Although the vehicle that Lutz drove is still very much an engineering mule, the battery pack installed in the electric car was a lithium ion unit which has already been tested in the lab. Apparently, this first test-pack was delivered back in April, which marks a bit of a watershed moment in the development of the Volt. It's way too early in the development of the E-Flex platform to get your checkbooks out, as Lutz clearly states, but actual moving prototypes powered by lithium ion batteries is an important milestone. Read the official blog posting by the man himself here.
[Source: GM Fastlane Blog]