Highly Durable Solid Oxide Fuel Cells: Prevention of Chemical Inter-Diffusion By Introducing a 4-Layered Structure

Abstract

Solid oxide fuel cell (SOFC) poses great potential for stationary power generation. Nevertheless, its full-scale commercialization has lagged due to the inadequacy of long-term durability. Along with diverse background of performance deterioration, the inter-diffusion between the cathode and electrolyte have been identified as a leading fatal factor. Herein, we introduced a robust GDC layer by sequential lamination approach that completely suppresses the detrimental phase of SrZrO3 at electrolyte interface during high temperature operation. This buffer layer is fabricated via green film sequential lamination, in which the anode support, anode functional layer, electrolyte and GDC layers were sequentially co-laminated by iso-static pressing and co-sintered at 1300-1400°C. The enhanced interfacial connectivity and desired packing density of electrolyte and buffer layer were attained by controlling the shrinkages behaviors of each component. Thus, the formation of detrimental secondary phases (SrZrO3) at interface of electrolyte and decomposition of cathode are successfully restrained during fabrication and operation at critical current density. The scale-able and mass production are also confirmed through the fabrication of large area cells (144cm2) having active area 100cm2. The sequentially co-laminated GDC layer exhibited extreme low degradation rate of 0.2%/khr, which fulfils the critical longevity benchmark for commercialization of technology. This work features a cost-effective, scalable, and reproducible method for larger scale production of robust multi-layer anode supported SOFC.Keywords: Durability, Sequential lamination, life expectancy, Detrimental phases, iso-static pressing