In the northern Swedish city of Skellefteå, 250 construction workers brave the cold every morning to build what's expected to be the largest battery-recycling facility in the world. It believes recycling old batteries locally and using recovered rare earth materials as feedstock for new batteries is the solution to the sustainability and supply-chain woes of the market. "The city, home to 75,000 people, looks set to also become the stage of a battery-recycling revolution