By Kyle Proffitt
January 13, 2025 | The 2024 Advanced Automotive Battery Conference was held December 9-12 in Las Vegas and included a range of speakers dedicated to topics influencing batteries in EVs. GM, Ford, and Redwood Materials shared perspectives on reducing EV costs, improving charging infrastructure, enabling vehicle-to-grid charging, and moving to local supply chains supported by recycled materials.
Colin Campbell, CTO of Redwood Materials, discussed efforts to close the loop on batteries with recycling right here in the United States. Previously, Campbell spent over 16 years at Tesla in various roles up through VP of Powertrain Engineering. He was pleased with industry progress around batteries and EVs, but in the back of his mind, he knew something needed to be done to reduce the material costs and responsibly dispose of used batteries. He said this industry just did not exist, but then Redwood’s founder and CEO JB Straubel shared his vision, and Campbell was excited to join.
A primary goal for Redwood is reducing material costs, so it made sense to look at the most expensive component, the cathode active material. “It contains all of the critical metals” and “makes up nearly half the cost of the cell,” Campbell said. Preparing that cathode correctly is pivotal to the success of the entire EV idea, Campbell says. “The microstructure is super critical to the range, the performance, the durability, and the safety and the cost of the vehicles, and no one is producing it at scale in the U.S. today,” he said. Based on this analysis, Redwood intends to produce cathode active material from recycled batteries.
Collapsed Supply Chain
Another factor in the cost of batteries, Campbell says, is the sheer length and complexity of the supply chain. “If you were to follow an atom of nickel out of the mine through all of the various processing steps to the EV that you’re parking in your driveway, it would travel more than 50,000 miles to get there,” he said. “Our goal is to collapse this entire supply chain onto a single site.”
Campbell focused on Redwood’s Tahoe site outside Reno, Nevada, a sprawling 300-acre campus with plans to occupy 5.5 million square feet. Campbell showed aerial video and images, with 2 GWh of end-of-life batteries arranged in neat stacks and rows in a giant field, waiting to find new life. The entire site, Campbell said, is about ¾ of a mile, end to end.
Recycling has a lot of different meanings, Campbell says, but “at Redwood, we really wanted to mean taking old batteries, all-comers, every shape, every size, and transforming them through all of the steps to a fresh cathode active material that we can sell to a battery maker.” He says they get everything from “giant utility-scale energy storage packs, buckets of wireless headphones, boxes of bare cells, and obviously tons of EV packs.”
To process these varying cell types, Redwood has a one-size-fits-all approach. “We’ve developed a process that we’re quite proud of, which is this reductive calcination process,” Campbell said. “It doesn’t require any disassembly of the cells, doesn’t require any discharge, and it is powered by residual energy that is contained in the cells.”
“The output of that calcination process we then feed into a hydrometallurgy flow sheet; its main function is to separate the critical metals from each other… and refine them and prepare them for entry in the cathode synthesis flow stream,” he said. The next step should be for these metals to go into cathode active material, but the facility where this will take place is still under construction. That was all part of the plan, though, as the intermediate materials already have value. “We’ve had north of $200 million of revenue this year selling these intermediate products; that is allowing us to bootstrap and really operate and get to scale quickly before the entire change is complete,” Campbell said. Because of the size of their operation and this supply of intermediate materials, Campbell says you could call Redwood the first nickel “mine” to open in the US in a decade, and also the only commercial-scale supply of lithium in the US in decades. And while he believes we will need mines for a while to support the growing electrification, he added that “it’s way faster to build these recycling facilities than to open a mine,” roughly 2 vs. 10 years.
Recycling vs Mining
Redwood worked with a group at Stanford to perform a full life cycle analysis of their process compared to refining virgin metal ore. This study showed (DOI: 10.2139/ssrn.4309094) that their process is “five times less resource intensive than digging things out of the ground” in terms of energy and water use and CO2 production. Campbell highlighted that while they use water in their process, they are a “zero liquid discharge operation” with nothing going to the drain or being picked up for treatment or disposal elsewhere. Referring back to Kelty’s discussion of break-even time for EVs in CO2 emissions, Campbell says that their work in reducing the CO2 emissions related to battery manufacture will have a very significant impact on how soon in their lifetime EVs are better on this metric.
According to Campbell, a key to the future success of this venture is putting everything in one place. It “really opens up interesting opportunities for integrating processing steps.” For instance, they discovered that wastewater from the cathode manufacturing process could just be sent “back up the hill to the hydrometallurgy plant”, where they are already processing lithium-containing water. These little “nested loops of circularity” that increase efficiencies only appeared when everything was at a single site.
In the meantime, business is booming. At the Tahoe site, “we are today recycling 20 GWh a year of battery materials,” Campbell said, but they plan to produce 20 GWh of high-nickel cathode by 2026 and to scale from there to 100 GWh/year—enough to power 1.3 million EVs.
