Olivine LiFePO4 nanocrystallites embedded in carbon-coating matrix for high power Li-ion batteries

Plate-like LiFePO4@C nanostructures, in which LiFePO4 nanocrystallites with a size less than 50 nm embedded in carbon coating matrix, with excellent high rate capacity and cycle performance have been successfully prepared via a conventional hydrothermal route in virtue of the assistance of the triblock copolymer P123. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM) and high-resolution TEM, and thermogravimetric analysis were employed to characterize the prepared samples. The adsorption of P123 on the surfaces results in the plate-like LiFePO4@P123 nanostructures self-assembled with nanocrystallites. After annealing in inert Ar atmospheres, the plate-like LiFePO4@P123 nanostructures transform to plate-like LiFePO4@C nanostructures due to the carbonization of the adsorbed P123 film matrix. The plate-like LiFePO4@C nanostructures as Li-ion cathode materials deliver excellent high rate capacity and cycle stability, 128 mAh g−1 discharge at 10 C and 98% retention of the initial discharge capacity (151 mAh g−1) at 0.1 C after 100 cycles.