•  
  •  
 

Corresponding Author

Zhi-Yuan TANG

Abstract

The molybdenum-doped Li3V2-xMox(PO4)3/C (x = 0.01, 0.02 and 0.03) cathode materials were prepared with a sol-gel method by using Li2CO3, NH4H2PO4, V2O5 and MoO3 as raw materials, and citric acid as both chelating reagent and carbon source. The X-ray diffraction (XRD) analyses showed that the crystal structure of as-prepared samples is monoclinic with space group P21/n. Scanning electron microscopy (SEM) observations indicated the uniform morphology for Li3Mo0.02V1.98(PO4)3/C sample. Galvanostatic charge/discharge tests revealed that the optimal Mo-doping proportion is x = 0.02, and the best initial discharge capacity of Li3Mo0.02V1.98(PO4)3/C reaches 122.3 mAh?g-1 in the voltage range of 3.0 ~ 4.3 V at 1C rate with almost no capacity loss after 50 cycles. However, at x = 0, 0.01 and 0.03, the initial discharge capacities are 117.1 mAh?g-1,115.1 mAh?g-1 and 116.0 mAh?g-1, respectively. Even at 3C and 5C rates, the Li3Mo0.02V1.98(PO4)3/C sample also exhibits excellent electrochemical performance.

Graphical Abstract

Keywords

cathode material, lithium vanadium phosphate, Mo-doping, sol-gel

Publication Date

2012-04-28

Online Available Date

2012-01-14

Revised Date

2011-12-29

Received Date

2011-11-24

References

[1] Padhi A K, Nanjundaswamy, K S, Masquelier C, et al. Mapping of transition metal reclox energies in phosphates with NASICON structure by lithium intercalation [J]. Journal of The Electrochemical Society, 1997, 144(8): 2581-2586.

[2] Padhi A K, Nanjundaswamy K, Goodenough J B. Phospho-olivines as positive electrode materials for rechargeable lithium batteries [J]. Journal of The Electrochemical Society, 1997, 144(4): 1188-1193.

[3] Delacourt C, Poizot P, Morcrette M, et al. One-step low-temperature route for the preparation of electrochemically active LiMnPO4 powders [J]. Chemistry of Materials, 2004, 16(1): 93-99.

[4] Amine K, Yasuda H, Yamachi M. Olivine LiCoPO4 as 4.8 V electrode material for lithium batteries [J]. Electrochemical and Solid-State Letters, 2000, 3(4): 178-179.

[5] Herle P S, Ellis B, Coombs N, Nazar L F. Nano-network electronic conduction in iron and nickel olivine phosphates [J]. Nature Materials, 2004, 3(3): 147-152.

[6] Yin S C, Grondey H, Nazar L F, et al. Electrochemical property: structure relationships in monoclinic Li3-yV2(PO4)3 [J]. Journal of the American Chemical Society, 2003, 125(34): 10402-10411.

[7] Huang H, Yin S C, Nazar L F et al. Nanostructure composites: a high capacity, fast rate Li3V2(PO4)3/carbon cathode for rechargeable lithium batteries [J]. Advanced Materials, 2002, 14(21): 1525-1528.

[8] Wang J W, Liu J, Yang G L, et al. Electrochemical performance of Li3V2(PO4)3/C cathode material using a novel carbon source [J]. Electrochimica Acta, 2009, 54(26): 6451-6454.

[9] Jiang T, Pan W C, Wang J, et al. Carbon coated Li3V2(PO4)3 cathode material prepared by a PVA assisted sol-gel method [J]. Electrochimica Acta, 2010, 55(12): 3864-3869.

[10] Rui X H, Li C, Liu J et al. The Li3V2(PO4)3/C composites with high-rate capability prepared by a maltose-based sol-gel route [J]. Electrochimica Acta, 2010, 55(22): 6761-6767.

[11] Zhai J, Zhao M S, Wang D D, et al. Effect of MgO nanolayer coated on Li3V2(PO4)3/C cathode material for lithium-ion battery [J]. Journal of Alloys and Compounds, 2010, 502(2): 401-406.

[12] Ren M M, Zhou Z, Li Y Z, et al. Preparation and electrochemical studies of Fe-doped Li3V2(PO4)3 cathode materials for lithium-ion batteries [J]. Journal of Power Sources, 2006, 162(2): 1357-1362.

[13] Kuang Q, Zhao Y M, An X N, et al. Synthesis and electrochemical properties of Co-doped Li3V2(PO4)3 cathode materials for lithium-ion batteries [J]. Electrochimica Acta, 2010, 55(5): 1575-1581.

[14] Huang J S, Yang L, Liu KY, et al. Synthesis and characterization of Li3V(2?2x/3)Mgx(PO4)3/C cathode material for lithium-ion batteries [J]. Journal of Power Sources, 2010, 195(15): 5013-5018.

[15] Dai C S, Chen Z Y, Jin H Z, et al. Synthesis and performance of Li3(V1?xMgx)2(PO4)3 cathode materials [J]. Journal of Power Sources, 2010, 195(17): 5775-5779.

[16] Ren M M, Zhou Z, Gao X P, et al. Core shell Li3V2(PO4)3@C composites as cathode materials for lithium-Ion batteries [J]. Journal of Physical Chemistry C, 2008, 112(14): 5689-5693.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.