As the electric vehicle market grows and batteries reach the end of their 10-year lifespan, the world is set to face another recycling crisis. A team of chemical engineering students in the US might have found a solution.
According to Bloomberg Businessweek, the tally of expended lithium-ion battery packs removed from cars in 2018 had reached 55,000 in July. Bloomberg predicts this number will balloon to more than 3.4 million in the next five years as the global market for electric cars and buses rapidly expands.
And that doesn’t take into account batteries from mobile devices and cameras, or storage units for renewable energy in homes and industry.
A team of chemical engineering students at Michigan Technological University (MTU) have found an economical solution based on mineral processing technology that has been used by the mining industry for a century.
Inspiration for the new recycling technique, unveiled earlier this year at the People, Prosperity and the Planet competition in Washington, D.C., came from the student’s project leader, who has a background in mining engineering.
Assistant Professor Lei Pan had the idea that the techniques used to extract metal from ore could be used to break expended batteries down to their component parts.
According to one of the students, Zachary Oldenburg, their research was received enthusiastically.
“We got a lot of ‘oh wow!’ responses, from 8-year-olds wanting to know how it worked to EPA officials wondering why no one had done this before,” he said.
“My response to the EPA was, ‘Because no one else had a project leader who’s a mining engineer’,” he added.
The response was well deserved: the students were able to separate all of the battery components, including lithium metal oxide. The separate components can be recycled into new batteries.
“For the purpose of remanufacturing, our recycled materials are as good as virgin materials, and they are cheaper,” Oldenburg said.
Pan added that using “tried and true” technology will make the process appeal to industry.
“We use standard gravity separations to separate copper from aluminum, and we use froth flotation to recover critical materials, including graphite, lithium and cobalt. These mining technologies are the cheapest available, and the infrastructure to implement them already exists,” Pan said.
Technology such as this could be put to good use in Australia, which has room for improvement in its battery recycling rate.
“Only 3 per cent of Australian batteries are currently recovered. It’s the lowest rate in the OECD,” said Sustainability Victoria CEO Stan Krpan in April.
Victorian company Envirostream opened the nation’s first local reprocessing plant for lithium-ion batteries in January 2017. The plant also reprocesses other types of batteries, including spent alkaline and nickel metal hydride power cells. In its first 12 months of operation, Envirostream’s facility diverted 240,000 kg of batteries from landfill, according to Sustainability Victoria.
The large amount of retired electric car batteries has also led to the establishment of businesses in several countries, including Australia, that specialise in putting used car batteries to use in applications ranging from powering beer fridges and car charging stations to storing renewable energy in homes.
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