Preparation and performance of silver micro-nanoparticles for electrode silver paste

The silver particles in micro-nanometer size were prepared by solution chemical reduction method using AgNO₃ as the precursor, C₆H₈O₆ as the reducing agent, and tannin as the dispersant. The effects of reactant concentration, dispersant dosage, and pH value on the morphology, average particle size, and tap density of the silver powders were studied by X-ray diffractometer, scanning electron microscope, laser particle size analyzer, tapping apparatus, and solar energy performance tester. The results show that, the well-dispersed silver powders with spherical shape are synthesized under the optimal conditions as the pH value of 1, the AgNO₃ concentration of 0.1 mol·L^-1, the C₆H₈O₆ concentration of 0.1 mol·L^-1, the tannin concentration of 0.01 mol·L^-1, and the reaction temperature of 25℃. The silver powders with the maximum tap density of 6.1 g·mL^-1 can be obtained by mixing the silver powders in an average particle size of 1.16 μm and 0.66 μm. According to the surface morphology and battery performance of silver electrode, the silver electrode based on the mixed silver powders in the tap density of 6.1 g·mL^-1 shows the best relative density, and the photoelectric conversion efficiency of the solar cell is the highest, reaching 17.16%.