Fabrication of particle-stacking porous anode for solid oxide fuel cell using laser powder bed fusion

Interconnected micropores play a critical role as fuel gas flow channels in solid oxide fuel cell (SOFC), which is quite difficult to prepare using conventional methods. In this work, an interconnected microporous structure of Ni-based anode was newly fabricated by laser powder bed fusion (LPBF), controlling the melting behavior of particles and stacking them up to form a high-porosity space net structure with point contacts. The results show that the YSZ sprayed powder initially behaves as nanoparticles, forming an unmanageable sub-microporous structure. After densification, however, it melts as microparticles and forms micropores distributing with a wider manageable range. In addition, densified YSZ powder forms interconnected pores with isolated islandshaped sintered particles finely distributed along the laser scanning direction at XY orientation. Due to a narrow molten pool and large sintering shrinkage generated, an overlapped area forms only at Z orientation. These overlaps can be improved by adding Ni element, behaving as a particle binder in the matrix, but this is easy to form Ni segregations and deteriorate the element homogeneity. In contrast, adding NiO can promote a finer composition distribution.