GM to use "stack and fold" manganese-spinel chemistry for Volt's batteries

At a pres conference on January 13th 2009, General Motors revealed the T-shaped lithium-ion battery pack for its new Chevy Volt and announced the battery cells will be built by Korean battery manufacturer LG Chem – who will be using a manganese-spinel chemistry for the battery’s positive electrode.

GM will use battery cells from LG Chem’s plant in Korea, then build the entire battery assembly in a Michigan based GM plant. “We’ll start preparing the factory in early 2009 and we will start loading the (manufacturing) equipment into the factory at mid-year of 2009,” says GM spokesman Rob Peterson.

The manganese-spinel chemistry combines with battery separator technology that enhances safety. Known as a Proprietary Safety Reinforced Separator, the semi-permeable membrane is coated with a ceramic material, which is said to make it mechanically and thermally superior to other separators.

A “stack-and-fold” configuration (as opposed to the common cylindrical design) in a laminated package will be used to make the batter easier to manufacture. “Stack-and-fold is easier for a large electrode manufacturer,” said Mohamed Alamgir, director of research for Compact Power, Inc. “Winding them around a mandrel would be no trivial task.”

“Right now, we don’t see any hurdles in our way for having the battery ready by 2010.” GM representatives said.