Mechanism and model of current response of hydroxylamine nitrate-based energetic polymer electrolytes under high voltage

The polymer electrolyte formed by incorporating hydroxylammonium nitrate into a polyvinyl alcohol gel exhibits electrically controlled combustion characteristics, making it a promising candidate for a novel solid propellant. The current response mechanism of the propellant under high voltage is a key technical issue that remains unclear at present. In this paper, the current response and ignition characteristics of the propellant at different voltage conditions, as well as the electrode potentials of the anode and cathode, were first experimentally investigated using sensors and cameras. Under high voltage, electrolysis occurs at the anode interface involving water and nitrate, while at the cathode interface, electrolysis involves water and hydroxylamine. Due to water being electrolyzed preferentially over hydroxylamine and nitrate, a brief and intense current peak is formed during the initial electrification period. Since the electrolysis of nitrate requires a high voltage, the anode potential remains high throughout the electrification process, and the majority of the electrical energy is concentrated and injected into the propellant at the anode interface, causing it to heat up and ignite. The high temperature and melting of the propellant accelerate the electrochemical reactions, resulting in a secondary increase in current. Based on the experimental results, the kinetic relationships between the electrode potentials and the current are fitted, and the simplified electrochemical model has been established. The calculated results are in good agreement with the experimental data, thereby theoretically validating the proposed high-voltage current response mechanism of the propellant.