the motor to power EVs, but also in components of existing internal combustion engines,” said Ryou Murakami, manager of Nissan’s Advanced Materials Laboratory.
Using less rare earth content is a goal of the Nissan Green Program 2016, part of a commitment to minimize use of scarce natural resources.
Cutting dysprosium in the LEAF also helps Nissan avoid supply constraints, with the large majority of the element mined in China, and lower costs as demand grows.
“Rare-earth metals, dysprosium in this case, are a scarce resource, which also impacts the environment during the mining process,” said Takagi. “Reducing the usage of such resources will reduce this impact.”
For a new generation of Nissan LEAF owners, greener production is already complementing zero-emission motoring.