Protonic Ceramic Electrochemical Cells for a Sustainable Future

Objective

Protonic ceramic fuel and electrolysis cells (PCFC/PCEC) are an emerging and attractive technology which can facilitate the transition from fossil fuels to low carbon, and secure energy supplies. However, there remain distinct barriers to their widespread practical applications. The challenges concern the refractory nature of the protonic ceramics, the limited chemical stability, and scalability. Further complexity is added from the established co-sintering process of the electrode and electrolyte using conventional sintering with a slow temperature ramp up and prolonged dwell time of several hours at high temperatures, typically resulting in cross diffusion, formation of secondary phase in the electrolyte and consequently performance degradation. Herein, to overcome these longstanding challenges, we aim at opening a new avenue for fabrication of electrolyte-supported protonic ceramic electrochemical cells for intermediate temperature operation (400 – 600 ℃). The proposed methodology exploits the novel technology of Ultrafast High-temperature Sintering (UHS) as the pivotal manufacturing procedure, which enables sintering of such cells in seconds to minutes. Pure BaZr0.8Y0.2O3-δ (BZY20) and 0.5 wt% NiO-added BZY20, both characterized by a high conductivity and chemical stability, are selected for the electrolyte. Novel experimental set-up and procedures are proposed to extensively facilitate the sintering process of protonic ceramic cells to produce structurally dense 30×30 mm2 electrolyte and to enable simultaneous sintering of the two electrodes (NiO-BZY20, and Ba0.5Sr0.5Fe0.8Zn0.2O3-δ). Advanced characterization techniques (Impedance Spectroscopy, XRD, SEM, TEM, and Atomic Probe Tomography) will be utilized to examine the correlations of processing, microstructure and properties. Overall, the procedure offers a transformative, scalable, and all-inclusive approach to extensively facilitate development and deployment of PCFC/PCEC.