Subcontinuous 2D La0.6Sr0.4CoO3-δ nanosheet as an efficient charge conductor for boosting the cathodic activity of solid oxide fuel cells

Highlights: • 2D LSC perovskite nanosheet structure enhance the electrochemical performance. • 2D networking enables the extension of charge transfer to the bulk region. • Low loading level and the ultrathin structure allow for minimal pore volume reduction • Cell employing the 2D LSC leads to a peak power density twice that of the reference. -- Abstract: The formation of La_0.6Sr_0.4CoO_3-δ (LSC) nanoparticles on cathode surfaces enhances the charge conductivity, thus enabling high performance in solid oxide fuel cells. However, the 0D structure has limitations such as inefficient charge conducting paths and fading of reaction sites due to the excessive loading level needed to ensure continuity of the nanoparticles. In this study, we report a uniformly grown ultrathin 2D La_0.6Sr_0.4CoO_3-δ nanosheet that can be used to enhance cathode performance. The continuous 2D form more efficiently enlarges the reaction site and has a low loading level compared to the conventional 0D form. The 2D nanosheet structure is ideal for enlarging the charge conducting path because it shows favorable networking within the cathode scaffold compared to other structures. A solid oxide fuel cell using a 2D La_0.6Sr_0.4CoO_3-δ nanosheet exhibits an enhanced power density of 1.2 W cm⁻² at 600 °C. This improvement occurs because the nanosheet facilitates charge conducting within the cathode. Our strategy provides a method to build high-performance solid oxide fuel cells using a cathode structure design.