Solid-State Cathode Materials for Lithium Batteries: Effect of Synthesis Temperature on the Physical and Electrochemical Properties of Silver Vanadium Oxide

Silver vanadium oxide (SVO, AgV₂O_5.5) was synthesized for use as a cathode material in lithium/SVO batteries. The material was prepared via a solid-state thermal reaction of silver nitrate and vanadium pentoxide in the presence of air. The surface morphology of the final product was found to be dependent on the temperature of synthesis of the material, as evidenced by SEM analysis of the samples. SVO synthesized at 320 and 375 °C displayed irregularly shaped particles, while material prepared at 450 °C was needlelike. SVO synthesized at 540 ° C appeared to be a mixture of large crystalline plates and irregular particles. All of the samples were analyzed by DSC, chemical analysis, X-ray powder diffraction, resistivity measurements, and constant-resistance discharge of Li/SVO test cells. The experimental capacities of the lower temperature materials (320, 375 °C) were similar to that found for SVO prepared at 450 °C. A significant decrease in delivered capacity was noted when the SVO prepared at 540 °C was used as a cathode material.