Although metal–air batteries emerge as a highly promising class of fuel cells, improved efficiency is required for the oxygen reduction reaction (ORR) at the air–electrode cathode. Perovskite-type oxides, such as Co-doped LaNiO 3 , can serve as low-cost alternatives to conventional precious-metal-based oxygen electrocatalysts. However, achieving high specific surface areas and oxygen reduction activities necessitates the optimization of the synthesis process. In this study, LaNi 0.5 Co 0.5 O 3 (MV-LNCO), a high-performance perovskite ORR catalyst, is synthesized via an innovative sol–gel method combined with microwave heating. This approach involves the use of polyvinylpyrrolidone as a complexing agent and activated carbon as a pore-forming agent. Notably, the specific surface area of MV-LNCO (50.78 m 2 g −1 ) is nearly twice as large as that of the corresponding catalyst synthesized using the traditional method. Moreover, electrochemical tests revealed that MV-LNCO achieves an improved onset potential (0.87 V), half-wave potential (0.68 V), and limiting current density (5.57 mA cm −2 ) for ORR. In addition to its excellent catalytic activity in ORR, MV-LNCO demonstrates no notable decrease in current output over 8 h, indicating excellent stability. Thus, the developed synthesis method has the potential to provide novel high-performance catalysts for metal–air batteries.
This research addresses the issue of particle agglomeration and a low catalytic activity in the traditional sol–gel preparation of LaNi 0.5 Co 0.5 O 3 (LNCO). A new synthetic strategy is proposed, leveraging the combination of polyvinylpyrrolidone (PVP) serving as a complexing agent and graphene nanosheet (GN) functioning as a template, successfully producing a high-activity LNCO cathode material (GN-LNCO) with a layered structure. Various characterizations confirmed that incorporating PVP and GN effectively suppressed particle agglomeration at high temperatures. The optimized GN-LNCO exhibited excellent physicochemical properties, including a specific surface area of 45.21 m 2 g −1 , a more regular mesoporous structure, a higher electronic conductivity, and a greater oxygen vacancy concentration. Electrochemical performance tests showed that the GN-LNCO cathode demonstrated an outstanding performance in solid oxide fuel cells at 800 °C, with a peak power density of 350.91 mW cm −2 . This represented an improvement of 28.65% over the conventional LNCO. Additionally, a 72 h long-term stability test of a GN-LNCO single cell revealed a voltage decay rate of only 1.60%, indicating its excellent stability. Overall, this study provides a novel material design strategy for developing high-performance cathodes, which has significant implications for advancing solid oxide fuel cell technologies.
危险品化学品经营许可证（带存储）