Systematic experimental investigation of electrode geometry, material, and polarity effects on ignition of perchlorate-based electrically controlled solid propellants

This study investigates the effects of electrode geometry (plate and mesh) and material (titanium, copper, and 304 stainless steel) on the ignition characteristics of perchlorate-based electrically controlled solid propellants (ECSPs) under atmospheric conditions. Using thermogravimetric-mass spectrometry, high-speed cinematography, thermocouple thermometry, and scanning electron microscopy, systematic experiments reveal the influence of electrode parameters on ignition behavior. For identical electrode polarity and material, mesh electrodes reduced the ECSP surface ignition delay by 66% compared to plate electrodes, an effect attributed to concentrated current density and enhanced ohmic heating, together with the improved mass transport provided by the open pore network. Material-dependent analysis further showed that copper electrodes suppressed cathode ignition when serving as the cathode, yet reduced the cathode ignition delay by 6.7–20% when serving as the anode and paired with Ti or SS cathodes. The influence of electrode parameters on ECSP ignition is governed by three interdependent factors: polarity determines the electrolytic reaction pathways, geometry governs the current density distribution, and material controls interfacial heat accumulation and corrosion-mediated decomposition behavior. This work provides novel experimental evidence and physical insights to advance ECSP research and enable engineering applications.