This study demonstrates the fabrication of a highly activated and integrated nanoscale interlayer of cathodes in low-temperature solid oxide fuel cells (SOFCs) using the precursor-solution electrospray method. Uniform, crack-free La0.6Sr0.4CoO3−δ (LSC) and LSC-CeO2 thin-film layers are fabricated by using optimized precursor-solution electrospray and sintering conditions. The LSC–CeO2 composite layer served as a nanoscale-cathode-functional layer (nCFL) by suppressing grain growth and increasing the number of triple-phase boundaries. The LSC nanoscale-adhesive layer (nAL) played a limited role as an adhesive layer due to a large amount of grain growth and limited triple-phase boundaries. Low-temperature SOFCs with the nAL and nCFL nanoscale interlayers showed maximum power densities of ∼1.108 and 1.150 W cm−2 at 650 °C, which were ∼13% and 18% higher, respectively, than those of a reference cell without nanoscale interlayers. Display omitted •A modified precursor-solution electrospray was used for forming nanoscale layer.•This structure was applied as a highly activated and integrated interlayer of SOFC.•The composite interlayer of LSC and GDC provides better performance and stability.•Interlayer assisted cells resulted in peak power density of ∼1.150 W cm−2 at 650 °C.