Abstract Nanohybrids of graphene-decorated carbon-coated LiFePO4 nanospheres are prepared using a ball milling-assisted rheological phase method combined with a solid-state reaction. The hybrids are characterized by XRD, SEM, TEM, HRTEM, XPS, Raman and TGA, and their electrochemical properties are studied by CV, EIS and galvanostatic charge-discharge. The experimental results exhibit that multilayer graphene films are decorating carbon-coated LiFePO4 nanospheres without stacking, which results in an abundance of mesopores constituting a unique 3D “sheets-in-pellets” and “pellets-on-sheets” conducting network structure. This structure highlights the improvements of the rate and cyclic performance as a cathode material for lithium-ion batteries, because the highly conductive and plentiful mesopores promote electronic and ionic transport. As a result, the hybrids with approximately 3 wt% graphene exhibit an outstanding rate capability with an initial discharge capacity of 163.8 and 147.1 mA h g−1 at 0.1 C and 1 C, and the capacity is retained at 81.2 mA h g−1 even at 20 C. Moreover, the composites also reveal an excellent cycling stability with only an 8% capacity decay at 10 C after 500 cycles.

中文翻译：

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石墨烯装饰的碳包覆 LiFePO 4 纳米球作为锂离子电池的高性能正极材料

摘要 采用球磨辅助流变相法结合固相反应制备了石墨烯修饰的碳包覆 LiFePO4 纳米球的纳米杂化物。通过XRD、SEM、TEM、HRTEM、XPS、拉曼和TGA对杂化物进行表征，并通过CV、EIS和恒电流充放电研究其电化学性能。实验结果表明，多层石墨烯薄膜在没有堆叠的情况下装饰了碳包覆的 LiFePO4 纳米球，从而产生了大量的介孔，构成了独特的 3D “片中片”和“片上片”导电网络结构。这种结构突出了作为锂离子电池正极材料的倍率和循环性能的提高，因为高导电性和丰富的介孔促进了电子和离子传输。因此，