Ask two battery recyclers how to handle a dead pack and you may get two incompatible answers. One says: recover the metals — break the cells down to cobalt, nickel and lithium salts you can sell back into the supply chain. The other says: that is wasteful — restore the cathode material directly, skipping the costly trip back to raw metal. The 2022 patent record shows both philosophies funded and filing.On the recovery side, Northvolt's US11509000B2 claims a process for recovering cathode materials by removing aluminum and iron — a hydrometallurgical approach, dissolving and purifying. Worcester Polytechnic's US11502345B2 claims a method and apparatus for recycling that recovers metals. These are the descendants of mining-style metallurgy applied to batteries.On the direct side, Hulico's US11394062B2 claims relithiation in oxidizing conditions — putting lithium back into a depleted cathode so the cathode itself can be reused. Storagenergy's US11492267B2 claims a flame-assisted method to directly recycle and even upcycle spent cathode. The bet here is that rebuilding the cathode is cheaper than melting it down and synthesizing a new one.Why the split matters to economics: smelting and full hydrometallurgy are energy-hungry and capital-intensive, but they handle messy, mixed feedstock. Direct recycling is far cheaper in energy if it works, but it demands clean, sorted, single-chemistry feedstock — which the real waste stream rarely provides. The method you pick is really a bet on how clean your feedstock will be.Northvolt's presence on this list is worth a flag for filing-watchers: a vertically integrated cell maker patenting recovery chemistry signals it wants recycling inside its own supply loop, not outsourced. That is the off-take story — recycled metal as a captive, price-hedged input rather than a commodity bought on the open market.The shared CPC code H01M 10/54 marks all of these as battery-reclamation patents, but the divergent secondary codes — C22B metallurgy classes for the recovery camp, H01M cathode classes for the direct camp — are where the philosophy shows. Read the secondary codes and you can tell which bet a recycler is making before you read a word of the claims.