Electrochemical hydrogen storage in porous carbons with acidic electrolytes: Uncovering the potential

Electrochemical hydrogen storage in porous carbon materials is emerging as a cost-effective hydrogen storage and transport technology with competitive power and energy densities. The merits of electrochemical hydrogen storage using porous conductive carbon-based electrodes are reviewed. The employment of acidic electrolytes in such storage systems is compared with alkaline electrolytes. The recent innovations of a proton battery for smaller-scale electricity storage, and a proton flow reactor system for larger (grid)-scale storage and bulk export of hydrogen produced from renewable energy, are briefly described. It is argued that such systems, along with variants proposed by others, all of which rely on electrochemical hydrogen storage in porous carbons, can contribute to the search for energy storage technologies essential for the transition to a zero-emission global economy.