Low Voltage Electrochemical Aqueous Hydrogen Storage

Abstract

Recent years have witnessed the hydrogen production techniques being cheaper and greener. Therefore, as the mass use of hydrogen in energy applications is revisited, hydrogen storage became an important part of the supply chain. However, safety concerns of compressed gas storage made it impossible for mass hydrogen storage in places like airports and industries. By using an aqueous quinone-based flow battery setup operated under room temperature, hydrogen can be stored up to 2.5 M, which is in equivalent to a 56-atm gas tank in terms of hydrogen density. The release of hydrogen can be achieved at 0.25 V and a roundtrip energy requirement for < 7 kWh/kgH2. The Coulomb efficiency for 100 mA/cm^2 cells is at 99.8% and the fade rate of AQDS is around 0.1%/day. This work aims to find a way of safe and cost-efficient hydrogen storage and raises some possibilities of the design for next-generation hydrogen storage techniques.