Processing‐Centric Innovative Strategies for Protonic Ceramic Electrochemical Cells

ABSTRACT Protonic ceramic electrochemical cells (PCECs) are advancing as low‐to‐intermediate temperature (300°C–600°C) devices for efficient power generation and sustainable chemicals production. While remarkable progress has been achieved through the development of advanced electrolytes and electrodes, it is becoming increasingly clear that further gains in performance and durability cannot be realized by materials innovation alone. Equally important is the manner in which these materials are integrated and processed into multilayer ceramic architectures, as device‐level behavior is strongly shaped by fabrication pathways. In practice, key performance metrics, including ohmic resistance, polarization losses, and long‐term stability, are highly sensitive to fabrication‐induced features such as compositional uniformity, interfacial bonding quality, microstructural evolution, and defect chemistry. These challenges become particularly pronounced when transitioning from laboratory‐scale button cells to larger‐area devices, complex geometries, and stack‐level configurations, thereby underscoring the critical importance of fabrication processes. This review examines processing‐centric strategies and maps the fabrication landscape of high‐performance PCECs. By integrating recent advances across deposition, sintering, surface and interface functionalization, microstructural design, and scale‐up strategies, it clarifies how processing choices govern performance, durability, and scalability. This review article provides actionable fabrication guidance that enables the reliable translation of state‐of‐the‐art materials into commercially viable and technologically robust PCEC systems.