The performance of new state-of-the-art Ba0.5Sr0.5(Co0.7Fe0.3)0.6875W0.3125O3-d (BSCFW) cathode materials for solid oxide fuel cells, which are composites of single- (SP) and double- perovskite (DP) phases we published recently, is highly correlated to the preparation route and processing conditions. This is mediated by the interplay between the separate phases through lattice mismatch and ability for the exchange of W6+ from DP to SP at operating conditions, significantly enhancing material stability. Using high-resolution neutron diffraction, we aim to understand the subtle structural differences induced through different preparative conditions in these materials. This knowledge will inform future processing routes to such materials as part of our current collaboration with industry for industrial-scale testing.