Iñigo Garbayo

• PhD
• Hydrogen Area Manager at National Renewable Energy Centre

Energy transition towards a net-zero emission scenario requires, primarily, a significant increase on the renewable energy production capabilities. However, the inherent intermittency of most common renewable sources, added to the limitations of full electrification in some important hard-to-abate sectors (heavy-duty transport, aviation, steel indu...

The thrust of green hydrogen as energy vector for the consolidation of a net-zero emitting global energy system implies the necessity of a fast development of high performing and highly efficient fuel cells and electrolyzers. Among the commercial choices, solid oxide cells can be considered as a better performing alternative compared to commercial...

Climate crisis and the subsequent increase of fossil fuels prices have encouraged the search for alternative and renewable energy sources. In this scenario, the use of hydrogen as green energy carrier is nowadays regarded as one of the keys to achieve the transition to a fully renewable energy system. Among the existent and commercial technologies...

Green hydrogen is widely considered as a reliable solution to provide flexibility to a renewable energy-based system, decarbonize hard-to-abate-sectors and achieve a net zero emissions scenario. In this sense, Solid Oxide Electrolyzers (SOE) are meant to play an important role for the production of green hydrogen. In order to fulfill high performan...

In this work, the guidelines for the design of the thermal management of solid oxide fuel cells (SOFC) by means of computational fluid dynamics (CFD) and numerical optimization tools are proposed. These approaches combine acting both on operating conditions and cell geometry. Initially, the influence of inlet gas flows is evaluated, describing how...

Hydrogen is gaining increasing attention in the recent years as an effective energy carrier for grid flexibilization and the decarbonization of hard-to-abate sectors. Among the different technologies under development for power-to-hydrogen conversion, solid oxide electrolysis (SOE) outstands due to its high conversion efficiency, fuel flexibility (...

The substitution of an organic liquid electrolyte with lithium-conducting solid materials is a promising approach to overcome the limitations associated with conventional lithium-ion batteries. These constraints include a reduced electrochemical stability window, high toxicity, flammability, and the formation of lithium dendrites. In this way, all-...

Motivated by the vast potential of the technology, at CENER we recently launched the H2 area to contribute to the development of SOE as a key player in the efficient production of green hydrogen. This poster gives a brief introduction to our activities, which are divided in (i.) the integration of new materials into SOE cells and stacks and (ii.) m...

The increasing demand for electrical energy storage requires the exploration of alternative battery chemistries that overcome the limitations of the current state‐of‐the‐art lithium‐ion batteries. In this scenario, lithium‐sulfur batteries stand out for their high theoretical energy density. However, several inherent limitations still hinder their...

The use of gel polymer electrolytes (GPEs) is of great interest to build high-performing rechargeable lithium metal batteries (LMBs) owing to the combination of good electrochemical properties and improved safety. Herein, we report a facile and scalable one-pot preparation method of a GPE based on highly safe polyethylene glycol dimethyl ether (PEG...

Unveiling point defects concentration in transition metal oxide thin films is essential to understand and eventually control their functional properties, employed in an increasing number of applications and devices. Despite this unquestionable interest, there is a lack of available experimental techniques able to estimate the defect chemistry and e...

Lithium solid-state batteries (SSBs) are considered as a promising solution to the safety issues and energy density limitations of state-of-the-art lithium-ion batteries. Recently, the possibility of developing practical SSBs has emerged thanks to striking advances at the level of materials; such as the discovery of new highly-conductive solid-stat...

Lithium–sulfur batteries are attracting extensive attention for energy storage owing to their high theoretical energy density. However, their practical implementation is hindered because of inherent issues of the technology such as the shuttling effect of the polysulfide intermediates and the formation of dendritic lithium metal (Li⁰) deposits duri...

The defect chemistry of La1−xSrxFeO3−δ (LSF) thin films is unveiled for intermediate‐to‐low temperature range using a novel in situ ellipsometry approach. The evolution of the concentration of holes in the LSF thin films with oxygen partial pressure and temperature is obtained. This technique pushes the limits for tracking the defect chemistry in L...

Unveiling point defects concentration in transition metal oxide thin films is essential to understand and eventually control their functional properties, employed in an increasing number of applications and devices. Despite this unquestionable interest, there is a lack of available experimental techniques able to estimate the defect chemistry and e...

Introducing a small dose of electrolyte additive in solid polymer electrolytes (SPEs) is an appealing strategy for improving the quality of solid-electrolyte-interphase (SEI) layer formed on lithium metal (Li°) anode, thereby extending the cycling life of solid-state lithium metal batteries (SSLMBs). In this work, we report a new type of SPEs compr...

Spanish educational laws specify the percentage of a student’s grades that correspond to knowledge, skills, and behavior. In recent years, the percentage assigned to attitudes has grown due to the importance that pedagogues and psychologists place on good attitude and coexistence in learning processes. In this regard, this study explores how teache...

Stabilized bismuth vanadate thin films are presented here as superior oxide ionic conductors, for application in solid state electrochemical devices operating near room temperature. Widely studied in the 90´s in bulk form due to their unbeatable ionic conduction, this family of materials was finally discarded due to poor stability above 500 ºC. Her...

A critical parameter for the large-scale integration of solid-state batteries is to establish processing strategies to assemble battery materials at the lowest processing temperature possible while keeping lithium conduction up. Despite extensive research efforts, integrating ceramic film electrolytes while keeping a high lithium concentration and...

Free-standing solid-state ion conducting thin film membranes are key components in micro-energy conversion devices such as micro-solid oxide fuel cells or electrolyzers. Through this work, we explore the design and fabrication of thin film architectures with either straight, zigzag or spiral-shaped columnar grain nanostructures of 8 mol% doped Yttr...

Grain boundaries in Sr-doped LaMnO3 thin films have been shown to strongly influence the electronic and oxygen mass transport properties, being able to profoundly modify the nature of the material. The unique behaviour of the grain boundaries can be correlated with substantial modifications of the cation concentration at the interfaces, which can b...

Interface-dominated materials such as nanocrystalline thin films have emerged as an enthralling class of materials able to engineer functional properties of transition metal oxides widely used in energy and information technologies. In particular, it has been proved that strain-induced defects in grain boundaries of manganites deeply impact their f...

Grain boundaries of strontium‐doped lanthanum manganite thin films are characterized by Albert Tarancón and co‐workers in article number 1805360, by a strong modification of both the anionic and cationic composition. The grain‐boundary local nonstoichiometry can be altered by tuning the overall cationic content in the thin films, offering a tool to...

Grain boundaries in Sr-doped LaMnO3±δ thin films have been shown to strongly influence the electronic and oxygen mass transport properties, being able to profoundly modify the nature of the material. The unique behavior of the grain boundaries can be correlated with substantial modifications of the cation concentration at the interfaces, which can...

Interface-dominated materials such as nanocrystalline thin films have emerged as an enthralling class of materials able to engineer functional properties of transition metal oxides widely used in energy and information technologies. In particular, it has been proven that strain-induced defects in grain boundaries of manganites deeply impact their f...

The behavior of interface-dominated metal-oxide thin films is largely influenced by nanoionic effects. The control and engineering of interfaces becomes a powerful tool for the design of optimized electrochemical devices, in which ion movement plays a primary role. This chapter provides a comprehensive description of the most relevant ionic phenome...

There is a growing interest in the development of functional metal oxides with mixed ionic electronic conduction for their application in different strategic fields. In particular, ionic transport-related phenomena are of primary importance in energy transformation and storage devices, such as solid oxides fuel cells (SOFC) or batteries. Traditiona...

Ion transport in solid-state devices is of great interest for current and future energy and information technologies. A superior enhancement of several orders of magnitude of the oxygen diffusivity has been recently reported for grain boundaries in lanthanum strontium manganites. However, the significance and extent of this unique phenomenon is not...

New emerging disciplines such as Nanoionics and Iontronics are dealing with the exploitation of mesoscopic size effects in materials, which become visible (if not predominant) when downsizing the system to the nanoscale. Driven by the worldwide standardisation of thin film deposition techniques, the access to radically different properties than tho...

New emerging disciplines such as Nanoionics and Iontronics are dealing with the exploitation of mesoscopic size effects in materials, which become visible (if not predominant) when downsizing the system to the nanoscale. Driven by the worldwide standardisation of thin film deposition techniques, the access to radically different properties than tho...

In the goal of a sustainable energy future, either the energy efficiency of renewable energy sources is increased, day‐to‐day energy consumption by smart electronic feedback loops is managed in a more efficient way, or contribution to atmospheric CO2 is reduced. By defining a next generation of fast‐response electrochemical CO2 sensors and material...

Ion transport in solid-state devices is of great interest for current and future energy and information technologies. A superior enhancement of several orders of magnitude of the oxygen diffusivity has been recently reported for grain boundaries in lanthanum-strontium manganites. However, the significance and extent of this unique phenomenon are no...

Solid state electrolytes, such as Li‐Garnets, are fastest Li‐ionic conductor materials that have attracted attention for safe hybrid and full solid state battery architectures. Turning to oxide‐based low voltage anodes gives opportunities to avoid Li‐dendrite formation and also to reach full thin film microbattery architectures based on garnets as...

Ceramic Li7La3Zr2O12 garnet materials are promising candidates for the electrolytes in solid state batteries due to their high conductivity and structural stability. In this paper, the existence of “polyamorphism” leading to various glass-type phases for Li-garnet structure besides the known crystalline ceramic ones is demonstrated. A maximum in Li...

Portable electronic devices are already an indispensable part of our daily life; and their increasing number and demand for higher performance is becoming a challenge for the research community. In particular, a major concern is the way to efficiently power these energy-demanding devices, assuring long grid independency with high efficiency, sustai...

Portable electronic devices are already an indispensable part of our daily life; and their increasing number and demand for higher performance is becoming a challenge for the research community. In particular, a major concern is the way to efficiently power these energy-demanding devices, assuring long grid independency with high efficiency, sustai...

Enhancing the efficiency of micro-energy conversion devices through engineering of the structure-transport relationship is a prerequisite toward next generation micro-electrolysers and fuel cells. Here, oxygen ion conducting free-standing thin films are key elements, forming buckled and strained membranes for gas exchange and energy conversion. The...

Garnet-based Al-doped Li7La3Zr2O12 has the potential to be used as a solid state electrolyte for future lithium microbattery architectures, due to its relatively high Li(+) conductivity and stability against Li. Through this work, a model experiment is presented in which the effect of post-lithiation on phase formation and chemical stability is stu...

A novel design of a silicon-based micro-reformer for onboard hydrogen generation from ethanol is presented in this work. The micro-reactor is fully fabricated with mainstream MEMS technology and consists of an active low-thermal-mass structure suspended by an insulating membrane. The suspended structure includes an embedded resistive metal heater a...

Lithium stuffed garnet oxides such as Li 7 La 3 Zr 2 O 12 have attracted considerable attention as promising candidate for solid electrolytes for All Solid State Lithium Ion Batteries. Their high Li-ion conductivity of ca. 1x10 ⁻³ Scm ⁻¹ , wide temperature stability window, stability against metallic lithium and compatibility with high voltage new...

The next generation of energy storage devices relies on a broad and adaptable range of volumetric and gravimetric energies to compete with the challenges in stationary, mobile and portable electronics electricity supply. Here, all solid state batteries based on Li-garnet structures are interesting model systems as these allow for complete solid sta...

Next generation energy storage devices for stationary as well as mobile electronics will not only need high gravimetric and volumetric capacity, but also long term stability even in rough environments at elevated temperature. Here, all solid state batteries based on Li-garnet structures are shown as interesting model systems that: i.) can partially...

Fuel cells convert chemical energy directly into electricity with high efficiency. Solid-oxide fuel cells (SOFCs) have the highest performance and durability. Traditional SOFCs operate at temperatures above 600 °C, and lowering the temperature to 400–500 °C is the key to new applications, for example, miniaturized systems with fast start/stop cycli...

New emerging disciplines are specifically devoted to study trivial and non-trivial effects resulting from working in the nanoscale, however, the implementation of these nanostructures in real devices is still a major challenge. Thin film deposition and silicon microtechnology is probably the most promising and straightforward combination for the re...

Increasing the efficiencies for micro energy conversion devices based on oxygen ion conducting solid state membranes are the prerequisite toward next generations' electrolysers and fuel cells. Here, gadolinium-doped ceria free-standing thin films are a key element i.e. for micro solid oxide fuel cells (μSOFCs). In this work, we investigate the diff...

The next generation of energy storage devices relies on a broad and adaptable range of volumetric and gravimetric energies to compete with the challenges in stationary, mobility and portable electronic electricity supply. Here, all solid state batteries based on Li-garnet-based structures are interesting model systems as these allow for complete so...

Oxygen ion conducting membranes are the key for micro energy conversion devices, ie. electrolyte of micro solid oxide fuel cell (µSOFC). In particular, gadolinium-doped ceria thin films are currently intensively studied, as one of the most promising electrolyte candidates due to their good ionic conductivity at intermediate temperatures. For better...

New emerging disciplines are specifically devoted to study trivial and non-trivial effects resulting from working in the nanoscale, however, the implementation of these nanostructures in real devices is still a major challenge. Thin film deposition and silicon microtechnology is probably the most promising and straightforward combination for the re...

A novel design of a fuel-flexible micro-reactor for hydrogen generation from ethanol and methane is proposed in this work. The micro-reactor is fully fabricated with mainstream MEMS technology and consists of an array of more than 20000 through-silicon vertically aligned micro-channels per cm² of 50 μm in diameter. Due to this unique configuration,...

Development of micro power generation systems employing hydrogen-fed solid oxide fuel cells (SOFCs) is gaining interest because they may reach higher energy densities than state-of-the-art rechargeable lithium-ion batteries. However, there still exist several technological challenges to be overcome before the technology is introduced into the real...

A cross plane potentiometric micro gas sensor has been developed. The device is based on a thin electrolyte membrane deposited on a silicon micromachined platform. This new fabrication route combines industrial clean room batch production processes with the use of nanometric thin films of Ytria Stabilized Zirconia as solid electrolyte. The membrane...

Batteries, with a limited capacity, have dominated the power supply of portable devices for decades. Recently, the emergence of new types of highly efficient miniaturized power generators like micro fuel cells has open alternatives for continuous operation on the basis of unlimited fuel feeding. This work addresses for the first time the developmen...

Yttria-stabilized zirconia thin films for micro solid oxide fuel cell applications were grown by pulsed laser deposition onto silicon-based microfabricated substrates. In order to obtain pinhole-free membranes, the influence of the microstructure of the target on the ejection of particulates to the film was studied. Targets with different contents...

Yttria-stabilized zirconia free-standing membranes were fabricated by pulsed laser deposition on Si/SiO2/Si3N4 structures for developing silicon-based micro devices for micro solid oxide fuel cell applications. Their mechanical stability under working conditions was evaluated satisfactorily by applying thermal cycling to the membranes. Membranes me...

The present study is devoted to analyze the compatibility of yttria-stabilized zirconia thin films prepared by pulsed laser deposition and metalorganic chemical vapor deposition techniques, with microfabrication processes based on silicon technologies for micro solid oxide fuel cells applications. Deposition of yttria-stabilized zirconia on Si/SiO2...

The present work is devoted to study the development of yttria-stabilized zirconia membranes self-supported on silicon-based microplatforms, to be used as electrolytes on micro solid oxide fuel cells. The microfabrication process to obtain yttria-stabilized zirconia membranes is detailed, and some key aspects for the integration of yttria-stabilize...

The present study is devoted to analyze the compatibility of yttria-stabilized zirconia thin films prepared by pulsed laser deposition technique for developing new silicon-based micro devices for micro solid oxide fuel cell applications. Yttria-stabilized zirconia free-standing membranes with thicknesses from 60 to 240 nm and surface areas between...

The present study is devoted to analyze the compatibility of yttria-stabilized zirconia thin films prepared by pulsed laser deposition technique for developing new silicon-based micro devices for micro solid oxide fuel cells applications. Yttria-stabilized zirconia free-standing membranes with thicknesses from 60 to 240 nm and surface areas between...

The increasing interest in fully integrated electronic systems for portable applications has originated new research developments in micropower sources. In this context, micro fuel cells arise as a promising solution for the power supply of portable microsystems [1,2]. The main issue in order to use such devices for this purpose is to be able to fa...