Effect of $B_{2}O_{3}$ addition on mechanical strength and microstructure of a porous $LiAlO_{2}$ electrolyte support for molten carbonate fuel cells

용융 탄산염 연료전지용 gamma $LiAlO_{2}$ 전해질 지지체의 미세구조 및 기계적 강도 변화에 대한 $B_{2}O_{3}$ 첨가의 영향

  • 함형철 (한국과학기술연구원 연료전지연구센터) ;
  • 윤성필 (한국과학기술연구원 연료전지연구센터) ;
  • 홍성안 (산자부 수소.연료전지개발사업)
  • Published : 2007.03.26

Abstract

A sintering aid, $B_{2}O_{3}$ have been included into a $LiAlO_{2}$ electrolyte support by a tape casting method in order to reinforce mechanical strength of the support for molten carbonate fuel cells [MCFCs). Starting idea originates from the low melting point of $B_{2}O_{3}$ ($450^{\circ}C$), which can provide the low temperature consolidation of ceramic materials. The mechanical properties and the microstructure changes of the $B_{2}O_{3}$-included electrolyte support were examined by scanning electron microscope, mercury porosimetry, X-ray powder diffraction [XRD], high temperature differential scanning calorimeter and three-point bending strength measurement. The mechanical strength was clearly improved by addition of $B_{2}O_{3}$. The increase of mechanical strength results from the neck growth of a new $LiAlO_{2}$ phase between $LiAlO_{2}$ particles by the liquid phase sintering. Average pore size and porosity of the electrolyte support reinforced by addition of the sintering aid, $B_{2}O_{3}$, was $0.24{\mu}m$ and 59%, respectively which were suitable microstructure of a matrix for an application of MCFCs.

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