Chapter 11: Prototyping Development of Integrated Solar-driven Water-splitting Cells

Producing fuels directly from sunlight using cost effective, and earth-abundant materials, with scalable processes, offers a unique opportunity and design space for long-term, grid-scale energy storage. Efficient solar-fuel devices require synergistic assembly of light absorbers, electrocatalysts, membrane separators and electrolytes. This book chapter summaries key materials, components and device designs that are critical to advance this technology, as well as attempts on integration of materials and components at different length scales during the original phase of JCAP. Not only successful device demonstrations but also failed attempts and lessons learned during the research and development will be presented, including stability and compatibility of various epoxy materials in different electrolytes, experimental handling and integration of ion-exchange membranes, and failed attempts on light absorber materials and lessons learned on electrolyte conditions and constraints. The book chapter is organized as follows: first, the selections of materials and components that constitute efficient, stable, scalable and safe solar fuel devices will be discussed in detail. Then, full device design, characterization and benchmarking will be reviewed and discussed. At the end, a system engineering approach will be introduced and specific examples of hierarchical requirements relating to the solar-fuel devices will be given. Prototyping and benchmarking integrated solar-driven water-splitting devices play a critical role in evaluating newly discovered materials and components in the real world settings and provide technical readiness level for practical development and deployment. Significant efforts in developing standard protocols for benchmarking are still needed to advance photoelectrochemical hydrogen production.