scholarly journals Synthesis of Hydronium-Potassium Jarosite; Effect of pH and Aging Time on their Structural, Morphological and Electrical Properties

2020 ◽  
Author(s):  
Elías Hernández-Lazcano ◽  
E. Cerecedo-Sáenz ◽  
J. Hernández-Ávila ◽  
Norman Toro ◽  
T.V.K. Karthik ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Properties ◽  
Aging Time ◽  
Anode Materials ◽  
Lithium Ion ◽  
Life Time ◽  
Rietveld Analysis ◽  
Morphological Properties ◽  
Hydronium Jarosite ◽  
Cationic Site

Structural and morphological properties of the hydronium-potassium jarosite microstructures were investigated in this work, and their electrical properties were evaluated. All microstructures were synthesized at a reasonable temperature of 343 K with a reduced reaction time of 3 hours. Increase in the pH from 0.8 to 2.1 decreased the particle sized from 3 µm to 200 nm and increasing the aging time from 0, 3 to 7 days resulted in semispherical, spherical and euhedreal jarosite structures, respectively. A Rietveld analysis also was done, finding that increasing pH, the amount of hydronium substitution by potassium in the cationic site also increases, having a 77.72 % of hydronium jarosite (JH) plus 22.29 % potassium jarosite (JK) at pH 0.8; 82.44 % (JH) and 17.56 % (JK) at pH 1.1, and 89.98 % (JH) plus 10.02 % (JK) at pH 2.1. The results obtained in this work show that the obtained hydronium potassium jarosite microstructures with reduced particle size and euhedreal morphology can be used as anode materials for improving the life time of lithium ion batteries, due that during the analysis of the voltage obtained using electrodes made with this particles and graphite, this ranged from 0.89 to 1.36 V.

scholarly journals Synthesis of Hydronium-Potassium Jarosites: The Effect of pH and Aging Time on Their Structural, Morphological, and Electrical Properties

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 80
Author(s):  
Elías Hernández-Lazcano ◽  
E. Cerecedo-Sáenz ◽  
J. Hernández-Ávila ◽  
Norman Toro ◽  
T. V. K. Karthik ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Aging Time ◽  
Anode Materials ◽  
Lithium Ion ◽  
Rietveld Analysis ◽  
Morphological Properties ◽  
Particle Sizes ◽  
Ph Values ◽  
Hydronium Jarosite ◽  
Cationic Site

Structural and morphological properties of hydronium-potassium jarosite microstructures were investigated in this work, and their electrical properties were evaluated. All the microstructures were synthesized at a very low temperature of 70 °C with a reduced reaction time of 3 h. An increase in the pH from 0.8 to 2.1 decreased the particle sizes from 3 µm to 200 nm and an increase in the aging time from zero, three, and seven days resulted in semispherical, spherical, and euhedral jarosite structures, respectively. The Rietveld analysis also confirmed that the amount of hydronium substitution by potassium in the cationic site increased with an increase in pH. The percentages of hydronium jarosite (JH)/potassium jarosite (JK) for pH values of 0.8, 1.1, and 2.1 were 77.72/22.29%, 82.44/17.56%, and 89.98/10.02%, respectively. Microstructures obtained in this work were tested as alternative anode materials and the voltage measured using these electrodes made with hydronium-potassium jarosite microstructures and graphite ranged from 0.89 to 1.36 V. The results obtained in this work show that with reduced particle size and euhedral morphology obtained, modified jarosite microstructures can be used as anode materials for improving the lifetime of lithium-ion batteries.

scholarly journals Crystal Chemistry, Rietveld Analysis, Structural and Electrical Properties of Cobalt-Erbium Nano-Ferrites

2021 ◽  
Author(s):  
Edapalli Sumalatha ◽  
Dachepalli Ravinder ◽  
Nyathani Maramu ◽  
Shubha ◽  
Butreddy Ravinder Reddy ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Crystallite Size ◽  
Rietveld Analysis ◽  
Tem Analysis ◽  
Lattice Volume ◽  
Edax Analysis ◽  
Cobalt Ferrites ◽  
Structural Variables

Synthesis of Cobalt-Erbium nano-ferrites with formulation CoErxFe2-xO4 (x = 0, 0.005, 0.010, 0.015, 0.020, 0.025, and 0.030) using technique of citrate-gel auto-combustion was done. Characterization of prepared powders was done by using XRD, EDAX, FESEM, AFM and FTIR Spectroscopy, DC resistivity properties respectively. XRD Rietveld Analysis, SEM, TEM and EDAX analysis were taken up in studying spectral, structural, magnetic and electrical properties. XRD pattern of CEF nano particles confirm single phase cubic spinal structure. The structural variables given by lattice constant (a), lattice volume (v), average crystallite size (D) and X-ray density(dx), Bulk density (d), porosity (p), percentage of pore space (P%), surface area (s), strain (ε), dislocation density (δ), along with ionic radii, bond length and hoping length were calculated. SEM and TEM results reveal homogeneous nature of particles accompanied by clusters having no impurity pickup. TEM analysis gives information about particle size of nanocrystalline ferrite while EDAX analysis confirm elemental composition. Emergence of two arch shaped frequency bands (ν1 and ν2) that represent vibrations at tetrahedral site (A) and octahedral site(B) was indicated by spectra of FTIR. The samples electrical resistivity (DC) was measured between 30°C -600°C with Two probe method. XRD Rietveld analysis confirm crystallite size lying between 20.84 nm–14.40 nm while SEM analysis indicate formation of agglomerates and TEM analysis indicate particle size ranging between 24 nm–16 nm. DC Electrical measurements indicate continuous decrease in resistivity with increasing temperature while increasing doping decreases curie temperature. The Magnetic parameters such as Saturation magnetization (Ms), Remanent magnetization (Mr), Coercivity (Hc) and Squareness ratio (R = Mr/Ms), Magnetic moment (nB) were altered by doping of Er+3 content in the increasing order (x = 0.00 to 0.030). The increasing erbium content decreases magnetization thus converting the sample into soft magnetic material. Observations indicated strong dependence of magnetic properties on Erbium substitution and coercivity varies in accordance with anisotropy constant. Due to the presence of magnetic dipole Erbium substituted cobalt ferrites can be used in electromagnetic applications. The present study investigates the effect of different compositions of Er3+ replaced for Fe on structural properties and electrical resistivity of cobalt ferrites.

Mechanochemical Synthesis and Electrochemical Performances of Li4Ti5O12 Anode Materials for Lithium Ion Batteries

2012 ◽  
Vol 512-515 ◽  
pp. 1660-1663 ◽  
Author(s):  
Yang Li ◽  
Hua Qing Xie ◽  
Jing Li ◽  
Ji Feng Wang
Keyword(s):  
Particle Size ◽  
Anode Materials ◽  
Particle Distribution ◽  
Rate Capability ◽  
Lithium Ion ◽  
Electrochemical Performances ◽  
Particle Sizes ◽  
Sem Images ◽  
Sintered Temperature ◽  
Uniform Particle Size

Li4Ti5O12anode materials have been synthesized via mechnochemical method and subsequent sintering with nanosized TiO2and Li2CO3as reagents. XRD measurements indicated that well crystallized Li4Ti5O12could be obtained above 800 °C. The sizes of Li4Ti5O12particles increased with sintered temperature augmenting. Various particle distribution and particle sizes are presented in SEM images. In electrochemical investigations, Li4Ti5O12sintered at 800 °C presented excellent discharge-charge performances and rate capability. The discharge capacity could achieve 168 mAh/g and 140 mAh/g at 0.1 C and 1.0 C rate, respectively, which was attributed to its uniform particle size distribution and relatively small particle size.

scholarly journals Well-Dispersed ZnFe2O4 Nanoparticles onto Graphene as Superior Anode Materials for Lithium Ion Batteries

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 304 ◽  
Author(s):  
Yiseul Park ◽  
Misol Oh ◽  
Jae Kim
Keyword(s):  
Particle Size ◽  
Anode Materials ◽  
Low Cost ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Lithium Storage ◽  
Graphene Composite ◽  
Graphene Sample ◽  
Graphene Flakes ◽  
One Step

We prepared well-dispersed ZnFe2O4 (ZFO) nanoparticles on a graphene sheet by a facile one-step hydrothermal method using glucose as a novel linker agent and low-cost graphene flake. It was found that the glucose linkage on graphene not only prevented the aggregation of ZFO particles, but also induced the exfoliation of graphene flakes. The addition of glucose during the synthesis made surface linkages on the graphene surface, and it reacted with ZFO precursors, resulting in the well-dispersed ZFO nanoparticles/graphene composite. Furthermore, the size distribution of the resultant composite particles was also shifted to the smaller particle size compared to the composite prepared without glucose. The newly prepared ZFO/graphene composite provided a higher lithium storage capability and cycle performance compared to the ZFO/graphene sample which was prepared without glucose. The good dispersion of ZFO nanoparticles on graphene and the small particle size of the composite led to markedly improved electrochemical performance. Its reversible discharge capacity was 766 mAh g−1 at 1 A g−1, and it also maintained as 469 mAh g−1 at 6 A g−1.

Li4Ti5O12-based anode materials with low working potentials, high rate capabilities and high cyclability for high-power lithium-ion batteries: a synergistic effect of doping, incorporating a conductive phase and reducing the particle size

2014 ◽  
Vol 2 (26) ◽  
pp. 9982-9993 ◽  
Author(s):  
Chunfu Lin ◽  
Xiaoyong Fan ◽  
Yuelong Xin ◽  
Fuquan Cheng ◽  
Man On Lai ◽  
...  
Keyword(s):  
Particle Size ◽  
Synergistic Effect ◽  
Lithium Ion Batteries ◽  
High Power ◽  
Anode Materials ◽  
Lithium Ion ◽  
Size Reduction ◽  
High Rate ◽  
Electrochemical Performances ◽  
Particle Size Reduction

Fe2+/Cr3+ doped LTO/MWCNT composites were made by combining doping, compositing and particle-size reduction, and exhibit improved electrochemical performances.

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