New Energy-Consuming Carbon Materials Derived from Hydrolytic Lignin

2020 ◽  
Vol 992 ◽  
pp. 814-820
Author(s):  
Yury M. Nikolenko ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
A. Sokolov ◽  
Albert M. Ziatdinov
Keyword(s):  
Lithium Battery ◽  
Specific Capacity ◽  
Electrochemical Process ◽  
Physical Activation ◽  
Operating Voltage ◽  
Thermally Activated ◽  
New Energy ◽  
Hydrolytic Lignin ◽  
Different Temperatures ◽  
Energy Consuming

Hydrolytic lignin (HL) has been used in manufacturing of graphitized carbon via HL one-step physical activation. It was found that the layered carbon products of pyrolysis of hydrolytic lignin (AHL) at different temperatures may be used as cathode materials in primary current sources. The galvanostatic discharge of lithium battery at a current density of 100 μA/cm2 between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of lithium battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process. Some fluorinated AHL samples show the promise of their use as supercapacitor electrodes.

Hydrolytic Lignin: It’s Activated and Fluorinated Forms

2019 ◽  
Vol 806 ◽  
pp. 100-105 ◽  
Author(s):  
Yury M. Nikolenko ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
Vladimir E. Silant'ev ◽  
Valery G. Kuryavyi ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Energy Intensity ◽  
Electronic Conductivity ◽  
High Vacuum ◽  
Electrochemical Process ◽  
Physical Activation ◽  
Operating Voltage ◽  
Thermally Activated ◽  
Hydrolytic Lignin ◽  
Structural Blocks

The hydrolytic lignin (HL) derivatives have been prepared via its physical activation (high-temperature annealing in vacuum) followed by chemical modification (fluorination). It was found that the graphitized product of thermal activation up to 1000 °C at a low temperature gain rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes it potentially useful as sorbent, catalytic substrate, or electrode material. It was revealed from the experimental data the manufactured graphitized material consists of nanometric structural blocks, possibly nanographites and/or few-layer nanographenes. The edges of graphenes in agglomerates in activated hydrolytic lignin (AHL) have armchair and zigzag shapes. The nontrivial electronic structure of the zigzag edges, along with the electronic conductivity and the ability of AHL to absorb oxygen, can cause an increase in the energy intensity of lithium battery (LB) manufactured using AHL.The carbon-fluorine bond of semi-ionic type was detected in HL and AHL fluorinated in the temperature range of synthesize 60 – 300 oC. The fluorinated forms of both HL and its thermally activated product show increased values of operating voltage due to the participation of fluorine bound to carbon in the electrochemical process.

High-Capacity Derivatives Produced from Hydrolytic Lignin as Electrode Materials for Energy Storage and Conversion

2018 ◽  
Vol 386 ◽  
pp. 359-364
Author(s):  
Yury M. Nikolenko ◽  
Denis P. Opra ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
Valery G. Kuryavyi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Energy Storage ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Energy Storage And Conversion ◽  
Operating Voltage ◽  
X Ray ◽  
Thermally Activated ◽  
Hydrolytic Lignin

The hydrolytic lignin derivatives have been prepared via its physical activation (high-temperature heating in vacuum) followed by chemical modification (fluorination). The obtained products were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that the graphitized product of thermal activation up to 1000 °C at a low rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes its potentially useful as sorbent, catalytic substrate or electrode material. To clarify the potentialities of hydrolytic lignin derivatives for energy storage and conversion, the electrochemical system with metallic lithium anode was applied. The galvanostatic discharge of battery at a current density of 100 μA/cm2between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The improve of the electrochemical performance of product originates from its graphitization, increasing electronic conductivity, and, possibly, enhanced ability to adsorb of oxygen. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process.

scholarly journals Surface Modification of Fly Ash for Active Catalysis

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Deepti Jain ◽  
Renu Hada ◽  
Ashu Rani
Keyword(s):  
Fly Ash ◽  
Heterogeneous Catalysts ◽  
Chemical Activation ◽  
Alumina Content ◽  
Precipitation Method ◽  
Solid Base ◽  
Thermally Activated ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Different Temperatures

Fly ash based effective solid base catalyst (KF/Al2O3/fly ash473, KF/Al2O3/fly ash673, and KF/Al2O3/fly ash873) was synthesized by loading KF over chemically and thermally activated fly ash. The chemical activation was done by treating fly ash with aluminum nitrate via precipitation method followed by thermal activation at 650°C to increase the alumina content in fly ash. The increased alumina content was confirmed by SEM-EDX analysis. The alumina enriched fly ash was then loaded with KF (10 wt%) and calcined at three different temperatures 473 K, 673 K and 873 K. The amount of loaded KF was monitored by XRD, FTIR spectroscopy, SEM-EDX, TEM and Flame Atomic Absorption Spectrophotometer. The catalytic activities of the catalysts were tested in the Claisen-Schmidt condensation of benzaldehyde and 4-methoxybenzaldehyde with 2′-hydroxyacetophenone to produce 2′-hydroxychalcone and 4-methoxy-2′-hydroxychalcone respectively. Higher conversion (83%) of benzaldehyde and (89%) of 4-methoxybenzaldehyde reveals that among these heterogeneous catalysts KF/Al2O3/fly ash673 is very active.

scholarly journals Research of MnCO3/CB Composite on Properties Apply to Supercapacitors

2020 ◽  
Vol 185 ◽  
pp. 04023
Author(s):  
Liqiong Han ◽  
Yifan Liu ◽  
Rongyu Li
Keyword(s):  
Energy Storage ◽  
Electrode Material ◽  
Specific Capacity ◽  
Chemical Properties ◽  
Manganese Carbonate ◽  
Mixed Solution ◽  
Storage Material ◽  
New Energy ◽  
Energy Storage Material ◽  
Liquid Deposition

In order to improve the electro-conductibility of new energy storage material-manganese carbonate(MnCO3) and the properties apply to supercapacitors, we produce MnCO3/CB composite at room temperature by using a simple and mild liquid phase deposition method. Using dilute HNO3 to purify and activate the CB(carbon black), then put the handled CB into NH4HCO3/MnSO4 mixed solution for liquid deposition. Observed through infrared and XPS methods, we found that - after purified by dilute HNO3, the negatively charged groups(carboxyl & quinonyl) on CB surface increase, which makes CB uneasy to reunite in water and benefits the producing of a homogeneous compound. Observed the compound under SEM:40nm diameter CB granules wrap the Lotus-shaped MnCO3 granule, and form a porous structure between MnCO3 granules. The result of electro-chemical properties indicated by galvanostatic charge-discharge tests shows that the specific capacity of MnCO3/CB composite electrode material is twice of the pure MnCO3 electrode material, while the MnCO3/CB composite has a good cycle capacitive retention ratio. As a newly discovered energy storage material, MnCO3 provides a new direction to make composite material for supercapacitor electrodes.

Effect of Fluorine Content on the Electrochemical Properties of PVDF-Derived Carbons for Lithium Ion Battery

2012 ◽  
Vol 463-464 ◽  
pp. 730-733 ◽  
Author(s):  
Lu Shi ◽  
Chao Lin Miao ◽  
Gai Rong Chen ◽  
Bin Xu ◽  
Shi Chen
Keyword(s):  
Electrochemical Properties ◽  
Carbon Materials ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Fluorine Content ◽  
Lithium Ion ◽  
Bet Surface Area ◽  
Different Temperatures ◽  
Positive Effect ◽  
Initial Coulombic Efficiency

The carbon materials prepared by PVDF carbonization at different temperatures have similar BET surface area and pores volume. The content of fluorine in the carbons decreased with the carbonization temperature from 1.46% (atm %) at 600°C to 0.18 %( atm %) at 1000°C. The first cycle specific capacity and the initial coulombic efficiency decreases with the decrease of fluorine content in the samples. The first cycle discharge capacity decreased from 982 mAh/ g at 600°C to 752 mAh/ g at 1000°C and the initial coulombic efficiency decreased from 31.8% at 600°C to 24% at 1000°C. It is believed that fluorine contained in the carbon materials has a positive effect to improve the electrochemical properties as anode materials for Li-ion batteries.

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.

scholarly journals Preparation of Composite Monolith Supercapacitor Electrode Made from Textile-Grade Polyacrylonitrile Fibers and Phenolic Resin

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 655
Author(s):  
Karim Nabil ◽  
Nabil Abdelmonem ◽  
Masanobu Nogami ◽  
Ibrahim Ismail
Keyword(s):  
Electrical Resistivity ◽  
Surface Area ◽  
Phenolic Resin ◽  
Physical Adsorption ◽  
Chemical Activation ◽  
Specific Capacity ◽  
Physical Activation ◽  
Gravimetric Analysis ◽  
Capacitive Properties

In this work a composite monolith was prepared from widely available and cost effective raw materials, textile-grade polyacrylonitrile (PAN) fibers and phenolic resin. Two activation procedures (physical and chemical) were used to increase the surface area of the produced carbon electrode. Characterization of the thermally stabilized fibers produced was made using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and Carbon-Hydrogen-Nitrogen(CHN) elemental analysis, in order to choose the optimum conditions of producing the stabilized fibers. Characterization of the produced composite monolith electrode was performed using physical adsorption of nitrogen at 77 °K, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrical resistivity in order to evaluate its performance. All the electrodes prepared had a mixture of micropores and mesopores. Pressing the green monolith during the curing process was found to reduce largely the specific surface area and to some degree the electrical resistivity of the chemically activated composite electrode. Physical activation was more suitable than chemical activation, where it resulted in an electrode with specific capacity 29 F/g, good capacitive behavior and the stability of the electrical resistivity over the temperature range −130 to 80 °C. Chemical activation resulted in a very poor electrode with resistive rather than capacitive properties.

scholarly journals Long-term hydrophilization of polydimethylsiloxane (PDMS) for capillary filling microfluidic chips

2019 ◽  
Vol 24 (1) ◽  
Author(s):  
Farzin Jahangiri ◽  
Tuuli Hakala ◽  
Ville Jokinen
Keyword(s):  
Cold Storage ◽  
Storage Temperature ◽  
Microfluidic Channel ◽  
Vibration Band ◽  
Microfluidic Chips ◽  
Thermally Activated ◽  
Capillary Filling ◽  
Different Temperatures ◽  
Long Term Preservation

AbstractWe present a simple and facile method for long-term preservation of hydrophilicity of oxygen plasma-hydrophilized poly (dimethylsiloxane) (PDMS) by cold storage. We show that storage under temperature of − 80 °C can maintain superhydrophilicity of plasma-exposed PDMS for at least 100 days. Storage at − 15 °C and at 22 °C room temperature (RT) is shown to exhibit, respectively, about half and full recovery of the original hydrophobicity after 100 days in storage. Furthermore, we investigated the implications of the cold storage for microfluidic applications, the capillary filling rate and the ability of the flow to bypass geometrical obstacles in a microfluidic channel. It is shown that the preservation of capillary filling properties of microchannels is in close agreement with the contact angle (CA) measurements and that the colder the storage temperature, the better the capillary filling capability of the channels is preserved. We ascribe the significantly reduced recovery rate to reduced thermally activated relaxation phenomena such as diminished diffusion of low molecular weight species (LMW) in the polymer matrix at colder temperatures. This is supported by ATR-FTIR measurements of the OH vibration band over time for samples stored at different temperatures.

The Meyer–Neldel Rule in Conduction Mechanism of the Electrospun ZnO Nanofibers

NANO ◽  
2016 ◽  
Vol 11 (03) ◽  
pp. 1650025 ◽  
Author(s):  
Andrzej Stafiniak ◽  
Marek Tłaczała
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Conduction Mechanism ◽  
Deep Level ◽  
Electrical Measurements ◽  
Thermally Activated ◽  
Theoretical Assumptions ◽  
Different Temperatures ◽  
Zno Nanofibers ◽  
Improved Model

An analytical model describing the conductivity of ZnO nanofibers depending on the grains size is proposed. The research is based on the thermal dc electrical measurements of a single electrospun ZnO nanofiber calcined at different temperatures. In the our previous research, we showed that electrical conduction of ZnO nanofibers is mainly thermally activated. The activation energy of conductivity was strongly dependent on the grain size, which in turn depended on the calcination temperature. This could be due to migration of a point defect in the grain of ZnO and could change the carrier concentration. Our recent studies have shown that ZnO nanofibers behavior is consistent with the Meyer–Neldel rule. This indicates an exponential energy distribution of deep level traps in the material. Based on the theoretical assumptions and experimental data, the improved model of conductivity in a single ZnO nanofiber calcined at different temperatures was proposed.

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