ENTREPRENEURIAL ALERTNESS.

What happens to spent batteries?  There might be money in that scrap pile.

Over the past decade, the world’s lithium-ion production capacity has increased tenfold to meet the growing demand for EVs. Now vehicles from that first production wave are just beginning to reach the end of their lifespan. This marks the beginning of a tsunami of spent batteries, which will only get worse as more electric cars hit the road. The International Energy Agency predicts an 800 percent increase in the number of EVs over the next decade, each car packed with thousands of cells. The dirty secret of the EV revolution is that it created an e-waste timebomb—and cracking lithium-ion recycling is the only way to defuse it.

That's something metal manufacturers probably figured out about the time the first battlefield littered with dead knights had to be cleaned up.  (They've gotten a lot better at it in the years since.)

There are two main ways to deactivate lithium-ion batteries. The most common technique, called pyrometallurgy, involves burning them to remove unwanted organic materials and plastics. This method leaves the recycler with just a fraction of the original material—typically just the copper from current collectors and nickel or cobalt from the cathode. A common pyro method, called smelting, uses a furnace powered with fossil fuels, which isn’t great for the environment, and it loses a lot of aluminum and lithium in the process. But it is simple, and smelting factories that currently exist to process ore from the mining industry are already able to handle batteries. Of the small fraction of lithium-ion batteries that are recycled in the US—just 5 percent of all spent cells—most of them end up in a smelting furnace.

It's challenging when the vaporization temperature of some metals is lower than the melting temperature of others, and for all the chemistry involved, a battery well-might be an alloy waiting to happen. Could be easier to expose Chinese slave laborers to the hazards of digging out more rare earths (which aren't that rare, they're just messy to isolate.)

The other approach is called hydrometallurgy. A common form of this technique, called leaching, involves soaking lithium-ion cells in strong acids to dissolve the metals into a solution. More materials, including lithium, can be recovered this way. But leaching comes with its own challenges. Recyclers must preprocess the cells to remove unwanted plastic casings and drain the charge on the battery, which increases cost and complexity. It’s part of the reason why spent lithium-ion batteries have been treated as waste ever since the first commercial cells hit the market in the early 1990s. It was often several times cheaper to mine new material, especially lithium, than recover it with leaching.

But a battery is a carefully-contained exothermic reaction (something that owners of hoverboards or small dead rail locomotives sometimes learn the hard way) and there might lie an opportunity.

Redwood uses a combination of pyrometallurgy and hydrometallurgy to recover these valuable materials. First, technicians wearing reflective silver heat suits cook the batteries in converters to separate the metals. Rather than using fossil fuels to burn the material, like in a conventional smelting process, Redwood’s pyro technique uses residual energy in the batteries, such as the organics in the electrolyte, to drive the conversion process. The stuff that’s left over is a metal alloy that is filtered through a hydrometallurgical process to recover individual compounds.

Repeated smelting of metals weakens them and introduces impurities, that's what made Nucor's Thin Strip Caster fed with recycled steel such a challenging project.  Apparently at the atomic level, the act of discharging a battery does not change lead into gold, or lithium into baking soda.

Many of the challenges that come with lithium-ion recycling stem from the fact that the facilities that process them weren’t designed specifically for cooking down batteries. But people at the vanguard of battery recycling expect that creating dedicated facilities will improve the industry’s economics. “We’re focused on a bespoke process that is specifically designed for lithium ion batteries because we’re starting to see increased volumes,” says Tim Johnston, the cofounder of Li-Cycle, a Canadian battery recycler. “Historically, batteries were viewed as waste, and we seek to turn that on its head by focusing on them as a resource.”

There's still work to be done.

A battery’s cathode, for example, is nanoengineered to boost performance. So some battery experts are working on a process called direct recovery, which salvages cathode material without destroying its crystalline nanostructure. This would dramatically reduce the cost of reusing the material.

There's a lot more at the link, including other promising developments, other potential dead ends, and the ever-present market tests. As long as there are dollar bills on the sidewalk, though, somebody's going to pick them up.