The nonstoichiometric LiFePO4/C core–shell composites (as microscale LiFePO4 cores coated with 3–5nm thin carbon shells) are synthesized by a novel solid-state reaction method. All samples show outstanding coulombic efficiency (about 100%) and good battery cyclability, along with high tap density (>1.70gcm−3). On this basis, the electrochemical properties of two different core–shell composites as Li1.02Fe0.99PO4/C and Li0.98Fe1.01PO4/C are compared. The results show that the rate performance of Li1.02Fe0.99PO4/C is obviously better than the rate performance of Li0.98Fe1.01PO4/C.