Month: February 2025

With the material system operating at lower temperatures, protonic ceramic electrochemical cells (PCECs) can offer high energy efficiency and reliable performance for both power generation and hydrogen production, making them a promising technology for reversible energy cycling. However, PCEC faces technical challenges, particularly regarding electrode activity and durability under high current density operations. To address these challenges, we present a scalable nano-architecture ultra-porous oxygen electrode with triple conductivity, designed to enhance catalytic activity and interfacial stability through a self-assembly approach. Electrochemical cells incorporating this advanced electrode have demonstrated robust performance, achieving a peak power density of 1.50 W cm⁻² at 600 °C in fuel cell mode and a current density of 5.04 A cm^-2 at 1.60 V in electrolysis mode, with enhanced stability on transient operations and thermal cycles. The underlying mechanisms are closely related to the improved surface activity and mass transfer due to the dual features of the electrode structure. Additionally, the enhanced interfacial bonding between the oxygen electrode and electrolyte contributes to increased durability and thermomechanical integrity. This study underscores the critical importance of optimizing electrode microstructure to achieve a balance between surface activity and durability.

https://www.nature.com/articles/s41467-025-59477-9

The emerging applications of steam electrolysis and electrochemical synthesis at 300-600 ^oC set stringent requirements on the stability of protonic ceramic cells, which cannot be met by Ce-rich electrolytes. A promising candidate is Ce-free BaZr_0.8Y_0.2O_3−δ (BZY), yet its usage has long been denied due to sinterability conundrum in protonic devices. Here we resolved the issue by a renovated co-sintering process, in which the shrinkage stress of a readily sinterable support layer helps densify pure BZY electrolyte membrane at record low temperatures. It eliminates Ce and harmful sintering aids in zirconate cells and enhances Faraday efficiency and electrochemical stability, especially under harsh operation conditions. The protonic zirconate cells have exceptional performance and demonstrate stable high-steam-pressure electrolysis up to 0.7 atm steam pressure, −2 A cm⁻² current density, and over 800 hours of dynamic operation at 600 ^oC. Our processing breakthrough enables stabilized protonic cells in demanding applications in future energy infrastructure.

This work was completed by multiple institutions including Idaho National Laboratory, New Mexico State, OU, Georgia Tech, Tsinghua University, and MIT.

https://www.nature.com/articles/s44160-025-00765-z