Improved electrochemical performance of Li4Ti5O12 by reducing rutile TiO2 phase impurity and particle size

2016 ◽  
Vol 32 (3) ◽  
pp. 196-201 ◽  
Author(s):  
Hari Raj ◽  
Sobhit Saxena ◽  
Anjan Sil
2012 ◽  
Vol 512-515 ◽  
pp. 261-264
Author(s):  
Li Shen ◽  
Jin Hu ◽  
Da Ping Wu

As anionic surfactant, a commercial salt of lauryl sodium sulfate was used. The effects of different amounts of dispersant on the measurement of particle size distribution between two titanium dioxide powders (anatase and rutile) in aqueous media were discussed. Diluted aqueous suspensions were characterized in terms of particle size distribution and zeta potential. The results demonstrate that the measurement of particle size distribution strongly depends on the amounts of dispersant. The amounts of dispersant have a significant effect on the behavior of the rutile-TiO2 particles. The particle size first decreases significantly with an increase in the amounts of dispersant and then lesser increases with a further increase in the amounts of dispersant. The tendency show significant differences between two particles.


Author(s):  
Malcolm Stein ◽  
Chien-Fan Chen ◽  
Matthew Mullings ◽  
David Jaime ◽  
Audrey Zaleski ◽  
...  

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.


2013 ◽  
Vol 712-715 ◽  
pp. 257-261
Author(s):  
Yin Lin Wu ◽  
Qing Hui Wang ◽  
Ling Wang ◽  
Hai Yan Zhao

The La0.75Sr0.25Cr0.5Mn0.5O3-δnanometer powders were prepared by citric acid sol-gel method.The samples were characterized by DTA, FT-IR, XRD, TEM techniques. The preparation process, morphology of synthesized powders, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 800°C. The particle size is about 30nm and Ea is 0.071 eV.


2015 ◽  
Vol 185 ◽  
pp. 297-303 ◽  
Author(s):  
Negar Mosavati ◽  
Venkateswara Rao Chitturi ◽  
Leela Mohana Reddy Arava ◽  
Steven O. Salley ◽  
K.Y. Simon Ng

2017 ◽  
Vol 20 (4) ◽  
pp. 920-925 ◽  
Author(s):  
Matheus de Aquino Barbosa ◽  
Guilherme da Silva Lopes Fabris ◽  
Mateus Meneghetti Ferrer ◽  
Douglas Henrique Marcelino de Azevedo ◽  
Julio Ricardo Sambrano

2015 ◽  
Vol 1112 ◽  
pp. 241-244 ◽  
Author(s):  
Slamet Priyono ◽  
Bambang Prihandoko ◽  
Anne Zulfia Syahrial

Li4Ti5O12 pure and Li4Ti5O12 with Na and Al doped Li(3-x/3)AlxNaTi(5-2x/3)O12 (x=0, 0.025, 0.05, 0.075) as anodes for Li-ion batteries are synthesized at 850°C via solid state reaction using Li2CO3, TiO2-anatase, Al2O3 and Na2CO3 as precursor. The effect of substitution of Al and Na in Li4Ti5O12 on characterization of precursor and electrochemical performance is studied. It is found that Na doped in Li4Ti5O12 pure affected the formation of three phase i.e NaLiTi3O7, Li4Ti5O12, dan Li2TiO3. Meanwhile, Al doped contributed to the formation of NaLiTi3O7 phase significantly. The SEM images show that the particles have polyhedral shape with uniform size distribution. Na doped in the Li4Ti5O12 affected particle size become larger against Al doped particle size become smaller than undoped material, the best particle size measured by PSA is 30,89 . All characterization of material will determine the electrochemical performance of Li-ion battery.


Author(s):  
Ju Guo ◽  
Fuyong Wu

Abstract First, nano-spherical iron phosphate was prepared using the hydrothermal method. Then, the carbothermal reduction method was applied to synthesize the LiFePO4/C composite material capable of good carbon coating effect with the prepared nano-spherical iron phosphate as a precursor. By means of scanning electron microscope, transmission electron microscope, Zeta potentiometer, inductively coupled plasma spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical testing, and other methods, the material was characterized and tested for its morphology, particle size, composition, structure, and electrochemical performance. According to the test results, when the initial mass concentration of Fe3+ in the reaction solution is 2%, the amount of N and S impurity is merely 19 and 27 ppm, respectively. In the meantime, particle size is small, with a range of roughly 50–100 nm, and a spherical morphology is shown. The synthesized LiFePO4/C retains its nano-spherical morphology, which leads to a desirable carbon coating effect and an excellent electrochemical performance. The first charge–discharge specific capacity at 0.1 C rate reached 163.7 and 161.4 mAh/g, the charge–discharge efficiency was 98.6%, and the capacity retention rate at 50 charge–discharge cycles at 1 C rate reached 98.52%.


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