【公開日：2024.07.25】【最終更新日：2024.05.29】

課題データ / Project Data

課題番号 / Project Issue Number

23UT0011

利用課題名 / Title

Microstructure of Solid Oxide Cells

利用した実施機関 / Support Institute

東京大学 / Tokyo Univ.

機関外・機関内の利用 / External or Internal Use

内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)

技術領域 / Technology Area

【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-

【重要技術領域 / Important Technology Area】（主 / Main）革新的なエネルギー変換を可能とするマテリアル/Materials enabling innovative energy conversion（副 / Sub）マテリアルの高度循環のための技術/Advanced materials recycling technologies

キーワード / Keywords

燃料電池/ Fuel cell,電極材料/ Electrode material,電子顕微鏡/ Electronic microscope,資源使用量低減技術/ Technologies for reducing resource usage

利用者と利用形態 / User and Support Type

利用者名（課題申請者）/ User Name (Project Applicant)

SCIAZKO Anna

所属名 / Affiliation

東京大学 生産技術研究所

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes

Yosuke Komatsu,Zewei Lyu,Qiuqiu Lyu,Terufumi Miyagawa,Gao Yao,Ryo Kato,Yuichiro Nakazawa,Dongxu Cui

利用形態 / Support Type

（主 / Main）機器利用/Equipment Utilization（副 / Sub）-

利用した主な設備 / Equipment Used in This Project

UT-102：高分解能走査型分析電子顕微鏡

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

The electrochemical performance of Solid Oxide Fuel Cells (SOFCs) and Solid Electrolysis Cells (SOECs) greatly depends on the microstructure of their electrodes. The investigation of the microstructure of SOFC electrodes in the bulk and deteriorated states are essential in order to clarify the degradation mechanisms and provide the guidelines for cell fabrication and operation strategies.

実験 / Experimental

The various designs of SOFC and SOEC electrodes were fabricated in order to investigate the influence of electrode design, materials, particle size and electrochemical operation strategies. The degradation experiments were conducted for evaluating the influence of applied current density, inlet gas composition, operation time and temperature. The particular focus was on the degradation due to the methane coking over nickel electrode and influence of transitional metals on nickel migration. The investigations were carried for anode and electrolyte supported cells as well as patterned electrodes. Some of the samples were infiltrated with resin and polished with cross-sectional polisher in order to clearly observe microstructural properties. The samples were observed by Scanning Electron Microscope SEM with energy-dispersive X-ray spectroscopy (JSM-7800F). In order to improve SEM imagining some of the samples were pretreated with carbon coating.

結果と考察 / Results and Discussion

The studies focused on improving long time stability of SOC fuel electrode. Firstly, the attempt to improve performance by introducing transitional metals into the electrode was undertaken. Electrochemical performance and microstructure change during potentiostatic operation were tested for  Ni-M (M = Fe, Cu, Mn) bimetallic patterned fuel electrodes in SOFC and SOEC cells. The fuel cell performance of Ni-M electrodes were lower than pure Ni, while the degradation Ni-Fe and Ni-Mn electrodes were smaller than the others. It was shown that Ni migration was suppressed by Fe and Mn addition, whereas it was enhanced by Cu addition. Addition of Fe and Mn improved the adhesion between Ni film and YSZ substrate and resulted in smaller degradation rate in both SOFC and SOEC operation. The strength of Ni-O bond, surface tension and melting point are influenced by the addition of transition metal elements and results in the various degradation patterns of SOC electrodes. Secondly, the microstructure modification due to the coking were investigated. Ni-based anodes exhibit high catalytic properties in direct cracking of hydrocarbon, however it may sometimes lead to carbon deposition on the Ni surface and result in pulverization and failure of SOFC electrode. The different operation conditions as current density, temperature and inlet humidity were tested to identify most influential parameters. In particular, it was shown that the Ni surface in the vicinity of active TPB near the electrolyte is free from carbon formation, while remaining Ni surface at some distances from TPB exhibits severe carbon deposition.

図・表・数式 / Figures, Tables and Equations

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

This work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO), by Japan Society for the Promotion of Science KAKENHI [grant number 21K14090] and by Advanced Research Infrastructure for Materials and Nanotechnology in Japan (ARIM Japan).

成果発表・成果利用 / Publication and Patents

論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)

1. Anna Sciazko, Correlation Between Microstructure and Performance of GDC-Based Electrodes, ECS Transactions, 111, 349-356(2023).
   DOI: 10.1149/11106.0349ecst
   
2. Dongxu Cui, Three dimensional microstructures of carbon deposition on Ni-YSZ anodes under polarization, Journal of Energy Chemistry, 87, 359-367(2023).
   DOI: 10.1016/j.jechem.2023.08.035
   
3. Anna Sciazko, 3D microstructures of solid oxide fuel cell Ni-YSZ anodes with carbon deposition, Chemical Engineering Journal, 460, 141680(2023).
   DOI: 10.1016/j.cej.2023.141680
   
4. Zhufeng Ouyang, Influence of Transition Metal Elements on Ni Migration in Solid Oxide Cell Fuel Electrodes, Journal of The Electrochemical Society, 170, 124511(2023).
   DOI: 10.1149/1945-7111/ad11b2
   
5. Zhufeng Ouyang, Effects of Transition Metal Elements on Ni Migration in Solid Oxide Cell Fuel Electrodes, ECS Transactions, 111, 171-179(2023).
   DOI: 10.1149/11106.0171ecst
   

口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.

1. シチョンシコ アンナ.，小松洋介，志村敬彬，鹿園直毅, "ガドリニウムドープ セリア固体酸化物形電解セル燃料極の性能と安定性," 第32回SOFC研究発表会 講演要旨集，2023年12月14－15日，216B (2023).

特許 / Patents

特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件