To Create an Eco-Friendly EV Battery, Think From the Inside
The premium for pure cathode material is expected to expand as battery manufacturers move to designs using cheaper raw materials. These include LFP batteries, which contain lithium, iron, and phosphorus at the cathode, and no longer expensive metals such as nickel and cobalt. Kyburz has long used LFP batteries for its cars, and larger manufacturers including Tesla are now following suit. But they are less attractive to recyclers because of the cheap raw materials. “They asked for a lot of money to get them,” Groux said.
Removing cathodes from dead batteries, which is inexpensive, requires redesigning the batteries from the ground. That has been done before, Gaines points out, especially 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, which means recyclers can take any battery and put it in an automated process. Recyclers take the major components — lead and polyurethane, a type of plastic — and then separate them into holes filled with water. Simple: Floating plastics; lead sinks.
Lithium-ion batteries are more complex, involving many parts and materials, and many variations in their designs. But equally, “you don’t have to be a fool and design the hardest 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 make life easier for dismantlers. They can use screws instead of laser welding, for example, and choose adhesives that are easier to remove. But these small changes can be one of the hardest to do, explains Jeff Spangenberger, who manages the ReCell Center, because small costs add up to large amounts. Spending $ 2 extra per battery for screws, in order to save $ 1 on deconstructing a battery, is never worth it to the producer — as long as they are not responsible for the cost of recycling.
Groux encountered that problem with Kyburz recently when he was researching making more powerful batteries with modules. He likes batteries sealed with screws, but almost all of the Chinese manufacturers he consulted use laser welding. However, a company like Kyburz has some advantages. Its vehicles are relatively low -powered, designed to travel around Swiss villages for a few hours at a time, not flying across the Mojave without stopping. For the most part, the company uses a large number of cells that don’t come with modules, so they can be easily disassembled. That means Groux’s machine can work in a semi-automated way.
Tesla batteries, of course, are 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, Abbott explained. He taught the “Blade” battery, a new type of LFP battery made by Chinese automaker BYD for its passenger cars, as an example of progress. LFP batteries have known advantages: They are cheaper than batteries filled with cobalt and nickel, they last longer, and they are usually less likely to start a fire. But they are believed to not be able to store enough power to power a car for hundreds of miles — so the Blade surprised many observers.
For Abbott, one of the most exciting design changes is that the battery pack is not broken into modules. Instead, the cells are arranged in rows directly inside the package. The cells are long and rectangular — hence “blades” —instead of cylindrical jelly rolls. BYD found that it was possible to place these rectangles inside the battery pack that was denser than the cylinders, to make the overall package more powerful. Abbott didn’t have time to review the design directly, but he doubted the simplified design would make it easier to separate the batteries. Other companies, including Tesla, say they plan to make battery packs without modules, even if the cell designs are different.