The XRD pattern of the LLZNO powder is shown in Figure 2b and was identified as cubic phase (PDF 63-0174). The LD result and SEM image of the LLZNO powder after the attrition milling process, which demonstrated a submicron powder, are showed in Figure 2a and Table 1. The D(10), D(50), D(90), and primary particle size of the submicron LLZNO powder were 0.43 µm, 0.59 µm, 0.812 µm, and about 0.1 µm, respectively. The value of D(3,2) (0.575 µm) is similar to that of D(4,3) (0.607 µm), which indicates that the prepared powder had a uniform particle-size distribution. In addition, the powder also had a higher specific surface area (2007 m2/kg), which means that the powder had a high sintering activity, which can promote crystal growth and the rapid densification of ceramics in the sintering process.