Synthesis of Li2FeP2O7/Carbon nanocomposite as cathode materials for Li-ion batteries

• Li2FeP2O7/Carbon nanocomposite was prepared by a novel preparation route.
• Li2FeP2O7/Carbon nanocomposite was agglomerates of primary particles.
• The carbon was well distributed on the surface of agglomerates.
• The nanocomposite cathode delivered 100 mAh g−1 at 0.05 C.

A Li2FeP2O7/Carbon (C) nanocomposite was successfully synthesized via a combination of spray pyrolysis and wet ball milling followed by annealing from a precursor solution; in which LiNO3, H3PO4 and Fe(NO3)3·9H2O were stoichiometrically dissolved into distilled water. Ascorbic acid was added to the precursor solution as a reduction agent. The peaks of the Li2FeP2O7/C nanocomposite obtained by X-ray diffraction analysis were indexed to the monoclinic structure with the space group P21/c. The Li2FeP2O7/C nanocomposite cathode delivered a first discharge capacity of 100 mAh g−1 at 0.05 C, which corresponded to 91% of its theoretical capacity. After various higher discharge rates from 0.05 to 2 C in the cycle performance test, a discharge capacity of 93 mAh g−1 was achieved at 0.05 C, which showed an excellent capacity retention (93%) after 29 cycles.