"What we do in this department is take material from discovery through pubescence and teenage years, exercise it and then take it to death and see what changed," said Ira Bloom, chemist and lab manager for the testing facility.
Once the batteries are put out of their misery, scientists conduct an autopsy in the Post-Test Facility. Lithium reacts with air and moisture, so the whole procedure is done in sealed glove boxes filled with inert gases, using tools like saws and ceramic scissors to prevent short circuits in what Bloom described as "a very inelegant process."
After cutting open the batteries, the researchers analyze what happened to the electrolytes, the cathodes, the anodes and other components. Using Raman spectroscopy, an X-ray photoelectron spectrometer, a gas chromatograph, a scanning electron microscope and a thermogravimetric analyzer, they can find out what happened to the battery as it grew old, what compounds it gave off, how its structure changed and what parts wore out. The team can then determine what led to the observed results and figure out ways to control these factors.
Bloom found that batteries are most significantly affected by temperature, followed by how intensely they are charged and discharged. Lithium-ion cells in particular don't like to sit idle, which can shorten their lifespans.
With information like this, battery and automobile manufacturers can figure out how to set up a warranty for their energy storage systems, while getting a handle on the limits of the technology in terms of performance and safety. "Right now, they're shooting for a 15-year life of the battery," Bloom said.
The facility's capacity is expected to double to cope with a large backlog of test materials, according to Bloom. The process is incremental, and he expects it will be five to 10 years before some of these designs hit the market. "It's been more of an evolution than a revolution," he said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500