scholarly journals Polypyrrole|zinc supercapattery with the aqueous electrolyte

2017 ◽  
Vol 71 (6) ◽  
pp. 479-485
Author(s):  
Marija Janackovic ◽  
Milica Gvozdenovic ◽  
Branimir Grgur
Keyword(s):  
Discharge Capacity ◽  
Current Density ◽  
Discharge Current ◽  
Aqueous Electrolyte ◽  
Constant Current ◽  
Charge Capacity ◽  
Columbic Efficiency ◽  
Specific Discharge ◽  
Current Densities ◽  
Charge Discharge

Polypyrrole (PPY) electrode was obtained by electrochemical oxidative polymerization of pyrrole on graphite electrode from aqueous electrolyte containing 0.1 mol dm?3 pyrrole monomer and 1.0 mol dm?3 HCl. Polymerization was achieved at the constant current density of 2 mA cm?2 during 1 h. The estimated active mass of PPY (assuming that the maximal doping degree of 0.33 was achieved and the polymerization efficiency of 100%) was 14 mg. Electrochemical characterization of PPY electrode was performed by galvanostatic experiments of charge (doping) and discharge (dedoping) with different current densities in the range between 0.5 and 1.5 mA cm?2. The experiments were performed in aqueous electrolyte containing 2.0 mol dm?3 NH4Cl and 1.1 mol dm?3 ZnCl2. Based on galvanostatic charge/discharge curves, following parameters of PPY electrode were evaluated: discharge capacity, specific discharge capacity, charge capacity, specific charge capacity, and Columbic efficiency. Both charge and discharge capacities were dependent on charge/discharge currents. The values decreased by increasing charge/discharge current, except for the lowest current density where Columbic efficiency exceeded 100%, which was explained by involvement of cations, from the electrolyte, in the doping process. An electrochemical cell in which PPY electrode served as a cathode and zinc electrode as the anode with an aqueous electrolyte containing 2.0 mol dm?3 NH4Cl and 1.1 mol dm?3 ZnCl2, was formed and relevant electrochemical and electrical parameters of the cell were estimated and discussed. Charge of the Zn|PPY cell was dependent on the charge/discharge current. Charge of the cell started between 0.5 and 0.7 V and proceeded up to 1.5 V, while the open circuit voltage of the fully discharged cell was 1.3 V. Specific discharge capacity of Zn|PPY cell, calculated based on discharge times, ranged from 95 to 70 mA h g?1, decreasing linearly with increasing discharge current density. On the other hand, calculated values of the theoretical capacity of the Zn|PPY cell was 105 mA g?1, meaning that practically 90% of the theoretical capacity can be achieved by discharging the cell with low current densities, while 67% of the theoretical capacity was obtained with the highest used current density. Based on Ragon parameters, the estimated values of specific energy that ranged between 46 and 68 W h kg?1, and the specific power between 125 and 380 W kg?1, Zn|PPY cell might be classified as a ?supercapattery?.

Synthesis and Characterization of Nano Mn3O4 for Lithium-Ion Batteries

2014 ◽  
Vol 687-691 ◽  
pp. 4331-4334
Author(s):  
Han Ping Zhu ◽  
Peng Ding ◽  
Song Fang ◽  
Hailin Liu
Keyword(s):  
Discharge Capacity ◽  
Current Density ◽  
Solvothermal Method ◽  
Lithium Ion ◽  
Constant Current ◽  
Initial Discharge Capacity ◽  
Initial Discharge ◽  
Structure Morphology ◽  
Specific Discharge

nanoMn3O4was prepared by a simple solvothermal method. The structure, morphology and electrochemical properties of the products were investigated by XRD, SEM and constant current discharge-charge test. The results of XRD and SEM shows that nanoMn3O4is high-purity, and it’s diameter is about 30 nm. It could deliver an initial discharge capacity of 1324.4 mAh g-1at the current density of 25.5 mA g-1, and the specific discharge capacity is 586.9 mAh g-1after 30 cycles at the current density of 30.4 mA g-1.

Enhanced Electrochemical Performance of CoB Amorphous Alloy through the Addition of Lanthanum

2018 ◽  
Vol 914 ◽  
pp. 102-108
Author(s):  
Wei Zhao ◽  
Yi Lin Liao ◽  
Shu Jun Qiu ◽  
Hai Liang Chu ◽  
Yong Jin Zou ◽  
...  
Keyword(s):  
Amorphous Alloy ◽  
Electrochemical Performance ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Current Density ◽  
Discharge Current ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
High Rate ◽  
Discharge Current Density

In order to investigate the effect of lanthanum on the electrochemical properties of CoB amorphous alloy, Co-Lax-B alloys (x = 0, 0.1, 0.5, and 1) were prepared by chemical reduction method. As negative electrodes in alkaline rechargeable batteries, Co-Lax-B alloys exhibit superior electrochemical properties. For Co-La0.1-B alloy, at the discharge current density of 100 mA/g, the initial discharge capacity is 830.6 mAh/g and the discharge capacity has remained around 317.3 mAh/g even after 100 cycles. Moreover, the high-rate discharge ability (HRD) of Co-La0.1-B alloy electrode at the discharge current density of 300 mA/g, 600 mA/g, and 900 mA/g is 98.16%, 95.17%, and 91.86%, respectively. The anodic polarization (AP) and the electrochemical impedance spectra (EIS) measurements indicate that the kinetics of electrochemical performance of the alloys is remarkably improved with the addition of lanthanum.

Effect of High Loading Glycine on Fe2O3 Nano Oval as Anode for Lithium-Ion Battery

2019 ◽  
Vol 964 ◽  
pp. 215-220
Author(s):  
Lukman Noerochim ◽  
Agny Muchamad Reza ◽  
Budi Agung
Keyword(s):  
Lithium Ion Battery ◽  
Discharge Capacity ◽  
Lithium Ion ◽  
Nyquist Plot ◽  
Discharge Process ◽  
Promising Candidate ◽  
Hydrothermal Temperature ◽  
Specific Discharge ◽  
Li Ion ◽  
Charge Discharge

In this work, Fe2O3 nanooval is successfully synthesized with variation of glycine composition of 9, 12, and 15 mmol at hydrothermal temperature of 160 °C. The Fe2O3 nanooval is indexed by XRD as α-Fe2O3. SEM and TEM images show that the 12 mmol of glycine has the largest diameter with the perfect nanooval form. Nyquist plot shows that the 12 mmol of glycine sample has the best conductivity value of 8.26x10-5 S/m. The CV of sample 12 mmol delivers the best intercalate/de-intercalate with ΔV of 0.82 V. The 12 mmol sample shows the largest specific discharge capacity of 631.62 mAh/g. It is attributed to high conductivity and high kinetics reaction of Li ion during charge-discharge process. Therefore, Fe2O3 nanooval is a promising candidate as anode for lithium-ion battery.

Facile construction of ultrathin standing α-Ni(OH)2 nanosheets on halloysite nanotubes and their enhanced electrochemical capacitance

2014 ◽  
Vol 2 (29) ◽  
pp. 11299-11304 ◽  
Author(s):  
Jin Liang ◽  
Bitao Dong ◽  
Shujiang Ding ◽  
Cuiping Li ◽  
Ben Q. Li ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Discharge Current ◽  
Halloysite Nanotubes ◽  
Cycling Stability ◽  
Hybrid Nanostructures ◽  
Electrochemical Capacitance ◽  
Discharge Current Density ◽  
High Charge ◽  
Charge Discharge

α-Ni(OH)2 nanosheets@HA hybrid nanostructures exhibit an excellent specific capacitance and cycling stability at a high charge–discharge current density.

MnO2 nanowires-decorated carbon fiber cloth as electrodes for aqueous asymmetric supercapacitor

2018 ◽  
Vol 11 (02) ◽  
pp. 1850034 ◽  
Author(s):  
Congcong Hong ◽  
Xing Wang ◽  
Houlin Yu ◽  
Huaping Wu ◽  
Jianshan Wang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Specific Capacitance ◽  
Current Density ◽  
Discharge Current ◽  
High Specific Capacitance ◽  
High Energy ◽  
Discharge Current Density ◽  
Carbon Fiber Cloth ◽  
A Charge ◽  
Charge Discharge

Manganese dioxide nanowires (MnO2 NWs) anchored on carbon fiber cloth (CFC) were fabricated through a simple hydrothermal reaction and used as integrated electrodes for supercapacitor. The morphology-dependent electrochemical performance of MnO2 NWs was confirmed, yielding good capacitance performance with a high specific capacitance of 3.88[Formula: see text][Formula: see text] at a charge–discharge current density of 5[Formula: see text][Formula: see text] and excellent stability of 91.5% capacitance retention after 3000 cycles. Moreover, the composite electrodes were used to fabricate supercapacitors, which showed a high specific capacitance of 194[Formula: see text][Formula: see text] at a charge–discharge current density of 2[Formula: see text][Formula: see text] and high energy density of 0.108[Formula: see text][Formula: see text] at power density of 2[Formula: see text][Formula: see text], foreboding its potential application for high-performance supercapacitor.

Electromigration Reliability of Electroplated Gold Interconnects

2014 ◽  
Vol 1692 ◽  
Author(s):  
Steve H. Kilgore ◽  
Dieter K. Schroder
Keyword(s):  
Current Density ◽  
Open Circuit ◽  
Constant Current ◽  
Measured Temperature ◽  
Lifetime Distributions ◽  
Current Densities ◽  
Log Normal ◽  
Equipment Application ◽  
A Current

ABSTRACTThe electromigration lifetimes of a very large quantity of passivated electroplated Au interconnects were measured utilizing high-resolution in-situ resistance monitoring equipment. Application of moderate accelerated stress conditions with current density limited to 2 MA/cm2 and oven temperatures in the range of 300°C to 375°C prevented large Joule-heated temperature gradients and electrical overstress failures. A Joule-heated Au film temperature increase of 10°C on average was determined from measured temperature coefficients of resistance (TCRs). A failure criterion of 50% resistance degradation was selected to avoid thermal runaway and catastrophic open circuit failures. All Au lifetime distributions followed log-normal statistics. An activation energy of 0.80 ± 0.05 eV was measured from constant-current electromigration tests at multiple temperatures. A current density exponent of 1.91 ± 0.03 was extracted from multiple current densities at a single constant temperature.

scholarly journals In-Situ Arc Discharge-Derived FeSn2/Onion-Like Carbon Nanocapsules as Improved Stannide-Based Electrocatalytic Anode Materials for Lithium-Ion Batteries

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 950 ◽  
Author(s):  
Dandan Han ◽  
Amrita Chatterjee ◽  
Long Hin Man ◽  
Siu Wing Or
Keyword(s):  
Crystal Growth ◽  
Discharge Capacity ◽  
Arc Discharge ◽  
Lithium Ion ◽  
Core Shell ◽  
Discharge Process ◽  
Capacity Retention ◽  
Specific Discharge ◽  
Charge Discharge

Core/shell-structured FeSn2/onion-like carbon (FeSn2/OLC) nanocapsules of confined size range of sub-50 nm are synthesized via an in-situ arc-discharge process, and are evaluated in comparison with FeSn2 nanoparticles as an improved stannide-based electrocatalytic anode material for Li-ion batteries (LIBs). The in-situ arc-discharge process allows a facile one-pot procedure for forming crystalline FeSn2 stannide alloy nanoparticle cores coated by defective OLC thin shells in addition to a confined crystal growth of the FeSn2 nanoparticle cores. The LIB cells assembled using the FeSn2/OLC nanocapsules as the electrocatalytic anodes exhibit superior full specific discharge capacity of 519 mAh·g−1 and specific discharge capacity retention of ~62.1% after 100 charge-discharge cycles at 50 mA·g−1 specific current. The electrochemical stability of FeSn2/OLC nanocapsules is demonstrated from the good cycle stability of the LIBs with a high specific discharge capacity retention of 67.5% on a drastic change in specific current from 4000 to 50 mA·g−1. A formation mechanism is proposed to describe the confined crystal growth of the FeSn2 nanoparticle cores and the formation of the FeSn2/OLC core/shell structure. The observed electrochemical performance enhancement is ascribed to the synergetic effects of the enabling of a reversible lithiation process during charge-discharge of the LIB cells by the FeSn2 nanoparticle cores as well as the protection of the FeSn2 nanoparticle cores from volume change-induced pulverization and solid electrolyte interphase-induced passivation by the OLC shells.

scholarly journals Euler potentials for two layers with non-constant current densities in the ambient magnetic field aligned to the layers

2016 ◽  
Vol 34 (12) ◽  
pp. 1165-1173
Author(s):  
Marek Vandas ◽  
Eugene P. Romashets
Keyword(s):  
Magnetic Field ◽  
Current Density ◽  
Previous Treatment ◽  
Homogeneous Magnetic Field ◽  
Constant Current ◽  
Constant Current Density ◽  
New Approach ◽  
Current Densities ◽  
The Magnetic Field ◽  
Birkeland Currents

Abstract. The Euler potentials for two current layers aligned to an ambient homogeneous magnetic field are found. Previous treatment of such a system assumed constant current density in the layers. However, the magnetic field becomes infinite at the edges. The new approach eliminates this inconsistency by introducing an inhomogeneous current density. Euler potentials are constructed semi-analytically for such a system. Charged-particle motion and trapping in it are examined by this representation. Using Euler potentials, the influence of current sheets of zero and non-zero thicknesses on energetic-particle fluxes is investigated, and characteristic flux variations near the sheets are presented. The results can be applied to Birkeland currents.

Preparation and Electrochemical Properties of LiMn2O4 Nanofibers via Electrospinning for Lithium Ion Batteries

2012 ◽  
Vol 562-564 ◽  
pp. 799-802 ◽  
Author(s):  
Shuai Liu ◽  
Yun Ze Long ◽  
Hong Di Zhang ◽  
Bin Sun ◽  
Cheng Chun Tang ◽  
...  
Keyword(s):  
Discharge Capacity ◽  
Lithium Ion ◽  
Average Diameter ◽  
Potential Range ◽  
Charge Capacity ◽  
High Discharge ◽  
High Discharge Capacity ◽  
Initial Charge ◽  
Charge Discharge ◽  
Scanning Electron

LiMn2O4 nanofibers were prepared via electrospinning and followed by calcination. The surface morphology of as-spun and pure LiMn2O4 nanofibers was characterized by a scanning electron microscope (SEM) with an average diameter of 180 nm. After calcination at 800 °C in air for 5 h, charge/discharge capacity of pure LiMn2O4 nanofibers was measured in the potential range of 3.0 to 4.3 V. Battery testing showed that LiMn2O4 have a high discharge capacity of 80 mAh/g and 85% of the initial charge capacity was maintained for 5 cycles.

scholarly journals Porous Fe2O3 nanorod-decorated hollow carbon nanofibers for high-rate lithium storage

2021 ◽  
Author(s):  
Zhiwen Long ◽  
Luhan Yuan ◽  
Chu Shi ◽  
Caiqin Wu ◽  
Hui Qiao ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Volume Expansion ◽  
Anode Materials ◽  
Carbon Nanofiber ◽  
Lithium Ion ◽  
Rate Performance ◽  
Current Densities ◽  
Hollow Carbon ◽  
Charge Discharge

AbstractTransition metal oxides (TMOs) are considered as promising anode materials for lithium-ion batteries in comparison with conventional graphite anode. However, TMO anodes suffer severe volume expansion during charge/discharge process. In this respect, a porous Fe2O3 nanorod-decorated hollow carbon nanofiber (HNF) anode is designed via a combined electrospinning and hydrothermal method followed by proper annealing. FeOOH/PAN was prepared as precursors and sacrificial templates, and porous hollow Fe2O3@carbon nanofiber (HNF-450) composite is formed at 450 °C in air. As anode materials for lithium-ion batteries, HNF-450 exhibits outstanding rate performance and cycling stability with a reversible discharge capacity of 1398 mAh g−1 after 100 cycles at a current density of 100 mA g−1. Specific capacities 1682, 1515, 1293, 987, and 687 mAh g−1 of HNF-450 are achieved at multiple current densities of 200, 300, 500, 1000, and 2000 mA g−1, respectively. When coupled with commercial LiCoO2 cathode, the full cell delivered an outstanding initial charge/discharge capacity of 614/437 mAh g−1 and stability at different current densities. The improved electrochemical performance is mainly attributed to the free space provided by the unique porous hollow structure, which effectively alleviates the volume expansion and facilitates the exposure of more active sites during the lithiation/delithiation process. Graphical abstract Porous Fe2O3 nanorod-decorated hollow carbon nanofibers exhibit outstanding rate performance and cycling stability with a high reversible discharge capacity.

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