Nanostructured LiFePO₄ powder with a narrow particle size (ca. 100 nm) for high rate lithium-ion battery cathode application was obtained by microwave heating and using citric acid as carbon source. The microstructures and morphologies of the synthesized materials were investigated by X-ray diffraction and scanning electron microscope while the electrochemical performances were evaluated by galvanostatic charge–discharge. The carbon coating and Ti⁴⁺ could improve the conductivity both between the LiFePO₄ particles and the intrinsic electronic conductivity. The LiFePO₄ doped with 5% C and 1% Ti⁴⁺ resulted in a specific capacity of 114.95 mAh.g^-1 and 102.4 mAh.g^-1 at discharge rates of 0.3C and 1C, respectively, and the cycle performance is very good.

The perovskite Yb-doped strontium cerate–zirconate material, SrCe_0.4Zr_0.4Yb_0.2O_2.9, was prepared by solid-state reaction and the structure was characterized by X-ray diffraction. The calcination process of the powder was investigated by thermogravimetric/differential thermal analysis (TG–DTA). The high temperature conductivities were measured by d.c. four-probe technique in the temperature range from 500 to 950°C in wet hydrogen and effect of temperature on conductivity was investigated. The conductivity increased with the elevation of temperature from 500 to 950°C. The highest conductivity of 4.4 × 10^-2 S.cm^-1 was observed for SrCe_0.4Zr_0.4Yb_0.2O_2.9 at 950°C. The current–voltage (𝐼–𝑉) and current–power (𝐼–𝑃) characteristics of the single cell (H₂, Pt/SrCe_0.4Zr_0.4Yb_0.2O_2.9/Pt, O₂) at temperature range from 600 to 850°C were tested. With the temperature increasing from 600 to 850°C, the open circuit voltage (OCV) decreased from 1.164 to 1.073 V and the ionic transfer number decreased from 0.996 to 0.946. At 850°C, the maximum power density of 25.2 mW.cm^-2 was observed.