Chromium deposition and poisoning of La ₂ NiO ₄ cathode of solid oxide fuel cell were studied. La ₂ NiO ₄ cathode showed stable performance in the presence of metallic interconnects. Comparing with the polarization resistance ( R _p ) of La ₂ NiO ₄ cathode in the absence of metallic interconnects, R _p did not change in the presence of metallic interconnect. After electrical conductivity relaxation method, La ₂ NiO ₄ with high surface oxygen diffusion coefficients working under Cr atmosphere improved the oxygen reduction kinetics and increased cathode O ₂ reduction reaction rates. No chromium deposition was observed on the La ₂ NiO ₄ cathode surface after polarization for 20 h at 800°C. The chemical compatibility of La ₂ NiO ₄ /Cr ₂ O ₃ and La ₂ NiO ₄ /Gd _0.1 Ce _0.9 O _1.95 (GDC) study indicates that La ₂ NiO ₄ did not react with Cr ₂ O ₃ and GDC under the operating temperature. The results indicate that La ₂ NiO ₄ cathode is a potential chromium-tolerant material of solid oxide fuel cell.

Zinc–air batteries are one of the most excellent of the next generation energy devices. However, their application is greatly hampered by the slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) of air electrode. It is of great importance to develop good oxygen electrocatalysts with long durability as well as low cost. Here, A-site deficient (SmSr)_0.95Co_0.9Pt_0.1O₃ perovskites have been studied as potential OER electrocatalysts prepared by EDTA–citrate acid complexing method. OER electrocatalytic performance of (SmSr)_0.95Co_0.9Pt_0.1O₃ was also evaluated. (SmSr)_0.95Co_0.9Pt_0.1O₃ electrocatalysts exhibited good OER activities in 0.1 M KOH with onset potential and Tafel slope of 1.50 V and 87 mV dec⁻¹, similar to that of Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃ (BSCF-5582). Assembled rechargeable Zn–air batteries exhibited good discharge potential and charge potential with high stability, respectively. Overall, all results illustrated that (SmSr)_0.95Co_0.9Pt_0.1O₃ is an excellent OER electrocatalyst for zinc–air batteries. Additionally, this work opens a good way to synthesize highly efficient electrocatalysts from A-site deficient perovskites.

Carbon-based materials were prepared to catalyze the V³⁺/V²⁺ couple of vanadium redox flow battery using chitosan as the preliminary material and FeCl₃ as activating agent. Graphite microcrystals were the main structures of the obtained catalyst (CTS-Fe-900) activated by FeCl₃, and they contained a large number of curled and overlapped carbon nanosheets. Compared with CTS-D-900 (without FeCl₃ as an activating agent), CTS-Fe-900 exhibits a better structure, higher graphitization degree, stronger current response, and smaller charge transfer resistance. The charge/discharge measurements indicates that the performances of the cell are improved by using the CTS-Fe-900-modified negative electrode in terms of increased discharge capacity and energy efficiency. Compared with pristine cell, the capacity retention for the CTS-Fe-900 modified cell maintains 82.2% at 50 mA cm⁻² after 50 cycles, increased by 5.2%, and the corresponding energy efficiency reaches 81.3%, enhanced by 5.1%. This work reveals that CTS-Fe-900 catalyst can improve the comprehensive energy storage performance. The excellent electrocatalytic properties are mainly attribute to the effect of the FeCl₃ template and the increase in the degree of graphitization.

Due to the insufficient stability and expensive price of commercial precious metal catalysts like Pt/C and IrO₂, it is critical to study efficiently, stable oxygen reduction reaction as well as oxygen evolution reaction (ORR/OER) electrocatalysts of rechargeable Zn-air batteries. PrBa_0.5Sr_0.5Co_1.5Fe_0.5O₅ (PBSCF) double perovskite was adopted due to its flexible electronic structure as well as higher electro catalytic activity. In this study, PBSCF was prepared by the citrate-EDTA method and the optimized amount of PBSCF-Pt/C composite was used as a potential ORR/OER bifunctional electrocatalyst in 0.1 M KOH. The optimized composite exhibited excellent OER intrinsic activity with an onset potential of 1.6 V and Tafel slope of 76 mV/dec under O₂-saturated 0.1 M KOH. It also exhibited relatively competitive ORR activity with an onset potential of 0.9 V and half-wave potential of 0.78 V. Additionally, Zn–air battery with PBSCF composite catalyst showed relatively good stability. All these results illustrate that PBSCF-Pt/C composite is a promising bifunctional electrocatalyst for rechargeable Zn-air batteries.

The oxygen reduction reaction (ORR) is paid much more attention because of the high overpotential required for driving the four-electron process in the field of storage and sustainable energy conversion, including fuel cell applications. In this paper, PtCo nanoparticles encapsulated on carbon supports were prepared by a simple modified polyol method with ethylene glycol. Structural as well as electrochemical characterizations illustrated that the PtCo/C electrocatalysts had a minimum particle size of 4.8 nm, which is close to the commercial 40 wt% Pt/JM. Moreover, the electrochemical measurements indicated that ORR activity was competitive with the commercial 40 wt% Pt/JM catalyst. The synthesis method is a critical way to produce PtCo/C catalysts for use in polymer electrolyte membranes in fuel cells (PEMFCs).

The commercialization of proton-conducting fuel cells (PCFCs) is hindered by the limited electroactivity and durability of cathodes at intermediate temperatures ranging from 400 to 700 °C, a challenge exacerbated by an insufficient understanding of high-entropy perovskite (HEP) materials for oxygen reduction reaction (ORR) optimization. This study introduces an yttrium-doped HEP to address these limitations. A comparative analysis of Ce_0.2−xY_xBa_0.2Sr_0.2La_0.2Ca_0.2CoO_3−δ (x = 0, 0.2; designated as CBSLCC and YBSLCC) revealed that yttrium doping enhanced the ORR activity, reduced the thermal expansion coefficient (19.9 × 10⁻⁶ K⁻¹, 30–900 °C), and improved the thermomechanical compatibility with the BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3−δ electrolytes. Electrochemical testing demonstrated a peak power density equal to 586 mW cm⁻² at 700 °C, with a polarization resistance equaling 0.3 Ω cm². Yttrium-induced lattice distortion promotes proton adsorption while suppressing detrimental Co spin-state transitions. These findings advance the development of durable, high-efficiency PCFC cathodes, offering immediate applications in clean energy systems, particularly for distributed power generation.