Mitsubishi Chemical Slashes Cobalt Content of Lithium Ion Batteries

January 24, 2010 by Jeff Shepard

Mitsubishi Chemical Corp. has developed a material for the positive electrode of lithium ion batteries that contains just one-third the normal amount of costly cobalt. The company will begin shipping samples this year with an eye on the potentially huge market of batteries for hybrid cars and electric vehicles.

The company is preparing a system for volume production of this new positive electrode material at two of its factories and intends to add capacity as demand for hybrid and electric cars grows.

In the case of electric vehicles, the battery module now accounts for roughly half of the overall cost of the car. Finding ways to reduce battery cost is thus considered key to the widespread adoption of electric vehicles.

The positive electrode is a core component of lithium ion batteries and a determining factor in the battery’s capacity to store charge. Most lithium ion batteries now use positive electrodes made from a mix of oxides of cobalt and magnesium.

There are also so-called "three element" electrode materials made from a mix of cobalt, magnesium and nickel. Mitsubishi Chemical already makes this type of electrode material with equal 33% amounts of the three elements. But now the company has succeeded in reducing the cobalt ratio to just 10% without a loss in electrode performance.