Preparation and Characterization of High-Density Li0.99W0.01FePO4/C Composite Cathodes

2012 ◽  
Vol 554-556 ◽  
pp. 399-403
Author(s):  
Mei E Zhong
Keyword(s):  
Low Cost ◽  
Specific Capacity ◽  
Rate Capability ◽  
Bimodal Distribution ◽  
Cycle Performance ◽  
Structure Morphology ◽  
Composite Cathodes ◽  
Tap Density ◽  
Current Densities

High tap-density Li0.99W0.01FePO4/C composite have been synthesized via a simple and low-cost solid state-carbothermal reduction method, using Fe2O3and citrate ferric as the Fe3+precursors and citric radical containing in citrate ferric as both carbon source and reducing agent. The structure, morphology, and physicochemical properties of Li0.99W0.01FePO4/C composite were characterized by XRD, SEM, laser diffraction and scattering measurement, and tap-density testing. It is observed the particle distribution of the Li0.99W0.01FePO4/C composite is bimodal distribution. Because of the smaller particles filling in the space between the larger particles, the Li0.99W0.01FePO4/C composite exhibits less vacancy, which resulted in a high tap density of 1.50 g•cm-3. The Li0.99W0.01FePO4/C composite also shows good rate capability and cycle performance. At current densities of 0.2, 0.5, 1.0 and 1.5 C, the composite material has initial discharge specific capacity of 141, 133, 130 and 125 mAh•g-1, respectively.

scholarly journals Synthesis of Hierarchical Graphene-MnO2 Nanowire Composites with Enhanced Specific Capacitance

2019 ◽  
Vol 31 (8) ◽  
pp. 1709-1718
Author(s):  
T. Veldevi ◽  
K. Thileep Kumar ◽  
R.A. Kalaivani ◽  
S. Raghu ◽  
A.M. Shanmugharaj
Keyword(s):  
Surface Area ◽  
Electrode Materials ◽  
High Surface ◽  
Specific Capacity ◽  
High Surface Area ◽  
Rate Capability ◽  
Sulfate Solution ◽  
High Rate ◽  
Chemical Compositions ◽  
Structure Morphology

Hierarchical nanostructured graphene–manganese dioxide nanowire (G-MnO2-NW) composites have been prepared by hydrothermal synthesis route using water/1-decanol as the medium. Synthesized materials were analyzed using various characterization tools to corroborate their chemical compositions, structure/morphology and surface area. Electrochemical measurements of the synthesized G-MnO2-NW electrode materials delivered the highest specific capacity (255 Fg-1), high rate capability and improved cycling stability at 0.5 Ag–1 in 1M sodium sulfate solution and this fact may be attributed to its high surface area and porosity. Moreover, synthesized G-MnO2-NW electrodes displayed better energy and power density, when compared to the MnO2-NW based electrodes.

Optimization of Synthesis Condition for LiFePO4/C Cathode Material

2011 ◽  
Vol 236-238 ◽  
pp. 698-702
Author(s):  
Ling Zhi Zhu ◽  
En Shan Han ◽  
Ji Lin Cao
Keyword(s):  
Citric Acid ◽  
Room Temperature ◽  
Specific Capacity ◽  
Carbon Coatings ◽  
Treatment Processes ◽  
Initial Discharge ◽  
Structure Morphology ◽  
Tap Density ◽  
Pre Treatment ◽  
Acid Coating

This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. Common and cheap organic matters (Glucose anhydrous, Citric acid, Vitamin C, Sucrose) were selected for carbon coatings on LiFePO4. The four pre-treatment processes were employed to optimize the carbon coating process, and through solid state-carbothermal reduction synthesis of LiFePO4/C composites. The structure, morphology and electrochemical performance of the material were studied by XRD, SEM and galvanostatic charge-discharge methods. It is observed that the tap density of citric acid coating material can reach 1.44 g/ml. Conductivity increased four orders of magnitude. At room temperature, the initial discharge specific capacity of the materials is as high as 89.6 mAh/g at 5.0 C (corresponding to 850 mA/g). After 30 cycles, the capacity is 83.9 mAh/g and decay only 2.0 %.

scholarly journals Novel, Simple and Low-Cost Preparation of Ba-Modified TiO2 Nanotubes for Diclofenac Degradation under UV/Vis Radiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2714
Author(s):  
Mario Bohač ◽  
Tihana Čižmar ◽  
Vedran Kojić ◽  
Jan Marčec ◽  
Krunoslav Juraić ◽  
...  
Keyword(s):  
Tio2 Nanotubes ◽  
Low Cost ◽  
Electrochemical Anodization ◽  
Oh Radicals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Titanium Thin Films ◽  
Current Densities ◽  
Photogenerated Charge Separation

A novel low-cost synthesis of barium-modified TiO2 nanotube (TNT) arrays was used to obtain an immobilized photocatalyst for degradation of diclofenac. TNT arrays were prepared by electrochemical anodization of titanium thin films deposited on fluorine-doped tin oxide (FTO) coated glass by magnetron sputtering, ensuring transparency and immobilization of the nanotubes. The Ba-modifications were obtained by annealing solutions of Ba(OH)2 spin coated on top of TNT. Three different concentrations of Ba(OH)2 were used (12.5 mM, 25 mM and 50 mM). The crystalline structure, morphology and presence of Ba were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Ba-modified TiO2 nanotubes (BTNT) were tested for photocatalytic degradation of diclofenac under UV/Vis radiation and it was proven that all of the Ba-modified samples showed an increase in photocatalytic activity with respect to the unmodified TNTs. The most efficient photocatalyst was the sample prepared with 25 mM Ba(OH)2 which showed 90% diclofenac degradation after 60 min. This result was in agreement with cyclic voltammetry measurements that showed the largest increase in photo-oxidation current densities for the same sample due to the increased generation of •OH radicals obtained by a more efficient photogenerated charge separation.

scholarly journals An Alternative Synthesis Route of LiFePO4-Carbon Composites for Li-Ion Cathodes

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Yongbing Lou ◽  
Jingjing Zhang ◽  
Lin Zhu ◽  
Lixu Lei
Keyword(s):  
Low Cost ◽  
Specific Capacity ◽  
Rate Capability ◽  
Cycling Performance ◽  
Environmentally Benign ◽  
Capping Agent ◽  
Discharge Performance ◽  
Peg 400 ◽  
Dispersive Effect ◽  
Good Crystallinity

LiFePO4-Carbon (LFP/C) composites with high purity and good crystallinity were prepared by an improved environmentally benign and low-cost solvothermal method. Capping agent polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG-400) showed no significant dispersive effect during the synthesis. These capping agents were converted into networking carbons after annealing, which consequently improved the charge and discharge performance. It was able to deliver a high initial discharge specific capacity of 154.1 mAh g−1for sample prepared with PVP and 145.6 mAh g−1for sample prepared with PEG-400 while having great capacity retention. The rate capability and cycling performance of LFP/C samples prepared with PVP or PEG-400 at high current rates were significantly improved compared to the LFP/C sample prepared without a capping agent.

Synthesis and electrochemical properties of SrWO4/graphene composite as anode material for lithium-ion batteries

2014 ◽  
Vol 07 (02) ◽  
pp. 1450010 ◽  
Author(s):  
Linsen Zhang ◽  
Qingling Bai ◽  
Linzhen Wang ◽  
Aiqin Zhang ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Sol Gel ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Electrochemical Performances ◽  
Graphene Composite ◽  
Discharge Method ◽  
Charge Discharge

SrWO 4/graphene composite was synthesized via a sol–gel method. The morphology and structure of the products were analyzed by SEM, TEM and XRD. The electrochemical performances of SrWO 4/graphene composite were investigated by galvanostatic charge/discharge method, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the first cycle of the reversible specific capacity of SrWO 4/graphene composite can reach to 575.9 mAh g-1 at 50 mA g-1. The charge/discharge cycling study indicates that the SrWO 4/graphene composite was provided with excellent cycle performance and outstanding rate capability.

Preparation and Characterization of Nano-LiFePO4/C Using Two-Fluid Spray Dryer

2014 ◽  
Vol 563 ◽  
pp. 62-65 ◽  
Author(s):  
Lin Chen ◽  
Cheng Lu ◽  
Qi An Chen ◽  
Yi Jie Gu ◽  
Meng Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Primary Particle ◽  
Raw Materials ◽  
Specific Capacity ◽  
Initial Discharge ◽  
Tap Density ◽  
Initial Charge ◽  
Discharge Efficiency ◽  
Two Fluid

Nano-LiFePO4/C materials were synthesized by two-fluid spray-drying using FePO4·2H2O, LiOH·H2O as raw materials. The morphology, physical and electrochemical properties of the LiFePO4/C were tested and analyzed. The morphology of the synthesis LiFePO4/C was spherical and its aggregated particle size was smaller than 10μm, primary particle size was smaller than 200nm, the tap density of the material up to 1.25g/cm3. The LiFePO4/C had an initial discharge specific capacity of 163.3mAh/g at 0.1C and its specific capacities were 147.7mAh/g and 121.8mAh/g at 1C and 5C, respectively. The initial charge/discharge efficiency reached 96.6%. Under low temperature 253K, the discharge capacity is 59.6% of that at 298K with 0.2C.

scholarly journals A Natural Polymer Captor for Immobilizing Polysulfide/Polyselenide in Working Li–SeS2 Batteries

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yin Zhang ◽  
Menglei Wang ◽  
Yi Guo ◽  
Lingzhi Huang ◽  
Boya Wang ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Low Cost ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Rate Capability ◽  
Lewis Base ◽  
Organic Polymer ◽  
Binding Interaction ◽  
Attenuation Rate ◽  
Design Protocol

AbstractSeS2 has become a promising cathode material owing to its enhanced electrical conductivity over sulfur and higher theoretical specific capacity than selenium; however, the working Li–SeS2 batteries have to face the practical challenges from the severe shuttling of soluble dual intermediates of polysulfide and polyselenide, especially in high-SeS2-loading cathodes. Herein, a natural organic polymer, Nicandra physaloides pectin (NPP), is proposed to serve as an effective polysulfide/polyselenide captor to address the shuttling issues. Informed by theoretical calculations, NPP is competent to provide a Lewis base-based strong binding interaction with polysulfides/polyselenides via forming lithium bonds, and it can be homogeneously deposited onto a three-dimensional double-carbon conductive scaffold to finally constitute a polysulfide/polyselenide-immobilizing interlayer. Operando spectroscopy analysis validates the enhanced polysulfide/polyselenide trapping and high conversion efficiency on the constructed interlayer, hence bestowing the Li–SeS2 cells with ultrahigh rate capability (448 mAh g−1 at 10 A g−1), durable cycling lifespan (≈ 0.037% capacity attenuation rate per cycle), and high areal capacity (> 6.5 mAh cm−2) at high SeS2 loading of 15.4 mg cm−2. Importantly, pouch cells assembled with this interlayer exhibit excellent flexibility, decent rate capability with relatively low electrolyte-to-capacity ratio, and stable cycling life even under a low electrolyte condition, promising a low-cost, viable design protocol toward practical Li–SeS2 batteries.

Preparation of Ni-Co Alloy by Electrodeposition

2014 ◽  
Vol 525 ◽  
pp. 58-61
Author(s):  
Yusrini Marita ◽  
Ridwan ◽  
Satri Nanda ◽  
Nurdin
Keyword(s):  
Current Density ◽  
Low Cost ◽  
Alloy Coating ◽  
Grain Structure ◽  
Cobalt Alloy ◽  
Nickel Cobalt ◽  
Structure Morphology ◽  
Ni Alloy ◽  
Current Densities ◽  
Composition Structure

Nickel-cobalt alloy coatings were prepared on copper substrates by electrochemical deposition at various deposition current densities of 10, 20, 30, 40 and 50 mA cm-2. Ni-Co alloy coating have been prepared by elecrodeposition technique due its low cost, easily maintainable equipment, easy control of film thickness and the method is also environmentally friendly. The effect of current density on deposit composition, structure, morphology and microhardness of electrodeposited Co-Ni alloy deposits were studied and discussed. The values of the current efficiency obtained are in the range of 68 95 %. From surface morphology obtained the current density increasing promotes the formation colony structure. Increasing the current density led to finer grain structure in Ni-Co deposit. The microhardness of electrodeposited Ni-Co coatings are in the range 482-610 HV.

scholarly journals Synthesis of Bi2O3-MnO2 Nanocomposite Electrode for Wide-Potential Window High Performance Supercapacitor

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3320 ◽  
Author(s):  
Saurabh Singh ◽  
Rakesh K. Sahoo ◽  
Nanasaheb M. Shinde ◽  
Je Moon Yun ◽  
Rajaram S. Mane ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Rate Capability ◽  
Analytical Techniques ◽  
Structure Morphology ◽  
In Series ◽  
State Chemical ◽  
Real Time Application ◽  
A Current ◽  
Wide Potential

In this work, we report the synthesis of a Bi2O3-MnO2 nanocomposite as an electrochemical supercapacitor (ES) electrode via a simple, low-cost, eco-friendly, and low-temperature solid-state chemical process followed by air annealing. This as-synthesized nanocomposite was initially examined in terms of its structure, morphology, phase purity, and surface area using different analytical techniques and thereafter subjected to electrochemical measurements. Its electrochemical performance demonstrated excellent supercapacitive properties in a wide potential window. Its specific capacitance was able to reach 161 F g−1 at a current density of 1A g−1 and then showed a superior rate capability up to 10 A g−1. Furthermore, it demonstrated promising cycling stability at 5 A g−1 with 95% retention even after 10,000 charge–discharge cycles in a wide potential window of 1.3 V, evidencing the synergistic impact of both Bi2O3 and MnO2 in the Bi2O3-MnO2 ES electrode. Additionally, the practical reliability of the envisioned electrode was ascertained by the fabrication of a symmetric Bi2O3-MnO2//Bi2O3-MnO2 pencil-type supercapacitor device that displayed an energy density of 18.4 Wh kg−1 at a power density of 600 W kg−1 and a substantial cyclic stability up to 5000 cycles. Subsequently, an LED was also powered at its full brightness using three of these devices connected in series in order to demonstrate the real-time application of the Bi2O3-MnO2 ES electrode.

scholarly journals Communication—Lithium Titanate as Mg-Ion Insertion Anode for Mg-Ion Sulfur Batteries Based on Sulfurated Poly(acrylonitrile) Composite

2021 ◽  
Author(s):  
Janina Trueck ◽  
Peiwen Wang ◽  
Elizaveta Buch ◽  
Jonas Groos ◽  
Stefan Niesen ◽  
...  
Keyword(s):  
Low Cost ◽  
Rate Capability ◽  
Lithium Titanate ◽  
High Rate ◽  
Cycle Performance ◽  
Long Term Stability ◽  
Spinel Lithium Titanate ◽  
Magnesium Ion Batteries ◽  
Poly Acrylonitrile

Abstract Spinel lithium-titanate Li4Ti5O12 (LTO) is a promising anode material for magnesium batteries due to its non-toxicity, low-cost, zero-strain characteristics and long-term stability. Nevertheless, the application of LTO in a magnesium full cell has been rarely investigated. Herein, we give a proof of concept for the feasibility of LTO as anode in full magnesium ion batteries, which might prevent the passivation of metallic Mg anodes. Mg2+ was electrochemically inserted into LTO prior to cycling against a sulfur-based cathode material, i.e. sulfurated poly(acrylonitrile), SPAN, resulting in stable cycle performance with 800 mAh/gS at 0.3C and high-rate capability.

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