Periodic Reporting for period 2 - EPISTORE (Thin Film Reversible Solid Oxide Cells for Ultracompact Electrical Energy Storage)
Periodo di rendicontazione: 2022-01-01 al 2023-06-30
In the last decades, advanced thin film technology has enabled a wide range of technological breakthroughs that have transformed entire sectors such as electronics and lighting by the implementation of outstanding nanoscale phenomena in reliable products that involve ultralow contents of critical raw materials (CRMs). Epistore aims to revolutionize the energy storage sector by developing pocket-sized kW-range stacks based on thin film reversible Solid Oxide Cells (TF-rSOCs) that will be able to efficiently store renewable electricity for applications where the use of batteries is inefficient due to size constraints or long term storage requirements, e.g. off-shore power generation or transportation. Nanoscale breakthroughs and never explored materials will be combined in revolutionary TF-rSOCs giving rise to radically new ultracompact and fast response Power-to-Gas and Power-to-Power storage solutions with superior performance (hydrogen production of 10kg/l per hour and specific power of 2.5kW/kg) and negligible use of CRMs (50mg/kW). In order to enable this science-to-technology step forward, our nano-enabled TF-rSOCs will be integrated in scalable silicon technology to show their viability as a potentially low-cost new paradigm of large-scale energy storage.
The work performed during the first reporting period is divided into work packages (WP) as follows:
WP2 – Advanced tools for solid state nanoionics
Understanding nanoscale phenomena is challenging, especially under electrochemical device operating conditions. A range of advanced techniques applicable to the structural and functional characterisation of thin film solid oxide electrolysers have been evaluated, and data from both electrodes and electrolytes recorded. Findings have been combined with new theoretical approaches to develop and advance understanding of the key ionic and electonic transport properties of materials, including newly developed high entropy oxides.
WP3 – Nanoscale enhanced and stable TF electrolytes
Suitable structures for thin film measurements have been fabricated, and impedance spectra under fields recorded. High-entropy oxide (HEO) compositions synthesized, phase purity checked, and sintering behavior examined. Oxygen diffusion simulations reveal lower diffusivities in HEO materials. Barrier layer deposition progress was made. Thin film properties were studied for microstructure, chemistry, and electrochemical performance. YSZ remains the favorable electrolyte based on simulations and measurements, while exploring high entropy oxides by eliminating or replacing some of the active elements.
WP4 – Nanoscale engineered high performing TF electrodes
Novel high-performance fuel and oxygen electrodes based on VAN, HEO, and ex-solution have been developed. HEO materials have been successfully fabricated with high purity and stability. Low-temperature ex-solution of metal from a perovskite matrix has been demonstrated. Through this research, the performance limiting ASR of the oxygen electrode has been reduced in line with the target value. Novel VAN electrodes show promise performance in SOFC and SOEC modes. The consortium have likewise been successful in collaborating with industrial partners to upscale fabrication of multiple HEO candidate materials.
WP5 – Micro & nano technologies for thin film rSOC cells
Silicon on Nothing (SoN) is the main technique proposed for the silicon skin formation. Initial SoN samples were fabricated. Alternatives to the SoN approaches have been successfully developed, first skins have been transferred. Activities to transfer those skins onto the machined metal counterparts are on-going. Membranes fabricated using a novel process exhibited a good electrochemical performance. AP-SALD technique has been used for large area deposition. In addition, a bulge test station has been set up with a pressure controller and a Michelson interferometric microscope.
WP6 – TF-rSOC stacks and P2G and P2P electrical energy storage
Initial metal plate designs for TF-rSOC stack interconnectors has been proposed based on design requirements. Series and parallel fluidic connections have been explored, focusing on series gas flow for initial tests. A sealing procedure for SRUs developed using high-temperature glass sealing and robocasting has been proposed and tested on a dummy stack. Also a encapsulation designs for s-SOC stack fabricated using SLA-printed ceramic pieces has been designed. Operational conditions have been determined for various r-SOC regimes, leading to a defined balance of plant. All components for the system have been chosen.
WP2 – Advanced tools for solid state nanoionics
Understanding nanoscale phenomena is challenging, especially under electrochemical device operating conditions. A range of advanced techniques applicable to the structural and functional characterisation of thin film solid oxide electrolysers have been evaluated, and data from both electrodes and electrolytes recorded. Findings have been combined with new theoretical approaches to develop and advance understanding of the key ionic and electonic transport properties of materials, including newly developed high entropy oxides.
WP3 – Nanoscale enhanced and stable TF electrolytes
Suitable structures for thin film measurements have been fabricated, and impedance spectra under fields recorded. High-entropy oxide (HEO) compositions synthesized, phase purity checked, and sintering behavior examined. Oxygen diffusion simulations reveal lower diffusivities in HEO materials. Barrier layer deposition progress was made. Thin film properties were studied for microstructure, chemistry, and electrochemical performance. YSZ remains the favorable electrolyte based on simulations and measurements, while exploring high entropy oxides by eliminating or replacing some of the active elements.
WP4 – Nanoscale engineered high performing TF electrodes
Novel high-performance fuel and oxygen electrodes based on VAN, HEO, and ex-solution have been developed. HEO materials have been successfully fabricated with high purity and stability. Low-temperature ex-solution of metal from a perovskite matrix has been demonstrated. Through this research, the performance limiting ASR of the oxygen electrode has been reduced in line with the target value. Novel VAN electrodes show promise performance in SOFC and SOEC modes. The consortium have likewise been successful in collaborating with industrial partners to upscale fabrication of multiple HEO candidate materials.
WP5 – Micro & nano technologies for thin film rSOC cells
Silicon on Nothing (SoN) is the main technique proposed for the silicon skin formation. Initial SoN samples were fabricated. Alternatives to the SoN approaches have been successfully developed, first skins have been transferred. Activities to transfer those skins onto the machined metal counterparts are on-going. Membranes fabricated using a novel process exhibited a good electrochemical performance. AP-SALD technique has been used for large area deposition. In addition, a bulge test station has been set up with a pressure controller and a Michelson interferometric microscope.
WP6 – TF-rSOC stacks and P2G and P2P electrical energy storage
Initial metal plate designs for TF-rSOC stack interconnectors has been proposed based on design requirements. Series and parallel fluidic connections have been explored, focusing on series gas flow for initial tests. A sealing procedure for SRUs developed using high-temperature glass sealing and robocasting has been proposed and tested on a dummy stack. Also a encapsulation designs for s-SOC stack fabricated using SLA-printed ceramic pieces has been designed. Operational conditions have been determined for various r-SOC regimes, leading to a defined balance of plant. All components for the system have been chosen.
The main expected impact of the Epistore project is the foundation of a new science-enabled technology for zero-emission compact energy storage by defining a ground-breaking approach that combines nanoscale concepts with new materials. Regarding the technical aspects, Epistore gives rise to an entirely new technology paradigm based on ground-breaking nanoscale concepts and never-explored materials for ultracompact energy storage, the TF-rSOCs and pocket-sized stacks (scalable to larger systems), able to store electricity in the form of gas (P2G) or standalone power-to-power units (P2P).
During this first reposting period, several candidate materials have been studied for the development of high entropy oxides (HEO) and vertically aligned nanocomposites (VANs) to be used as electrodes and electrolytes. Solid conclusions arose from the molecular dynamincs simulations that demonstrate that the presence of grain boundaries on those materials hinder the diffusion of oxygen. Some of the electrodes were successfully deposited using the novel spatial atomic layer deposition (SALD) technique. Ex-solution has been investigated with the main purpose to improve the performance of the electrodes. Finally, great progress have been done towards the fabrication of silicon skin based on the silicon-on-nothing (SoN) technique. However, further development is still required to create the whole device on SoN and subsequently transfer to a metallic thin film.
After the achievement of the stablished targets, our technology will address part of the P2G market of Electrical Energy Storage (EES) from variable Renewable Energy Sources (RES) with expected revenues exceeding €3 billion by 2030. In particular, Epistore targets off-grid applications where the footprint is relevant such as EES for off-shore power generation (a growing market expanding at 9.5% CAGR). Beyond existing applications, Epistore standalone P2P technology will foster the emerging market of zero-emission portable energy storage and power generation for transportation (e.g. airliners/ships) by reducing the pollution compared to combustion engines. In addition, the project will strongly impact in the economic innovation by promoting KET enabling technologies, reducing the use of critical raw materials and reinforcing the EU value chain, which creates highly qualified jobs. Finally, great environmental benefits are expected due to the direct substitution of fossil fuels and radical reduction of rare and toxic materials
During this first reposting period, several candidate materials have been studied for the development of high entropy oxides (HEO) and vertically aligned nanocomposites (VANs) to be used as electrodes and electrolytes. Solid conclusions arose from the molecular dynamincs simulations that demonstrate that the presence of grain boundaries on those materials hinder the diffusion of oxygen. Some of the electrodes were successfully deposited using the novel spatial atomic layer deposition (SALD) technique. Ex-solution has been investigated with the main purpose to improve the performance of the electrodes. Finally, great progress have been done towards the fabrication of silicon skin based on the silicon-on-nothing (SoN) technique. However, further development is still required to create the whole device on SoN and subsequently transfer to a metallic thin film.
After the achievement of the stablished targets, our technology will address part of the P2G market of Electrical Energy Storage (EES) from variable Renewable Energy Sources (RES) with expected revenues exceeding €3 billion by 2030. In particular, Epistore targets off-grid applications where the footprint is relevant such as EES for off-shore power generation (a growing market expanding at 9.5% CAGR). Beyond existing applications, Epistore standalone P2P technology will foster the emerging market of zero-emission portable energy storage and power generation for transportation (e.g. airliners/ships) by reducing the pollution compared to combustion engines. In addition, the project will strongly impact in the economic innovation by promoting KET enabling technologies, reducing the use of critical raw materials and reinforcing the EU value chain, which creates highly qualified jobs. Finally, great environmental benefits are expected due to the direct substitution of fossil fuels and radical reduction of rare and toxic materials