Synthesis and Electrochemical Properties of LiFePO4C by a Novel Carbothermal Reduction Technology

2011 ◽  
Vol 233-235 ◽  
pp. 1108-1118 ◽  
Author(s):  
Fang Xiang Tan ◽  
Li Li Meng ◽  
Fan Wang ◽  
Hai Feng Su ◽  
Yun Fei Long ◽  
...  
Keyword(s):  
Discharge Capacity ◽  
Carbothermal Reduction ◽  
Sintering Temperature ◽  
Heating Temperature ◽  
Electrochemical Performances ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Sintering Time ◽  
Temperature Solution

LiFePO4/C composites were synthesized by a novel carbothermal reduction method based on the low-temperature solution reaction between LiNO3-Fe (NO3)3-NH4H2PO4-sucrose. The sucrose amount, sintering temperature, sintering time, and heating temperature for synthesis of LiFePO4/C cathode was optimized. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and charge–discharge tests. The results showed that sintering temperature and sucrose amount have more significant effects on discharge capacity than drying temperature and sintering time. Optimum LiFePO4/C was prepared by sintering the precursor obtained by heating at 60 with a sucrose amount of 5.0g at 800.0 for 12 h. Being charged–discharged at 0.5C between 2.5 and 4.2 V, the LiFePO4/C synthesized at the optimum conditions shows good electrochemical performances with an initial discharge capacity of 138.7 mAh·g−1and a capacity retention ratio of 98.6% after 50 cycles.

Synthesis and Characterization of LiNi0.4Co0.2Mn0.4O2 Cathode Material via Urea Co-Precipitation Method

2011 ◽  
Vol 295-297 ◽  
pp. 700-703
Author(s):  
Sheng Kui Zhong ◽  
Yue Bin Xu ◽  
Yan Wei Li ◽  
Chang Jiu Liu ◽  
Yan Hong Li
Keyword(s):  
Discharge Capacity ◽  
Sintering Temperature ◽  
Lithium Ion ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Electrochemical Characteristics ◽  
Sintering Time ◽  
Structure Morphology ◽  
Co Precipitation

LiNi0.4Co0.2Mn0.4O2 sampleswas synthesized via urea co-precipitation method. The XRD, SEM and electrochemical measurements were used to examine the structure,morphology and electrochemical characteristics, respectively. LiNi0.4Co0.2Mn0.4O2 powders show excellent electrochemical performances. The optimum sintering temperature and sintering time are 800°C and 20 h, respectively. The LiNi0.4Co0.2Mn0.4O2 powders shows the discharge capacity of 145.1 mAh·g-1in the range of 3.0-4.5 V at the first cycle, and the discharge capacity remains 132.3 mAh·g-1after 30 cycles. The urea co-precipitation method is suitable for the preparation of LiNi0.4Co0.2Mn0.4O2 cathode materials with good electrochemical performances for lithium ion batteries.

One-step Carbothermal Reduction Synthesis of Li3V2(PO4)3 /C as Cathode Material for Lithium Ion Batteries

2011 ◽  
Vol 233-235 ◽  
pp. 1123-1131
Author(s):  
Mei Lin Li ◽  
Li Li Meng ◽  
Fan Wang ◽  
Hai Feng Su ◽  
Yun Fei Long ◽  
...  
Keyword(s):  
Carbon Content ◽  
Carbothermal Reduction ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Retention Rate ◽  
Rate Capability ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Sintering Time ◽  
One Step

Li3V2(PO4)3/C has been synthesized by a simple one-step carbothermal reduction technology using LiH2PO4, V2O5as the raw materials and sucrose as carbon source. X-ray diffraction (XRD) and scanning electron microscope (SEM) measurements showed that Li3V2(PO4)3/C synthesized by one-step carbothermal reduction had monoclinic structure. The structure and particle-size of the as-prepared Li3V2(PO4)3/C can be adjusted by the amount of carbon content, sintering temperature and sintering time in the synthesis processes. Li3V2(PO4)3/C prepared with a carbon content 0.4, sintering temperature 800°C and sintering time 20 h showed the largest discharge capacity 121.4mAh.g−1and an capacity retention rate of 98.3% after 50 cycles at 0.5C. The Li3V2(PO4)3/C obtained also exhibits an excellent rate capability with high discharge capacities of 111.0 mAh.g−1at 2.0C and 102.1 mAh.g−1at 5.0C.

scholarly journals Synthesis and Na+ Ion Conductivity of Stoichiometric Na3Zr2Si2PO12 by Liquid-Phase Sintering with NaPO3 Glass

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Ion Conductivity ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Sintering Time ◽  
Lower Activation

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.

Tris(trimethylsilyl) phosphite (TMSPi) as an electrolyte additive for LiNi0.5Co0.2Mn0.3O2 cathode materials at elevated voltage and temperature

2021 ◽  
Author(s):  
Xiao Yu ◽  
Zhiyong Yu ◽  
Jishen Hao ◽  
Hanxing Liu
Keyword(s):  
Discharge Capacity ◽  
Cathode Materials ◽  
Solid Electrolyte Interphase ◽  
Rate Capability ◽  
Electrochemical Performances ◽  
Initial Discharge Capacity ◽  
Capacity Retention ◽  
Electrolyte Additive ◽  
Interface Impedance ◽  
Initial Discharge

Electrolyte additive tris(trimethylsilyl) phosphite (TMSPi) was used to promote the electrochemical performances of LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 (NCM523) at elevated voltage (4.5 V) and temperature (55[Formula: see text]C). The NCM523 in 2.0 wt.% TMSPi-added electrolyte exhibited a much higher capacity (166.8 mAh/g) than that in the baseline electrolyte (118.3 mAh/g) after 100 cycles under 4.5 V at 30[Formula: see text]C. Simultaneously, the NCM523 with 2.0 wt.% TMSPi showed superior rate capability compared to that without TMSPi. Besides, after 100 cycles at 55[Formula: see text]C under 4.5 V, the discharge capacity retention reached 87.4% for the cell with 2.0 wt.% TMSPi, however, only 24.4% of initial discharge capacity was left for the cell with the baseline electrolyte. A series of analyses (TEM, XPS and EIS) confirmed that TMSPi-derived solid electrolyte interphase (SEI) stabilized the electrode/electrolyte interface and hindered the increase of interface impedance, resulting in obviously enhanced electrochemical performances of NCM523 cathode materials under elevated voltage and/or temperature.

scholarly journals Effects of Calcination Conditions on the Formation and Hydration Performance of High-Alite White Portland Cement Clinker

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 494 ◽  
Author(s):  
Lei Huang ◽  
Geling Cheng ◽  
Shaowen Huang
Keyword(s):  
Portland Cement ◽  
Mineral Composition ◽  
Sintering Temperature ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Free Lime ◽  
Sintering Time ◽  
Portland Cement Clinker ◽  
White Portland Cement

The purpose of this study was to evaluate the effects of sintering temperature and sintering time on mineral composition of high-alite white Portland cement clinker and hydration activity of the clinker. Effects of sintering temperature and sintering time on clinker mineral composition, C3S polymorph and size and hydration heat release rate were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), differential scanning calorimetry&Thermogravimetric Analysis (DSC-TG) and isothermal heat-conduction calorimetry. Results shown that, with the increase of sintering temperature (1450–1525 °C) and sintering time (60–240 min), free lime (f-CaO) in clinker decreased, C3S grain size increased, and C3S crystal type changed from T3 to M type and R type, which exhibits higher symmetry. The hydration activity of different C3S crystals ranged from high to low as follows: T3→M1→M3→R@.

Synthesis and Characterization of Li0.97K0.03FePO4/Graphene Composites by Carbonthermal Reduction Method

2014 ◽  
Vol 687-691 ◽  
pp. 4327-4330
Author(s):  
Yan Wang ◽  
Zhe Sheng Feng ◽  
Lu Lin Wang ◽  
Jin Ju Chen ◽  
Zhen Yu He
Keyword(s):  
Discharge Capacity ◽  
Photoelectron Spectroscopy ◽  
Reduction Method ◽  
Electrochemical Impedance ◽  
Impedance Spectra ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Electrochemical Impedance Spectra ◽  
X Ray

Li0.97K0.03FePO4 and Li0.97K0.03FePO4/graphene composites were synthesized by carbothermal reduction method using acetylene black as carbon source. The structure and electrochemical properties of the prepared materials were investigated with X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, galvanostatic charge and discharge and electrochemical impedance spectra tests. The results indicated that K doping improves the cyclic stability of samples, the addition of small amounts of graphene results in better electronic properties on sample. Li0.97K0.03FePO4/graphene showed discharge capacity of 158.06 and 90.55 mAh g-1 at 0.1 C and 10 C, respectively. After the 50 cycle test at different rates, the reversible discharge capacity at 0.1 C was 158.58 mAh g-1, indicating the capacity retention ratio of 100.32%.

THE SUPERCONDUCTING STUDY OF TlBaCaCu2Oy

1988 ◽  
Vol 02 (09) ◽  
pp. 1095-1101
Author(s):  
JIE YAN ◽  
XIAOMING YANG ◽  
GUANGWEN PEI ◽  
ZHENYU MEN ◽  
DEYING SONG
Keyword(s):  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Sintering Atmosphere ◽  
X Ray ◽  
Cell Parameters ◽  
Sintering Time ◽  
Zero Resistance ◽  
Annealing Rate ◽  
The Stability

The relation of the superconductivity of TlBaCaCu 2 O y to the sintering temperature, sintering time, annealing rate and sintering atmosphere was studied. It was shown that the zero-resistance temperature of the superconductors of the type was up to 118K and the stability was to some extent quite good. Through X-ray diffraction analysis, the TlBaCaCu 2 O y was found to possess two kinds of tetragonal structures. The T co =118 K sample has the unit cell parameters of a=5.446(2)Å, c=35.698(2)Å; while for T co =93.5 K , one has the parameters of a=5.469(2)Å, c=30.051(2)Å, the substitution of Tl, Ba, Ca , by many other elements show that only TlBaMgCu 2 O y and TlMg 2 Cu 2 O y are superconductors and others are insulators.

Preparation and Characterization of the Ceramsites with Microscale Pores from Iron Tailing and Fly Ash

2020 ◽  
Vol 12 ◽  
Author(s):  
Zeyang Xue ◽  
Zi Wang ◽  
Chunhu Yu ◽  
Yajing Mao ◽  
Lizhai Pei
Keyword(s):  
Fly Ash ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Time ◽  
Duration Time ◽  
Important Significance ◽  
Scanning Electron

Background: Iron tailing causes great environmental and social problems which contaminate water, air and soil. Therefore, it is of important significance to prepare iron tailing ceramsites with microscale pores which can recycle the deposited iron tailing. Objective: The aim of the research is to obtain iron tailing ceramsites with microscale pores and good mechanical performance. Methods: The iron tailing ceramsites have been characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). Influence of the content of iron tailing, temperature and duration time on the mechanical performance of the obtained ceramsites was performed and the optimal sintering parameter was determined. The bulk density, apparent density and cylinder compressive strength of the obtained ceramsites increase obviously as improving the iron tailing content, temperature and sintering time. Results: Duration time and sintering temperature play important roles in the formation and size of the pores of the ceramsites. The optimal iron tailing content and sintering parameter are 70wt.%, 1100 ℃ for 40 min. The iron tailing ceramsites mainly consist of orthorhombic CaAl2Si2O8, monoclinic CaSiO3, hexagonal Ca7Si2P2O16, triclinic MgSiO3, triclinic Al2SiO5 and triclinic Ca2Fe2O5 phases. Iron tailing ceramsites from 1100 ℃ for 40 min are composed of irregular particles with several hundreds of micrometers improving the density and strength of the ceramsites. Conclusion: Iron tailing ceramsites containing microscale pores were prepared using iron tailing and fly ash, and exhibit excellent potential for the application in the field of construction.

scholarly journals Ceramsite production from sediment in Beian River: characterization and parameter optimization

2019 ◽  
Vol 6 (8) ◽  
pp. 190197 ◽  
Author(s):  
Yong Jin ◽  
Songyu Huang ◽  
Qunhui Wang ◽  
Ming Gao ◽  
Hongzhi Ma
Keyword(s):  
Pollution Control ◽  
Sintering Temperature ◽  
Heating Temperature ◽  
Orthogonal Experiment ◽  
Metal Leaching ◽  
Firing Time ◽  
Optimum Conditions ◽  
Heavy Metal Leaching ◽  
Binder Ratio ◽  
Maximum Content

In order to realize pollution control and resource recovery, sediment from Beian River in Mudanjiang City China was used for ceramsite production. The maximum content of total nitrogen (TN), total phosphorus (TP) and organic matter (OM) in sediments of Beian River were 2975 mg kg −1 , 2947 mg kg −1 and 29.6%, respectively. So, it should be treated properly for resource utilization. The orthogonal experiment of L 16 (4 5 ) was adopted to determine the best conditions for ceramsite production and the result demonstrated that the sewage sludge ratio of 15%, binder ratio of 5%, pre-heating temperature of 450°C, sintering temperature of 1150°C and firing time of 23 min were the optimum conditions. The corresponding product met with the standard of CJ/T 299-2008 and the heavy metal leaching experiment showed it was lower than the threshold of China's industrial standard. Thus, it demonstrated that ceramsite production was a feasible way for utilization of sediment.

Synthesis of Al2OC Ceramic Powder by a Carbothermal Reduction Process

2014 ◽  
Vol 881-883 ◽  
pp. 1017-1020
Author(s):  
Shuang Shuang Ding ◽  
Peng Cui ◽  
Hong Xi Zhu ◽  
Cheng Ji Deng ◽  
Chao Yu
Keyword(s):  
Carbothermal Reduction ◽  
Raw Materials ◽  
Heating Temperature ◽  
Ceramic Powder ◽  
Reduction Process ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Argon Flow ◽  
Micro Morphology

A12OC ceramic powder was successfully synthesized via a carbothermal reduction method using Al2O3, B2O3 and activated carbon powders as raw materials. The effects of synthesis temperature on the phase transformation and micro-morphology of A12OC were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the content of A12OC in the products was increased with the increasing heating temperature. The optimized process for preparing A12OC was heating the mixtures at 1700 °C for 2 h in argon flow. A12OC particles synthesized at 1700 °C were hexagon plate-like with thickness of 5 μm and size of about 50 μm. Keywords: A12OC, synthesis, microstructure

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