報告書番号

W94016

タイトル（和文）

ＳＯＦＣ用燃料極の高性能化に関する研究－電極ミクロ構造の改良による長寿命化－

タイトル（英文）

RESEARCH AND DEVELOPMENT OF HIGH-PERFORMANCEANODE FOR SOLID OXIDE FUEL CELLS -IMPROVEMENT OF MICROSTRUCTURE FOR LONG LIFE-

概要 （図表や脚注は「報告書全文」に掲載しております）

当研究所の従来のＳＯＦＣ用燃料極材料（Ｎｉ－ＹＳＺサーメット）は，Ｎｉ粒子の凝集や電極自体のち密化が急速に進行して，発電性能低下の大きな原因となっていた。そこで，燃料極のミクロ構造を改良して，この劣化挙動の抑制を試みた。本報告書では，改良された燃料極材料の製法を示すとともに，この燃料極の長寿命化に対する効果を明らかにした。

概要 （英文）

A POWDER MIXTURE OF FINE PARTICLE NICKEL OXIDE (NIO) AND FINE PARTICLE YTTRIA STABILIZED ZIRCONIA (YSZ) WAS USED ASANODE MATERIAL FOR SOLID OXIDE FUEL CELLS (SOFC) IN OUR LABORATORY. THE PERFORMANCE OF SINGLE CELLS WITH THIS ANODE MATERIAL SHOWED SHARP DEGRADATION WITHIN 20 OR 30 HOURS. INVESTIGATIONS SHOWED THAT THE ANODE DETERIORATION LED TO A DROP IN CELL PERFORMANCE. NEW ANODE MATERIALS WEREDEVELOPED BY BLENDING YSZ WITH NIO TO SOLVE THE ABOVE PROBLEMS OF THE CONVENTIONAL ANODE. PARTICLE-SIZE CONTROLLED POWDERS OF COARSE YSZ,NIO AND FINE YSZ WERE MIXED TO PREVENT CHANGES IN PARTICLE SIZES. THE COARSE YSZ (I)RESISTS THERMAL EXPANSION OF YSZ ELECTROLYTE,(II)PREVENTS SINTERING SHRINKAGE,AND (III)FORMS AND RETAINS MICROPORES IN THE LAYER. THENIO PARTICLES WERE DISPERSED AROUND THE COARSE YSZ PARTICLES TO PLUG SPACES BETWEEN THE COARSE YSZ. THE FINE YSZ IS ADDED AT THE FINAL MANUFACTURING STAGE AND PLAY ON IMPORTANT ROLE IN SHRINKAGE CONTROL,FIXATION OF NI PARTICLES,AND EXTENSION THE THREE PHASE BOUNDARY. AFTER REDUCTIONAT 1000DEGREE,CHANGES IN POROSITY AND SHRINKAGE OF THE NEW MATERIAL WERE MUCH SMALLER THAN IN CONVENTIONAL MATERIAL. A SINGLE CELL WITH THE BEST NEW ANODE HAS BEEN TESTED FOR OVER 2,500 HOURS WITH STABLE PERFORMANCE; THIS LIFE IS ABOUT 100 TIMES THAT OF THE FORMER CELL,AND THE DROP IN CELL VOLTAGE IS 2.2 % PER 1,000 HOURS.

報告者

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