Synthesized K2O·11Al2O3 as sagger matrix for the preparation of Li‐ion battery cathode materials at high temperatures

Abstract Refractory materials such as mullite, andalusite, forsterite, and cordierite are generally used to prepare saggers for the calcination of Li‐ion battery Li(Ni x Co y Mn z )O 2 (LNCM) cathode material. However, these compounds are prone to be attacked by the LNCM materials, thereby leading to short life spans and contamination of the Li‐ion battery cathode materials. To improve the corrosion resistance of refractory sagger materials, the most clear cut‐way is enhancing the corrosion resistance of matrix using a new refractory component. Potassium aluminate (K 2 O·11Al 2 O 3 , KA 11 ) with an excellent corrosion resistance against alkaline oxide was synthesized via solid‐state method using potassium carbonate (K 2 CO 3 ) and industrial alumina powder (Al 2 O 3 ). Interactions between KA 11 and LNCM cathode materials at 800°C–1100°C were characterized by refractory‐LNCM precursor laboratory‐scale tests to understand the corrosion behavior of KA 11 . The microstructure and phase composition of synthesized KA 11 and the calcined KA 11 ‐LNCM mixture cylinders were analyzed with SEM and XRD. The observations reveal that KA 11 shows a better corrosion resistance to LNCM materials compared with mullite, cordierite, and forsterite. The addition of synthesized KA 11 also favors the thermal shock resistances of mullite‐based sagger materials.