Researchers Improve the Speed and Efficiency of Battery Recycling — in a Literal Flash
Yields of up to 98 percent in a fraction of the time and with weaker acids, the research team claims of its approach's potential.
Researchers from Rice University have come up with a new approach to better battery recycling — recovering more valuable metals in, quite literally, a flash.
"We developed a high-yield, low-cost method of reclaiming metals directly from 'black mass' — the combined cathode and anode waste the industry traditionally tries to recycle — that significantly reduces the environmental footprint of spent battery processing," co-lead author Jinhang Chen explains.
"It takes less than 20 minutes to dissolve the same amounts as opposed to 24 hours [with traditional recycling. Our findings have the potential to reduce the cost of battery waste recycling through decreased energy, water and acid consumption and lower carbon dioxide emissions."
The trick to the team's technique: rapid temperature increases, using something the researchers call pulsed-DC flash Joule heating to raise the temperature of the "black mass" to above 2,100 Kelvin (around 3,320°F) in mere seconds — resulting, they found, in a three-orders-of-magnitude increase in what they call "leaching kinetics," reducing processing time, allowing for the use of significantly more dilute acids, and improve yields of usable metals to above 98 percent.
"Currently, 95 percent of batteries are not recycled because we don't have the capacity to recycle them, even as waste from electronics is increasing at an annual rate of nine percent," claims James Tour, professor of chemistry and senior author on the paper. "A lot of current battery recycling processes involve the use of very strong acids, and these tend to be messy, cumbersome processes.
"What we found is that if you 'flash' the black mass, then you can easily separate out the critical metals using only low-concentration hydrochloric acid," Tour continues. "You could say the flash liberates the metals, so they dissolve easier. We’re still using acid, but much less. That’s why the economics is so much better."
The team's work has been published under open-access terms in the journal Science Advances.
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