以Li_2SiO_3纳米棒-微米球为前驱体合成的Li_2FeSiO_4/C材料及其电性能的研究
|
摘要
含聚阴离子基团的锂离子电池正极材料硅酸亚铁锂(Li_2FeSiO_4)因其稳定的循环性能和优异的安全性能、且材料廉价、对环境友好得到了人们的广泛重视和研究。以硅酸锂(Li_2SiO_3)纳米棒-微米空球(Li_2SiO_3NR-MS)为前驱体,使用流变相合成法成功合成了纯相的硅酸铁锂(Li_2FeSiO_4/C)。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对Li_2FeSiO_4/C材料进行了表征,并用恒电流充放电测试了其作为锂离子电池正极材料的电化学性能。研究结果表明:Li_2FeSiO_4/C能继承前驱体的微球形貌,在室温,0.1C条件下,Li_2FeSiO_4/C首圈的充电比容量为142.2mAh/g,放电比容量为141.8mAh/g,库伦效率高达99.7%;循环40圈后放电比容量为136.5mAh/g,放电比容量损失率为3.8%。
Li_2FeSiO_4 anode material of lithium ion batteries containing poly(anionic group)has attracted extensive attention and research because of its stable cycle and excellent safety performance,and its low cost and friendly environment.Li_2SiO_3 nanorods(Li_2SiO_3 NR-MS-micron hollow spheres)as a precursor for the first time using rheological phase reaction method,lithium iron silicate phase pure Li_2FeSiO_4/C was successfully synthesized.Li_2FeSiO_4/C materials were characterized by X ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM).by constant current charge discharge test,its electrochemical performance as anode material for lithium ion battery was studied.The results showws that Li_2FeSiO_4/C synthesized with Li_2SiO_3 nanorods and micrometer spheres can inherit the microsphere morphology of precursor.Under 0.1 Ccurrent density,the first cycle charge capacity was 142.2 mAh/g,and discharge capacity was 141.8 mAh/g,the coulomb efficiency was up to 99.7%.After 40 cycles,the stable discharge specific capacity of 136.5 mAh/g can be obtained,the loss ratio of discharge capacity was 3.8%.
Li_2FeSiO_4 anode material of lithium ion batteries containing poly(anionic group)has attracted extensive attention and research because of its stable cycle and excellent safety performance,and its low cost and friendly environment.Li_2SiO_3 nanorods(Li_2SiO_3 NR-MS-micron hollow spheres)as a precursor for the first time using rheological phase reaction method,lithium iron silicate phase pure Li_2FeSiO_4/C was successfully synthesized.Li_2FeSiO_4/C materials were characterized by X ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM).by constant current charge discharge test,its electrochemical performance as anode material for lithium ion battery was studied.The results showws that Li_2FeSiO_4/C synthesized with Li_2SiO_3 nanorods and micrometer spheres can inherit the microsphere morphology of precursor.Under 0.1 Ccurrent density,the first cycle charge capacity was 142.2 mAh/g,and discharge capacity was 141.8 mAh/g,the coulomb efficiency was up to 99.7%.After 40 cycles,the stable discharge specific capacity of 136.5 mAh/g can be obtained,the loss ratio of discharge capacity was 3.8%.
引文
[1]Xiang J,Chang C,Zhang F,et al.Rheological phase synthesis and electrochemical properties of Mg-doped LiNi0.8Co0.2O2cathode materials for lithium-ion battery[J].Journal of the Electrochemical Society,2008,155(7):A520-A525.
[2]Ren H,Wang Y,Li D,et al.Synthesis of LiNi1/3Co1/3Mn1/3O2as a cathode material for lithium battery by the rheological phase method[J].Journal of Power Sources,2008,178(1):439-444.
[3]Lou X M,Zhang Y X.Synthesis of LiFePO4/C cathode materials with both high-rate capability and high tap density for lithium-ion batteries[J].Journal of Materials Chemistry,2011,21(12):4156-4160.
[4]Wang M,Yang Y,Zhang Y.Synthesis of micro-nano hierarchical structured LiFePO4/C composite with both superior high-rate performance and high tap density[J].Nanoscale,2011,3(10):4434-4439.
[5]Wang M,Xue Y,Zhang K,et al.Synthesis of FePO4·2H2Onanoplates and their usage for fabricating superior high-rate performance LiFePO4[J].ElectrochimicaActa,2011,56(11):4294-4298.
[6]Li Y S,Cheng X,Zhang Y.Achieving high capacity by vanadium substitution into Li2FeSiO4[J].Journal of The Electrochemical Society,2012,159(9):A69-A74.
[7]Choi S,Kim S J,Yun Y J,et al.Controlled shape with enhanced electrochemical performance of various ions doped Li2MnSiO4cathode nanoparticles[J].Materials Letters,2013,105(5):113-116.
[8]Zhang S,Deng C,Fu B L,et al.Doping effects of magnesium on the electrochemical performance of Li2FeSiO4for lithium ion batteries[J].Journal of Electroanalytical Chemistry,2010,644(2):150-154.
[2]Ren H,Wang Y,Li D,et al.Synthesis of LiNi1/3Co1/3Mn1/3O2as a cathode material for lithium battery by the rheological phase method[J].Journal of Power Sources,2008,178(1):439-444.
[3]Lou X M,Zhang Y X.Synthesis of LiFePO4/C cathode materials with both high-rate capability and high tap density for lithium-ion batteries[J].Journal of Materials Chemistry,2011,21(12):4156-4160.
[4]Wang M,Yang Y,Zhang Y.Synthesis of micro-nano hierarchical structured LiFePO4/C composite with both superior high-rate performance and high tap density[J].Nanoscale,2011,3(10):4434-4439.
[5]Wang M,Xue Y,Zhang K,et al.Synthesis of FePO4·2H2Onanoplates and their usage for fabricating superior high-rate performance LiFePO4[J].ElectrochimicaActa,2011,56(11):4294-4298.
[6]Li Y S,Cheng X,Zhang Y.Achieving high capacity by vanadium substitution into Li2FeSiO4[J].Journal of The Electrochemical Society,2012,159(9):A69-A74.
[7]Choi S,Kim S J,Yun Y J,et al.Controlled shape with enhanced electrochemical performance of various ions doped Li2MnSiO4cathode nanoparticles[J].Materials Letters,2013,105(5):113-116.
[8]Zhang S,Deng C,Fu B L,et al.Doping effects of magnesium on the electrochemical performance of Li2FeSiO4for lithium ion batteries[J].Journal of Electroanalytical Chemistry,2010,644(2):150-154.