Outdated EV batteries may turn into a beneficial useful resource. A brand new methodology pulls lithium out cleanly and effectively, turning waste into ready-to-use battery materials.
As electrical automobiles unfold quickly, previous battery packs have gotten a rising supply of waste. Mining and refining lithium is dear, and most recycling strategies use numerous power and chemical substances, often producing lithium carbonate that then wants additional processing to turn into lithium hydroxide.
Engineers at Rice College have discovered a cleaner means. As a substitute of smelting or dissolving shredded battery supplies in sturdy acids, they recharge the waste cathodes to launch lithium ions into water, the place they react with hydroxide to create high-purity lithium hydroxide.
A brand new recycling methodology applies the identical precept as battery charging to waste cathode supplies. In a working battery, charging pulls lithium ions out of the cathode. The system adapts this response to supplies resembling lithium iron phosphate. Lithium ions transfer throughout a skinny cation-exchange membrane right into a flowing water stream, whereas water on the counter electrode is cut up to generate hydroxide. The lithium and hydroxide then mix to kind high-purity lithium hydroxide with out utilizing sturdy acids or further chemical substances.
The strategy makes use of a zero-gap membrane-electrode reactor that requires solely electrical energy, water, and battery waste. In some working modes, it consumed as little as 103 kilojoules of power per kilogram of fabric, roughly ten occasions lower than standard acid-leaching strategies. The reactor was scaled to twenty sq. centimeters, ran constantly for 1,000 hours, and processed 57 grams of business black mass whereas sustaining almost 90% lithium restoration.
The method produces lithium hydroxide exceeding 99% purity, prepared for direct use in battery manufacturing. It really works with a number of battery chemistries, together with lithium iron phosphate, lithium manganese oxide, and nickel-manganese-cobalt variants. A roll-to-roll demonstration confirmed that whole lithium iron phosphate electrodes could possibly be processed instantly from aluminum foil, with out scraping or pretreatment, highlighting potential integration into automated recycling traces.
Future plans give attention to bigger reactor stacks, larger black mass loading, and improved membranes for better effectivity at larger lithium hydroxide concentrations. Publish-processing steps like focus and crystallization are recognized as key alternatives to additional cut back power use and emissions. This strategy simplifies lithium restoration, lowers waste, and will assist make the battery provide chain extra sustainable.
