The Industrial Technology Research Institute (ITRI) of Taiwan is coming out with something that may keep you from being consumed in a fireball.
The organization has developed an internal component for lithium-ion batteries called Stoba that shuts down the battery once the internal temperature passes a critical threshold, which in turn prevents a thermal runaway reaction (i.e., a fire) from occurring.
"It is just like a thermal fuse in a battery," said Dr. Alex Peng, the deputy general director at ITRI, who was in California this week. "It is a new mechanism to ensure the battery is safer."
Notebooks and cell phones equipped with Stoba-equipped batteries may come out in the first quarter of next year. The group is now working on tweaking the technology for batteries for electric cars and plug-in hybrids.
Stoba essentially is a temperature-sensitive film that goes from being a Swiss cheese to a barrier. Under normal conditions, a standard lithium-ion cobalt battery may operate at 50 degrees Celsius. At that temperature, Stoba is porous, allowing lithium ions to pass freely.
If, however, an internal short exists, the temperature in a battery can climb rapidly. At 130 degrees Celsius, the material degrades, the pores close and lithium ions no longer freely sling shot inside the cell. The change in the film is irreversible – the battery won't work again – but at least no fire occurred.
The technology in a sense is a counterpart to the work conducted by Tesla Motors in developing its battery pack. Tesla builds its batteries out of standard lithium cobalt cells, but wires them, and arranges them, in such a way that they can be isolated from each other in the event of a thermal reaction.
The initial target market lay in lithium-cobalt batteries, where the problems with lithium batteries have occurred. The film reduces power by 1 percent or so, so consumers don't notice he said.
The car market will come later. Most car manufacturers are looking at lithium phosphate and, more often, lithium-manganese batteries. The potential for runaway thermal reactions with these batteries exists, but remains lowers, although lithium-phosphate batteries also have a lower power density as a result.
The slight reduction in power caused by the film will also have to be fixed. Conceivably, if ITRI could fix the problem, auto makers could adopt lithium cobalts. Tesla, so far, is the only manufacturer to adopt lithium-cobalt batteries and it is already examining other chemistries. Others such as Nissan have adopted different chemistries (lithium polymer for Nissan) or said privately that they won't adopt cobalt.
"We need to modify it to minimize the power effect," he said.