Synthesis and Characterization of LiFePO4-C/ PANI Composite for Cathode Material of Lithium Ion Battery

Abstract:

Article Preview

In-situ polymer coated LiFePO4-C composite material has been synthesized using different oxidizing agents viz. (NH4)2S2O8, KMnO4 and K2Cr2O7. Polyaniline (PANI) with chains having diameter ≤ 200 nm have been grown separately by self oxidation process of aniline monomers using the above oxidizing agents. For the synthesis of LiFePO4-C active material, initially raw material FePO4/PANI has been synthesized by chemical precipitation method and added with LiCOOCH3 followed by heat treatment at 700°C under reducing (Ar/H2=90/10) atmosphere for 16 hrs. The synthesized LiFePO4-C material has particle size of about 100 nm. The polymer coated LiFePO4-C composite was synthesized by undergoing in-situ polymerization of aniline monomers added with fixed quantity of LiFePO4-C. XRD analysis reveals formation of single phase pure active material LiFePO4-C and mixed phase containing LiFePO4 to FePO4 for polymer coated LiFePO4-C composite. The carbon content in the LiFePO4-C was estimated to be 5 wt%, however, the PANI content in the composites was different with different oxidizing agent. These PANI contents in the composites synthesized with (NH4)2S2O8, KMnO4 and K2Cr2O7 are 14, 15 and 17 wt% respectively which have been estimated by thermal gravimetric analysis (TGA) of the materials. Electrical conductivities of the composite materials were determined by Impedance spectroscopy method. The composite material synthesized with (NH4)2S2O8 has higher conductivity compared to those synthesized with KMnO4 and K2Cr2O7. The higher conductivity of the composite synthesized with (NH4)2S2O8 may be attributed to the presence of partial chain structure in polymer coating as seen by microstructural observations on the composite.

Info:

Periodical:

Edited by:

B.S.S. Daniel and G.P. Chaudhari

Pages:

240-244

Citation:

R. Sehrawat and A. Sil, "Synthesis and Characterization of LiFePO4-C/ PANI Composite for Cathode Material of Lithium Ion Battery", Advanced Materials Research, Vol. 585, pp. 240-244, 2012

Online since:

November 2012

Export:

Price:

$38.00

[1] S. Franger, C. Bourbon, and F. Le Cras, Optimized Lithium Iron Phosphate for High-Rate Electrochemical Applications, J. Electrochem. Soc. 151 (2004) A1024-A1027.

DOI: https://doi.org/10.1149/1.1758721

[2] C. Wang and J. Hong, Ionic/Electronic Conducting Characteristics of LiFePO4 Cathode Materials, Electrochemical and Solid-State Letters, 10 (2007) A65-A69.

DOI: https://doi.org/10.1149/1.2409768

[3] Y. Wang, Y. Wang, E. Hosono, K. Wang, and Haoshen Zhou, The design of a LiFePO4/Carbon nanocomposite with a core–shell structure and its synthesis by an in situ polymerization restriction method, Angew. Chem. Int. Ed. 47 (2008) 7461-7465.

DOI: https://doi.org/10.1002/anie.200802539

[4] C. Delacourt, P. Poizot, S. Levasseur, and C. Masquelier, Size Effects on Carbon-Free LiFePO4 Powders The Key to Superior Energy Density, Electrochemical and Solid-State Letters, 9 (7) (2006) A352-A355.

DOI: https://doi.org/10.1149/1.2201987

[5] M. Wagemaker, Brian L. Ellis, D. Lu. Hecht, F. M. Mulder, and L. F. Nazar, Proof of Supervalent Doping in Olivine LiFePO4, Chem. Mater. 20 (2008) 6313-6315.

DOI: https://doi.org/10.1021/cm801781k

[6] R. Dominko, M. Bele, M. Gaberscek, M. Remskar, D. Hanzel, S. Pejovnik, and J. Jamnika, Impact of the Carbon Coating Thickness on the Electrochemical Performance of LiFePO4/C Composites, J. Electrochem. Soc. 152 (3) (2005) A607-A610.

DOI: https://doi.org/10.1149/1.1860492

[7] W. M. Chen, L. Qie, L. X. Yuan, S.A. Xia, X. Lu Hu, W. X. Zhang, Y. H. Huang, Insight into the improvement of rate capability and cyclability in LiFePO4/PANI composite cathode, Electrochimica Acta, 56 (2011) 2689-2695.

DOI: https://doi.org/10.1016/j.electacta.2010.12.041

[8] H. C. Shin, W. I. Cho, H. Jang, Electrochemical properties of the carbon-coated LiFePO4 as a cathode material for lithium-ion secondary batteries, Journal of Power Sources, 159 (2006) 1383-1388.

DOI: https://doi.org/10.1016/j.jpowsour.2005.12.043

[9] K. Fei-yul, M.A. Jun, L. Bao-hua, Effects of carbonaceous materials on the physical and electrochemical performance of a LiFePO4 cathode for lithium-ion batteries, New Carbon Materials, 26 (3) (2011) 161-170.

DOI: https://doi.org/10.1016/s1872-5805(11)60073-5

[10] J. K. Kim, G. Cheruvally, J. H. Ahn, H. J. Ahn. Electrochemical properties of LiFePO4/C composite cathode material: Carbon coating by the precursor method and direct addition, Journal of Physics and Chemistry of Solids, 69 (2008) 1257-1260.

DOI: https://doi.org/10.1016/j.jpcs.2007.10.047

[11] D. K. Kim, P. Muralidharan, H. W. Lee, R. Ruffo, Yuan Yang, C. K. Chan, H. Peng, R. A. Huggins and Yi Cui, Spinel LiMn2O4 Nanorods as Lithium Ion Battery Cathodes, Nano Lett. 8 (2008) 3948-3952.

DOI: https://doi.org/10.1021/nl8024328

[12] O. K. Park, Y. Cho, S. Lee, H. C. Yoo, H. K. Song and J. Cho. Who will drive electric vehicles, olivine or spinel?, Energy Environ. Sci. 4 (2011) 1621-1633.

DOI: https://doi.org/10.1039/c0ee00559b

[13] X. Wang, Y. Huang, D. Jia, Z. Guo, Duo Ni, M. Miao, Preparation and characterization of high-rate and long-cycle LiFePO4/C nanocomposite as cathode material for lithium-ion battery, J. Solid State Electrochem. 16 (2012) 17-24.

DOI: https://doi.org/10.1007/s10008-010-1269-4