Increasing the efficiency of water electrolysis with the application of pulsing electric fields

Abstract

Due to hydrogen's beneficial characteristics as a sustainable energy carrier, the application of pulsing electric fields has been researched for its effectiveness during water electrolysis. Although there have been conflicting findings on the benefits of the application of pulsing electric fields, this research highlights the potential it has to enhance the efficiency of water electrolysis while providing clarity on past discrepancies. This research achieves this by identifying distinctive energy flow profiles that result from various power input waveforms, along with subsequent hydrogen production rates and efficiencies, while also utilising a novel method of measuring the capacitance of the electrolyte to detect shifts in the molecular energy. The results indicate that pulsing electric fields can increase efficiency by up to 20 % or decrease efficiency by over 40 %, depending on the energy flow profiles of the electrical, molecular, and electrochemical dynamics. Furthermore, the use of pulsing electric fields also enabled load adaptability by allowing the electrolyser to operate effectively throughout a range of power inputs. For example, the power input could be increased to cause a 279 % increase in hydrogen production without compromising efficiency; while conversely enabling electrolysis at >65 % efficiency using power input levels which were otherwise too low to drive electrochemical reactions. This study provides another step towards making renewable hydrogen viable as a sustainable energy carrier by identifying factors which influence and are influenced by changing electrical, molecular and electrochemical dynamics, while also providing a foundation for further research into more efficient use of energy to produce hydrogen gas.