**Abstract**

In this chapter, we will study the spray pyrolysis process, which is a bottom-up process, and examine the composite electrode powder synthesis process and properties of the core-shell structure. Generally, it is difficult to produce fine particles from metal powders using the top-down method. Thus, the liquid phase method, which is a bottom-up process, is mainly used. However, the liquid phase method has a problem in that impurities exist in the particles. In addition, it is difficult to control the precipitation when synthesizing powder using a solution containing several types of metal salts. The spray pyrolysis process introduced here made it possible to produce composite particles in a one-pot manner without any additional processes for synthesizing the core-shell structure. In the case of core-shell structure of Ag-glass composite powder, the specific resistance of the composite electrode was significantly lowered, compared to the electrode formed by mixing glass frits individually, which improved the dispersibility of the glass. In the case of Cu composite particles with a coating layer, both Ag and glass coating layers formed a passivation layer to improve atmospheric stability, and the introduction of a coating material also improved electrical properties.

**Keywords:** spray pyrolysis, electrode materials, conductive powder, core-shell structure, composite
