Novel approaches to prepare high performance dense electrolyte and interconnect applicable to SOFC by atmospheric plasma spraying

Plasma spraying is considered a promising cost-effective manufacturing process to deposit electrolyte and ceramic interconnect for solid oxide fuel cells. However, it is generally difficult to deposit highly dense electrolyte and interconnect with desirable compositions for multiple components ceramics following the conventional process routine. In this paper, a novel approach based on the critical bonding temperature concept is presented to prepare dense electrolytes by plasma spraying. The spray particle size was utilized to control preferential element evaporation and subsequent composition of spray deposits. YSZ and LSGM are used as typical electrolytes. It is revealed that both plasma-sprayed electrolytes and interconnects present a gas permeability less than 1×10^-7 cm⁴gf^-1s^-1 and can be directly applied to SOFC high temperature operation. Moreover, the deposited electrolytes present an ionic conductivity of over 80% sintered bulk materials which can be used to assemble SOFC with excellent performance.