Erosion Mechanism of Li-Ion Batteries Cathode Materials on Si3N4-SiC and SiO2-SiC Refractories

The erosion mechanism of Li-ion ternary cathode material on Si3N4-SiC and SiO2-SiC refractory slabs was studied at 780 °C for 20h. The results show that the erosion resistance of Si3N4-SiC is much better than that of SiO2-SiC refractory slab after heat treatment for 20h. Erosion mechanism of the two kinds of refractory slabs are different. Inward diffusion of Li2O reacts with a large amount of SiO2 in the SiO2-SiC system. This leads to a large number of reaction products, so that the incompletely reacted SiC particles fall off along with the reaction product, causing the erosion of SiO2-SiC. For Si3N4-SiC, it is mainly because the dense SiO2 protective layer produced by oxidation of Si3N4 prevents further oxidation of Si3N4 and SiC in the system, giving the material excellent erosion resistance.