Mobility revolution: Refractory saggars for calcination of ternary cathode materials
2024-09-18 , K3

The automotive industry is changing to attain the global aim of emission-free mobility. In the last few years, the ratio of electric driven vehicles is constantly growing, which results in a booming battery industry. The most used battery technology for electric vehicles is the lithium-ion battery (LIB).
Ternary materials such as NMC (Lim-n(NixMnyCo1-x-y)O2) and NCA (Lim-n(NixCoyAl1-x-y)O2) are commonly used for the cathode of LIBs for electric vehicles. These materials are usually prepared through solid-state reactions at temperatures between 500 and 1000 °C [1, 2]. Refractory saggars are necessary for this calcination process. Due to the low thermal expansion coefficient, good hot modulus of rupture, and low cost, saggars are commonly manufactured from cordierite-mullite materials. These show severe damage in consequences of corrosion after a few sintering cycles, which results in periodic replacing of the saggars and contamination of the cathode materials. To avoid these disadvantages, a high corrosion resistance against battery materials is a key property of new saggar materials.
The corrosion resistance of common saggar materials and other interesting refractory materials of STEULER were investigated. For ranking the materials in relation to their corrosion resistance a modified and repeated crucible test, also called cup test, was implemented, which reflects the requirements during the calcination. In addition to the crucible test, the reaction products between the potential saggar materials and the lithium carbonate containing precursor were discovered by X-ray diffraction analysis.