Circular Economy in Batteries

"A metal atom is a metal atom," says Alan Nelson, senior vice president for battery materials at Redwood Materials, a company that specializes in recycling.

Redwood is one of a number of companies trying to turn a supply of old batteries into materials for new ones. The company says it plans to produce enough cathode material for 100 GWh worth of battery cells by 2025-roughly equivalent to what CATL, the dominant battery maker in China, produced last year. According to Benchmark Mineral Intelligence, a group that studies the battery supply chain, China currently makes 78 percent of the world's cathode materials, and that share is poised to grow to 90 percent by 2030, despite efforts in the US to invest in domestic battery supply chains.

One reason Chinese firms remain so dominant is that they have a closed loop of battery production, says Hans Eric Melin, founder of Circular Energy Storage, a consultancy that tracks battery recycling. Having battery cell production at home means it's possible to break down scrap materials and quickly put the valuable metals back into production. The tests, which were performed by independent researchers at Argonne National Lab, are an early step in a qualification process to reassure battery makers of the quality of these hand-me-down materials. The process begins by taking the battery apart and breaking its components down with heat and acids into metal sulfate compounds, composed of elements like cobalt, manganese, and nickel.

The result is a cathode material that could be stuck into battery cells and run through a set of standard tests. "Honestly, it's a pretty boring result," says Jason Croy, a battery scientist at Argonne National Laboratory who led the research. In the meantime, Redwood and other recycling startups are competing to secure a diverse array of battery sources, including from hybrid cars, power tools, and small devices like phones that, despite their tiny batteries, often contain a high ratio of cobalt. Due to declining demand for cobalt in newer battery designs, he expects recycling to cover all of Redwood's needs for the metal. Still, the company will also need to source plenty of new material for its cathodes, just like battery makers everywhere. That's likely to remain the case for some time, he says, as the flow of dying batteries remains a trickle relative to demand for new ones.