Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the s...Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.展开更多
A Co-Mg co-substituted LiNi0.87Co0.10Mg0.03O2 cathode material was prepared by a co-precipitation method. The prepared LiNi0.87Co0.10Mg0.03O2 exhibits excellent electrochemical properties, such as initial discharge ca...A Co-Mg co-substituted LiNi0.87Co0.10Mg0.03O2 cathode material was prepared by a co-precipitation method. The prepared LiNi0.87Co0.10Mg0.03O2 exhibits excellent electrochemical properties, such as initial discharge capacities of 202.6 mA.h/g and 190.5 mA.h/g at 0.2C and 1C rate, respectively, in operating voltage range of 3.0-4.3 V （versus Li^＋/Li）. The capacity retentions are 96.1% and 93.4% at 0.2C and 1C, respectively, after 50 cycles. Moreover, the cycle performance of the sample was investigated in a 053048-type square Li ion battery. This type of battery can keep 81.7% of initial capacity after 500 charge-discharge cycles at 1C rate, which is close to that of commercial LiCoO2 battery. Therefore, the as-prepared material is capable of such high energy applications as portable product power.展开更多
Spherical and homogeneously mixed metal hydroxide Ni0.8Co0.1Mn0.1（OH）2 precursor was successfully synthesized by co-precipitation method in a simple and small vessel with the volume of 1L.The conditions of synthetic...Spherical and homogeneously mixed metal hydroxide Ni0.8Co0.1Mn0.1（OH）2 precursor was successfully synthesized by co-precipitation method in a simple and small vessel with the volume of 1L.The conditions of synthetic process including amount of chelating agent,stirring speed and temperature were studied.LiNi0.8Co0.1Mn0.1O2 samples were obtained by calcinating the precursors.The crystal structure,morphology and electrochemical properties were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,charge-discharge test,AC impedance and cyclic voltammetry.In the voltage range of 2.8-4.3 V,the initial discharge capacities of LiNi0.8Co0.1Mn0.1O2 at 0.1C and 1C rates were 199 and 170 mA·h/g,respectively.After 80 cycles at 1C,the discharge capacity retention was 92%,suggesting its promising application as the cathode material for Li-ion batteries.展开更多
基金Project(50721003)supported by the National Natural Science Foundation of ChinaProject(07JJ6082)supported by the Natural Science Foundation of Hunan Province,ChinaProject supported by the Open Project of State Key Laboratory of Powder Metallurgy in Central South University,China
文摘Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.
基金Project(2010DFA72760)supported by US.China Collaboration on Cutting-edge Technology Development of Electric VehiclesProjects(50901009,51271029)supported by the National Natural Science Foundation of ChinaProject(12QNJJ013)supported by the Fundamental Research Funds for the Central Universities,China
文摘A Co-Mg co-substituted LiNi0.87Co0.10Mg0.03O2 cathode material was prepared by a co-precipitation method. The prepared LiNi0.87Co0.10Mg0.03O2 exhibits excellent electrochemical properties, such as initial discharge capacities of 202.6 mA.h/g and 190.5 mA.h/g at 0.2C and 1C rate, respectively, in operating voltage range of 3.0-4.3 V （versus Li^＋/Li）. The capacity retentions are 96.1% and 93.4% at 0.2C and 1C, respectively, after 50 cycles. Moreover, the cycle performance of the sample was investigated in a 053048-type square Li ion battery. This type of battery can keep 81.7% of initial capacity after 500 charge-discharge cycles at 1C rate, which is close to that of commercial LiCoO2 battery. Therefore, the as-prepared material is capable of such high energy applications as portable product power.
基金Project(2014CB643406)supported by the National Basic Research Program of China
文摘Spherical and homogeneously mixed metal hydroxide Ni0.8Co0.1Mn0.1（OH）2 precursor was successfully synthesized by co-precipitation method in a simple and small vessel with the volume of 1L.The conditions of synthetic process including amount of chelating agent,stirring speed and temperature were studied.LiNi0.8Co0.1Mn0.1O2 samples were obtained by calcinating the precursors.The crystal structure,morphology and electrochemical properties were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,charge-discharge test,AC impedance and cyclic voltammetry.In the voltage range of 2.8-4.3 V,the initial discharge capacities of LiNi0.8Co0.1Mn0.1O2 at 0.1C and 1C rates were 199 and 170 mA·h/g,respectively.After 80 cycles at 1C,the discharge capacity retention was 92%,suggesting its promising application as the cathode material for Li-ion batteries.
