Old disused tires can be utilised to help make batteries that last longer and also have long-term stability.

Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) believe that lithium-ion batteries, storing wind and solar energy and powering plug-in electric vehicles, could be developed at a lower cost, both financially and to the environment, by developing a better anode made from a substance found in recycled tires.

An anode is a negatively charged electrode used as a host for storing lithium during charging.

The substance, recovered from discarded tires, is carbon black.

Modifying its microstructural characteristics is the solution to developing a better anode, says the team led by Parans Paranthaman and Amit Naskar.

“This technology addresses the need to develop an inexpensive, environmentally benign carbon composite anode material with high-surface area, higher-rate capability and long-term stability,” Naskar said.

“Using waste tires for products such as energy storage is very attractive not only from the carbon materials recovery perspective but also for controlling environmental hazards caused by waste tire stock piles,” Paranthaman added.

Outlined in a paper published in the journal RSC Advances, the ORNL technique uses a proprietary pretreatment to recover pyrolytic carbon black material.

The material is similar to graphite but man-made.

The researchers produced a small, laboratory-scale battery with a reversible capacity that is higher than what is possible with commercial graphite materials.

After 100 cycles, the capacity measures nearly 390 milliamp hours per gram of carbon anode, exceeding the best properties of commercial graphite which researchers say is due to the unique microstructure of the carbon black material.

“This kind of performance is highly encouraging, especially in light of the fact that the global battery market for vehicles and military applications is approaching $78 billion and the materials market is expected to hit $11 billion in 2018,” Paranthaman commented.