Abstract
To enable the practical implementation of electrical ignition systems for spacecraft thrusters using an energetic ionic liquid, understanding the relationship between the composition, propellant performance, and electrochemical properties
is important. The objective of this study is to investigate the effect of composition on propellant properties (e.g., theoretical specific impulse, solid precipitation at -35℃) and electrochemical properties (e.g., electrolysis onset potential and specific resistivity) in a binary mixture of ammonium dinitramide and 2-hydroxylethylhydrazinium nitrate (ADN/HEHN). The theoretical specific impulse for ADN/HEHN mixtures increased with increasing ADN content, reaching a maximum of 298 s at an ADN molar ratio of 62%. A freezing test at -35℃ revealed that no solid precipitation occurred at ADN molar ratios of 50% or lower. Linear sweep voltammetry measurements showed that the electrolysis onset potential for the anode was 1.5±0.3 V vs. Ag, whereas the electrolysis onset potential for the cathode was -1.0 V vs. Ag for pure HEHN and -0.4 V vs. Ag for compositions containing ADN. Electrochemical impedance spectroscopy measurements showed that the specific resistivity decreased with increasing ADN molar ratio, reaching approximately one-third of the value for pure HEHN (611 Ω･cm) at an ADN molar ratio of 60% (195 Ω･cm). Among the compositions without solid precipitation at -35℃, the ADN/HEHN
