Abstract：Porous V2O5 microspheres were synthesized by a facile hydrothermal reaction followed by high temperature calcination. The crystal structure of V2O5 microspheres was analyzed by X-ray diffraction (XRD). The morphology and microstructure were observed and analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the microspheres are single phase V2O5 with homogeneous porous morphology. As cathode material for lithium batteries, porous V2O5 microspheres electrode exhibits excellent electrochemical performance at different voltage ranges. The initial discharge capacity of the porous V2O5 microspheres electrode is 145 (mA·h)/g at the current density of 100 mA/g during 2.5-4 V, which is very close to the theoretical value. The capacity retention is 95.2% based on the initial capacity after 50 cycles. In addition, the electrode demonstrates excellent long-term cycling stability with the discharge specific capacity maintained at 82.8 (mA∙h)/g after 1 000 cycles at 2 A/g current density, and the average single-cycle specific capacity attenuation rate is only 0.022%. The excellent electrochemical properties of the material benefit from the three-dimensional porous microsphere structure.
[1] ARMAND M, TARASCON J M.Building better batteries[J]. Nature, 2008, 451(7179): 652-657. [2] GOODENOUGH J B, KIM Y.Challenges for rechargeable Li batteries[J]. Chemistry of Materials, 2010, 22(3): 587-603. [3] HOWARD W F, SPOTNITZ R M.Theoretical evaluation of high-energy lithium metal phosphate cathode materials in Li-ion batteries[J]. Journal of Power Sources, 2007, 165(2): 887-891. [4] LIU R, ZHANG H, HUANG Y, et al.In situ gelatin carbonation to prepare a binder-free LiFePO4 cathode for high-power lithium ion batteries[J]. Electrochimica Acta, 2012, 78(1): 563-568. [5] KONAROVA M, TANIGUCHI I.Synthesis of carbon-coated LiFePO4 nanoparticles with high rate performance in lithium secondary batteries[J]. Journal of Power Sources, 2010, 195(11): 3661-3667. [6] JO M, HONG Y S, CHOO J, et al.Effect of LiCoO2 cathode nanoparticle size on high rate performance for Li-Ion batteries[J]. Journal of the Electrochemical Society, 2009, 156(6): A430-A434. [7] LEE M J, LEE S, OH P, et al.High performance LiMn2O4 cathode materials grown with epitaxial layered nanostructure for Li-ion batteries[J]. Nano Letters, 2014, 14(2): 993-999. [8] CAO A M, HU J S, LIANG H P, et al.Self-assembled vanadium pentoxide (V2O5) hollow microspheres from nanorods and their application in lithium-ion batteries[J]. Angewandte Chemie, 2005, 117(28): 4465-4469. [9] SARAVANAKUMAR B, PURUSHOTHAMAN K K, MURALIDHARAN G.Interconnected V2O5 nanoporous network for high-performance supercapacitors[J]. ACS Applied Materials & Interfaces, 2012, 4(9): 4484-4490. [10] CHOU S L, WANG J Z, SUN J Z, et al.High capacity, safety, and enhanced cyclability of lithium metal battery using a V2O5 nanomaterial cathode and room temperature ionic liquid electrolyte[J]. Chemistry of Materials, 2008, 20(22): 7044-7051. [11] LIU Y J, SCHINDLER J L, DEGROOT D C, et al.Synthesis, structure, and reactions of poly(ethylene oxide)/V2O5 intercalative nanocomposites[J]. Chemistry of Materials, 1996, 8(2): 525-534. [12] WANG S, LU Z, WANG D, et al.Porous monodisperse V2O5 microspheres as cathode materials for lithium-ion batteries[J]. Journal of Materials Chemistry, 2011, 21(17): 6365-6369. [13] CHAN C, PENG H, TWESTEN R, et al.Fast, completely reversible Li insertion in vanadium pentoxide nanoribbons[J]. Nano Letters, 2007, 7(2): 490-495. [14] WHITTINGHAM M S.The role of ternary phases in cathode reactions[J]. Journal of the Electrochemical Society, 1976, 123(3): 315-320. [15] LIANG S, HU Y, NIE Z, et al.Template-free synthesis of ultra-large V2O5 nanosheets with exceptional small thickness for high-performance lithium-ion batteries[J]. Nano Energy, 2015, 13: 58-66. [16] LIU Y, UCHAKER E, ZHOU N, et al.Facile synthesis of nanostructured vanadium oxide as cathode materials for efficient Li-ion batteries[J]. Journal of Materials Chemistry, 2012, 22(46): 24439-24445. [17] FANG G, ZHOU J, LIANG C, et al.General synthesis of three-dimensional alkali metal vanadate aerogels with superior lithium storage properties[J]. Journal of Materials Chemistry A, 2016, 4(37): 14408-14415. [18] HU L, ZHONG H, ZHENG X, et al.CoMn2O4 spinel hierarchical microspheres assembled with porous nanosheets as stable anodes for lithium-ion batteries[J]. Scientific Reports, 2012, 2(1): 986. [19] WU H B, PAN A, HNG H H, et al.Template-assisted formation of rattle-type V2O5 hollow microspheres with enhanced lithium storage properties[J]. Advanced Functional Materials, 2013, 23(45): 5669-5674. [20] KIM H, HAN B, CHOO J, et al.Three-dimensional porous silicon particles for use in high-performance lithium secondary batteries[J]. Angewandte Chemie, 2008, 120(52): 10305-10308. [21] PAN A, WU H B, YU L, et al.Template-free synthesis of VO2 hollow microspheres with various interiors and their conversion into V2O5 for lithium-ion batteries[J]. Angewandte Chemie, 2013, 125(8): 2282-2286. [22] MAI L, AN Q, WEI Q, et al.Nanoflakes-assembled three-dimensional hollow-porous V2O5 as lithium storage cathodes with high-rate capacity[J]. Small, 2014, 10(15): 3032-3037. [23] SUN C, RAJASEKHARA S, GOODENOUGH J B, et al.Monodisperse porous LiFePO4 microspheres for a high power Li-ion battery cathode[J]. Journal of the American Chemical Society, 2011, 133(7): 2132-2135. [24] WANG S, LI S, SUN Y, et al.Three-dimensional porous V2O5 cathode with ultra high rate capability[J]. Energy & Environmental Science, 2011, 4(8): 2854-2857. [25] JIA Y, YU X Y, LUO T, et al.Two-step self-assembly of iron oxide into three-dimensional hollow magnetic porous microspheres and their toxic ion adsorption mechanism[J]. Dalton Transactions, 2013, 42(5): 1921-1928. [26] FANG G, LIANG C, ZHOU J, et al.Effect of crystalline structure on the electrochemical properties of K0.25V2O5 nanobelt for fast Li insertion[J]. Electrochimica Acta, 2016, 218(10): 199-207. [27] LIU H, WANG Y, LI L, et al.Facile synthesis of NaV6O15 nanorods and its electrochemical behavior as cathode material in rechargeable lithium batteries[J]. Journal of Materials Chemistry, 2009, 19(42): 7885-7891. [28] ZHOU J, ZHANG Z, XING W, et al.Nitrogen-doped hierarchical porous carbon materials prepared from meta- aminophenol formaldehyde resin for supercapacitor with high rate performance[J]. Electrochimica Acta, 2015, 153(20): 68-75. [29] WANG Q, YAN J, WANG Y, et al.Three-dimensional flower-like and hierarchical porous carbon materials as high-rate performance electrodes for supercapacitors[J]. Carbon, 2014, 67(1): 119-127. [30] WU L, HU X, QIAN J, et al.Sb-C nanofibers with long cycle life as an anode material for high-performance sodium-ion batteries[J]. Energy & Environmental Science, 2014, 7(1): 323-328. [31] TONG Z, HAO J, ZHANG K, et al.Improved electrochromic performance and lithium diffusion coefficient in three- dimensionally ordered macroporous V2O5 films[J]. Journal of Materials Chemistry A, 2014, 2(18): 3651-3658. [32] SEMENENKO D A, KULOVA T L, SKUNDIN A M, et al.Impedance spectroscopy study of lithium ion diffusion in a new cathode material based on vanadium pentoxide[J]. Mendeleev Communications, 2010, 20(1): 12-14.
2019, Vol. 24 
