Perspectives and Challenges for Cost-Effective Manufacturing of Robust Protonic Ceramic Cells in Metal-Supported Architecture

Kurzfassung

Manufacturing Protonic Ceramic Cells (PCCs) by scalable techniques is still challenging. One of the main hurdles originated from the characteristics of the State-of-the-Art electrolyte materials, i.e. Ba(Zr,Ce,Y)O3-d perovskites, which requires high sintering temperatures to fabricate gas-tight electrolyte layers via ceramic processing routes. We present here our challenges in the development of PCCs in a Metal Supported architecture (MS-PCC). Our strategy is employing commercial metal supports, applying ceramic multilayers by wet-chemical processing to synthesize porous electrodes and fabricating gas-tight thin-film BZCY electrolyte by a Physical Vapour Deposition (PVD), allowing all the manufacturing process below 1000 °C to avoid metal degradation. Our MS-PCC concept was demonstrated using a commercial porous metal substrate and Pulsed Laser Deposition (PLD) [1], which showed a good performance in steam electrolysis operation at moderate temperatures. As a next step, we replace the processes by cost-effective and scalable techniques to develop MS-PCCs in a practical cell size. As an alternative to PLD, Electron-Beam PVD (EB-PVD) was investigated, which is feasible to manufacture 1~2 micron-thick homogeneous gas-tight BZCY in a large cell area of ~100 cm2. Due to the significant elemental mass differences in the BZCY compound, compositional adjustment was necessary in the EB-PVD, which was successfully demonstrated to achieve the targeted phase of a reasonable proton conductivity. Critical issues for materials and manufacture techniques in the development of MS-PCC will be discussed.