In this essay,based on iron powder for iron source,the precursor of LiFePO4 which is the cathode material of lithium ion battery were synthesized by sulfuric acid assisted circulation. The results showed that the excess sulfuric acid could make the reaction of iron powder and phosphate thorough,and it could be used circularly in the system,then the whole system did not produce any waste stream. The results of XRD and SEM indicated that the structure,morphology and size of FePO4 which were composed in the fi...