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Arata Nakajo

Cette personne a quitté l’EPFL

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Publications associées (40)

Page 2 sur 2

Prediction of crack nucleation and propagation in porous ceramics using the phase-field approach

Arata Nakajo

The relevance of the phase-field approach to simulate the fracture in porous ceramics has been investigated. For this purpose, the conditions for the crack initiation using the phase-field model have been compared to the theoretical predictions of the coup ...

ELSEVIER2022

Compilation of mechanical properties for the structural analysis of solid oxide fuel cell stacks. Part II: Metallic interconnect, sealants and gas diffusion layers

Jan Van Herle, Arata Nakajo

Solid oxide fuel cell (SOFC) stacks are extremely vulnerable to mechanical failures in any of their constituents, which ultimately lead to cell cracking. Like all devices, distinct failure sequences arise from different events or design particularities. Th ...

2011

Simulation of thermal stresses in anode-supported solid oxide fuel cell stacks. Part II: Loss of gas-tightness, electrical contact and thermal buckling

Jan Van Herle, Daniel Favrat, Zacharie Wuillemin, Arata Nakajo

Structural stability issues in planar solid oxide fuel cells arise from the mismatch between the coefficients of thermal expansion of the components. The stress state at operating temperature is the superposition of several contributions, which differ depe ...

2009

Characterization of Cracks and their Effects on the Effective Transport Pathways in Ni-YSZ Anodes after Reoxidation Using X-Ray Nanotomography

Jan Van Herle, Jian Wang, Siyuan Wang, Arata Nakajo, Fabio Greco

Reduction-oxidation cycling of Ni-based electrodes for solid oxide fuel/electrolysis cells irreversibly alters their microstructure and can cause the fracture of the electrolyte. Non-destructive 3-D imaging enables tracking of microstructural changes that ...

2015

Production and Reliability Oriented SOFC Cell and Stack Design

Jan Van Herle, Arata Nakajo, Zacharie Wuillemin, Fabio Greco

This paper presents an innovative development methodology for a production and reliability oriented SOFC cell and stack design aiming at improving the stacks robustness, manufacturability, efficiency and cost. Multi-physics models allowed a probabilistic a ...

2017

The Effects of Dynamic Dispatch on the Degradation and Lifetime of Solid Oxide Fuel Cell Systems

Jan Van Herle, Daniel Favrat, Arata Nakajo

Understanding of mechanisms affecting degradation, durability and performance of solid oxide fuel cell (SOFC) stacks and integrated systems has become important due to increasing worldwide deployment. A novel simulation approach accounting for state-of-the ...

2011

Role of microstructure on electrode operating mechanisms for mixed ionic electronic conductors: From synchrotron-based 3D reconstruction to electrochemical modeling

Arata Nakajo

A typical La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) electrode was reconstructed by X-ray nanotomography. The new Nano Imaging beamline ID16A-NI of the European Synchrotron Radiation Facility (ESRF) was used to conduct the investigation. Particular attention was ...

Elsevier Science Bv2016

Modelling the impact of creep on the probability of failure of a solid oxide fuel cell stack

Jan Van Herle, Arata Nakajo, Fabio Greco

In solid oxide fuel cell (SOFC) technology a major challenge lies in balancing thermal stresses from an inevitable thermal field. The cells are known to creep, changing over time the stress field. The main objective of this study was to assess the influenc ...

2014

Thermo-mechanical Reliability of SOFC Stacks During Combined Long-term Operation and Thermal Cycling

Jan Van Herle, Zacharie Wuillemin, Arata Nakajo, Fabio Greco

Thermo-mechanical issues in solid oxide fuel cells (SOFC) must be understood and overcome to meet the reliability standards for market implementation. This study presents a thermo-mechanical model of an SOFC-stack SRU. The analysis starts with the simulati ...

2015

The Effects of Component Tolerances on the Thermo-Mechanical Reliability of SOFC Stacks

Jan Van Herle, Arata Nakajo, Zacharie Wuillemin, Fabio Greco

The reliability of solid oxide fuel cell (SOFC) systems is closing the gap to meet the requirements for market implementation. Finite-element (FE) stack models, typically used for stack reliability analyses, commonly consider idealized components. In reali ...

2017

Experimental Real-Time Optimization of a Solid Oxide Fuel Cell Stack via Constraint Adaptation

Dominique Bonvin, Grégory François, Zacharie Wuillemin, Arata Nakajo, Gene Bunin, Leonidas Tsikonis

The experimental validation of a real-time optimization (RTO) strategy for the optimal operation of a solid oxide fuel cell (SOFC) stack is reported in this paper. Unlike many existing studies, the RTO approach presented here utilizes the constraint-adapta ...

2010

Evolution of the Morphology Near Triple-Phase Boundaries in Ni–Yttria Stabilized Zirconia Electrodes Upon Cathodic Polarization

Jan Van Herle, Marco Cantoni, Arata Nakajo, Priscilla Caliandro, Guillaume Jeanmonod, Giorgio Rinaldi, Lucie Navratilova

Microstructural changes in Ni–yttria stabilized zirconia (YSZ) near the YSZ electrolyte were examined by three-dimensional (3D) electron microscopy after electrolysis and fuel cell operation up to 10,700 h and 15,000 h, respectively. The depletion of Ni an ...

2020

Mechanical reliability and durability of SOFC stacks. Part II: Modelling of mechanical failures during ageing and cycling

Jan Van Herle, Daniel Favrat, Arata Nakajo

Intricate relationships between mechanical and electrochemical degradation aspects likely affect the durability of solid oxide fuel cell stacks. This study presents a modelling framework that combines thermo-electrochemical models including degradation and ...

2012

Effects of Polarization on the Microstructural Changes at the YSZ/Ni-YSZ Interface

Jan Van Herle, Arata Nakajo, Priscilla Caliandro, Giorgio Rinaldi, Lucie Navratilova

This study examines the effect of Ni migration near the interface with the electrolyte after fuel cell (SOFC) and electrolysis mode (SOEC) operation on nickel-yttria stabilized zirconia (Ni-YSZ) electrodes. The experimental dataset consists in a series of ...

2019

Impact of Materials and Design on Solid Oxide Fuel Cell Stack Operation

Jan Van Herle, Stefan Diethelm, Zacharie Wuillemin, Arata Nakajo, Nordahl Autissier

Planar SOFC stack technology based on a unique concept (SOFConnex™) uses structured gas distribution layers between unprofiled metal sheet interconnects and thin Ni-YSZ anode supported electrolyte cells. The layers are flexible both in material and designa ...

2008

Evolution of 3-D Transport Pathways and Triple-Phase Boundaries in the Ni-YSZ Hydrogen Electrode upon Fuel Cell or Electrolysis Cell Operation

Jan Van Herle, Marco Cantoni, Arata Nakajo, Pierre Burdet

The degradation of the Ni-YSZ electrode was investigated after SOFC or SOEC operation for up to 4,700 h and 10,700 h, respectively. 3-D FIB-SEM serial sectioning combined with 3-D EDS elemental mapping allowed the measurement of structural, material and el ...

2017

Mechanical reliability and durability of SOFC stacks. Part I: Modelling of the effect of operating conditions and design alternatives on the reliability

Jan Van Herle, Daniel Favrat, Arata Nakajo

Electrochemical and mechanical aspects in solid oxide fuel cell stack must be understood to meet the reliability targets for market implementation. This study presents a stack modelling framework that combines thermo-electrochemical models, including degra ...

Elsevier2012

Strontium Migration at the GDC-YSZ Interface of Solid Oxide Cells in SOFC and SOEC Modes

Jan Van Herle, Emad Oveisi, Marco Cantoni, Arata Nakajo, Pierre Burdet, Giorgio Rinaldi

Strontium migration from the oxygen electrode to the interface between the electrolyte and interlayer was investigated in solid oxide cells in fuel cell (SOFC) and electrolysis (SOEC) modes. Four samples were imaged by focused ion beam scanning electron mi ...

2017

Experimental Real-Time Optimization of a Solid Oxide Fuel Cell Stack via Constraint Adaptation

Dominique Bonvin, Grégory François, Zacharie Wuillemin, Arata Nakajo, Gene Bunin, Leonidas Tsikonis

2012

Emerging Investigators in Electrochemical Energy Conversion and Storage 2020

Arata Nakajo

ASME2020