Cu3P is studied as a potential material to be used as anode in a Li-ion battery. Depending on the synthetic route, solvothermal, ball-milling (with or without annealing), spray method or ceramic, used for its preparation, Cu3P shows various particle sizes and crystallinities. The electrochemical reactivity towards lithium of these various Cu3P powders is discussed through galvanostatic and potentiodynamic measurements, electron microscopy techniques, and X-ray diffraction on powder. Electrochemical performances, especially initial capacity and capacity retention, are shown to strongly correlate to the powder morphologies: small particle size favors high capacity values and the operation scan rate affects the capacity depending on the degree of crystallinity of the powder. On other hand, the battery capacity retention is better with microsized powders.