scholarly journals Synthesis of a TEMPO-Substituted Polyacrylamide Bearing a Sulfonate Sodium Pendant and Its Properties in an Organic Radical Battery

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2076 ◽  
Author(s):  
Junfeng Zhu ◽  
Ting Zhu ◽  
Huan Tuo ◽  
Wanbin Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nitroxyl Radical ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Control Sample ◽  
Organic Radical ◽  
Resonance Spectroscopy ◽  
Electrochemical Performances ◽  
Styrene Sulfonate ◽  
Charge Discharge

A novel nitroxyl radical polymer poly(TEMPO-acrylamide-co-sodium styrene sulfonate) (abbreviated as poly(TAm-co-SSS)) was synthesized using 4-acrylamido-2,2,6,6- tetramethylpiperidine (AATP) copolymerized with styrene sulfonate sodium (SSS). AATP was synthesized through a substitution reaction of acryloyl chloride. Meanwhile, poly(4-acrylamido-2,2,6,6-tetramethylpiperidine-1-nitroxyl radical) (PTAm) was prepared as a control sample. Then, the structures of products were characterized by nuclear magnetic resonance spectroscopy (1H-NMR), Fourier transform infrared spectroscopy (FT-IR), high performance liquid chromatography-mass spectrometry (HPLC-MS), differential scanning calorimetry (DSC), X-Ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR), respectively. Additionally, the electrochemical impedance spectra (EIS) and the charge-discharge cycling properties were studied. The results demonstrated that the poly(TAm-co-SSS) with the side group of sodium sulfonate adjacent to TEMPO group exhibits a better charge-discharge cycling stability than that of the PTAm. Moreover, the charge specific capacity of the poly(TAm-co-SSS) is larger than that of the PTAm. Besides, the first coulombic efficiency of poly(TAm-co-SSS) is higher in comparison with that of PTAm. These superior electrochemical performances were ascribed to the synergistic effect of sulfonate ions group and nitroxyl radical structure, which benefits the improvement of charge carrier transportation of the nitroxyl radical polymers. Consequently, the nitroxyl radical poly(TAm-co-SSS) is promising for use in organic radical battery materials, based on the good electrochemical properties.

Electrochemical performances of pyrolytic-cellulose for lithium and sodium ion batteries anode

2020 ◽  
Vol 10 (10) ◽  
pp. 1685-1691
Author(s):  
Lingfang Li ◽  
Dan Chen ◽  
Sichao Su ◽  
Bin Zeng
Keyword(s):  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
High Current Density ◽  
Energy Storage Materials ◽  
Electrochemical Performances ◽  
Hard Carbon ◽  
X Ray ◽  
Sodium Storage ◽  
Charge Discharge

At present, due to the depletion of fossil fuels and increasingly serious environmental problems, more and more attention has been paid to the development and application of functional nanostructured materials as renewable energy storage materials. Herein, lithium and sodium storage properties of hard carbons (HC) prepared by pyrolyzing cellulose were investigated. The orderliness and bonding mode of hard carbon were analyzed by X-Ray Diffraction and X-ray Photoelectron Spectroscopy. Electrochemical properties were characterized by Cyclic Voltammetry, electrochemical Impedance Spectroscopy and charge–discharge test. Results showed that the cellulose-derived hard carbon had good lithium and sodium storage performance. The charge–discharge capacity was about 400 mAh/g and 240 mAh/g, respectively, at a current density of 0.2 A/g, and capacity was also stable under high current density of 2 A/g.

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.

Effect of Graphite Matrix on Property of Silicon/Carbon Composite Anode Material for Lithium-Ion Battery

2018 ◽  
Vol 914 ◽  
pp. 64-70 ◽  
Author(s):  
Ying Wang ◽  
Hao Wu ◽  
Fang Ming Xiao ◽  
Ren Heng Tang ◽  
Tai Sun
Keyword(s):  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Expanded Graphite ◽  
Carbon Layer ◽  
Electrochemical Performances ◽  
Discharge Specific Capacity ◽  
Silicon Carbon ◽  
Initial Charge ◽  
Discharge Efficiency ◽  
Charge Discharge

Nano-silicon carbon coated and combined with different graphite matrixes was synthesized by ball milling，and spray dying-pyrolysis methods. The physical properties of Si/C composites were detected by X-ray diffraction（XRD），scanning electron microscopy（SEM），and all composites were completely coated by a carbon layer. Their electrochemical performances were studied by galvanostatic cycle and electrochemical impedance spectra. These analyses show that the discharge specific capacity of composited anode based on expanded graphite exhibits the best comprehensive electrochemical performance such as cycle stability and initial charge/discharge efficiency among various composites，owing to the co-effect of expanded graphite and amorphous carbon layer as the structural stabilizer and conductive additives to prevent the volume change and enhance the electronic conductivity of the composites. The discharge specific capacity is 700.9 mAhg-1 at a current density of 100mAg-1，initial charge/discharge efficiency is 77.4%. After 30 cycles，the capacity retention rate can reach 87.7%.

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 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.

Nitric Acid Activated Carbon Aerogels for Supercapacitors

2013 ◽  
Vol 302 ◽  
pp. 158-164 ◽  
Author(s):  
Ya Jie Li ◽  
Xing Yuan Ni ◽  
Jun Shen ◽  
Dong Liu ◽  
Nian Ping Liu
Keyword(s):  
Activated Carbon ◽  
Nitric Acid ◽  
Electrochemical Impedance ◽  
Carbon Aerogels ◽  
Electrochemical Performances ◽  
Galvanostatic Charge ◽  
Sem Images ◽  
Resorcinol Formaldehyde ◽  
Charge Discharge ◽  
Discharge Test

The electrochemical performances of resorcinol–formaldehyde-based carbon aerogels can be significantly enhanced by nitric acid activation.FT-IR spectra and SEM images reveal the constitution and morphology of samples .The electrochemical performances of materials were tested by cyclic voltammetry,galvanostatic charge/discharge test ,electrochemical impedance spectroscopy and cyclic test. The results show that activation does not influence the molecular structure of carbon aerogels,which maintains their nano-porous structure. Activation increases the specific capacitance by 50% and improves the conductivity of carbon aerogels,resulting in fenfect cycling stability. So nitric acid activated carbon aerogels is an ideal electrode material for supercapacitors.

In Situ Synthesis of Graphitized-Carbon Coated Li4Ti5O12/C Anode for High-Rate Lithium Ion Batteries

2015 ◽  
Vol 814 ◽  
pp. 358-364
Author(s):  
Peng Xiao Huang ◽  
Shui Hua Tang ◽  
Hui Peng ◽  
Xing Li
Keyword(s):  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Rate ◽  
Phase Method ◽  
Electrochemical Performances ◽  
Graphitized Carbon ◽  
Carbon Coated

Graphitized-Carbon coated Li4Ti5O12/C (Li4Ti5O12/GC) composites were prepared from Li2CO3, TiO2 and aromatic resorcinol via a facile rheological phase method. The microstructure and morphology of the samples were determined by XRD and SEM. The electrochemical performances of the samples were characterized by galvanostatic charge-discharge test and electrochemical impedance spectroscopy (EIS). The results reveal that the coating of graphitized carbon could effectively enhance the charge/transfer kinetics of the Li4Ti5O12 electrode. The Li4Ti5O12/GC could deliver a discharge specific capacity of 166 mAh/g at 0.2 C, 148 mAh/g at 1.0 C, 142 mAh/g at 3.0 C, 138 mAh/g at 5.0 C and 127 mAh/g at 10.0 C, respectively, and it still could remain at 132 mAh/g after cycled at 5.0 C for 100 cycles. The excellent rate capability of the Li4Ti5O12/C makes it a promising anode material for high rate lithium ion batteries.

scholarly journals Facile Synthesis of Carbon Nanospheres with High Capability to Inhale Selenium Powder for Electrochemical Energy Storage

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6760
Author(s):  
Mustafa Khan ◽  
Xuli Ding ◽  
Hongda Zhao ◽  
Xinrong Ma ◽  
Yuxin Wang
Keyword(s):  
Electrochemical Performance ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Discharge Rate ◽  
Specific Capacity ◽  
Rate Performance ◽  
X Ray Diffraction ◽  
Carbon Nanospheres ◽  
Surface Areas ◽  
Charge Discharge

Carbon–selenium composite positive electrode (CSs@Se) is engineered in this project using a melt diffusion approach with glucose as a precursor, and it demonstrates good electrochemical performance for lithium–selenium batteries. X-ray diffraction (XRD) and scanning electron microscopy (SEM) with EDS analysis are used to characterize the newly designed CSs@Se electrode. To complete the evaluation, electrochemical characterization such as charge–discharge (rate performance and cycle stability), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) tests are done. The findings show that selenium particles are distributed uniformly in mono-sized carbon spheres with enormous surface areas. Furthermore, the charge–discharge test demonstrates that the CSs@Se cathode has a rate performance of 104 mA h g−1 even at current density of 2500 mA g−1 and can sustain stable cycling for 70 cycles with a specific capacity of 270 mA h g−1 at current density of 25 mA g−1. The homogeneous diffusion of selenium particles in the produced spheres is credited with an improved electrochemical performance.

scholarly journals Nitrogen-Doped Carbon Aerogels Derived from Starch Biomass with Improved Electrochemical Properties for Li-Ion Batteries

2021 ◽  
Vol 22 (18) ◽  
pp. 9918
Author(s):  
Marcelina Kubicka ◽  
Monika Bakierska ◽  
Krystian Chudzik ◽  
Michał Świętosławski ◽  
Marcin Molenda
Keyword(s):  
Electrochemical Properties ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Potato Starch ◽  
Specific Capacity ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
Modern World ◽  
X Ray ◽  
Li Ion

Among all advanced anode materials, graphite is regarded as leading and still-unrivaled. However, in the modern world, graphite-based anodes cannot fully satisfy the customers because of its insufficient value of specific capacity. Other limitations are being nonrenewable, restricted natural graphite resources, or harsh conditions required for artificial graphite production. All things considered, many efforts have been made in the investigation of novel carbonaceous materials with desired properties produced from natural, renewable resources via facile, low-cost, and environmentally friendly methods. In this work, we obtained N-doped, starch-based carbon aerogels using melamine and N2 pyrolysis as the source of nitrogen. The materials were characterized by X-ray powder diffraction, elemental analysis, X-ray photoelectron spectroscopy, galvanostatic charge–discharge tests, cyclic voltammetry, and electrochemical impedance spectroscopy. Depending on the doping method and the nitrogen amount, synthesized samples achieved different electrochemical behavior. N-doped, bioderived carbons exhibit far better electrochemical properties in comparison with pristine ones. Materials with the optimal amount of nitrogen (such as MCAGPS-N8.0%—carbon aerogel made from potato starch modified with melamine and CAGPS-N1.2%—carbon aerogel made from potato starch modified by N2 pyrolysis) are also competitive to graphite, especially for high-performance battery applications. N-doping can enhance the efficiency of Li-ion cells mostly by inducing more defects in the carbon matrix, improving the binding ability of Li+ and charge-transfer process.

Hydrothermal synthesis of PANI nanowires for high-performance supercapacitor

2019 ◽  
Vol 32 (3) ◽  
pp. 258-267 ◽  
Author(s):  
Jia Chu ◽  
Xue Li ◽  
Qiaoqin Li ◽  
Jing Ma ◽  
Bohua Wu ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Scanning Electron Micrographs ◽  
X Ray ◽  
Different Temperatures ◽  
Polyaniline Nanowires ◽  
Charge Discharge

Polyaniline nanowires (PANI NWs) were synthesized under different temperatures through a facile hydrothermal method and used as electrodes for high-performance pseudocapacitor. The resulting samples were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron micrographs, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Electrochemical properties of these PANI electrodes are studied by cyclic voltammetry, galvanostatic charge–discharge test, and electrochemical impedance spectroscopy in 0.5M H2SO4 aqueous solution. The highest specific capacitance is obtained on the PANI NWs synthesized under 80°C (PANI-80) with 540.0 F g−1 at current density of 0.5 A g−1 accompanied with 82% specific capacitance retention after 1000 charge discharge cycles at 5 A g−1 current density.

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