Evaluating refractory material performance in pyrometallurgical recycling of lithium-ion batteries under a reducing atmosphere

• Published in: Ceramics international 2024-11, Vol.50 (21), p.43683-43698
• Main Authors: Wiszniewski, Lukas, Marschall, Irmtraud, Hochsteiner, Thomas, McFarlane Hoad, Thomas, Doschek-Held, Klaus, Raupenstrauch, Harald
• Format: Article
• Language: English
• Subjects: Batteries; Crucible test; InduRed; Pyrometallurgical recycling; Refractories (E); SiC (C)
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2024.08.220

Pyrometallurgical recycling of lithium-ion batteries (LIB) has emerged as the go-to approach in industrial recycling solutions, yet it encounters significant challenges, such as lithium (Li) slagging. This study explores a reactor for pyrometallurgical recycling, that offers the potential to overcome this bottleneck by simultaneously recovering lithium and phosphorous (P) via the gas stream, more noble elements including cobalt (Co), nickel (Ni) and copper (Cu) as an alloy and less noble elements like aluminum (Al), calcium (Ca) and silicium (Si) as a slag. However, to enhance the efficiency and performance of this reactor, a critical focus is placed on evaluating refractory materials with reduced corrosion and diffusion characteristics. Already explored refractory materials, including aluminum oxide (Al2O3) or magnesium oxide (MgO), have exhibited severe issues, such as accelerated corrosion and diffusion rates, leading to diminished performance and compromised efficiency. To evaluate a more suitable refractory material for pyrometallurgical recycling of LIB, tests using silicon carbide (SiC), chromium(III)-oxide (Cr2O3) and zirconium dioxide (ZrO2) were performed up to 1600 °C. The test results indicate that the investigated refractory materials offer distinct advantages and disadvantages. While SiC shows minimal to no wear by corrosion, Cr2O3 exhibits higher resistance to Li diffusion. Contrary, ZrO2 experienced severe corrosion and crack formation, showing unsuitability for LIB recycling. Based on these findings, a continuously operated reactor could use different refractory materials in specific zones. While the degasification zone could benefit from Cr2O3's minimal diffusion properties, areas with intense contact between the crucible and melt could utilize SiC's corrosion resistance. However, partial oxidation at the outer surface of the SiC crucible led to the formation of SiO2, another critical point to consider for scale-up plans, as it might influence the mechanical integrity long-term.