Research on Lithium Ion Battery Material LiCoO2 for Hybrid Supercapacitor

2011 ◽  
Vol 287-290 ◽  
pp. 1565-1568 ◽  
Author(s):  
Sheng Li Zhang ◽  
Li Hua Ma ◽  
Xiao Gang Li ◽  
Yan Hua Song ◽  
Wei Li
Keyword(s):  
Leakage Current ◽  
Composite Electrode ◽  
Electrochemical Impedance ◽  
Retention Rate ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Constant Current ◽  
Electrochemical Impedance Spectrum ◽  
Hybrid Supercapacitor

The electrochemical performance of capacitor was studied with LiCoO2/AC as composite cathode and activated carbon (AC) as anode, in 1.0 mol/L LiPF6/EC+DMC electrolyte. Cyclic Voltammetary, Constant-Current Charge and Discharge, Electrochemical Impedance Spectrum (EIS) and Leakage Current Test were tested to study the characteristics of supercapacitors. The results illustrate that recharging voltage of hybrid supercapacitor can reach to 3.0 V and show good capacitance characteristics. The supercapacitor can rapidly charge and discharge and show good cycling performance. There is a great effect to the performance of the capacitors by adopting different proportional composite electrode. When the ratio of composite electrode is 6:4, we get maximum symmetrical Cyclic Voltammetary and short charge-discharge time only 26.4min; When the ratio is 7:3, the minimum AC impedance of 26.2W can be attained and least leakage current is only 19.92mA/g; When the ratio is 5:5, the best first specific capacity can reach to 70.17F/g but a lower capacity retention rate is 74.86%.

Synthesis and Electrochemical Properties of Spherical LiFePO4/C Composite via Spray Drying

2015 ◽  
Vol 1120-1121 ◽  
pp. 554-558 ◽  
Author(s):  
Juan Mei Wang ◽  
Bing Ren ◽  
Ying Lin Yan ◽  
Qing Zhang ◽  
Yan Wang
Keyword(s):  
Diffusion Coefficient ◽  
Electrochemical Properties ◽  
Spray Drying ◽  
Electrochemical Impedance ◽  
Retention Rate ◽  
Lithium Ion ◽  
Constant Current ◽  
Ion Diffusion ◽  
Electrochemical Tests ◽  
Li Ion

In this work, spherical LiFePO4/C composite had been synthesized by co-precipitation and spray drying method. The structure, morphology and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), transmission electron microscope (TEM), constant current charge-discharge tests and electrochemical impedance spectroscopy (EIS) tests. The spherical LiFePO4/C particles consisted of a number of smaller grains. The results showed that the morphology of LiFePO4/C particles seriously affected the Li-ion diffusion coefficient and electrochemical properties of lithium ion batteries. Electrochemical tests revealed the spherical LiFePO4/C composite had excellent Li-ion diffusion coefficient which was calculated to be 1.065×10-11 cm2/s and discharge capacity of 149 (0.1 C), 139 (0.2 C), 133 (0.5 C), 129 (1 C) and 124 mAhg-1(2 C). After 50 cycles, the capacity retention rate was still 93.5%.

Preparation and Electrochemical Performance of Mg2 + Doped Li4Ti5O12 Anode Materials for Lithium-Ion Batteries

2019 ◽  
Vol 960 ◽  
pp. 238-243
Author(s):  
Ming Wang ◽  
Xue Ming Zhang ◽  
Ying Bo Wang ◽  
Li Li Cheng ◽  
Xue Lei Wang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Electrochemical Impedance ◽  
Solid Phase ◽  
Retention Rate ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Transfer Resistance

Spinel Li4Ti5O12 (LTO) doped with Mg2+ was synthesized by solid-phase reaction method. The Mg2+ doping quantity was 3%, 6%, 9%, and 12%, respectively. The structure and electrochemical performance of the prepared LTO composites were investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and galvanostatic charge-discharge tests. It was found that the doped Mg ion did not change the structure of Li4Ti5O12, and it was evenly distributed around Li4Ti5O12. When Mg2+ doping quantity increased from 3% to 12%, the internal resistance and charge transfer resistance of the composite both decreased. The first discharge specific capacity of 6%-Mg2+ doped LTO composite was 168 mAh/g, which was close to the theoretical capacity of pure lithium titanate (175 mAh/g), and the capacity retention rate was 98% after 100 cycles.

scholarly journals λ-MnO2 Thin Films with Sponge-Like Structures: Synthesis, Characterization and Physiochemical Applications

2021 ◽  
Vol 21 (5) ◽  
pp. 1187
Author(s):  
Khalid Abdelazez Mohamed Ahmed
Keyword(s):  
Thin Films ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Particle Growth ◽  
Crystal Form ◽  
Electrochemical Impedance Spectrum ◽  
Significant Research ◽  
Physicochemical Features ◽  
Adsorption Desorption

Manganese dioxide has acquired significant research attentiveness in many fields over the past years because of its exciting physicochemical features. The magnetized λ-MnO2 thin films with sponge-like structures (TSLs) were prepared by hydrothermal-soft chemical and delithiation-lithium manganese process. The XRD, XPS, EDX, FESEM, TEM, HR-TEM, and N2 adsorption-desorption techniques were used to characterize the as-prepared product’s structure composition, morphology, and surface area. The particle growth details of λ-MnO2 are postulated by the oxidation-ionic change-delithiation (OID) mechanism. The electrochemical property was analyzed by galvanostatic discharge-charging, electrochemical impedance spectrum (EIS), and cyclic voltammetry (CV). Special attention of λ-MnO2 S.L.s is given to their applications in the degradation of methyl orange (MO) from wastewater under O2 air bubble pump and cathodic substance in the lithium-ion battery. Due to the peculiarity crystal form and morphology face, the λ-MnO2 TSLs might be promisingly applied in the various physicochemical area.

Study on Electrochemical Impedance Spectrum Analysis of LiFePO4 in Aqueous Solutions by Using Powder Microelectrode

2013 ◽  
Vol 805-806 ◽  
pp. 1348-1351
Author(s):  
Na Ha ◽  
Jie Min Liu
Keyword(s):  
Cathode Materials ◽  
Electrochemical Method ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Electrochemical Impedance Spectrum ◽  
Quick Response ◽  
Modeling Process ◽  
Electrochemical Parameters ◽  
Powder Microelectrode

LiFePO4 is becoming promising lithium ion cathode material. Because period of testing call is long, sometimes it cannot accurately characterize for cathode materials. By using Electrochemical Impedance Spectrum, it would be better to describe performance of materials. The electrochemical parameters have been obtained by modeling process of insertion and desertion by Electrochemical Impedance Spectrum, which is helpful to analyze LiFePO4 electrochemical performance. Because of quick response and preciseness of electrochemical method, it would be better to analyze cathode materials.

scholarly journals In-situ synthesize of graphene-Mn3O4 nanocomposites for high-rate pseduocapacitive electrodes

2018 ◽  
Author(s):  
Danfeng Qiu ◽  
Xiao Ma ◽  
Jingdong Zhang ◽  
Bin Zhao ◽  
Zixia Lin
Keyword(s):  
Composite Electrode ◽  
Electrode Materials ◽  
Retention Rate ◽  
Graphene Nanosheets ◽  
Specific Capacity ◽  
High Rate ◽  
Constant Current ◽  
Specific Power ◽  
Constant Current Charge ◽  
Mn3o4 Nanoparticles

Mn3O4 /graphene nanosheets (GNS) composites serve as very excellent electrode materials for supercapacitors. They can fully combine the advantages of two materials such as graphene and metal oxide. Meanwhile, they can improve not only the specific energy and specific power of the materials, but also the cyclic stability of the materials. The results of the cyclic voltammetry and constant current charge discharge test on the composite electrode material have shown that the Mn3O4 /GNS powder sample has good capacitive performance. When the scanning rate is 5~50mV, the specific capacity retention rate of the composite electrode is 80.3% and 88% respectively. Mn3O4 nanoparticles, with the highest ratio of network coated GNS, exhibit a specific capacitance value of 957.6 F g−1 at a current density of 2 A g−1 in 1 M Na2SO4 solution. Besides, its network structure demonstrates high specific capacity and multiplying performance.

A High Rate, High Capacity and Long Life (LiFePO4+AC)/Li4Ti5O12 Hybrid Battery-Supercapacitor

2014 ◽  
Vol 936 ◽  
pp. 496-502
Author(s):  
Xue Bu Hu ◽  
Zi Ji Lin ◽  
Yong Long Zhang
Keyword(s):  
Leakage Current ◽  
Electrochemical Impedance ◽  
Discharge Rate ◽  
Performance Testing ◽  
High Energy ◽  
High Energy Density ◽  
Constant Current ◽  
Electrochemical Performances ◽  
Capacity Loss ◽  
Charge Discharge

A hybrid battery-supercapacitor (LiFePO4+AC)/Li4Ti5O12 using a Li4Ti5O12 anode and a LiFePO4/activated carbon (AC) composite cathode was built. The electrochemical performances of the hybrid battery-supercapacitor (LiFePO4+AC)/Li4Ti5O12 were characterized by constant current charge-discharge, rate charge-discharge, electrochemical impedance spectra, internal resistance, leakage current, self-discharge and cycle performance testing. The results show that (LiFePO4+AC)/Li4Ti5O12 hybrid battery-supercapacitors have rapid charge-discharge performance, high energy density, long cycle life, low resistance, low leakage current and self-discharge rate, which meet the requirements of practical power supply and can be applied in auxiliary power supplies for hybrid electric vehicles. At 4C rate, the capacity loss of (LiFePO4+AC)/Li4Ti5O12 hybrid battery-supercapacitors in constant current mode is no more than 7.71% after 2000 cycles, and the capacity loss in constant current-constant voltage mode is no more than 4.51% after 1500 cycles.

scholarly journals Study on the Synthesize, Characterization, and Conductive Performance of Nickelzircomolybdnum Heteropoly Acid Salt with Keggin Structure

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Zhihong Zhang ◽  
Baoying Wang ◽  
Yijing Zhang ◽  
Gehong Zhang ◽  
Yujing Wang
Keyword(s):  
Conduction Mechanism ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Heteropoly Compound ◽  
Electrochemical Impedance Spectrum ◽  
Acid Salt ◽  
X Ray Diffraction ◽  
Protonic Conduction ◽  
X Ray

A novel heteropoly acid salt, Na6[Ni(Mo11ZrO39)]·20H2O, has been synthesized by the means of acidification and adding the reactants into the solution step by step. The heteropoly compound was characterized by elemental analysis, TGA/DSC, infrared spectrum, ultraviolet spectrum, X-ray diffraction, and SEM. Its protonic conduction was measured by the means of the electrochemical impedance spectrum. The results showed that it belongs to the Keggin type, and its conductivity value was 1.23 × 10–2 S/cm at 23°C when the relative humidity was 60%, and the conductivity enhanced with the elevated temperature. Its proton conduction mechanism was in accordance with vehicle mechanism, and the activation energy was 27.82 kJ/mol.

Modification of High Potential, High Capacity Li2FeP2O7 Cathode Material for Lithium Ion Batteries

2012 ◽  
Vol 1440 ◽  
Author(s):  
Jiajia Tan ◽  
Ashutosh Tiwari
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
High Capacity ◽  
Lithium Ion ◽  
Discharge Rates ◽  
Electronic Conductivities ◽  
Fast Discharge

ABSTRACTLi2FeP2O7 is a newly developed polyanionic cathode material for high performance lithium ion batteries. It is considered very attractive due to its large specific capacity, good thermal and chemical stability, and environmental benignity. However, the application of Li2FeP2O7 is limited by its low ionic and electronic conductivities. To overcome the above problem, a solution-based technique was successfully developed to synthesize Li2FeP2O7 powders with very fine and uniform particle size (< 1 μm), achieving much faster kinetics. The obtained Li2FeP2O7 powders were tested in lithium ion batteries by measurements of cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge cycling. We found that the modified Li2FeP2O7 cathode could maintain a relatively high capacity even at fast discharge rates.

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