Scalable recycling and characterization of end-of-life solid oxide cell ceramic component materials

By recycling solid oxide cells (SOCs) end-life materials, the environmental impact can be reduced, and the materials' closed-loop life cycle can help preserve natural resources and create a sustainable and circular system. This study presents a technique for recovering NiO, La_xSr_1-xCoO₃ (LSC) and Zr_1-xY_xO_2-x/2 (YSZ) components from SOC end-of-life products. First, the entire cell components, including the electrolyte, fuel and air electrodes were crushed, ball-milled, and leached with nitric acid. Following the maximum dissolution of cations, centrifugation was used to remove the non-leached YSZ as a sediment. The leached solution, which is rich in nickel, cobalt, strontium, and lanthanum ions was treated with dimethylglyoxime (C₄H₈N₂O₂ DMG) and Ni is preferentially precipitated as C₈H₁₄N₄NiO₄. LSC is then recovered from thermal treatment of solution leftover from C₈H₁₄N₄NiO₄ centrifugation and filtration. About 90 wt% of the ceramic components were successfully recovered. The compositions of recovered materials show a commercial-grade purity i.e about 99 at% for NiO, 96 at% for LSC and 97 at% for YSZ.