By Sean Jendry
I often joke with colleagues about the awkward pause when meeting someone new and they ask, “What do you do?” and your answer is “asphalt.”
Most people don’t think much of asphalt outside of roads, so I typically like to mention alternatives to paving like roofing and sound or waterproofing. Or a great conversation starter nowadays is the recyclability of asphalt. Recently, I think I have discovered a new response; batteries. That’s right, asphalt in batteries.
In the rechargeable battery space, the most common are lithium-ion batteries (LIBs). Most portable electronics and most electric vehicles use LIBs. These batteries typically use graphite as the material to allow current to flow into the device from an external circuit (also known as an anode material).
Unfortunately, these graphite-based LIBs are subject to long charge times but surprisingly, asphalt could be a solution to this problem.
In a 2017 study, scientists at Rice University discovered that using asphalt in LIBs could drastically decrease charge times, potentially from two or more hours to only five minutes.
In a 2019 study, an NYU Tandon research team led by Professor André Taylor searched for alternatives to LIBs because of the costs associated with lithium. As the study notes, “the cost of LIBs is one of the major hurdles standing in the way of widespread use of electric cars.”
Some of the alternatives to lithium are sodium batteries (NIBs) and potassium batteries (KIBs).
Although graphite is used in LIBs for its cost efficiency, using graphite in NIBs or KIBs has shown to be both inefficient and potentially unstable. In developing a functional NIB, the NYU researchers found a way to utilize asphalt to create the anode material required while maintaining stability.
In a 2021 study in China, researchers at the Changsha University of Science and Technology created a carbon anode using recycled asphalt from damaged road pavement. In this study, the researchers were successful in creating a material that was capable of being universal between lithium, sodium and potassium batteries.
Another potential advantage to NIBs or KIBs is their use for large-scale applications. As the global economy pushes towards more variable renewable energy, and with the high abundance of both sodium and potassium elements, these large-scale batteries could even be used for grid-level applications.
The quick progression from using asphalt to enhance LIB charge times to creating a carbon host material from recycled asphalt in only five years is very intriguing.
“That makes things really exciting,” Professor Taylor said when discussing the idea of using asphalt for batteries. “We can take that and use that as a feed stream and then make something that’s storing renewable energy.”
Renewable energy, carbon net-zero, sustainability. All of these are at the forefront of conversations and news articles today with a large focus on fossil fuels and the energy sector. The asphalt business is no stranger to this but the use of asphalt in batteries is a very new idea. The potential is there: faster charging times, cheaper base ion components and sustainable asphalt.
Jendry is Director of Supply for Associated Asphalt in Virginia.