Electrochemical Performances of Yttrium Doped Li3V2–XYX(PO4)3/C Cathode Material for Lithium Secondary Battery

In this study, the Li3V2–X YX(PO4)3 compounds have been synthesized by a simple solid state method. In addition, a polyurethane was added to apply carbon coating on the surface of the Li3V2–X YX(PO4)3 particles for enhancement of the electrical conductivity. The crystal structure and morphology of the synthesized Li3V2–XYX(PO4)3/C (LVYP/C) was investigated using an X-ray diffraction (XRD) and a scanning electron microscopy (SEM) systematically. The electrochemical performance of synthesized material, such as the initial capacity, rate capability, cycling performance and EIS was evaluated. The sizes of synthesized particle ranged from 1 to 5 μm. The Li3V2–XYX(PO4)3/C (X = 0.02) delivered the initial discharge capacity of 171.5 mAh · g–1 at 0.1C rate. It showed a capacity retention ratio of 73.0% at 1.0C after 100th cycle. The electrochemical impedance spectroscopies (EIS) results revealed that the charge transfer resistance of the material decreases by Y doping.

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Preparation and electrochemical characterization of PANI/MnCo2O4 nanocomposite as supercapacitor electrode material

Canadian Journal of Chemistry ◽

10.1139/cjc-2017-0423 ◽

2018 ◽

Vol 96 (5) ◽

pp. 477-483 ◽

Cited By ~ 3

Author(s):

Saeid Panahi ◽

Moosa Es’haghi

Keyword(s):

Specific Capacitance ◽

Surface Characterization ◽

Electrochemical Impedance ◽

Rate Capability ◽

Cycling Performance ◽

Charge Transfer Resistance ◽

X Ray Diffraction ◽

Supercapacitor Electrode ◽

Transfer Resistance

In this work, PANI/MnCo2O4 nanocomposite was prepared via in-situ chemical polymerization method. Materials synthesized were characterized by FTIR spectroscopy, X-ray diffraction, and scanning electron spectroscopy. In addition, surface characterization of samples such as specific surface area, pore volume, and pore size distribution was studied. Supercapacitor capability of materials was investigated in 1 mol L–1 Na2SO4 solution using cyclic voltammetry in different potential scan rates and electrochemical impedance spectroscopy (EIS). The specific capacitance of materials was calculated, and it was observed that the specific capacitance of PANI/MnCo2O4 nanocomposite was 185 F g−1, much larger than PANI. Moreover, the prepared nanocomposite exhibited better rate capability in scan rate of 100 mV s−1 with respect to PANI. The EIS experiments revealed that the nanocomposite has lower charge transfer resistance compared with pure PANI. Subsequently, it was shown that the nanocomposite cycling performance was superior to the PANI cycling performance.

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Enhanced Electrochemical Performances of LiFePO4/C Cathode Materials by Deposited with Ge Film

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.480 ◽

2014 ◽

Vol 936 ◽

pp. 480-485

Author(s):

Yan Dan Huang ◽

Ying Bin Lin ◽

Zhi Gao Huang

Keyword(s):

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Active Material ◽

Rate Capability ◽

Film Surface ◽

Charge Transfer Resistance ◽

Electrochemical Performances ◽

Cyclic Voltammograms ◽

Transfer Resistance ◽

Surface Modified

LiFePO4/C-Ge electrodes were prepared with vacuum thermal evaporation deposition by depositing Ge films on as-prepared LiFePO4/C electrodes. The effect of Ge film on the electrochemical performances of LiFePO4/C cells was investigated systematically by charge/discharge testing, cyclic voltammograms and AC impedance spectroscopy, respectively. It was found that Ge-film-surface modified LiFePO4/C showed excellent electrochemical performances compared to that of the pristine one in terms of cyclability and rate capability. At 60°C, LiFePO4/C-Ge film exhibited outstanding cyclability with less than 5% capacity fade after 50 cycles while the pristine one suffers 15%. Analysis from the electrochemical measurements showed that the presence of Ge film on the LiFePO4/C electrode would protect active material from HF generated by the decomposition of LiPF6 in the electrolyte and stabilize the surface structure of active material during the charge and discharge cycle. Electrochemical impedance spectroscopy (EIS) results indicated that Ge film mainly reduced the charge transfer resistance Rct of LiFePO4/C electrode, resulting from the suppression of the solid electrolyte interfacial (SEI) film.

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Effect of Zirconium Oxide Reinforcement on Microstructural, Electrochemical and Mechanical Properties of TiNi Alloy Produced Via Powder Metallurgy Route

Journal of Engineering Materials and Technology ◽

10.1115/1.4051308 ◽

2021 ◽

pp. 1-22

Author(s):

Syed Abbas Raza ◽

Muhammad Imran Khan ◽

Muhammad Ramzan Abdul karim ◽

Rashid Ali ◽

Muhammad Umair Naseer ◽

...

Keyword(s):

Electrochemical Impedance ◽

Passive Layer ◽

Charge Transfer Resistance ◽

Tini Alloy ◽

X Ray Diffraction ◽

Zro2 Content ◽

Transfer Resistance ◽

X Ray ◽

Conventional Sintering ◽

Layer Resistance

Abstract Equiatomic TiNi alloy composites, reinforced with 0, 5, 10 and 15 vol. % ZrO2, were synthesized using conventional sintering approach. Equiatomic TiNi pre-alloyed powder and ZrO2 powder were mixed in planetary ball mill for 6 hours followed by cold compaction and pressure-less sintering, respectively. The sintered density was found to vary inversely with the addition of ZrO2 content. The X-Ray diffraction spectra have shown the formation of multiple-phases which were resulted from the decomposition of the B19'and B2 phases of the equiatomic TiNi alloy due to the addition of ZrO2 and higher diffusion rate of Ni than that of Ti in the alloy composite. An increase in hardness was noted due to the addition of ZrO2, measured by micro and nanoindentation techniques. Potentiodynamic polarization scan revealed a 10% decrease in the corrosion rate of the composite containing 10 vol. % ZrO2. Electrochemical impedance spectroscopy results indicated an increase in passive layer resistance (Rcoat) due to the increase in charge transfer resistance (Rct) caused by the reduced leaching of ions from the surface.

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Facile Preparation of NiO/Ni Nanocomposite and its Electrochemical Capacitive Behaviors

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.134 ◽

2011 ◽

Vol 306-307 ◽

pp. 134-138 ◽

Cited By ~ 1

Author(s):

Wei Dong Yin ◽

Gui Lian Li ◽

Xian Ming Liu

Keyword(s):

Specific Capacitance ◽

Oxidation Process ◽

Aqueous Electrolyte ◽

High Specific Capacitance ◽

Cycling Performance ◽

Charge Transfer Resistance ◽

Electrochemical Performances ◽

Composite Electrodes ◽

Galvanostatic Charge ◽

Transfer Resistance

NiO/Ni nanocomposites were prepared by chemically reduction-oxidation process in tetra-ethylene glycol (TEG) solution. The structure and morphology of the samples were examined by XRD and SEM. The results indicated the composite consisted of NiO and Ni and exhibited spherical morphology with diameter of 50-200 nm. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy in 6M KOH aqueous electrolyte using three-electrode Swagelok systems. The results showed that the composite had a high specific capacitance and excellent capacitive behavior. The specific capacitance of the composite decreased to 192F/g after 500 cycles. Due to the existance of Ni, the charge transfer resistance is lower than 1Ω. It revealed that the composite exhibited good cycling performance.

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Graphene modified Li-rich cathode material Li[Li0.26Ni0.07Co0.07Mn0.56]O2 for lithium ion battery

Functional Materials Letters ◽

10.1142/s179360471440013x ◽

2014 ◽

Vol 07 (06) ◽

pp. 1440013 ◽

Cited By ~ 8

Author(s):

Xiangjun Li ◽

Hongxing Xin ◽

Xiaoying Qin ◽

Xueqin Yuan ◽

Di Li ◽

...

Keyword(s):

Electrochemical Impedance ◽

Rate Capability ◽

Lithium Ion ◽

Cycling Performance ◽

Precipitation Method ◽

Electrochemical Performances ◽

Charge Transfer Reaction ◽

Ion Diffusion ◽

Co Precipitation ◽

Kinetics Of

Lithium and Mn rich solid solution materials Li [ Li 0.26 Ni 0.07 Co 0.07 Mn 0.56] O 2 were synthesized by a carbonate co-precipitation method and modified with a layer of graphene. The graphene-modified cathodes exhibit improved rate capability and cycling performance as compared to the bare cathodes. Electrochemical impedance spectroscopy (EIS) analyses reveal that the improved electrochemical performances are due to acceleration kinetics of lithium-ion diffusion and the charge transfer reaction of the graphene-modified cathodes.

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Facile Synthesis of Polypyrrole Nanofibers/Co-MOF Composite and Its Lithium Storage Properties

Science of Advanced Materials ◽

10.1166/sam.2020.3630 ◽

2020 ◽

Vol 12 (4) ◽

pp. 486-491

Author(s):

Jinlei Wang ◽

Na Cao ◽

Huiling Du ◽

Xian Du ◽

Hai Lu ◽

...

Keyword(s):

Electrode Materials ◽

Rate Capability ◽

Lithium Ion ◽

Reversible Capacity ◽

Cycling Performance ◽

Charge Transfer Resistance ◽

Growth Strategy ◽

Composite Electrodes ◽

Lithium Storage ◽

Transfer Resistance

Metal-organic frameworks (MOFs) have recently emerged as promising electrode materials for lithium-ion batteries (LIBs). However, poor electrical conductivity in most MOFs limits their electrochemical performance. In this work, the integration of flaky cobalt 1,4-benzenedicarboxylate (Co-BDC) MOF with conductive polypyrrole (PPy) nanofibers via in-situ growth strategy was explored for developing novel anode materials for LIBs. Electrochemical studies showed that PPy/Co-BDC composites exhibited enhanced cycling performance (a reversible capacity of ca. 364 mA h g–1 at a current density of 50 mA g–1 after 100 cycles) and rate capability, com- pared with the pristine Co-BDC. The well dispersion of Co-BDC on polypyrrole nanofibers and the decrease in charge-transfer resistance of the composite electrodes accounted for the improvement of electrochemical properties.

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PREPARATION AND INVESTIGATION OF ELECTRODEPOSITED Ni–NANO-Cr2O3 COMPOSITE COATINGS

Surface Review and Letters ◽

10.1142/s0218625x15501115 ◽

2016 ◽

Vol 23 (02) ◽

pp. 1550111 ◽

Cited By ~ 3

Author(s):

JIBO JIANG ◽

CHENQI FENG ◽

WEI QIAN ◽

LIBIN YU ◽

FENGYING YE ◽

...

Keyword(s):

Electrochemical Impedance ◽

Composite Coatings ◽

Charge Transfer Resistance ◽

X Ray Diffraction ◽

Transfer Resistance ◽

X Ray ◽

Potentiodynamic Polarization Curves ◽

Nucleation Sites ◽

Passive Transition ◽

Steel Surfaces

The electrodeposition of Ni–nano-Cr2O3 composite coatings was studied in electrolyte containing different contents of Cr2O3 nanoparticles (Cr2O3 NPs) on mild steel surfaces. Some techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness, the potentiodynamic polarization curves (Tafel) and electrochemical impedance spectroscopy (EIS) were used to compare pure Ni coatings and Ni–nano-Cr2O3 composite coatings. The results show that the incorporation of Cr2O3 NPs resulted in an increase of hardness and corrosion resistance, and the maximum microhardness of Ni-nano-Cr2O3 composite coatings reaches about 495 HV. The coatings exhibit an active-passive transition and relatively large impedance values. Moreover, the effect of Cr2O3 NPs on Ni electrocrystallization is also investigated by cyclic voltammetry (CV) and EIS spectroscopy, which demonstrates that the nature of Ni-based composite coatings changes attributes to Cr2O3 NPs by offering more nucleation sites and less charge transfer resistance.

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Electrochemical Performance of Mg-Doped Li2FeSiO4/C as Cathode Material for Lithium-Ion Batteries

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.310.90 ◽

2013 ◽

Vol 310 ◽

pp. 90-94 ◽

Cited By ~ 1

Author(s):

Xiao Bing Huang ◽

Hong Hui Chen ◽

Huang Rong Li ◽

Qian Peng Yang ◽

Shi Biao Zhou ◽

...

Keyword(s):

Electrochemical Impedance ◽

Rate Capability ◽

Lithium Ion ◽

Impedance Spectra ◽

X Ray Diffraction ◽

Electrochemical Impedance Spectra ◽

Solid State Method ◽

X Ray ◽

Mg Doped ◽

Discharge Test

Li2FeSiO4/C and Li1.97Mg0.03FeSiO4/C composites were successfully prepared by a solid-state method. Both samples were systematically investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), the charge-discharge test and electrochemical impedance spectra measurement, respectively. It was found that the Li1.97Mg0.03FeSiO4/C composite exhibited an excellent rate capability with a discharge capacity of 144mAh g-1 at 0.2C and 97mAh g-1 at 5C, and after 100 cycles at 1 C, 96% of its initial capacity was retained.

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PREPARATION AND CHARACTERIZATION OF A POLY(PYRROLYL METHANE)/MULTIWALLED CARBON NANOTUBES COMPOSITES

NANO ◽

10.1142/s179329201350063x ◽

2013 ◽

Vol 08 (06) ◽

pp. 1350063

Author(s):

JINXIAN LIN ◽

PAN WANG ◽

YUYING ZHENG

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Electrochemical Impedance ◽

Charge Transfer Resistance ◽

Electrode System ◽

X Ray Diffraction ◽

Multiwalled Carbon ◽

Transfer Resistance ◽

Transmission Electron

A poly(pyrrolyl methane) (Poly[pyrrole-2, 5-diyl(4-methoxybenzylidane)], PPDMOBA)/multiwalled carbon nanotubes (MWNTs) composites are fabricated by in situ chemical polycondensation of pyrrole and 4-methoxybenzaldehyde on MWNTs. The structure, morphology, thermal stability and electrical property of the resulting composites are investigated via fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and a four-probe method. The electrochemical performance of the composites is determined in a three-electrode system using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. FTIR, FESEM and TEM confirm that the composites have been successfully prepared, and PPDMOBA is uniformly dispersed in MWNTs. Electrical conductivity of PPDMOBA/MWNTs composites is 1.39 S cm-1, which is significantly larger than that of pristine PPDMOBA. The specific capacitance and charge transfer resistance of the composites is 56 F g-1 (1 mA cm-2) and 0.3Ω, respectively.

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STUDY OF ZN-NI ALLOY COATINGSMODIFIED BY NANO-AL2O3 PARTICLES INCORPORATION

Acta Metallurgica Slovaca ◽

10.12776/ams.v22i3.706 ◽

2016 ◽

Vol 22 (3) ◽

pp. 171 ◽

Cited By ~ 1

Author(s):

Malika Diafi ◽

Said Benramache ◽

Elhachmi Guettaf Temam ◽

Adaika Mohamed Lakhdar ◽

Brahim Gasmi

Keyword(s):

Electrochemical Impedance ◽

Research Work ◽

Charge Transfer Resistance ◽

Diffraction Measurement ◽

X Ray Diffraction ◽

Corrosion Properties ◽

Transfer Resistance ◽

Characterization Methods ◽

Ni Alloy ◽

Steel Substrates

AbstractThe aim of this research work was to codeposit nano-Al2O3 particles into Zn-Ni alloy coatings in order to improve some surface ,properties, the influence of the concentration of Al2O3 is the principal object in order to improve the corrosion resistance of the deposit, which has been made by electroplating on steel substrates previously treated, have been studied by several characterization methods, as the X-ray diffraction, measurement of micro hardness and scanning electron microscopy (SEM), protection against corrosion properties studied in a solution of 3% NaCl in the potentiodynamic polarization measurements (Tafel), electrochemical impedance spectroscopy (EIS) to the potential of corrosion free. The parameters that characterize the corrosion behavior can be determined from the plots and Nyquist plots and chronopotentiometry. Trends of increasing the charge transfer resistance and the decrease of capacitance values. XRD and SEM results and identify any coatings Zn-Ni and Zn-Ni-Al2O3 alloy composition have similar phase ( γ-phase structure) and the addition of Al2O3 in the Zn-Ni matrix increases the microhardness, and we note the maximum hardness is obtained for 50 g/L Al2O3.

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