GM Selects LG Chem To Build Volt Batteries

By Charles J. Murray
Design News
January 13, 2009

Amidst the fanfare of a standing-room-only press conference in Detroit today, General Motors rolled out the T-shaped lithium-ion battery pack for the Chevy Volt and announced its cells will be built by Korean battery manufacturer LG Chem.

The press conference capped off a two-year wait in which the giant automaker auditioned two manufacturing teams for the role of battery supplier for the highly anticipated Chevy Volt, widely considered to be the biggest vehicle program in GM’s history.

General Motors’ embattled chairman, Rick Wagoner, told a media audience the decision to go with LG Chem instead of Massachusetts-based A123 Systems “was based on performance, production readiness, efficiency, durability and LG Chem’s demonstrated track record of exceptional quality.”

The competition for the GM battery development and manufacturing contract has been highly scrutinized in technical circles because one team (LG Chem and Compact Power, Inc.) is using a manganese-spinel chemistry for the battery’s positive electrode, while the other (A123 and Continental Automotive) employs a nano-phosphate material. Many experts said the choice of the chemistry would be critical so that the battery wouldn’t be plagued by so-called “thermal runaway,” which had reportedly been a problem for some lithium-ion batteries used in laptops and cell phones.

GM, however, said safety was only one of many reasons for the choice of LG Chem’s manganese-spinel. “Safety was definitely an important part, but ultimately it was no more of a factor than durability, cost, performance or manufacturability,” GM spokesman Rob Peterson told Design News.

The plan announced yesterday calls for GM to use battery cells from LG Chem’s plant in Korea, then build the entire battery assembly in a GM plant located in southeast Michigan. The assembly includes such items as electronic controls, heating, cooling and cabling. GM said Compact Power would initially do the integration and assembly for Volt prototypes, but added GM would take over the assembly process once its own plant is up and running.

“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,” Peterson said.

Engineers at Compact Power cited two technical advantages inherent in their team’s battery design. The manganese-spinel chemistry combines with battery separator technology that enhances safety, they said. 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.

Also key to the company’s technology was its use of a “stack-and-fold” configuration in a laminated package, which could provide GM with easier manufacturability. The stack-and-fold concept is used as an alternative to the well-known cylindrical design of conventional batteries.

“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.”

GM representatives said yesterday its decision to go with LG Chem is part of a strategy that has been unfolding for months. “We’re really confident that we have the right plan and the right balance of technology suppliers,” Peterson said. “Right now, we don’t see any hurdles in our way for having the battery ready by 2010.”

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