二氧化钛(Ti O2)作为有前景的钠离子电池负极材料,具有良好的循环稳定性,但由于其导电率较低,而导致容量和倍率性能不佳限制了其实际应用.本文采用喷雾干燥技术制备了氧化石墨烯/纳米Ti O2复合材料(GO/Ti O2),通过热处理获得还原氧化石...二氧化钛(Ti O2)作为有前景的钠离子电池负极材料,具有良好的循环稳定性,但由于其导电率较低,而导致容量和倍率性能不佳限制了其实际应用.本文采用喷雾干燥技术制备了氧化石墨烯/纳米Ti O2复合材料(GO/Ti O2),通过热处理获得还原氧化石墨烯/Ti O2复合材料(RGO/Ti O2).电化学测试结果表明,还原氧化石墨烯改性的RGO/Ti O2复合材料的电化学性能得到显著提升,RGO含量为4.0%(w)的RGO/Ti O2复合材料在各种电流密度下的可逆容量分别为183.7 m Ah?g-1(20 m A?g-1),153.7 m Ah?g-1(100 m A?g-1)和114.4 m Ah?g-1(600m A?g-1),而纯Ti O2的比容量仅为93.6 m Ah?g-1(20 m A?g-1),69.6 m Ah?g-1(100 m A?g-1)和26.5 m Ah?g-1(600m A?g-1).4.0%(w)RGO/Ti O2复合材料体现了良好的循环稳定性,在100 m A?g-1电流密度下充放电循环350个周期后,比容量仍然保持146.7 m Ah?g-1.同等条件下,纯Ti O2电极比容量只有68.8 m Ah?g-1.RGO包覆改性极大提高了Ti O2在钠离子电池中的电化学嵌钠/脱钠性能.RGO包覆改性技术在改进钠离子电池材料性能中将有很好的应用前景.展开更多
The microwave coprecipitation method was used to synthesize α-Ni0.8Co0.2(OH)2 precursor for preparing LiNi0.8Co0.2O2 cathode material.The precursor α-Ni0.8Co0.2(OH)2 was mixed with LiOH·H2O and then calcined in...The microwave coprecipitation method was used to synthesize α-Ni0.8Co0.2(OH)2 precursor for preparing LiNi0.8Co0.2O2 cathode material.The precursor α-Ni0.8Co0.2(OH)2 was mixed with LiOH·H2O and then calcined in O2 for 10 h at different temperatures(700℃,800℃,900℃).XRD,SEM analyses and electrochemical tests were used to study the physical and electrochemical performance of the cathode material.With increasing calcination temperature,the characteristic peaks of the cathode materials became stronger and sharper,corresponding to a perfect crystalization.The results of electrochemical tests indicate that the sample LiNi0.8Co0.2O2 (900℃)showed excellent electrochemical properties,with an initial discharge capacity of 189.1 mA·h·g-1 and an initial discharge efficiency of 92.5%.After 30 cycles,the discharge capacity was still 148 mA·h·g-1,showing good cyclic stability.展开更多
文摘二氧化钛(Ti O2)作为有前景的钠离子电池负极材料,具有良好的循环稳定性,但由于其导电率较低,而导致容量和倍率性能不佳限制了其实际应用.本文采用喷雾干燥技术制备了氧化石墨烯/纳米Ti O2复合材料(GO/Ti O2),通过热处理获得还原氧化石墨烯/Ti O2复合材料(RGO/Ti O2).电化学测试结果表明,还原氧化石墨烯改性的RGO/Ti O2复合材料的电化学性能得到显著提升,RGO含量为4.0%(w)的RGO/Ti O2复合材料在各种电流密度下的可逆容量分别为183.7 m Ah?g-1(20 m A?g-1),153.7 m Ah?g-1(100 m A?g-1)和114.4 m Ah?g-1(600m A?g-1),而纯Ti O2的比容量仅为93.6 m Ah?g-1(20 m A?g-1),69.6 m Ah?g-1(100 m A?g-1)和26.5 m Ah?g-1(600m A?g-1).4.0%(w)RGO/Ti O2复合材料体现了良好的循环稳定性,在100 m A?g-1电流密度下充放电循环350个周期后,比容量仍然保持146.7 m Ah?g-1.同等条件下,纯Ti O2电极比容量只有68.8 m Ah?g-1.RGO包覆改性极大提高了Ti O2在钠离子电池中的电化学嵌钠/脱钠性能.RGO包覆改性技术在改进钠离子电池材料性能中将有很好的应用前景.
基金supported by the National Key Basic Research Program of China(2007CB209705)National Natural Science Foundation of China(21006063,21073120)Science and Technology Commission of Shanghai Municipality,China(10DZ1202702)~~
基金supported by the National Natural Science Foundation of China (21073120, 20773087, 21006063)Science and Technology Commission of Shanghai Municipality, China (09DZ1203603, 10DZ1202702)~~
基金The project was supported by the National Key Basic Research Program of China(973)(2014CB932303)National Natural Science Foundation of China(21073120,21336003,21006063)~~
文摘The microwave coprecipitation method was used to synthesize α-Ni0.8Co0.2(OH)2 precursor for preparing LiNi0.8Co0.2O2 cathode material.The precursor α-Ni0.8Co0.2(OH)2 was mixed with LiOH·H2O and then calcined in O2 for 10 h at different temperatures(700℃,800℃,900℃).XRD,SEM analyses and electrochemical tests were used to study the physical and electrochemical performance of the cathode material.With increasing calcination temperature,the characteristic peaks of the cathode materials became stronger and sharper,corresponding to a perfect crystalization.The results of electrochemical tests indicate that the sample LiNi0.8Co0.2O2 (900℃)showed excellent electrochemical properties,with an initial discharge capacity of 189.1 mA·h·g-1 and an initial discharge efficiency of 92.5%.After 30 cycles,the discharge capacity was still 148 mA·h·g-1,showing good cyclic stability.
基金supported by the Natural Science Foundation of Shanghai the Science and Technology Commission Shanghai Municipality(19ZR1475100)the Equipment Pre-research Fund(61407210207)the Sichuan Science and Technology Program(2021JDRC0015)。
