以SnCl_4·5H_2O和尿素为原料,嵌段聚醚F127(EO_(106)-PO_(70)-EO_(106))为模板剂,通过水热法制备了介孔SnO_2材料。XRD、TEM和BET等分析结果表明,模板剂F127添加量对介孔SnO_2的孔结构有重要影响。F127添加量增加,SnO_2比表面积增...以SnCl_4·5H_2O和尿素为原料,嵌段聚醚F127(EO_(106)-PO_(70)-EO_(106))为模板剂,通过水热法制备了介孔SnO_2材料。XRD、TEM和BET等分析结果表明,模板剂F127添加量对介孔SnO_2的孔结构有重要影响。F127添加量增加,SnO_2比表面积增大,孔容增大,孔径分布变宽。电化学测试结果表明,介孔的存在不仅能为锂离子脱嵌提供通道,而且可以缓冲SnO_2的体积膨胀,从而提高介孔SnO_2负极材料的电化学性能;当F127添加量为6.0 g时,所制备SnO_2具有124 m2/g的比表面积,平均孔径为4.94 nm,表现出最佳的循环性能和倍率性能,在60 m A/g的电流密度下经30次循环后,其可逆容量仍保持在434 m Ah/g;循环伏安测试表明部分高活性Li2O的可逆还原提供了附加的可逆容量。展开更多
通过一种简单的共沉淀方法制备了Mn掺杂二氧化锡(SnO_2)颗粒,对前驱体在不同温度下热处理,并通过X射线衍射(X-my diffraction,XRD)和高分辨电子显微学(high-resolution transmission electron microscopy,HRTEM)对样品的微纳米结构进行...通过一种简单的共沉淀方法制备了Mn掺杂二氧化锡(SnO_2)颗粒,对前驱体在不同温度下热处理,并通过X射线衍射(X-my diffraction,XRD)和高分辨电子显微学(high-resolution transmission electron microscopy,HRTEM)对样品的微纳米结构进行了表征.结果表明:样品中除了四方相Sn02外,还存在正交相SnO_2.XRD测试结果显示,随着退火温度的增加,正交相SnO_2的峰强减弱,四方相的峰强增加.HRTEM分析表明:样品中可以同时找到四方相和正交相SnO_2的晶格像,进一步证实了正交相SnO_2的存在.Mn掺杂SnO_2后,Mn离子进入SnO_2晶胞,替代了Sn离子,因此引起晶格扭曲畸变,对正交相SnO_2的形成起着重要的作用.展开更多
A novel process for preparing tin oxide thin films directly on copper foil by electrodeposition was developed. An optimal preparation technology to obtain SnOz thin films was proposed with current density of 8 mA/cm^2...A novel process for preparing tin oxide thin films directly on copper foil by electrodeposition was developed. An optimal preparation technology to obtain SnOz thin films was proposed with current density of 8 mA/cm^2, the time of deposition of 120 min, the concentration of tin dichloride of 0.02 mol/L and the concentration of dissociated acid of 0. 03 mol/L. The phase identification, microstructure and morphology of the thin films were investigated by thermogravimetric analysis and differential thermal analysis, X-ray diffraction, Fourier transform infrared spectra,scanning electron microscopy and transmission electron microscopy. The as-deposited thin film was composed of SnO2·xH2O was obtained by drying at room temperature. Nanocrystalline SnO2 thin film having tetragonal structure with average grain size in the range of 8 to 20 nm and porous, uniform surface was obtained by heat-treating the as-deposited film at 400 ℃ for 2 h. Electrochemical characterization shows that SnO2 film can deliver a discharge capacity of 798 mAh/g and the SnO2 film with smooth surface and annealed at 400 ℃ for 2 h has better cycle performance than that with rough surface and annealed at 150℃ for 10 h.展开更多
文摘以SnCl_4·5H_2O和尿素为原料,嵌段聚醚F127(EO_(106)-PO_(70)-EO_(106))为模板剂,通过水热法制备了介孔SnO_2材料。XRD、TEM和BET等分析结果表明,模板剂F127添加量对介孔SnO_2的孔结构有重要影响。F127添加量增加,SnO_2比表面积增大,孔容增大,孔径分布变宽。电化学测试结果表明,介孔的存在不仅能为锂离子脱嵌提供通道,而且可以缓冲SnO_2的体积膨胀,从而提高介孔SnO_2负极材料的电化学性能;当F127添加量为6.0 g时,所制备SnO_2具有124 m2/g的比表面积,平均孔径为4.94 nm,表现出最佳的循环性能和倍率性能,在60 m A/g的电流密度下经30次循环后,其可逆容量仍保持在434 m Ah/g;循环伏安测试表明部分高活性Li2O的可逆还原提供了附加的可逆容量。
文摘通过一种简单的共沉淀方法制备了Mn掺杂二氧化锡(SnO_2)颗粒,对前驱体在不同温度下热处理,并通过X射线衍射(X-my diffraction,XRD)和高分辨电子显微学(high-resolution transmission electron microscopy,HRTEM)对样品的微纳米结构进行了表征.结果表明:样品中除了四方相Sn02外,还存在正交相SnO_2.XRD测试结果显示,随着退火温度的增加,正交相SnO_2的峰强减弱,四方相的峰强增加.HRTEM分析表明:样品中可以同时找到四方相和正交相SnO_2的晶格像,进一步证实了正交相SnO_2的存在.Mn掺杂SnO_2后,Mn离子进入SnO_2晶胞,替代了Sn离子,因此引起晶格扭曲畸变,对正交相SnO_2的形成起着重要的作用.
文摘A novel process for preparing tin oxide thin films directly on copper foil by electrodeposition was developed. An optimal preparation technology to obtain SnOz thin films was proposed with current density of 8 mA/cm^2, the time of deposition of 120 min, the concentration of tin dichloride of 0.02 mol/L and the concentration of dissociated acid of 0. 03 mol/L. The phase identification, microstructure and morphology of the thin films were investigated by thermogravimetric analysis and differential thermal analysis, X-ray diffraction, Fourier transform infrared spectra,scanning electron microscopy and transmission electron microscopy. The as-deposited thin film was composed of SnO2·xH2O was obtained by drying at room temperature. Nanocrystalline SnO2 thin film having tetragonal structure with average grain size in the range of 8 to 20 nm and porous, uniform surface was obtained by heat-treating the as-deposited film at 400 ℃ for 2 h. Electrochemical characterization shows that SnO2 film can deliver a discharge capacity of 798 mAh/g and the SnO2 film with smooth surface and annealed at 400 ℃ for 2 h has better cycle performance than that with rough surface and annealed at 150℃ for 10 h.
