In this study, Mg₂TiO₄ (inverse spinel) was added to the MgAl₂O₄ (spinel) sagger, used for calcination of LNCM (LiNi_1-x-y­Co_xMn_yO₂)-based secondary battery cathode materials, to improve the corrosion behavior by the cathode materials. Mg₂TiO₄ according to the molar ratio of MgO/TiO₂ was sintered by the solid phase synthesis method and added to MgAl₂O₄ sagger. The highest Mg₂TiO₄ crystal phase fraction (97.25%) was obtained for MgO:TiO₂ = 67:33 (molar ratio) at 1350 ℃ for 3 h. The difference in thermal expansion coefficient was similar to that of the conventional MgAl₂O₄ (1.81 × 10^-6/℃). After the corrosion behavior test of MgAl₂O₄ sagger containing Mg₂TiO₄ with cathode material precursors (Li₂CO₃:NCM811 = 1.1:1 (mol%)) at 950 ℃ for 10 h, the microstructure of the cross-section was analyzed by scanning electron microscopy. The sagger containing Mg₂TiO₄ formed a thin lithium reaction layer compared to the sagger containing only MgAl₂O₄.

Keywords: MgAl₂O₄-Mg₂TiO₄ solid solutions, Spinel, Corrosion, Sagger, Cathode materials.