Periodic Reporting for period 1 - EPISTORE (Thin Film Reversible Solid Oxide Cells for Ultracompact Electrical Energy Storage)
Okres sprawozdawczy: 2021-01-01 do 2021-12-31
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 description of the work performed during the first reporting period is explained by work packages (WP) below:
WP2 – Advanced tools for solid state nanoionics
Characterizing phenomena at the nanoscale is technically challenging, and is more complex when the characterization is performed under the operating conditions of the electrochemical devices under investigation in this projectIn order to achieve significant advances, we have utilized a range of advanced tools. Key challenges are associated with the migration of species (diffusive processes) and in particular the correlated transport of anion species at grain boundaries. In order to achieve these, we have combined experimental techniques with simulation.
WP3 – Nanoscale enhanced and stable TF electrolytes
Experimental investigations of field-dependent ionic conductivity face severe problems in terms of sample geometry and interfering bulk and interfacial effects. In this WP, suitable structures for such measurements (thin films with appropriate electrodes) have been successfully fabricated, and first impedance spectra under fields have been measured.A number of high-entropy oxide (HEO) compositions have been synthesized by means of mechanochemical, Pechini or flame-spray-pyrolysis routes. They have been examined for their phase purity with XRD. In addition, selected compositions have been examined for their sintering behaviour (with dilatometry) and for their homogeneity on the atomic scale. MD simulations of oxygen diffusion have also been carried out, and they indicate lower oxygen diffusivities in HEO materials compared to the parent (fluorite) material. Progress has also been made in the deposition of the barrier layer. The properties of these thin films have been studied in terms of microstructure, chemistry and electrochemical performance.
WP4 – Nanoscale engineered high performing TF electrodes
The present reporting period has seen the development of several novel high-performance fuel and oxygen electrode candidates based on VAN, HEO, and ex-solution strategies.
The HEO materials have been successfully fabricated, exhibiting high phase purity, homogenous elemental distribution, and stability up to 1200° C. Finally, low-temperature ex-solution of metal from a perovskite matrix has been demonstrated, with electron microscopy studies ongoing into the precise control of ex-solved particle size and population densities. Through this research, the performance limiting ASR of the oxygen electrode has been reduced to ~10 Ωcm2 at 500° C, a reduction of approximately four orders of magnitude compared to planar LSCF thin films.
WP5 – Micro & nano technologies for thin film rSOC cells
The main activities carried out have been technological revision of SoN procedures. Adequate equipment has been identified and processes have been setup with initial good results in all three cases. This is the substrate structure where Si-doped current collectors will be defined and onto which the functional thin films will be deposited. The whole ensemble will be detached and transferred to the cell metallic counterparts. Additional activities have been the study of technological alternatives as contingency plan.
WP2 – Advanced tools for solid state nanoionics
Characterizing phenomena at the nanoscale is technically challenging, and is more complex when the characterization is performed under the operating conditions of the electrochemical devices under investigation in this projectIn order to achieve significant advances, we have utilized a range of advanced tools. Key challenges are associated with the migration of species (diffusive processes) and in particular the correlated transport of anion species at grain boundaries. In order to achieve these, we have combined experimental techniques with simulation.
WP3 – Nanoscale enhanced and stable TF electrolytes
Experimental investigations of field-dependent ionic conductivity face severe problems in terms of sample geometry and interfering bulk and interfacial effects. In this WP, suitable structures for such measurements (thin films with appropriate electrodes) have been successfully fabricated, and first impedance spectra under fields have been measured.A number of high-entropy oxide (HEO) compositions have been synthesized by means of mechanochemical, Pechini or flame-spray-pyrolysis routes. They have been examined for their phase purity with XRD. In addition, selected compositions have been examined for their sintering behaviour (with dilatometry) and for their homogeneity on the atomic scale. MD simulations of oxygen diffusion have also been carried out, and they indicate lower oxygen diffusivities in HEO materials compared to the parent (fluorite) material. Progress has also been made in the deposition of the barrier layer. The properties of these thin films have been studied in terms of microstructure, chemistry and electrochemical performance.
WP4 – Nanoscale engineered high performing TF electrodes
The present reporting period has seen the development of several novel high-performance fuel and oxygen electrode candidates based on VAN, HEO, and ex-solution strategies.
The HEO materials have been successfully fabricated, exhibiting high phase purity, homogenous elemental distribution, and stability up to 1200° C. Finally, low-temperature ex-solution of metal from a perovskite matrix has been demonstrated, with electron microscopy studies ongoing into the precise control of ex-solved particle size and population densities. Through this research, the performance limiting ASR of the oxygen electrode has been reduced to ~10 Ωcm2 at 500° C, a reduction of approximately four orders of magnitude compared to planar LSCF thin films.
WP5 – Micro & nano technologies for thin film rSOC cells
The main activities carried out have been technological revision of SoN procedures. Adequate equipment has been identified and processes have been setup with initial good results in all three cases. This is the substrate structure where Si-doped current collectors will be defined and onto which the functional thin films will be deposited. The whole ensemble will be detached and transferred to the cell metallic counterparts. Additional activities have been the study of technological alternatives as contingency plan.
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