Rice University scientists led by chemist James Tour have used an ultrafast flash recycling method to regenerate the graphite anode from spent Li-ion batteries and recover valuable battery metal resources. Tour is the T.T. and W.F. Chao Chair in Chemistry and a professor of materials science and nanoengineering; Tour introduced the flash process for graphene in 2020. A paper on their work is published in Advanced Materials.
The generated inorganic salts, including lithium, cobalt, nickel, and manganese, can be easily recollected from the flashed anode waste using diluted acid, specifically 0.1 m HCl. The flash-recycled anode preserves the graphite structure and is coated with a solid-electrolyte-interphase-derived carbon shell, contributing to high initial specific capacity, superior rate performance, and cycling stability, when compared to anode materials recycled using a high-temperature-calcination method. Life-cycle-analysis relative to current graphite production and recycling methods indicate that flash recycling can significantly reduce the total energy consumption and greenhouse gas emission while turning anode recycling into an economically advantageous process. Flash-recycled anode particles as seen under through a scanning electron microscope. The particles are recovered from lithium-ion batteries and treated through Rice’s flash Joule heating process.
Flashing powdered anodes from commercial batteries recycles some of what the researchers called the staggering accumulation of waste they currently leave behind. In just a few seconds, a jolt of high energy decomposes inorganic salts including lithium, cobalt, nickel and manganese from an anode. These can be recovered by processing them with dilute hydrochloric acid.
The lab reported that flashing anodes degrades the solid-electrolyte interphase (SEI), which conducts lithium ions but also insulates the anode from detrimental reactions.
Flashing then coats the remaining graphite particles with an ion-permeable carbon shell that contributes to their future capacity, rate performance and cycling stability compared to materials conventionally recycled in a time-consuming and energy-intensive process known as high-temperature calcination.
The lab estimated it would cost about $118 to recycle one ton of untreated anode waste. They demonstrated that flash-recycled anodes have a recovered specific capacity of 351 milliAmp hours per gram at 32 degrees Fahrenheit, superior to the rate performance and electrochemical stability of untreated or calcinated recycled anodes.
The recycled, flashed anodes the researchers tested retained more than 77% of their capacity after 400 recharge cycles.
“The production of lithium-ion batteries in 2026 is expected to be five times what it was in 2017, and right now, less than 5% of them are recycled. That puts a heavy load on the environment, as these spent batteries are processed and the anodes burned for energy or sent for landfills. We’re claiming our process can recover critical metals and recondition anodes in a far more environmentally and economically friendly manner“, states James Tour.