A contribution by RobK in comments. Worth a post in case people missed it. Mostly quoted but not block-quoted for easier reading.
Recycled lithium is 5 x the cost of mined lithium.
The Afterlife of Electric Vehicles: Battery Recycling and Repurposing
BY IER MAY 6, 2019
By 2040, more than half of new-car sales and a third of the global fleet—equal to 559 million vehicles—is projected to be electric. This poses serious challenges. Electric vehicle batteries typically must be replaced every seven to 10 years for smaller vehicles and three to four for larger ones, such as buses and vans. Declining performance for an electric vehicle battery is evidenced by fewer miles of driving per charge and more frequent plug-ins by owners. The global stockpile of these batteries is expected to exceed 3.4 million by 2025, compared with about 55,000 last year. This is almost a 62-fold increase in 7 years. Automobiles have overtaken consumer electronics as the biggest users of lithium-ion batteries. Because batteries contain toxic chemicals that should not be placed into a landfills, they need to be either recycled, which involves an intensive manufacturing process, or repurposed for other uses.
China has the largest electric vehicle market in the world and the largest number of electric vehicle manufacturers. Electric cars make sense in China because of its dense and crowded cities that often mean shorter driving distances. China, where about half the world’s electric vehicles are sold, has made carmakers responsible for expired batteries and the European Union also has regulations on battery disposal.
Batteries can be recycled, but recycling them is not easy due to the sophisticated chemical procedures involved. If not handled properly, the heavy metal contained in the battery can lead to contamination of the soil and water.
Batteries can be recycled through smelting, direct recovery, and other, newer processes. A smelting process is used to recover many minerals (e.g. lithium, cobalt, nickel) contained in the battery. After a battery is smelted, the lithium ends up as a mixed byproduct and extracting it is costly. While the cost of fully recycling a lithium-ion battery is about €1 per kilogram, the value of the raw minerals reclaimed from the process is only about a third of that. Another way to look at the cost of extraction of lithium from old batteries is that it is 5 times more expensive than mined lithium.