Advanced uniform LiNi0.7Co0.15Mn0.15O2 microspheres were successfully synthesized and examined as cathode materials for lithium-ion batteries. The structure, morphology, and electrochemical performance of LiNi0.7Co0.15Mn0.15O2 calcined at different temperatures ranging from 650 to 900 °C were systematically investigated. The XRD results show that the material has a well-ordered layered structure with small amount of cation mixing. A distinct spherical morphology of the obtained powders prepared at different temperatures can be seen from the SEM images. The as-synthesized LiNi0.7Co0.15Mn0.15O2 powders have a very high-tap density of about 2.37 g·cm−3. Among all the samples, the sample calcined at 750 °C exhibits the best electrochemical performance with an initial discharge capacity of 185.2 mAh·g−1 (3.0–4.3 V, 0.2C rate) and capacity retention >94.77 % after 50 cycles. Moreover, this material shows high-specific capacity and good cycling stability. The LiNi0.7Co0.15Mn0.15O2 microspheres with high-specific capacity and high-tap density are promising to use as cathode materials for next-generation high-energy-density lithium-ion batteries.

Eu3+ doped La2Ti2O7 nanocrystals with pure monoclinic phase and size of about 100 nm were prepared by a citric acid (CA) assisted sol-gel method. Techniques of thermo-gravimetric (TG) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), as well as transmission electron microscopy (TEM) were employed to characterize the as-synthesized nanoparticles. Furthermore, photoluminescence (PL) performances of the Eu3+ doped La2Ti2O7 nanocrystals were evaluated with focus on the effects of calcination temperature and Eu3+ doping concentration on the photoluminescence properties.