In this study, we report a simple but efficient way to improve the thermal stability of a dye-sensitized solar cell by adding a small amount of commercial silica nano-powders in a non-volatile electrolyte system. The paste-like electrolyte not only shows better water repellence because of the hydrophobicity of silica powder but also allows film casting for replacing conventional injection process. Compared with the device using liquid type electrolyte or paste-like electrolyte using hydrophilic nano-powders, the device using hydrophobic paste shows superior thermal stability without costly sealing and extra encapsulation. (C) 2014 The Electrochemical Society.