Investigation of the electrical performance of molten carbonate electrolysis under dynamic operation

Dynamic operation involving current ripple has been shown to increase power consumption in alkaline and proton exchange membrane water electrolysis. However, this phenomenon remains unexplored in molten carbonate electrolysis. This study investigates the influence of current ripple on voltage response and power consumption during carbon dioxide electrolysis in molten lithium carbonate. The effects of the sine-wave current ripple, across different amplitudes and frequencies, on voltage response and power consumption are analyzed using voltage and current waveform measurements. Subsequently, the effect of other basic waveforms across frequencies on power consumption is also analyzed using the same technique. Results indicate that compared to constant direct current, the application of current ripple increases power consumption, with power consumption increasing as a function of ripple amplitude. Across the tested frequency range, the effect of frequency on ripple losses cannot be conclusively established from these measurements. Additional analysis of basic waveforms reveals that at 1 Hz, the ripple losses ordered from highest to lowest are square, sine, ramp-up, ramp-down, and triangular. Overall, the dynamic operation was found to increase the electrical power consumption in the molten lithium carbonate electrolysis system. • The effect of dynamic operation on molten carbonate electrolysis is studied. • The voltage response under current ripple is characterized. • Current ripple leads to higher power consumption. • Ripple loss increases with the amplitude of the current ripple. • Square waveform has the highest ripple loss compared to other waveforms.