Redwood touts emissions reductions

Nevada-based Redwood Materials says the battery materials recycling and processing plant it has developed in its home state uses 80 percent less energy, generates 70 percent fewer CO₂ emissions and requires 80 percent less water compared with a facility that would use mined materials.

The company uses the “mine above ground” analogy when saying its process “represent[s] the United States’ first nickel ‘mine’ and only commercial-scale source of lithium supply to come online in decades.”

“Unlike traditional mining projects, which often take more than 10 years to become operational, we built and activated our facility in less than a quarter of that time," the company says.

The Nevada facility potentially qualifies for zero-waste status, with Redwood saying, “Nothing goes to landfill, and no water leaves the facility (except the sanitary waste).”

Other battery materials recycling facilities are opening or being constructed in the U.S. However, recent research performed at Stanford University in California spells out the low emissions resulting from its process, Redwood says.

“Compared to other recycling technology, Stanford reports our process results in, at a minimum, 40 percent fewer emissions than other recyclers,” the company continues.

Since the paper was written, Redwood says many of its processes have evolved, some in response to its collaboration with Stanford, enabling the company to achieve even lower emissions than the paper reports. For example, Stanford helped it identify that the peroxide in its hydrometallurgy process contributed significantly to its total CO₂ footprint. The company says it's redesigned its hydrometallurgy process to use no peroxide.  

The company also calls its technology scalable, saying it can process more than 40,000 metric tons (about 15 to 20 gigawatt hours of battery power) annually.

Redwood's Nevada plant includes hydrometallurgical operations, a rotary calciner for large-scale recycling and technology to produce battery anode copper foil.

The hydrometallurgy facility recycles battery manufacturing scrap into raw nickel and cobalt and entails successfully reclaiming 95 percent of lithium from scrap battery materials, according to Redwood.

The recovered nickel, lithium and other metals are purified into intermediates or converted into chemicals for the production of high-grade cathode active materials.

The Redwood reductive calciner uses a thermal preprocess designed to handle live battery cells, consumer electronics and electric vehicle modules. “Reductive calcination fully liberates nickel, cobalt, graphite and lithium from other materials, but does not create alloys or a slag waste,” Redwood says.

The Nevada campus currently is processing 30,000 tons per year of end-of-life batteries and production scrap and its equipment can ramp to 60,000 tons of capacity by the end this year.

“Through our ongoing efforts, we’re redefining the production of battery materials, prioritizing sustainability, efficiency and innovation at every step,” the company says.