Modified calcium hexaaluminate with La2Ce2O7 and corrosion resistance to cathode materials for lithium-ion batteries

In the present work calcium hexaaluminate (CA6) was modified with different amounts of La2Ce2O7 to improve sintering and explore its application possibility as the saggers for lithium-ion battery cathode material. It was found that the addition of La2Ce2O7 causes incorporation of La3+ and Ce4+ ions into the CA6 grains accompanied by the formation of cation vacancy defects. Such behaviour greatly supported the CA6 grains to grow along the direction perpendicular to the basal plane and improved the densification of CA6 materials. Typically, the bulk density of CA6 with 6.0 wt.% La2Ce2O7 addition exceeded 3.50 g/cm3 and the apparent porosity decreased to below 3%. Moreover, the decrease in apparent porosity reduced the effective area between the Li+ and CA6 as well as inhibited the penetration of Li+, leading to the improvement in the corrosion resistance and service life.