Old tires may find their way back to cars – in their batteries
By Ben Coxworth
August 28, 2014
There may soon be a new use for discarded tires ... besides turning them into mattresses for cows, that is. Researchers from the US Department of Energy’s Oak Ridge National Laboratory have devised a method of harvesting the carbon black from them, and using it to make anodes for better-performing lithium-ion batteries.
The process was developed by a team led by Oak Ridge scientists Parans Paranthaman and Amit Naskar. It involves pretreating the tires and then using pyrolysis – the decomposition of organic materials by heat in the absence of oxygen – to recover pyrolytic carbon black material from the rubber.
Carbon black is similar to the graphite commonly used in battery anodes, although unlike graphite, it’s man-made.
When a lithium-ion battery with one of the carbon black anodes was tested in the lab, it was found to have a higher energy capacity than similar batteries with regular graphite anodes. This quality was attributed at least partly to the porous microstructure of the carbon black, which offers more surface area than that of graphite.
The Oak Ridge team is now working on a pilot project to scale up the process, with an eye towards ultimately licensing the technology to an industrial partner. Once the technique is commercialized, it is estimated that batteries made using it will actually be cheaper than conventional lithium-ions ... plus, of course, the tires will be diverted from sitting in a landfill.
A paper on the research was recently published in the journal RSC Advances.
Source: Oak Ridge National Laboratory