Return to article. Long Description Return to article. Long DescriptionA solution turns green as it pulls cobalt from a spent lithium-ion cathode. A Rice University laboratory is developing an environmentally friendly method to recover valuable metals from used batteries. Photo by Jeff Fitlow“This has been attempted before with acids,” said Rice graduate student and lead author Kimmai Tran. “They’re effective, but they’re corrosive and not eco-friendly. As a whole, recycling lithium-ion batteries is typically expensive and a risk to workers.”Other processes also have drawbacks, she said. Pyrometallurgy involves crushing and mixing at extreme temperatures, and the harmful fumes require scrubbing. Hydrometallurgy requires caustic chemicals, while other “green” solvents that extract metal ions often require additional agents or high-temperature processes to fully capture them.“The nice thing about this deep eutectic solvent is that it can dissolve a wide variety of metal oxides,” Tran said. “It’s literally made of a chicken feed additive and a common plastic precursor that, when mixed together at room temperature, form a clear, relatively nontoxic solution that has effective solvating properties.”A deep eutectic solvent is a mixture of two or more compounds that freezes at temperatures much lower than each of its precursors. In that way, she said, one can literally obtain a liquid from a simple combination of solids.“The large depression of freezing and melting points is due to the hydrogen bonds formed between the different chemicals,” Tran said. “By selecting the right precursors, inexpensive ‘green’ solvents with interesting properties can be fabricated.”When Tran joined, the Rice group was already testing a eutectic solution as an electrolyte in next-generation high-temperature supercapacitors.“We tried to use it in metal oxide supercapacitors, and it was dissolving them,” said Rice research scientist and co-corresponding author Babu Ganguli. “The color of the solution would change.” Rice University graduate student Kimmai Tran and her colleagues have developed an environmentally friendly solution to remove valuable cobalt and lithium metals from spent lithium-ion batteries. (Photo by Jeff Fitlow/Rice University) Share4NEWS RELEASEEditor’s note: Links to video and high-resolution images for download appear at the end of this release.David [email protected] [email protected] ‘blue-green’ solution for recycling world’s batteriesRice scientists show solvent leaches cobalt, lithium for reuse from spent batteriesHOUSTON – (April 1, 2019) – Rice University researchers literally have a solution to deal with the glut of used lithium-ion batteries left behind by the ever-increasing demand for electric vehicles, cellphones and other electronic devices.The Rice lab of materials scientist Pulickel Ajayan used an environmentally friendly deep eutectic solvent to extract valuable elements from the metal oxides commonly used as cathodes in lithium-ion batteries. The goal, researchers said, is to curtail the use of harsh processes to recycle batteries and keep them out of landfills.The solvent, made of commodity products choline chloride and ethylene glycol, extracted more than 90 percent of cobalt from powdered compounds, and a smaller but still significant amount from used batteries.“Rechargeable battery waste, particularly from lithium-ion batteries, will become an increasingly menacing environmental challenge in the future as the demand for these through their usage in electric vehicles and other gadgets increases dramatically,” Ajayan said.“It’s important to recover strategic metals like cobalt that are limited in supply and are critical for the performance of these energy-storage devices,” he said. “Something to learn from our present situation with plastics is that it is the right time to have a comprehensive strategy for recycling the growing volume of battery waste.”The results appear in Nature Energy. https://youtu.be/76VdelMJ280Video produced by Brandon Martin/Rice UniversityImages for download: https://news-network.rice.edu/news/files/2019/03/0325_RECYCLING-1-web-1r7wsfm.jpgRice University graduate student Kimmai Tran and her colleagues have developed an environmentally friendly solution to remove valuable cobalt and lithium metals from spent lithium-ion batteries. (Photo by Jeff Fitlow/Rice University) A solution turns green as it pulls cobalt from a spent lithium-ion cathode. A Rice University laboratory is developing an environmentally friendly method to recover valuable metals from used batteries. (Photo by Jeff Fitlow/Rice University) https://news-network.rice.edu/news/files/2019/03/0325_RECYCLING-4-web-2ard3y3.jpgThe blue-green color of solutions reveals the presence of cobalt taken from spent lithium-ion batteries through a new process developed at Rice University. (Photo by Jeff Fitlow/Rice University) Return to article. Long Description
"New bluegreen solution for recycling worlds batteries"