The recycling industry has a glamorous story — closing the loop, mining the city instead of the earth — and an unglamorous reality named black mass. When you shred dead batteries, what comes out is a dark, dirty powder: cathode metals, graphite, binders, bits of foil and casing, and a stew of impurities. Everything downstream is an attempt to turn that mess into something sellable.The 2024 grants are squarely about that problem. UT-Battelle, which runs Oak Ridge National Laboratory, holds US11916206B2 on efficient recovery processes for black mass from spent lithium-ion batteries. Green Li-ion's US11876196B2 claims a process for removing impurities in recycling. American Hyperform's US12021207B2 claims a flotation method — borrowed from ore processing — to recover cathode material from recycled cells and scrap.Why purification is the crux: a recycler is ultimately selling metal salts or recovered cathode back into the battery supply chain, and that supply chain has tight purity specs. Iron, copper and aluminum contamination from the shredded foils and casings will ruin a cathode if it carries through. The value of a recycling process is mostly its ability to take ugly black mass and produce battery-grade purity at the other end.Oak Ridge's presence on this list is a tell about where the hard problems sit. National-lab IP tends to cluster around the genuinely difficult, non-obvious chemistry that the private sector finds risky to fund. When a national lab is patenting black-mass recovery, it signals the purification step is still a frontier, not a solved commodity process.The off-take economics turn on yield and purity together. A process that recovers a high fraction of the nickel and cobalt at battery-grade purity is a business; one that recovers a lot at low purity, or a little at high purity, is not. The flotation and impurity-removal methods in these grants are all attempts to win on both axes at once — the only way the numbers close.For readers, black mass is the word to watch in any recycling pitch or filing. Ask what purity the process achieves and at what yield, because that pair of numbers is the whole business. The shared CPC code H01M 10/54 marks all of these as reclamation patents; the difference between them is how well they tame the ugly powder at the start of the line.