The article developed a lithium iron phosphate - composite cathode material of lithium vanadium phosphate. Using X-ray diffraction （XRD）, electronic scanning electron microscopy surface （SEM）, laser particle size ...The article developed a lithium iron phosphate - composite cathode material of lithium vanadium phosphate. Using X-ray diffraction （XRD）, electronic scanning electron microscopy surface （SEM）, laser particle size analyzer, carbon and sulfur analyzer, and X-ray photoelectron spectroscopy, etc. for the prepared composites were characterized and found the material is mainly crystalline structure of lithium iron phosphate, and lithium vanadium, wherein a small amount of impurities; finer particle size of the material, the particle size distribution is narrow and uniform, smooth particle surface, wrapping in good carbon composite with other materials prepared in comparison the case has a carbon content of about optimum conductivity. To assemble the material into a cell after the 0.1C, IC, 2C when and 5C, the first discharge capacity were 160,145,127 and 109 mA·h·g^-1, after 50 cycles, the discharge capacity of 162, respectively, 144,126 and 106 mA·h·g^-1, which showed good rate characteristics and cycle characteristics.展开更多
A new statistical fitting approach, named Statistical Distribution-Based Analytic （SDA） method, is proposed to fit single Gaussian-shaped Ka and KI3 X-ray peaks recorded by Si（PIN） and silicon drift detector （SDD...A new statistical fitting approach, named Statistical Distribution-Based Analytic （SDA） method, is proposed to fit single Gaussian-shaped Ka and KI3 X-ray peaks recorded by Si（PIN） and silicon drift detector （SDD）. In this method, we use the dis- crete distribution theory to calculate standard deviation of energy resolution a. The calibration of cr and energy （E） for two de- tectors between the energy ranges of 4.5-26 keV are also completed by measuring characteristic X-ray spectra of nineteen types of pure elements. With the spectrum fraction （SF） parameter proposed in this paper, the SDA method can be used to re- solve overlapping peaks. In measured spectra, the Gaussian part of X-ray peaks can be fitted by a Gaussian function with two parameters, ~ and SF. This new fitting approach is simpler than traditional methods and it achieves relatively good results when fitting the complex X-ray spectra of national standard alloy samples detected by Si（PIN） and SDD detectors. The 3（2 values are obtained for each spectrum to assess fitting results, and the SDA fitting method gives a preferable fit for the SDD detector.展开更多
文摘The article developed a lithium iron phosphate - composite cathode material of lithium vanadium phosphate. Using X-ray diffraction （XRD）, electronic scanning electron microscopy surface （SEM）, laser particle size analyzer, carbon and sulfur analyzer, and X-ray photoelectron spectroscopy, etc. for the prepared composites were characterized and found the material is mainly crystalline structure of lithium iron phosphate, and lithium vanadium, wherein a small amount of impurities; finer particle size of the material, the particle size distribution is narrow and uniform, smooth particle surface, wrapping in good carbon composite with other materials prepared in comparison the case has a carbon content of about optimum conductivity. To assemble the material into a cell after the 0.1C, IC, 2C when and 5C, the first discharge capacity were 160,145,127 and 109 mA·h·g^-1, after 50 cycles, the discharge capacity of 162, respectively, 144,126 and 106 mA·h·g^-1, which showed good rate characteristics and cycle characteristics.
基金supported by the National Natural Science Foundation of China(Grant Nos.40974065,41025015)the National High Technology Research and Development Program of China(Grant No.2012AA063501)Ph.D.Programs Foundation of Ministry of Education of China(Grant No.20125122110009)
文摘A new statistical fitting approach, named Statistical Distribution-Based Analytic （SDA） method, is proposed to fit single Gaussian-shaped Ka and KI3 X-ray peaks recorded by Si（PIN） and silicon drift detector （SDD）. In this method, we use the dis- crete distribution theory to calculate standard deviation of energy resolution a. The calibration of cr and energy （E） for two de- tectors between the energy ranges of 4.5-26 keV are also completed by measuring characteristic X-ray spectra of nineteen types of pure elements. With the spectrum fraction （SF） parameter proposed in this paper, the SDA method can be used to re- solve overlapping peaks. In measured spectra, the Gaussian part of X-ray peaks can be fitted by a Gaussian function with two parameters, ~ and SF. This new fitting approach is simpler than traditional methods and it achieves relatively good results when fitting the complex X-ray spectra of national standard alloy samples detected by Si（PIN） and SDD detectors. The 3（2 values are obtained for each spectrum to assess fitting results, and the SDA fitting method gives a preferable fit for the SDD detector.
