scholarly journals Solvothermal Synthesis of Flower-Flakes Like Nano Composites of Ni-Co Metal Organic Frameworks and Graphene Nanoplatelets for Energy Storage Applications

2021 ◽  
Author(s):  
Muhammad Ramzan Abdul Karim ◽  
Muhammad Noman ◽  
Khurram Imran Khan ◽  
Waseem Shehzad ◽  
Ehsan ul Haq ◽  
...  
Keyword(s):  
Energy Storage ◽  
Solvothermal Synthesis ◽  
Specific Capacity ◽  
Xrd Analysis ◽  
Charge Transfer Resistance ◽  
Graphene Nanoplatelets ◽  
Cobalt Metal ◽  
Energy Storage Devices ◽  
Transfer Resistance ◽  
Good Thermal Stability

Abstract Solvothermal synthesis of Ni-Co-MOF/graphene nanoplatelets (GNPs) nanocomposites was done for their potential application as electrode material in energy storage devices. Addition of GNPs and metallic precursors together with 2-methylimedazole in the same autoclave reactor produced smooth-nanoflakes like Ni-Co-MOF/GNPs nanocomposites as evaluated by SEM. XRD analysis showed the presence of GNPs where GNPs do not affect the growth of MOF crystals and Ni-Co-MOF crystalline phases remain unaffected in the composite structure. FTIR analysis confirmed the presence of organic links forming nickel-cobalt metal cations framework. Electrochemical testing(CV,EIS,GCD) of the produced composites demonstrated that GNPs addition can enhance the charge storage performance of MOFs nanocomposites. The largest cycle area and most discharge time have been shown by Ni-Co-MOF/GNP-50 composite electrode that delivered the highest specific capacity values (313 Cg-1@1 Ag-1), good reversibility and low internal resistance and charge transfer resistance. Moreover, Ni-Co-MOF/GNP-50 composite exhibited good thermal stability with 28% weight loss during thermogravimetric analysis. The electrochemical evaluations performed on asymmetric supercapacitor real device expressed a specific capacity of 136.5 [email protected] Ag-1, maximum energy density of 32.2 Whkg-1@425 Wkg-1 and maximum power density of 17000 [email protected] Whkg-1. Moreover, the device showed a stability performance of 92.5%@10 Ag-1 after 5000 CD cycles.

Synthesis and Electrochemical Properties of Polypyrrole Conducting Polymer in Sheath like Nanotube Arrays Structured over TiO2 for Supercapacitor Energy Storage Devices

2015 ◽  
Vol 1749 ◽  
Author(s):  
Navjot K. Sidhu ◽  
A.C. Rastogi
Keyword(s):  
Energy Storage ◽  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Nanotube Arrays ◽  
Energy Storage Devices ◽  
Transfer Resistance ◽  
Capacitance Density ◽  
Electrically Conducting ◽  
Supercapacitor Energy Storage

ABSTRACTThe vertical TiO2 nanotube arrays constituting the core of 3-D nanoscale electrode architecture were synthesized over Ti sheet by anodization. Such formed TiO2 nanotubes are electrically conducting and amorphous as confirmed by XRD studies. Nanotube morphology is affected by water content and in the present study, close-packed 3-4 μm long TiO2 nanotube arrays of 45-50 nm diameter are formed with 2% water as revealed by the transmission and scanning electron microscopy. The redox active polypyrrole sheath is created by ultra-short pulsed current electropolymerization. Electrochemical properties of the 3-D nanoscaled TiO2 nanotube core-polypyrrole sheath electrodes relevant to the energy storage were investigated using cyclic voltammetry (CV) plots, electrochemical impedance spectroscopy (EIS), Charge discharge (CD) tests. High areal capacitance density of 48 mF cm-2 and low charge transfer resistance 12 Ω cm-2 with least ion diffusion limitation are realized at optimized polypyrrole sheath thickness. The Raman spectra studies reveal anion at specific chain locations involve in the redox process.

scholarly journals Artificial Cathode-Electrolyte Interphase towards High-Performance Lithium-Ion Batteries: A Case Study of β-AgVO3

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 569
Author(s):  
Liang Liu ◽  
Wei Dai ◽  
Hongzheng Zhu ◽  
Yanguang Gu ◽  
Kangkang Wang ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Lithium Ion Batteries ◽  
High Performance ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Al2o3 Coating ◽  
Energy Storage Devices ◽  
Transfer Resistance

Silver vanadates (SVOs) have been widely investigated as cathode materials for high-performance lithium-ion batteries (LIBs). However, similar to most vanadium-based materials, SVOs suffer from structural collapse/amorphization and vanadium dissolution from the electrode into the electrolyte during the Li insertion and extraction process, causing poor electrochemical performance in LIBs. We employ ultrathin Al2O3 coatings to modify β-AgVO3 (as a typical example of SVOs) by an atomic layer deposition (ALD) technique. The galvanostatic charge-discharge test reveals that ALD Al2O3 coatings with different thicknesses greatly affected the cycling performance. Especially, the β-AgVO3 electrode with ~10 nm Al2O3 coating (100 ALD cycles) exhibits a high specific capacity of 271 mAh g−1, and capacity retention is 31%, much higher than the uncoated one of 10% after 100 cycles. The Coulombic efficiency is improved from 89.8% for the pristine β-AgVO3 to 98.2% for Al2O3-coated one. Postcycling analysis by cyclic voltammetry (CV), cyclic voltammetry (EIS), and scanning electron microscopy (SEM) disclose that 10-nm Al2O3 coating greatly reduces cathode-electrolyte interphase (CEI) resistance and the charge transfer resistance in the β-AgVO3 electrode. Al2O3 coating by the ALD method is a promising technique to construct artificial CEI and stabilize the structure of SVOs, providing new insights for vanadium-based electrodes and their energy storage devices.

scholarly journals Effect of nanostructured carbon coatings on the electrochemical performance of Li1.4Ni0.5Mn0.5O2+ x -based cathode materials

2016 ◽  
Vol 7 ◽  
pp. 1960-1970 ◽  
Author(s):  
Konstantin A Kurilenko ◽  
Oleg A Shlyakhtin ◽  
Oleg A Brylev ◽  
Dmitry I Petukhov ◽  
Alexey V Garshev
Keyword(s):  
Diffusion Coefficient ◽  
Charge Transfer ◽  
Specific Capacity ◽  
Charge Transfer Resistance ◽  
Poly Vinyl Alcohol ◽  
Nanostructured Carbon ◽  
Transfer Resistance ◽  
Carbon Coatings ◽  
Lithium Diffusion Coefficient ◽  
Electrochemical Cycling

Nanocomposites of Li1.4Ni0.5Mn0.5O2+ x and amorphous carbon were obtained by the pyrolysis of linear and cross-linked poly(vinyl alcohol) (PVA) in presence of Li1.4Ni0.5Mn0.5O2+ x . In the case of linear PVA, the formation of nanostructured carbon coatings on Li1.4Ni0.5Mn0.5O2+ x particles is observed, while for cross-linked PVA islands of mesoporous carbon are located on the boundaries of Li1.4Ni0.5Mn0.5O2+ x particles. The presence of the carbon framework leads to a decrease of the polarization upon cycling and of the charge transfer resistance and to an increase in the apparent Li+ diffusion coefficient from 10−16 cm2·s−1 (pure Li1.4Ni0.5Mn0.5O2+ x ) to 10−13 cm2·s−1. The nanosized carbon coatings also reduce the deep electrochemical degradation of Li1.4Ni0.5Mn0.5O2+ x during electrochemical cycling. The nanocomposite obtained by the pyrolysis of linear PVA demonstrates higher values of the apparent lithium diffusion coefficient, a higher specific capacity and lower values of charge transfer resistance, which can be related to the more uniform carbon coatings and to the significant content of sp2-hybridized carbon detected by XPS and by Raman spectroscopy.

Recent Advances on the Application of Graphene Quantum Dots in Energy Storage

2021 ◽  
Vol 15 ◽  
Author(s):  
Feng Shi ◽  
Quanrun Liu
Keyword(s):  
Quantum Dots ◽  
Energy Storage ◽  
Potential Application ◽  
Active Sites ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Graphene Quantum Dots ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
New Energy

Background: As an emerging carbon nanomaterial, graphene quantum dots (GQDs) have shown great potential application in new energy storage devices due to their unique small size effect and abundant edge active sites. This work introduces the main synthesis strategies of GQDs, which includes top-down and bottom-up methods; the application examples of GQDs and GQDs-based composites in energy storage are reviewed, and more, the unique advantages of GQDs are used in supercapacitors, Lithium-ion batteries (LIBs) and Lithium-sulfur batteries (Li–S batteries) are highlighted. The problems and development prospects in this growing area are also discussed. Method: We conducted a detailed search of “the application of GQDs in energy storage devices” in the published papers and the public patents based on Web of Science database in the period from 2014 to 2020. The corresponding literature was carefully evaluated and analyzed. Results: Sixty papers and twenty-eight recent patents were included in this mini-review. The significant advances in the recent years are summarized with comparative and balanced discussion. Thanks to the unique properties of large specific surface area, high conductivity and abundant active sites, GQDs have unparalleled potential application for new energy storage, especially improving the specific capacity and cycle stability of supercapacitors, LIBs and Li-S batteries. Conclusion: The findings of this mini-review confirm the importance of GQDs, show the enhanced electrochemical performance in supercapacitors, LIBs and Li-S batteries, and also provide a helpful guide to design and fabricate highefficiency electrode materials.

Porous Activity of Biomass-Activated Carbon Enhanced by Nitrogen-Dopant Towards High-Performance Lithium Ion Hybrid Battery-Supercapacitor

2021 ◽  
Author(s):  
Juan Yu ◽  
Xuyang Wang ◽  
Jiaxin Peng ◽  
Xuefeng Jia ◽  
Linbo Li ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Energy Storage ◽  
Pore Structure ◽  
High Performance ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Utilization Efficiency ◽  
Energy Storage Devices ◽  
Storage Devices

Abstract Biomass-activated carbon materials are promising electrode materials for lithium-ion hybrid capacitors (LiCs) because of their natural hierarchical pore structure. The efficient utilization of structural pores in activated carbon is very important for their electrochemical performance. Herein, porous biomass-activated carbon (PAC) with large specific surface area was prepared using a one-step activation method with biomass waste as the carbon source and ZnCl2 as the activator. To further improve its pore structure utilization efficiency, the PAC was doped with nitrogen using urea as the nitrogen source. The experimental results confirmed that PAC-1 with a high nitrogen doping level of 4.66% exhibited the most efficient pore utilization among all the samples investigated in this study. PAC-1 exhibited 92% capacity retention after 8000 cycles, showing good cycling stability. Then, to maximize the utilization of high-efficiency energy storage devices, LiNi0.8Co0.15Al0.05O2 (NCA), a promising cathode material for lithium-ion batteries with high specific capacity, was compounded with PAC-1 in different ratios to obtain NCA@PC composites. The NCA@PC-9 composite exhibited excellent capacitance in LiCs and an energy density of 210.9 Wh kg-1 at a high power density of 13.3 kW kg-1. These results provide guidelines for the design of high-performance and low-cost energy storage devices.

LiMn1.5Ni0.25Fe0.2M0.05O4 Nanoparticles as a Cathode Material for Rechargeable Li-Ion Batteries

2020 ◽  
Vol 835 ◽  
pp. 149-154
Author(s):  
Haitham A. Abdellatif ◽  
Mostafa M.M. Sanad ◽  
Elsayed M. Elnaggar ◽  
Mohamed M. Rashad ◽  
Gamal M. El-Kady
Keyword(s):  
Annealing Temperature ◽  
Sol Gel ◽  
Combustion Method ◽  
Xrd Analysis ◽  
Charge Transfer Resistance ◽  
Li Ion Batteries ◽  
Transfer Resistance ◽  
Auto Combustion ◽  
Li Ion ◽  
Kinetic Diffusion

New series of spinel LiNi0.25Fe0.2Mˊ0.05Mn1.5O4 (Mˊ = Cu, Mg or Zn) cathode materials have been purposefully tailored using sol-gel auto-combustion method at low annealing temperature ~ 700°C for 3 h. The XRD analysis showed that all substituted (LNFMO-Mˊ) samples are comported with the main structure of undoped (LNFMO) with crystalline disordered spinel Fd-3m structure. TEM images revealed the octahedron-shape like morphology for the particles and the LNFMO-Zn sample has the widest particle size distribution. EIS spectra evidenced that a typical one semicircle (LNFMO-Mg) was revealed for each cell, suggesting the absence of ionic conductivity contribution. The values of charge transfer resistance (Rct) were equal to 9.3, 6.7, 6.0 and 4.4 kΩ for LNFMO, LNFMO-Cu, LNFMO-Mg indicating that the Zn-doped sample has the fastest kinetic diffusion rate and lowest activation energy of conduction.

Electrochemical Properties of Natural and Modified Pyrite

2012 ◽  
Vol 554-556 ◽  
pp. 379-384
Author(s):  
Da Gang Wang ◽  
Li Ren Fan ◽  
Chou Fan
Keyword(s):  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Charge Transfer Resistance ◽  
Fatty Acid Salt ◽  
Transfer Resistance ◽  
Cyclic Voltammetry Measurement ◽  
Mean Grain Size ◽  
Specific Discharge ◽  
Voltage Plateau ◽  
Natural Pyrite

Pyrite utrafine powder was yielded through processing natural pyrite, including gravity separation, flotation and airflow grinding, which the contents of Fe and S are 45.30wt% and 50.95wt% respectively and the mean grain size is 13μm. Pyrite powder modified by fatty acid salt A was investigated by TG/DSC, XPS and XRD. The results indicate that the phase of powder is mostly pyrite FeS2 coating with organic modifier, and S exists in the form of [S2]2- principally on modified pyrite surface. Furthermore, electrochemical impedance spectroscopy, cyclic voltammetry measurement and galvanotactic current charge and discharge methods were applied to exhibit the electrochemical performance of pyrite sample. The results show that modified pyrite has lower charge transfer resistance and higher conductivity than that of natural pyrite, and the specific discharge capacity is as high as 850mAh/g under 0.354A current at room temperature and the cutoff of 0.5V closing to the theoretical specific capacity of pyrite (890mA•h/g), and the voltage plateau is 1.44V.

scholarly journals Electrochemical Impedance Spectroscopy on the Performance Degradation of LiFePO4/Graphite Lithium-Ion Battery Due to Charge-Discharge Cycling under Different C-Rates

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4507 ◽  
Author(s):  
Yusuke Abe ◽  
Natsuki Hori ◽  
Seiji Kumagai
Keyword(s):  
Charge Transfer ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Performance Degradation ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Charge Discharge

Lithium-ion batteries (LIBs) using a LiFePO4 cathode and graphite anode were assembled in coin cell form and subjected to 1000 charge-discharge cycles at 1, 2, and 5 C at 25 °C. The performance degradation of the LIB cells under different C-rates was analyzed by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. The most severe degradation occurred at 2 C while degradation was mitigated at the highest C-rate of 5 C. EIS data of the equivalent circuit model provided information on the changes in the internal resistance. The charge-transfer resistance within all the cells increased after the cycle test, with the cell cycled at 2 C presenting the greatest increment in the charge-transfer resistance. Agglomerates were observed on the graphite anodes of the cells cycled at 2 and 5 C; these were more abundantly produced in the former cell. The lower degradation of the cell cycled at 5 C was attributed to the lowered capacity utilization of the anode. The larger cell voltage drop caused by the increased C-rate reduced the electrode potential variation allocated to the net electrochemical reactions, contributing to the charge-discharge specific capacity of the cells.

Increasing Electrical Conductivity of Free-Standing Sulfurized Polyacrylonitrile Cathode for Lithium–Sulfur Batteries

2020 ◽  
Vol 12 (10) ◽  
pp. 1441-1445
Author(s):  
Huihun Kim ◽  
Seon-Hwa Choe ◽  
Milan K. Sadan ◽  
Changhyeon Kim ◽  
Kwon-Koo Cho ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Specific Capacity ◽  
Rate Capability ◽  
Charge Transfer Resistance ◽  
Acetylene Black ◽  
Free Standing ◽  
Transfer Resistance ◽  
Lithium Sulfur Batteries ◽  
Multi Walled Carbon Nanotubes ◽  
Lithium Sulfur

Sulfurized polyacrylonitrile (S-PAN) is one of the best materials for addressing some of the intrinsic drawbacks of lithium–sulfur batteries, such as the intrinsic insulating properties of sulfur and the shuttle phenomenon. Moreover, while S-PAN nanofiber composites are flexible, they still presents shortcomings, such as low rate capability, which is due to their semiconductor electrical conductivity. In this study, we prepared S-PAN webs with high electrical conductivity via electrospinning using conducting agents. Additionally, we analyzed the electrochemical properties of the S-PAN webs prepared using various conducting agents (acetylene black, Ketjen black, and multi-walled carbon nanotubes). The specific capacity of the S-PAN web prepared using acetylene black was 740 mAh g–1 at the charge rate of 5 C. The excellent rate capability of S-PAN prepared using acetylene black was attributed to its low electrical resistance and low charge transfer resistance.

EFFECT OF TiO2 PARTICLES ON MICRO-HARDNESS, CORROSION, WEAR AND FRICTION OF Ni–P–TiO2 COMPOSITE COATINGS AT DIFFERENT ANNEALING TEMPERATURES

2016 ◽  
Vol 23 (01) ◽  
pp. 1550082 ◽  
Author(s):  
PRASANNA GADHARI ◽  
PRASANTA SAHOO
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Composite Coatings ◽  
Corrosion Current ◽  
Xrd Analysis ◽  
Charge Transfer Resistance ◽  
Micro Hardness ◽  
Transfer Resistance ◽  
X Ray ◽  
Annealing Temperatures

The present study investigates the effect of titania particles on the micro-hardness, wear resistance, corrosion resistance and friction of electroless Ni–P–TiO2 composite coatings deposited on mild steel substrates at different annealing temperatures. The experimental results confirmed that the amount of TiO2 particles incorporated in the coatings increases with increase in the concentration of particles in the electroless bath. In presence of TiO2 particles, hardness, wear resistance and corrosion resistance of the coating improve significantly. At higher annealing temperature, wear resistance increases due to formation of hard Ni3P phase and incorporation of titania particles in the coated layer. Charge transfer resistance and corrosion current density of the coatings reduce with an increase in TiO2 particles, whereas corrosion potential increases. Microstructure changes and composition of the composite coating due to heat treatment are studied with the help of scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD) analysis.

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