The electrochemical extraction of Lithium from solid-state syathesised LiFePO4 has been studied by neutron powder diffraction. A "coffee-bag" type cell of configuration < Li-metal lliq. el.l LiFePO4> has been charged to 4.1 V, dismantled in a glovebox, and the composite cathode powder sample scraped from the current collector. Two-phase Rietveld refinement gave a triphylite (LiFePO4) to heterosite (FePO4) phase-ratio of 18:82. lin the absence of significant absorption effects, this ratio is a true representation of the conversion of LiFePO4 to FeFO4. Possible mechanisms for lithium extraction/insertion during the first-cycle are discussed.