Abstract. This study is intended to determine if the capacitive properties are improved when a specific amount of crystalline ruthenium oxide (c-RuO2) is added to an amorphous hydrous ruthenium oxide (a-RuO2) electrode fabricated by the spark plasma sintering technique. For at the cyclic voltammetry scan rates higher than 10 mV s−1, the capacitance of a highly pseudo-capacitive, but less …