Shengli Pang

Oxygen-ion conductors are central to clean energy technologies. Conventional long-range-ordered oxide-ion conductors require high operating temperatures, which increase cost and limit durability; overcoming the low temperature conductivity gap is a long-standing challenge. We created cerium (Ce)-gadolinium (Gd)-oxygen (O) clusters by thermal-shock exfoliation of fluorite Gd_0.1Ce_0.9O_1.95 and examined their structure and ion transport. These disordered, vacancy-isolated clusters form percolative oxygen-ion pathways without long-range order, delivering exceptional conductivity of 2.14 ± 0.09 siemens per centimeter at 400°C-more than 320-fold higher than most previously reported oxide-ion conductors under comparable conditions. Used as a 0.5 weight % cathode additive in solid oxide fuel cells, they tripled the peak power density to 2.87 ± 0.04 watts per square centimeter at 750°C compared with the pristine Pr_0.5Ba_0.25Ca_0.25CoO_3-δ/Gd_0.1Ce_0.9O_1.95 cathode and reversed degradation from -13.2 to +3.4% per 100 hours. These findings overturn the paradigm that high oxygen-ion conductivity requires long-range order and highlight Ce-Gd-O clusters as enablers for advanced energy technologies.

Solid oxide fuel cells (SOFCs) hold great promise for efficient energy conversion, yet their widespread adoption is hindered by intrinsic cathode limitations in catalytic activity, operational durability, and oxygen-ion conductivity. Although nanostructuring offers a potential solution, the high-temperature oxidizing environment of SOFC operation presents significant challenges. Herein, we report a microsecond-scale, thermal-strain-based strategy for in situ nanostructuring of PrBaCo2O5+δ micron particles. Thermal shock induces surface exfoliation of the perovskite lattice, forming a flexible 1–3 nm nanocluster layer that generates a unique chemical environment and expands the oxygen reduction reaction active region from the particle surface to the entire nanolayer, enhancing catalytic activity by ~2.8-fold. Simultaneously, thermal strain drives Pr/Ba gradient intermixing in the bulk and lattice expansion, which widen oxygen-ion migration pathways and improve ionic conductivity by ~12.5-fold. These synergistic surface and bulk modifications reduce area specific resistance by 60.5%, increase peak power density by 2.5-fold, and maintain exceptional long-term stability. This strategy establishes a generalizable approach for nanoscale engineering of micron- and submicron-sized particles, with broad implications for energy conversion, catalysis, and other functional materials.

Solid oxide fuel cells (SOFCs) hold great promise for efficient energy conversion, yet their widespread adoption is hindered by intrinsic cathode limitations in catalytic activity, operational durability, and oxygen-ion conductivity. Although nanostructuring offers a potential solution, the high-temperature oxidizing environment of SOFC operation presents significant challenges. Herein, we report a microsecond-scale, thermal-strain-based strategy for in situ nanostructuring of PrBaCo2O5+δ micron particles. Thermal shock induces surface exfoliation of the perovskite lattice, forming a flexible 1–3 nm nanocluster layer that generates a unique chemical environment and expands the oxygen reduction reaction active region from the particle surface to the entire nanolayer, enhancing catalytic activity by ~2.8-fold. Simultaneously, thermal strain drives Pr/Ba gradient intermixing in the bulk and lattice expansion, which widen oxygen-ion migration pathways and improve ionic conductivity by ~12.5-fold. These synergistic surface and bulk modifications reduce area specific resistance by 60.5%, increase peak power density by 2.5-fold, and maintain exceptional long-term stability. This strategy establishes a generalizable approach for nanoscale engineering of micron- and submicron-sized particles, with broad implications for energy conversion, catalysis, and other functional materials.

Solid oxide fuel cells (SOFCs) offer a promising solution for renewable energy conversion; however, their widespread adoption is hindered by the lack of fuel electrodes that combine high catalytic activity, redox stability, coking resistance, long‐term durability, and mechanical toughness. Herein, a heteroepitaxial GdO _x nanolayer, in situ grown on polycrystalline fluorite oxides using a scalable, cost‐efficient, strain‐driven method, is proposed as a multi‐functional fuel electrode. This design achieves polarization resistances as low as 0.091 and 0.194 Ω cm ² under hydrogen and methane conditions at 800°C, respectively, exhibiting excellent redox stability, superior coking resistance, and remarkable long‐term stability. The high concentration of oxygen vacancies promotes lattice softening, enhancing the fracture toughness to 4.3 MPa cm ^1/2 . This work introduces a novel paradigm for fuel oxidation catalysts, enhances the multi‐functional performance of materials, simplifies SOFC system complexity, and provides valuable insights into the design of next‐generation catalysts.

Solid oxide fuel cells are promising technologies for renewable energy conversion, yet their practical deployment requires oxygen electrodes that simultaneously support rapid oxygen‐ion transport and sustained high‐activity oxygen reduction reaction (ORR) catalysis. However, constructing such a microchemical environment remains a persistent challenge for perovskite oxides. Here, it is demonstrated that Cl ⁻ incorporation into PrBaCo ₂ O _5+δ partially replaces lattice oxygen, inducing localized metal–oxygen electronic states, enhanced lattice distortion, and Pr ³⁺ intermixing into BaO layers, collectively generating 3D fast pathways for oxygen‐ion diffusion. More significantly, it is revealed for the first time that Cl ⁻ preferentially segregates at the surface, forming an amorphous layer that creates an adaptive ORR interface and effectively overcomes the long‐standing issue of surface passivation. As a result, Cl ⁻ ‐engineered PrBaCo ₂ O _5+δ achieves a 3–5‐fold increase in ORR activity relative to the parent oxide and exhibits outstanding durability at 750 °C, transforming ≈15.1% degradation over 100 h into a ≈2.7% performance gain. This work establishes a halogen‐mediated mechanism for tailoring perovskite microchemistry, challenges the prevailing view that halogens merely stabilize oxide lattices, demonstrates one of the most pronounced catalytic enhancements reported to date, and offers a broadly applicable strategy for designing advanced oxygen electrodes.

The commercial application of lithium–sulfur (Li–S) batteries is limited by the inherent defects of poor conductivity of sulfur and the shuttling effect of polysulfides. To overcome these limitations, a modified layer comprising a porous network PVDF-PMMA skeleton and Ketjen black (KB) carbon nanoparticles was coated on the polyethylene (PE) separator using the phase inversion method. The PVDF-PMMA-KB (PPK) composite layer with a structure abundant in mesopores can effectively limit the shuttling effect of polysulfides via a physical barrier and adsorption. Moreover, the utilization of active substances substantially increased as the KB carbon nanoparticles could provide additional reaction sites for activating inactive polysulfides and depositing lithium sulfide. The electrochemical properties of the Li–S battery were considerably enhanced using the modified separator with a PPK layer, which was reflected in the higher rate capability and longer cycling life. The cell with a modified separator delivered a specific capacity of 723 mA h g⁻¹ at 1 C, and the capacity retention reached 73.3% after 400 cycles with a low decay rate of 0.223% per cycle. This work provides a novel preparation method for a modified layer on the separator and promotes the large-scale application of Li–S batteries.