Preparation and electrochemical properties of carbon-coated LiFePO₄ hollow nanofibers

Abstract

Carbon-coated LiFePO₄ hollow nanofibers as cathode materials for Li-ion batteries were obtained by coaxial electrospinning. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller specific surface area analysis, galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS) were employed to investigate the crystalline structure, morphology, and electrochemical performance of the as-prepared hollow nanofibers. The results indicate that the carbon-coated LiFePO₄ hollow nanofibers have good long-term cycling performance and good rate capability: at a current density of 0.2C (1.0C = 170 mA·g⁻¹) in the voltage range of 2.5–4.2 V, the cathode materials achieve an initial discharge specific capacity of 153.16 mAh·g⁻¹ with a first charge–discharge coulombic efficiency of more than 97%, as well as a high capacity retention of 99% after 10 cycles; moreover, the materials can retain a specific capacity of 135.68 mAh·g⁻¹, even at 2C.

Keywords

electrospinning / lithium-ion batteries / carbon coatings / phosphates / nanofibers / electrochemical properties

References

[1] Liu Z.L., Tay S.W., Hong L., Lee J.Y. Physical and electrochemical characterizations of LiFePO₄ incorporated Ag nanoparticles. J. Solid State Electrochem., 2011, 15(1): 205.

[2] Zhang W.J. Structure and performance of LiFePO₄ cathode materials: A review. J. Power Sources, 2011, 196(6): 2962.

[3] Lee J., Teja A.S. Synthesis of LiFePO₄ micro and nanoparticles in supercritical water. Mater. Lett., 2006, 60(17-18): 2105.

[4] Prosini P.P., Zane D., Pasquali M. Improved electrochemical performance of a LiFePO₄-based composite cathode. Electrochim. Acta, 2001, 46(23): 3517.

[5] Croce F., Epifanioa A.D., Hassouna J., Deptula A., Olczac T., Scrosati B. A novel concept for the synthesis of an improved LiFePO₄ lithium battery cathode. Electrochem. Solid State Lett., 2002, 5(3): A47.

[6] Hu G.R., Peng Q.Y., Peng Z.D., Cao Y.B., Du K. Comparison on properties of lithium iron phosphate/graphene composite prepared by two methods. Chin. J. Inorg. Chem., 2015, 31(6): 1153.

[7] Sanchez M.A.E., Brito G.E.S., Fantini M.C.A., Goya G.F., Matos J.R. Synthesis and characterization of LiFePO₄ prepared by sol-gel technique. Solid State Ionics, 2006, 177(5-6): 497.

[8] Lin Y., Gao M.X., Zhu D., Liu Y.F., Pan H.G. Effects of carbon coating and iron phosphides on the electrochemical properties of LiFePO₄/C. J. Power Sources, 2008, 184(2): 444.

[9] Needham S.A., Calka A., Wang G.X., Mosbah A., Liu H.K. A new rapid synthesis technique for electrochemically active materials used in energy storage applications. Electrochem. Commun., 2006, 8(3): 434.

[10] Shin H.C., Cho W.I., Jang H. Electrochemical properties of the carbon-coated LiFePO₄ as a cathode material for lithium-ion secondary batteries. J. Power Sources, 2006, 159(2): 1383.

[11] Liao X.Z., Ma Z.F., He Y.S., Zhang X.M., Wang L., Jiang Y. Electrochemical behavior of LiFePO₄/C cathode material for rechargeable lithium batteries. J. Electrochem. Soc., 2005, 152(10): A1969.

[12] Li D., Xia Y. Electrospinning of nanofibers: reinventing the wheel?. Adv. Mater., 2004, 16(14): 1151.

[13] Toprakci O., Ji L.W., Lin Z., Toprakci H.A.K., Zhang X.W. Fabrication and electrochemical characteristics of electrospun LiFePO₄/carbon composite fibers for lithium-ion batteries. J. Power Sources, 2011, 196(18): 7692.

[14] Lin H.Y., Yeh S.M., Chen J.S. Physical and electrochemical properties of LiFePO₄/C nanofibers synthesized by electrospinning. Int. J. Electrochem. Sci., 2014, 9(12): 6936.

[15] Shao D.Q., Wang J.X., Dong X.T., Yu W.S., Liu G.X., Zhang F.F., Wang L.M. Preparation and electrochemical performances of LiFePO₄/C composite nanobelts via facile electrospinning. J. Mater. Sci. Mater. Electron., 2014, 25(2): 1040.

[16] Lee S.H., Jung M.J., Im J.S., Sheem K.Y., Lee Y.S. Preparation and characterization of electrospun LiFePO₄/ carbon complex improving rate performance at high C-rate. Res. Chem. Intermed., 2010, 36(6): 591.

[17] Wang Y.Z., Zhang L.X., Wang Y.B. Synthesis and electrochemical performance of hollow ZnCo2O4 nanowires. New Chem. Mater., 2013, 41(2): 92.

[18] Padhi A.K., Nanjundaswamy K.S., Goodenough J.B.D. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries. J. Electrochem. Soc., 1997, 144(4): 1188.

[19] Huang F.Q., Tang X.C., Xiao Y.H., Gong M.L., Zheng Z.M., Jin Y. Synthesis and electrochemical properties of LiFePO₄ hierarchically nest-like microstructures. Chin. J. Inorg. Chem., 2014, 30(2): 235.

[20] Zhang S.H., Dong X.T., Xu S.Z., Wang J.X. Preparation and characterization of TiO₂/SiO₂ composite hollow nanofibres via an electrospinning technique. Acta Mater. Compos. Sin., 2008, 25(3): 138.

[21] Qian J.F., Zhou M., Cao Y.L., Ai X.P., Yang H.X. Template-free hydrothermal synthesis of nanoembossed mesoporous LiFePO₄ microspheres for high-performance lithium-ion batteries. J. Phys. Chem. C, 2010, 114(8): 3477.

[22] Arumugam D., Kalaignan G.P., Manisankar P. Synthesis and electrochemical characterizations of nano-crystalline LiFePO₄ and Mg-doped LiFePO₄ cathode materials for rechargeable lithium-ion batteries. J. Solid State Electrochem., 2009, 13(2): 301.

[23] Zhang Y.M., Jiang Z.Q., Jiang Z.J., Fang J.H., Hao X.G. Effects of carbon resources on electrochemical performance of LiFePO₄/C nanocomposites as cathode materials for lithium ion batteries. Chin. J. Power Sources, 2013, 37(8): 1314.