以V2O5、H3PO4为原料，在V2O5与H3PO4摩尔比为1：2.4条件下通过水热法制备VOPO4?xH2O，得到的VOPO4?xH2O再通过650℃煅烧制备纳米结构ε-VOPO4，通过X射线衍射对制备材料进行表征。采用SEM对产物形貌进行观察，考察原料配比条件对产物组成和晶相的影响；对纳米ε-VOPO4进行电化学性能测试。结果表明：在该条件下制备出的纳米ε-VOPO4物相纯；所制备纳米结构的ε-VOPO4颗粒粒径为200 nm，且颗粒度均匀；在0.2C倍率、电压范围为2.0~4.3 V充放电制度下，首次充电比容量可以达到227.9 mA?h/g,在0.5C倍率充放电制度下循环140次后，放电容量达160.49 mA?h/g。
VOPO4?xH2O was obtained through hydro-thermal method with V2O5 and H3PO4 as initial materials. Nanostructuredε-VOPO4 was synthesized from VOPO4?xH2O heated at 650℃when molar ratio of V2O5 to H3PO4 is 1:2.4. The nanostructed ε-VOPO4 has been characterization by X-ray. The product morphology was studied by SEM. The results show that the nanostructuredε-VOPO4 is pure with particle size of about 200 nm. The effects of the molar ratio of the initial reaction materials on the product components and crystal structure were studied. And the electrochemical performance of the nanostructured ε-VOPO4 was also studied. The best electrochemical performance and crystal of the obtained nanostructured ε-VOPO4 is from that molar ratio of the V2O5 and H3PO4 is 1:2.4. The particle size of the nanostructured ε-VOPO4 was about 200 nm. The nanostructured ε-VOPO4 exhibits an initial discharge capacity of 227.9 mA?h/g at 0.2C rate in the voltage window of 2.0-4.3 V. The discharge capacity is as high as 160.49 mA?h/g at the rate of 0.5C after the 140th cycle.
参考文献
| [1] | Natasha A. Chernova;Megan Roppolo;Anne C. Dillon .Layered vanadium and molybdenum oxides: batteries and electrochromics[J].Journal of Materials Chemistry: An Interdisciplinary Journal dealing with Synthesis, Structures, Properties and Applications of Materials, Particulary Those Associated with Advanced Technology,2009(17):2526-2552. |
| [2] | WHITTINGHAM M S .Hydrothermal synthesis of transition metal oxides under mild conditions[J].Current Opinion in Solid State and Materials Science,1996,1(02):227-232. |
| [3] | Yamamoto N.;Hiyoshi N.;Okuhara T. .Thin-layered sheets of VOHPO4 center dot 0(center dot)5H(2)O prepared from VOPO4 center dot 2H(2)O by intercalation-exfoliation-reduction in alcohol[J].Chemistry of Materials,2002(9):3882-3888. |
| [4] | Jordi Cabana;Montserrat Casas-Cabanas;Fredrick O. Omenya .Composition-Structure Relationships in the Li-Ion Battery Electrode Material LiNi_(0.5)Mn_(1.5)O4[J].Chemistry of Materials: A Publication of the American Chemistry Society,2012(15):2952-2964. |
| [5] | J.Gaubicher;T.L.Mercier .Li/β-VOPO4: A New4V System for Lithium Batteries[J].Journal of the Electrochemical Society,1999(12):4375-4379. |
| [6] | Mills P.L.;Randall H.T. .Redox kinetics of VOPO_4 with butane and oxygen using the TAP reactor system[J].Chemical Engineering Science,1999(15/16):3709-3721. |
| [7] | T. A. Kerr;J. Gaubicher;L. F. Nazar .Highly Reversible Li Insertion at 4 V in ε-VOPO_4/α-LiVOPO_4 Cathodes[J].Electrochemical and solid-state letters,2000(10):460-462. |
| [8] | 刘素琴,唐联兴,黄可龙,张静.新型锂离子电池正极材料Li3V2（PO4）3的合成及其性能[J].中国有色金属学报,2005(08):1294-1299. |
| [9] | 梁叔全,潘安强,刘军,钟杰,陈涛,周江.锂离子电池纳米钒基正极材料的研究进展[J].中国有色金属学报,2011(10):2448-2464. |
| [10] | 唐艳,郭孝东,聂翔,钟艳君,钟本和,刘恒,文嘉杰.不同有机-水混合溶剂的Li3V2（PO4）3/C合成及其性能[J].中国有色金属学报,2012(01):179-186. |
| [11] | GIRGSDIES F;SCHNEIDER M;BRüCKNER A;RESSLER T SCHL?GL R .The crystal structure of δ-VOPO 4 and its relationship to ω-VOPO 4[J].Solid State Sciences,2009,11(07):1258-1264. |
| [12] | Bustam M. Azmi;Tatsumi Ishihara;Hiroyasu Nishiguchi;Yusaku Takita .Vanadyl phosphates of VOPO_4 as a cathode of Li-ion rechargeable batteries[J].Journal of Power Sources,2003(119/121):273-277. |
| [13] | Hong, J;Wang, CS;Chen, X;Upreti, S;Whittingham, MS .Vanadium Modified LiFePO4 Cathode for Li-Ion Batteries[J].Electrochemical and solid-state letters,2009(2):A33-A38. |
| [14] | Zehua Chen;Qiyuan Chen;Liquan Chen .Electrochemical Behavior of Nanostructured ε-VOPO_4 over Two Redox Plateaus[J].Journal of the Electrochemical Society,2013(10):A1777-A1780. |
| [15] | 曹雁冰,段建国,彭忠东,杜柯,胡国荣.固相法合成原位碳包覆LiFePO4复合正极材料及其性能[J].中国有色金属学报,2012(04):1209-1215. |
| [16] | Gautier, R.;Hernandez, O.;Audebrand, N.;Bataille, T.;Roiland, C.;Elka?m, E.;Le Pollès, L.;Furet, E.;Le Fur, E. .DFT-assisted structure determination of α_1- and α_2-VOPO_4: New insights into the understanding of the catalytic performances of vanadium phosphates[J].Dalton transactions: An international journal of inorganic chemistry,2013(22):8124-8131. |
| [17] | Girgsdies F;Dong WS;Bartley JK;Hutchings GJ;Schlogl R;Ressler T .The crystal structure of epsilon-VOPO4[J].Solid state sciences,2006(7):807-812. |
| [18] | SONG Y;ZAVALIJ P Y;WHITTINGHAM M S .ε-VOPO4:Electrochemical synthesis and enhanced cathode behavior[J].Journal of the Electrochemical Society A,2005,152(04):721-728. |
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