Interface-engineering to boost the performance and durability of nickel-metal-supported reversible proton ceramic cells for power generation and hydrogen production

The metal-supported reversible proton ceramic cell (MS-rPCC) combines the dual advantages of metal support and proton conduction. It can simultaneously achieve efficient low-temperature operation, high mechanical strength, and excellent thermal cycling stability. However, a critical challenge in MS-rPCC fabrication lies in the element diffusion from the metal support and the mismatch between the metallic and ceramic layers. To address this, a rationally designed pure Ni metallic support combined with a transition layer (80 wt.% NiO-20 wt.% BaZr_0.1Ce_0.7Y_0.2O_3-δ (BZCY)) was introduced to engineer the interface, improving the strength and structural stability of MS-rPCC. The cell achieves a peak power density of 0.8 W cm^-2 in fuel cell (FC) mode at 650 °C and a current density of -1.25 A cm^-2 at 1.3 V in electrolysis cell (EC) mode. FC mode exhibits no significant degradation after 200 hours of operation, with a degradation rate of 0.02 mV h^-1. The cell demonstrated exceptional stability during 100 h of reversible fuel cell/electrolysis cycling, thermal cycling, and rapid start-up test. This work provides a new approach for the commercialization and widespread adoption of MS-rPCC for low-temperature, high-performance power generation and hydrogen production.