BATFactory is an integrated battery development platform covering the full value chain from active material design to battery cell and pack validation. Uniting 5 Wallonian universities, 3 research centres, and industrial partners, it supports a local and sustainable battery value chain for stationary energy storage. The platform and infrastructure combines quantum chemistry modelling with HPC, ML-based optimization, material functionalization, prototype-scale electrode manufacturing, cell assembly, and in-situ characterization to enable pre-industrial testing, durability assessment, and next-generation battery development through academic industrial collaboration.