Periodic Reporting for period 1 - FreeHydroCells (Freestanding energy-to-Hydrogen fuel by water splitting using Earth-abundant materials in a novel, eco-friendly, sustainable and scalable photoelectrochemical Cell system)
Okres sprawozdawczy: 2022-11-01 do 2024-04-30
The FreeHydroCells project aims to create a new photoelectrochemical (PEC) system capable of clean, efficient solar-to-chemical energy conversion, with hydrogen gas storing the chemical energy. The system would mimic the solar-energy absorption potential of a leaf by arraying cascades of nanometre thick semiconducting materials as buried pn-junctions that, when submerged in water and exposed to sunlight, are capable of freestanding PEC water splitting. A number of technological challenges restrict the cost-effective efficiency of clean, green, solar-to-chemical hydrogen, state-of-the-art systems, making it commercially unattractive, and severely limiting hydrogen’s role in decarbonisation. However, the FreeHydroCells project proposes to leverage a number of advancements in thin film materials, devices, and processes to make similar breakthroughs in PEC band-engineering for interconnected bands, defect minimisation, thin film thickness uniformity continuity to minimise drift-dominated transit times, carrier doping for high conductivity, carrier type selectivity and, importantly, preventing significant recombination of light-generated carriers by ensuring drift transport under multiple in-built electric fields.
These breakthroughs would transform the transfer efficiency of solar-to-chemical energy via the carefully aligned redox potential and propel the PEC water splitting reactions to morph solar energy into hydrogen bonds. The new materials system could be cost-effectively realised through modified delivery techniques of atomic layer deposition and chemical vapour deposition in manufacturing-compatible, large-area capable, equipment that is now common in commercial chip and solar cell processing technologies. FreeHydroCells’ multidisciplinary expertise is key to making this substantial science-to-technology leap: to verify a paradigm proof-of-concept for a self-driven system suitable for up-scaling and commercialisation.
The main objectives of the project are: to develop new component transparent conductive oxides (TCO) and transition-metal dichalcogenide (TMD) materials and a suitable TCO/substrate, integrate them via aligned processes into a buried multijunction integrated tandem PEC cell, and develop and optimise the created PEC cell from small area proof of concept to large area proof of concept and using commercially-compatible deposition tools of ALD or CVD. The aim is to eventually achieve unassisted water splitting with the PEC cells, with the redox driven by the supply of energy transferred from the absorption of photons into electron-hole pairs that are transferred in sufficient numbers within the structure to the two separate photoelectrode surfaces, or TCO/electrolyte interfaces, which then drives the redox potential to create hydrogen fuel.
The project also aims to take the novel developed PEC cell and use it within an innovative PEC system once the PEC cell-to-system challenges are overcome, which to date provide a bottleneck for the state-of-the-art (SOA) to develop a viable system. The issues preventing unassisted water splitting are many, and the issues preventing a sufficient solar-to-hydrogen efficiency versus cost (both in terms of production and operational financial and energy input costs). Sustainability and long service life are also critical factors for cost-effective uptake and supply continuity versus other, typically cheaper, competitor fossil fuel energy sources. Sustainability with local EU supply chains means we must use environmentally-benign elements to achieve our objectives, and a long service life means we must achieve both cell and system stability, durability and reliability. These issues are especially problematic at the PEC system level, and to date, the SOA has not achieved an affordable and viable efficiency/cost ratio for PEC water splitting hydrogen production. The project is considered by the EU to be a high-risk/high-reward research and innovation action, and hence the challenges before us are many and great. Within the tight timeline of the project we must progress from TRL 2-3 with emerging new materials components, scientifically engineer and integrate them into novel PEC cells, and create a new innovative PEC system into which the PEC cells will be placed. We combine this with test and characterisation along the way, and we aim to align the final proof of concept verification system at TRL 4 with the ability for rapid upscaling and commercialisation. The end of this first reporting period for months 1-18 gives us stepping-stone achievements towards these scientific and technological objectives.
These breakthroughs would transform the transfer efficiency of solar-to-chemical energy via the carefully aligned redox potential and propel the PEC water splitting reactions to morph solar energy into hydrogen bonds. The new materials system could be cost-effectively realised through modified delivery techniques of atomic layer deposition and chemical vapour deposition in manufacturing-compatible, large-area capable, equipment that is now common in commercial chip and solar cell processing technologies. FreeHydroCells’ multidisciplinary expertise is key to making this substantial science-to-technology leap: to verify a paradigm proof-of-concept for a self-driven system suitable for up-scaling and commercialisation.
The main objectives of the project are: to develop new component transparent conductive oxides (TCO) and transition-metal dichalcogenide (TMD) materials and a suitable TCO/substrate, integrate them via aligned processes into a buried multijunction integrated tandem PEC cell, and develop and optimise the created PEC cell from small area proof of concept to large area proof of concept and using commercially-compatible deposition tools of ALD or CVD. The aim is to eventually achieve unassisted water splitting with the PEC cells, with the redox driven by the supply of energy transferred from the absorption of photons into electron-hole pairs that are transferred in sufficient numbers within the structure to the two separate photoelectrode surfaces, or TCO/electrolyte interfaces, which then drives the redox potential to create hydrogen fuel.
The project also aims to take the novel developed PEC cell and use it within an innovative PEC system once the PEC cell-to-system challenges are overcome, which to date provide a bottleneck for the state-of-the-art (SOA) to develop a viable system. The issues preventing unassisted water splitting are many, and the issues preventing a sufficient solar-to-hydrogen efficiency versus cost (both in terms of production and operational financial and energy input costs). Sustainability and long service life are also critical factors for cost-effective uptake and supply continuity versus other, typically cheaper, competitor fossil fuel energy sources. Sustainability with local EU supply chains means we must use environmentally-benign elements to achieve our objectives, and a long service life means we must achieve both cell and system stability, durability and reliability. These issues are especially problematic at the PEC system level, and to date, the SOA has not achieved an affordable and viable efficiency/cost ratio for PEC water splitting hydrogen production. The project is considered by the EU to be a high-risk/high-reward research and innovation action, and hence the challenges before us are many and great. Within the tight timeline of the project we must progress from TRL 2-3 with emerging new materials components, scientifically engineer and integrate them into novel PEC cells, and create a new innovative PEC system into which the PEC cells will be placed. We combine this with test and characterisation along the way, and we aim to align the final proof of concept verification system at TRL 4 with the ability for rapid upscaling and commercialisation. The end of this first reporting period for months 1-18 gives us stepping-stone achievements towards these scientific and technological objectives.
In this first reporting period of the FreeHydroCells project, we have explored a variety of novel semiconductor and other material components in order to assess different property requirements for multijunction photoelectrochemical (PEC) cells. In addition, we have assessed various multijunction systems based on the materials assessments, and further investigated their bulk and interface properties. These activities have permitted the consortium to focus in on preferred material and junction solution pathways for the most appropriate PEC cells to advance. Furthermore, a novel cell-to-system approach has been developed that is specifically suited to the aims of the project. An initial design has been created and it is now being iteratively refined and in the early stages of manufacture alongside a novel gas management system design. This gas management subsystem design is now being iteratively refined and integrated into the cell-to-system design in order to implement a full photoelectrochemical system for proof of concept verification purposes. The testing scenarios and testing matrices have been designed and specified. This period of activity has been critical in focusing the project onto specific pathways to reach our objectives.
Since this is the first reporting period of M1-M18, we are too early in the project to be able to identify key needs for the end of project achievements. However, at this stage, we certainly need more research activity within the consortium to advance our stepping-stone achievements to date on novel materials, novel materials integration towards a new PEC cell, a parallel development of an innovative and integrated PEC system, and the stepping-stone advances we are making towards enabling a novel PEC cell-to-system transition. At the same time, we have the tools to ensure IPR protection is well balanced with our open science commitments, so that we can aim for uptake and success while keeping focused on our scientific and technological objectives for the end of the project, when we will be closer to potential impact pathways for positioning the developed technology for the next upscaling and commercialisation phase should our achievements be sufficient.