Bob Kruse is GM’s executive director of global vehicle engineering for hybrids, electric vehicles, and batteries. There is a report of a new interview with him. Bob is an executive integrally involved in producing the Volt and other future electric cars.
He discussed the current status of lithium-ion battery technology. He described the process of evaluating cells for the Volt ant noted "We selected LG as the cell source for Gen-one Volt; and we are also very intrigued and attracted to some of what A123 has to offer and are continuing to do advanced development with A123 for future applications – just not Gen-one Volt."
He talked about GM's recent battery pack announcement saying "We decided this battery pack business was really core to being in the electric vehicle market. So part of our [January 12] announcement was that, in addition to announcing LG as the cell source, that GM is also moving to design internally, and engineer internally, and validate internally, and ultimately manufacture internally the battery packs."
He admitted the packs are expensive but wouldn't say how much or whether they are more than $10,000. He explained how GM is working hard to push future battery costs down noting "in addition to the Gen-one battery system, I’m right now also working on Gen-two and Gen-three solutions that have elements of both performance and cost that are part of my expectations of my team to deliver future-gen systems."
Kruse responded to a question about thermal runaway/safety concerns of lithium-ion cells. He said "There are many layers of safety built into the Volt," including "all the way down to the cell level." He noted the importance of the prismatic cell shape and the use of LG Chem's proprietary anode/cathode separator in that regard. He said GM employed stringent safety testing standards and confirms "I can assure you we’ve met those standards with what we’ve designed and what we’ve selected."
He admitted it woudl be important to have a US-based cell supplier, saying " If and when there is a lithium-ion cell manufacturing footprint in the US, they will come onto our radar and get appropriate consideration." But he acknowledges that foreign sources such as LG Chem were the only ones up to speed at this point.
He explained GM's strategy to ensure the batteries will last 10 years or 100,000 miles citing proprietary GM intellectual property around battery management describing the process as "I have more battery capacity than I’m using. There’s a sweet spot in there. I won’t over charge the battery, or over discharge the battery."
He discussed risks of battery failure, noting how critical it is to have "pharmaceutical" grade battery purity. He explained that if even one cell falters it could strain the other cells in the pack, potentially degrading them. The solution to prevent this he explained as "part of what I have designed into the pack is a very sophisticated cell balancing capability, so that as the pack ages, the individual cells age. I will adapt the cells to the pack, constantly rebalancing my pack…. The software and hardware, the algorithm that does that, and how we do that, is also highly prized intellectual property.
Source ( Christan Science Monitor )