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Cation-Selective Defects Engineering in A-Site Ordered Layered Perovskites for High-Performance Reversible Protonic
Yixiao Song1, Yufei Song1, Yuhao Wang2
1State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 210009, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|August 20, 2025
Summary
Engineered cation defects in PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) improve performance for reversible protonic ceramic cells. Ba/Sr-deficient PBSCF shows superior electrochemical activity and stability at intermediate-to-low temperatures.
Area of Science:
- Materials Science
- Electrochemistry
- Renewable Energy
Background:
- Reversible protonic ceramic cells (RPCCs) are key for chemical-electrical energy conversion.
- Operation at intermediate-to-low temperatures (400–600 °C) is crucial for commercial viability but limited by air electrode performance.
- A-site ordered layered perovskite PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) shows promise but requires improved activity and stability.
Purpose of the Study:
- To investigate the impact of cation-selective defects on the performance of A-site ordered perovskites for RPCCs.
- To understand the defect-performance relationships in Pr-deficient (p-PBSCF) and Ba/Sr-deficient (bs-PBSCF) variants.
- To enhance electrochemical activity and long-term stability of PBSCF at intermediate-to-low temperatures.
Main Methods:
- Synthesis and characterization of Pr-deficient (p-PBSCF) and Ba/Sr-deficient (bs-PBSCF) perovskite materials.
- Electrochemical performance testing of the engineered materials as air electrodes in RPCCs.
- Analysis of defect structures, oxygen electrocatalysis, and stability under operating conditions.
Main Results:
- Pr defects enhance oxygen electrocatalytic activity by weakening Co-O covalency but reduce stability by lowering oxygen vacancy concentration.
- Ba/Sr defects significantly boost electrode activity by weakening Co-O covalency and increasing oxygen vacancy concentration.
- Ba/Sr-deficient PBSCF exhibits superior stability due to strengthened Ba-O/Sr-O bonds and suppressed cation segregation, despite increased hydration.
Conclusions:
- A-site cation-selective defect engineering is a viable strategy to tune the performance of layered perovskites for RPCCs.
- Ba/Sr deficiency in PBSCF offers a promising pathway to achieve high activity and stability at intermediate-to-low temperatures.
- Understanding defect chemistry is critical for designing advanced materials for efficient renewable energy utilization.
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