以LiOH溶液和不同粒径的自制球形TiO2为反应物,通过水热法快速地合成了尖晶石型结构的球形Li4Ti5O12,并考察了材料合成的水热反应机理和电化学性能。TiO2在100℃、5 mol/L Li OH溶液中经水热反应20 h得到前驱体,再经800℃热处理2 h便可...以LiOH溶液和不同粒径的自制球形TiO2为反应物,通过水热法快速地合成了尖晶石型结构的球形Li4Ti5O12,并考察了材料合成的水热反应机理和电化学性能。TiO2在100℃、5 mol/L Li OH溶液中经水热反应20 h得到前驱体,再经800℃热处理2 h便可得到粒径大小不同（0.5-1.5μm）且分布均匀的球形尖晶石Li4Ti5O12材料。Li OH在水热反应条件下扩散到球形TiO2内部,得到在分子水平混合均匀的Li-Ti-O中间体,利于高温下生成纯相的尖晶石Li4Ti5O12。所得粒径大小不同的Li4Ti5O12材料均表现出稳定的电化学循环充放电性能,其中,粒径为0.5μm的Li4Ti5O12材料的电化学性能最好：室温下,以0.2 C的倍率进行充放电,其可逆容量达到158 m Ah/g,70周后容量保持率高于99%;同时还表现出优异的高温循环稳定性,55℃下以0.2 C的倍率进行充放电,50次循环后其可逆放电比容量仍能达到125 m Ah/g。展开更多
Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are charac...Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller （BET） analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 ℃ or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfaetant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained.展开更多
Li4Ti5O(12)(LTO)has drawn great attention due to its safety and stability in lithium-ion batteries(LIBs).However,high potential plateau at 1.5 V vs.Li reduces the cell voltage,leading to a limited use of LTO.Dual-ion ...Li4Ti5O(12)(LTO)has drawn great attention due to its safety and stability in lithium-ion batteries(LIBs).However,high potential plateau at 1.5 V vs.Li reduces the cell voltage,leading to a limited use of LTO.Dual-ion batteries(DIBs)can achieve high working voltage due to high intercalation potential of cathode.Herein,we propose a DIB configuration in which LTO is used as anode and the working voltage was 3.5 V.This DIB achieves a maximum specific energy of 140 Wh/kg at a specific power of 35 W/kg,and the specific power of 2933 W/kg can be obtained with a remaining specific energy of 11 Wh/kg.Traditional LIB material shows greatly improved properties in the DIB configuration.Thus,reversing its disadvantage leads to upgraded performance of batteries.Our configuration has also widened the horizon of materials for DIBs.展开更多
文摘以LiOH溶液和不同粒径的自制球形TiO2为反应物,通过水热法快速地合成了尖晶石型结构的球形Li4Ti5O12,并考察了材料合成的水热反应机理和电化学性能。TiO2在100℃、5 mol/L Li OH溶液中经水热反应20 h得到前驱体,再经800℃热处理2 h便可得到粒径大小不同（0.5-1.5μm）且分布均匀的球形尖晶石Li4Ti5O12材料。Li OH在水热反应条件下扩散到球形TiO2内部,得到在分子水平混合均匀的Li-Ti-O中间体,利于高温下生成纯相的尖晶石Li4Ti5O12。所得粒径大小不同的Li4Ti5O12材料均表现出稳定的电化学循环充放电性能,其中,粒径为0.5μm的Li4Ti5O12材料的电化学性能最好：室温下,以0.2 C的倍率进行充放电,其可逆容量达到158 m Ah/g,70周后容量保持率高于99%;同时还表现出优异的高温循环稳定性,55℃下以0.2 C的倍率进行充放电,50次循环后其可逆放电比容量仍能达到125 m Ah/g。
基金V. ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20971117 and No.10979049） and the Education Department of Anhui Province （No.KJ2009A142）.
文摘Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller （BET） analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 ℃ or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfaetant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained.
基金the financial supports from the National Natural Science Foundation of China (51932003, 51902050, 51872115 & 51802110)Program for the Development of Science and Technology of Jilin Province (20190201309JC)+4 种基金the Open Project Program of Wuhan National Laboratory for Optoelectronics (2018WNLOKF022)the Jilin Province/Jilin University co-Construction Project-Funds for New Materials (SXGJSF2017-3, Branch-2/440050316A36)Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, 2017TD-09)the Fundamental Research Funds for the Central Universities JLU“Double-First Class” Discipline for Materials Science & Engineering.
文摘Li4Ti5O(12)(LTO)has drawn great attention due to its safety and stability in lithium-ion batteries(LIBs).However,high potential plateau at 1.5 V vs.Li reduces the cell voltage,leading to a limited use of LTO.Dual-ion batteries(DIBs)can achieve high working voltage due to high intercalation potential of cathode.Herein,we propose a DIB configuration in which LTO is used as anode and the working voltage was 3.5 V.This DIB achieves a maximum specific energy of 140 Wh/kg at a specific power of 35 W/kg,and the specific power of 2933 W/kg can be obtained with a remaining specific energy of 11 Wh/kg.Traditional LIB material shows greatly improved properties in the DIB configuration.Thus,reversing its disadvantage leads to upgraded performance of batteries.Our configuration has also widened the horizon of materials for DIBs.
