HomeScience & TechTo Make an Eco-Friendly EV Battery, Think From the Inside Out

To Make an Eco-Friendly EV Battery, Think From the Inside Out

The premium for pure cathode material is expected to widen as battery makers switch to designs using cheaper raw materials. Among them are LFP batteries, which contain lithium, iron, and phosphorus in the cathode, and forgo pricey metals like nickel and cobalt. Kyburz has long used LFP batteries for its vehicles, and bigger manufacturers including Tesla are now following suit. But they’re less attractive to recyclers because of the cheap raw materials. “They’re asking for a lot of money to take them,” Groux says.

Removing cathodes from dead batteries, cheaply, requires redesigning batteries from the ground up. That’s been done before, Gaines points out, most notably with lead-acid batteries, the type used to start the engines of conventional cars. More than 95 percent of lead-acid batteries are recycled. One reason is that manufacturers use standardized designs, meaning that recyclers can take just about any battery and put it through an automated process. Recyclers strip out the major ingredients—lead and polyurethane, a type of plastic—and then separate them in water-filled vats. It’s simple: Plastic floats; lead sinks.

Lithium-ion batteries are more complicated, involving more parts and materials, and more variety in their designs. But all the same, “you don’t have to be an idiot and design the most difficult battery to recycle,” says Andy Abbott, a battery researcher at the University of Leicester who studies recycling-friendly design. There are simple ways that battery makers could make life easier for dismantlers. They could use screws instead of laser welding, for example, and opt for adhesives that are easier to remove. But these small changes can be among the most difficult to make, explains Jeff Spangenberger, who directs the ReCell Center, because small costs add up to big ones at scale. Spending $2 more per battery for screws, to save $1 deconstructing a battery, simply isn’t worth it to the producer—so long as they’re not responsible for the recycling costs.

Groux experienced that problem at Kyburz recently when he researched making more powerful batteries with modules. He wanted batteries sealed with screws, but nearly all the Chinese manufacturers he consulted used laser welding. Still, a company like Kyburz has certain advantages. Its vehicles are relatively low-powered, designed to jaunt around Swiss villages for a couple hours at a time, not blitz across the Mojave without stopping. For the most part, the company uses single large cells that don’t come in modules, so they’re easier to dismantle. That means Groux’s machine can do the job in a semi-automated fashion.

Tesla batteries are, of course, far more complicated. But that doesn’t mean they can’t be designed in ways that are at least more predictable and allow for some automation, explains Abbott. He points to the “Blade” battery, a new type of LFP battery made by the Chinese automaker BYD for its passenger cars, as an example of progress. LFP batteries have known advantages: They are cheaper than cobalt- and nickel-filled batteries, they last longer, and they are generally less likely to start fires. But it was thought that they couldn’t store enough energy to power a car for hundreds of miles—so the Blade took many observers by surprise.

To Abbott, one of the most exciting changes in the design is that the battery pack is not broken into modules. Instead, the cells are arranged in rows directly inside the pack. The cells are long and rectangular—hence “blades”—instead of the cylindrical jelly rolls. BYD found it could stuff these rectangles inside the battery pack more densely than it could cylinders, to make the overall pack more powerful. Abbott hasn’t had a chance to inspect the design directly, but he suspects the simplified design will make the batteries easier to take apart. Other companies, including Tesla, have said they plan to produce battery packs without modules, though cell designs vary.

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