A newly-developed effective direct current assisted sintering technique for electrolyte film densification of anode-supported solid oxide fuel cells

In order to lower the sintering temperature and shorten firing time, a novel, effective and facile technique has been developed for sintering Yttria-stabilized zirconia (YSZ) electrolyte thin film. Herein this technique, which employs a weak direct current (DC), is used for the first time in the manufacture of the anode-supported solid oxide fuel cell (SOFC). A single cell is directly assembled using a pre-sintered anode/electrolyte and screen printed cathode and subsequently sintered under electric assistance from room temperature to 800 °C at a heating rate of 5 °C min−1. A fully dense YSZ electrolyte film can be observed by scanning electron microscopy (SEM) and the open circuit voltages (OCVs) are in accordance with theoretical values, confirming that the cell possesses a dense YSZ film. Using hydrogen fuel, the maximum power density of this cell was 0.8, 1.1 and 1.4 W cm−2 at 650, 700 and 750 °C, respectively. We believe this DC assisted sintering technique (DC-AST) may not only reduce the cost, but also maintain the anode nanostructure, thus offering a potentially useful manufacturing technique for SOFCs. ► A DC assisted sintering technique was developed for electrolyte film densification. ► A fully dense YSZ film was obtained with a short sintering time and low temperature. ► The grain growth was inhibited during the DC assisted sintering process. ► The perfect cell performance ascribed to the fine YSZ film and good anode structure. ► This technique may provide a promising way to fabricate nano-structured cells.