Princeton startup recycles rare minerals from lithium batteries

Two micrographs, one with little spheres covered in speckles, the other with similar spheres looking cleaner. — A new method for direct battery recycling uses low-temperature plasma to remove contaminants from aged lithium nickel cobalt manganese cathode materials (left), commonly used in electric vehicle batteries, and transform them directly into active cathode materials (right). Images copyright Princeton NuEnergywater

Bruce Koel compares recycling lithium-ion batteries to transforming a stale loaf of rye back into oven- ready bread dough.

The transformation strips impurities from the battery’s key section using low-temperature plasma, a reactive cloud of charged particles. Koel, now a professor emeritus of chemical and biological engineering, and his research team discovered that these plasmas could clean up materials for various chemical engineering processes.

The new method for direct battery recycling, developed at a startup company, applies plasma to a battery’s cathode, the positively charged part of the battery containing valuable materials like lithium, cobalt, and nickel. With contaminants removed and a little more processing, the cathode material is ready for reuse.

Conventional methods involve shredding used batteries and using acids or high temperatures to separate them into component atoms. These processes are energy-intensive and require reassembling the cathode material.

Koel co-founded Princeton NuEnergy in 2019 with Yiguang Ju, professor of mechanical and aerospace engineering, and postdoctoral researchers Xiaofang Yang and Chao Yan. Yan is now CEO and Yang is CTO.

The company received funding from Princeton’s Intellectual Property Accelerator Fund, the Department of Energy, and private investors. A pilot plant in Texas is operating at a scale of 500 tons per year and a demonstration plant now under construction in South Carolina is expected to operate at a scale of 10,000 tons per year of recycled cathode material.