Triple carbon coated LiFePO4 composite with hierarchical conductive architecture as high-performance cathode for Li-ion batteries

Triple carbon coated LiFePO4 composite is prepared by spray drying-carbothermal reduction (SD-CTR) method. The triple carbon sources (viz. graphene oxide, thermoplastic phenolic resin and water-solubility starch) play different roles in constructing the hierarchical conductive architecture. The structure, component and morphology of the as-obtained LiFePO4 composites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The results indicate that, compared with double carbon coated LiFePO4 counterparts, the triple carbon coated LiFePO4 composite possesses smaller crystallite and high-efficiency of carbon coating such as more complete coating, lower ID/IG ratio, and better conductive architecture. Benefited from the above mentioned superiority, the triple carbon coated LiFePO4 composite exhibits outstanding electrochemical performance, especially for high-rate capability, which reaches up to 120 mA h g−1 at 10 C.