scholarly journals AC-Filtering Supercapacitors Based on Edge Oriented Vertical Graphene and Cross-Linked Carbon Nanofiber

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 604 ◽  
Author(s):  
Wenyue Li ◽  
Nazifah Islam ◽  
Guofeng Ren ◽  
Shiqi Li ◽  
Zhaoyang Fan
Keyword(s):  
Surface Area ◽  
High Frequency ◽  
Electrode Materials ◽  
Carbon Nanofiber ◽  
Electronic Conductivity ◽  
Electrochemical Processes ◽  
High Electronic Conductivity ◽  
Plasma Pyrolysis ◽  
Rate Limiting ◽  
Aluminum Electrolytic Capacitors

There is strong interest in developing high-frequency (HF) supercapacitors or electrochemical capacitors (ECs), which can work at the hundreds to kilo hertz range for line-frequency alternating current (AC) filtering in the substitution of bulky aluminum electrolytic capacitors, with broad applications in the power and electronic fields. Although great progress has been achieved in the studies of electrode materials for ECs, most of them are not suitable to work in this high frequency range because of the slow electrochemical processes involved. Edge-oriented vertical graphene (VG) networks on 3D scaffolds have a unique structure that offers straightforward pore configuration, reasonable surface area, and high electronic conductivity, thus allowing the fabrication of HF-ECs. Comparatively, highly conductive freestanding cross-linked carbon nanofibers (CCNFs), derived from bacterial cellulose in a rapid plasma pyrolysis process, can also provide a large surface area but free of rate-limiting micropores, and are another good candidate for HF-ECs. In this mini review, advances in these fields are summarized, with emphasis on our recent contributions in the study of these materials and their electrochemical properties including preliminary demonstrations of HF-ECs for AC line filtering and pulse power storage applications.

Properties and Fabrication of Alumina Dispersion Strengthened Copper Alloy with High Softening Temperature

2013 ◽  
Vol 749 ◽  
pp. 425-431 ◽  
Author(s):  
Sheng Li Han ◽  
Xiao Dong Qin ◽  
Yi Xiang Cai ◽  
Kai Luo ◽  
Huan Wen Xie ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Copper Alloy ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Hot Extrusion ◽  
Softening Temperature ◽  
Resistance Welding ◽  
High Electronic Conductivity ◽  
High Softening Temperature ◽  
The Ideal

Cu-Al2O3 alloy combine both high electronic conductivity and high softening temperature. Cu-Al2O3 alloy was fabricated by internal oxidation and hot extrusion methods in the present investigation. Microstructure and properties of Cu-Al2O3 alloy was studied. The influence of preparation parameters, hot extrusion parameters and heat treatment on the properties of the alloy was investigated. The results indicated that the grain of the alloy was very small with a size between 2-10μm. Softening temperature of the Cu-0.6% Al2O3 alloy and Cu-1.0% Al2O3 alloy was 900. Cu-0.6%Al2O3 alloy and Cu-1.0% Al2O3 alloy meeting the requirements for electrode in resistance welding is the ideal substitution of the traditional electrode materials for resistance welding.

Metal Chloride-Graphite Compounds as Cathode and Anode Materials For Batteries

1982 ◽  
Vol 20 ◽  
Author(s):  
Serge Flandrois ◽  
Francis Baron
Keyword(s):  
Beneficial Effect ◽  
Anode Materials ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Nickel Chloride ◽  
Metal Chloride ◽  
Metal Chlorides ◽  
Alkaline Batteries ◽  
High Electronic Conductivity ◽  
Graphite Intercalation

ABSTRACTGraphite intercalation compounds can be used as electrode materials in batteries owing to the high electronic conductivity of carbon layers and the easy diffusion of ions between the layers. Moreover intercalation has the beneficial effect of impeding some parasitic reactions detrimental to good electrode reversibility. After a brief review of recent proposals, emphasis is given to transition metal chlorides. It is shown that, besides the nickel chloride-graphite compound proposed two years ago as a cathode material for alkaline batteries, other metal chlorides intercalated into graphite are excellent cathode or anode materials.

scholarly journals Carbon-Coated Three-Dimensional MXene/Iron Selenide Ball with Core–Shell Structure for High-Performance Potassium-Ion Batteries

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Su Hyun Yang ◽  
Yun Jae Lee ◽  
Heemin Kang ◽  
Seung-Keun Park ◽  
Yun Chan Kang
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
High Current Density ◽  
Electronic Conductivity ◽  
Three Dimensional ◽  
Ultrasonic Spray Pyrolysis ◽  
Reversible Capacity ◽  
Potassium Ion ◽  
Synthetic Strategy ◽  
High Electronic Conductivity

AbstractTwo-dimensional (2D) MXenes are promising as electrode materials for energy storage, owing to their high electronic conductivity and low diffusion barrier. Unfortunately, similar to most 2D materials, MXene nanosheets easily restack during the electrode preparation, which degrades the electrochemical performance of MXene-based materials. A novel synthetic strategy is proposed for converting MXene into restacking-inhibited three-dimensional (3D) balls coated with iron selenides and carbon. This strategy involves the preparation of Fe2O3@carbon/MXene microspheres via a facile ultrasonic spray pyrolysis and subsequent selenization process. Such 3D structuring effectively prevents interlayer restacking, increases the surface area, and accelerates ion transport, while maintaining the attractive properties of MXene. Furthermore, combining iron selenides and carbon with 3D MXene balls offers many more sites for ion storage and enhances the structural robustness of the composite balls. The resultant 3D structured microspheres exhibit a high reversible capacity of 410 mAh g−1 after 200 cycles at 0.1 A g−1 in potassium-ion batteries, corresponding to the capacity retention of 97% as calculated based on 100 cycles. Even at a high current density of 5.0 A g−1, the composite exhibits a discharge capacity of 169 mAh g−1.

Electrospun flexible lignin/polyacrylonitrile-based carbon nanofiber and its application in electrode materials for supercapacitors

2021 ◽  
pp. 004051752110371
Author(s):  
Hong Wu ◽  
Chengkun Liu ◽  
Zhiwei Jiang ◽  
Zhi Yang ◽  
Xue Mao ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrode Materials ◽  
Carbon Nanofiber ◽  
Electrochemical Impedance ◽  
Nickel Foam ◽  
Average Diameter ◽  
Raw Material ◽  
Equivalent Series Resistance

In this study, a lignin/polyacrylonitrile (PAN) composite nanofiber membrane is prepared by electrospinning and used as the precursor to prepare flexible carbon nanofibers (CNFs) through pre-oxidation and carbonization. The micromorphology, crystal structure, pore size distribution and specific surface area of the CNFs are characterized by field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy and specific surface adsorption analysis, respectively. The electrochemical properties of the CNF membrane are also investigated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy due to its potential application in binder-free electrode materials for supercapacitors. We successfully prepared flexible CNFs with an average diameter of about 539 nm and a specific surface area of 1053.78 m2/g when the mass ratio of lignin to PAN was 9:1 in a solution concentration of 28 wt%. The CNFs are loaded onto nickel foam to prepare the electrode materials for supercapacitors without a binder. When the current density is 0.5 A/g, the specific capacitance could be up to 201.27 F/g and the equivalent series resistance is only 0.57 Ω, which shows an excellent electrochemical performance. This study not only provides a theoretical basis for the high-value utilization of lignin and the preparation of flexible lignin/PAN-based CNFs, but also provides a new type of environmentally friendly raw material for the electrodes of supercapacitors and could be helpful to alleviate the energy crisis and environmental pollution.

Architecture engineering of supercapacitor electrode materials

2016 ◽  
Vol 09 (01) ◽  
pp. 1640001 ◽  
Author(s):  
Kunfeng Chen ◽  
Gong Li ◽  
Dongfeng Xue
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
High Specific Capacitance ◽  
High Energy ◽  
Supercapacitor Electrode

The biggest challenge for today’s supercapacitor systems readily possessing high power density is their low energy density. Their electrode materials with controllable structure, specific surface area, electronic conductivity, and oxidation state, have long been highlighted. Architecture engineering of functional electrode materials toward powerful supercapacitor systems is becoming a big fashion in the community. The construction of ion-accessible tunnel structures can microscopically increase the specific capacitance and materials utilization; stiff 3D structures with high specific surface area can macroscopically assure high specific capacitance. Many exciting findings in electrode materials mainly focus on the construction of ice-folded graphene paper, in situ functionalized graphene, in situ crystallizing colloidal ionic particles and polymorphic metal oxides. This feature paper highlights some recent architecture engineering strategies toward high-energy supercapacitor electrode systems, including electric double-layer capacitance (EDLC) and pseudocapacitance.

Carbon nanofiber-based nanostructures for lithium-ion and sodium-ion batteries

2017 ◽  
Vol 5 (27) ◽  
pp. 13882-13906 ◽  
Author(s):  
Weihan Li ◽  
Minsi Li ◽  
Keegan R. Adair ◽  
Xueliang Sun ◽  
Yan Yu
Keyword(s):  
Lithium Ion Batteries ◽  
Carbon Nanofibers ◽  
Electrode Materials ◽  
Carbon Nanofiber ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
One Dimensional ◽  
Conductive Additives

Carbon nanofibers (CNFs) belong to a class of one-dimensional (1D) carbonaceous materials with excellent electronic conductivity, leading to their use as conductive additives in electrode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (NIBs).

scholarly journals Nano-Fe3O4/Carbon Nanotubes Composites by One-Pot Microwave Solvothermal Method for Supercapacitor Applications

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2908
Author(s):  
Sul Ki Park ◽  
Jagadeesh Sure ◽  
D. Sri Maha Vishnu ◽  
Seong Jun Jo ◽  
Woo Cheol Lee ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Specific Capacitance ◽  
Electrode Materials ◽  
Mechanical Stability ◽  
Storage System ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
One Pot ◽  
High Electronic Conductivity ◽  
Nano Fe3o4

Carbon nanotubes (CNTs) are being increasingly studied as electrode materials for supercapacitors (SCs) due to their high electronic conductivity and chemical and mechanical stability. However, their energy density and specific capacitance have not reached the commercial stage due to their electrostatic charge storage system via a non-faradic mechanism. Moreover, magnetite (Fe3O4) exhibits higher specific capacitance originating from its pseudocapacitive behaviour, while it has irreversible volume expansion during cycling. Therefore, a very interesting and facile strategy to arrive at better performance and stability is to integrate CNTs and Fe3O4. In this study, we demonstrate the microwave-solvothermal process for the synthesis of Fe3O4 nanoparticles uniformly grown on a CNT composite as an electrode for SCs. The synthesized Fe3O4/CNT composite delivers a reversible capacitance of 187.1 F/g at 1 A/g, superior rate capability by maintaining 61.6% of 10 A/g (vs. 1 A/g), and cycling stability of 80.2% after 1000 cycles at 1 A/g.

scholarly journals Tailoring Ni and Sr2Mg0.25Ni0.75MoO6−δ Cermet Compositions for Designing the Fuel Electrodes of Solid Oxide Electrochemical Cells

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2394
Author(s):  
Lubov S. Skutina ◽  
Aleksey A. Vylkov ◽  
Dmitry K. Kuznetsov ◽  
Dmitry A. Medvedev ◽  
Vladimir Ya. Shur
Keyword(s):  
Electrode Materials ◽  
Electronic Conductivity ◽  
Electrode System ◽  
Solid Oxide ◽  
Electrochemical Cells ◽  
Low Thermal Expansion ◽  
High Electronic Conductivity ◽  
Fuel Cell Electrode ◽  
Cell Electrode ◽  
Expansion Behaviour

The design of new electrode materials for solid oxide electrochemical cells, which are stable against redox processes as well as exhibiting carbon/sulphur tolerance and high electronic conductivity, is a matter of considerable current interest as a means of overcoming the disadvantages of traditional Ni-containing cermets. In the present work, composite materials having the general formula (1−x)Sr2Mg0.25Ni0.75MoO6−δ + xNiO (where x = 0, 15, 30, 50, 70 and 85 mol.%) were successfully prepared to be utilised in solid oxide fuel cells. A detailed investigation of the thermal, electrical, and microstructural properties of these composites, along with their phase stability in oxidising and reducing atmospheres, was carried out. While possessing low thermal expansion coefficient (TEC) values, the composites having low Ni content (15 mol.%–70 mol.%) did not satisfy the requirement of high electronic conductivity. Conversely, the 15Sr2Mg0.25Ni0.75MoO6−δ + 85NiO samples demonstrated very high electrical conductivity (489 S sm−1 at 850 °C in wet H2) due to well-developed Ni-based networks, and no deterioration of thermal properties (TEC values of 15.4 × 10−6 K−1 in air and 14.5 × 10−6 K−1 in 50%H2/Ar; linear expansion behaviour in both atmospheres). Therefore, this material has potential for use as a component of a fuel cell electrode system.

Preparation and Improved Capacitive Behavior of NiO/TiO2 Nanocomposites as Electrode Material for Supercapacitor

2020 ◽  
Vol 16 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Palani Anandhi ◽  
Veerabadran Jawahar Senthil Kumar ◽  
Santhanam Harikrishnan
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Electrode Material ◽  
Electrode Materials ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Pure Tio2 ◽  
High Electronic Conductivity ◽  
Charge Discharge

Background: Of late, supercapacitors have been drawing great attention over other rechargeable energy storage devices. More efforts are made on the electrode materials of the supercapacitors, in order to improve the specific capacitance and energy density. Based on the past literature, it was stated that pure TiO2 (as electrode material) could promote faradaic reaction to a limited extent due to its low electronic conductivity. Further, this low conductivity could hinder the ion transfer process between electrolyte and electrode during intercalation and de-intercalation, resulting in poor energy density. Hence, it is essential to incorporate high electronic conductivity material into TiO2, for improving the electrochemical performance. Objective: In the present study, the preparation and electrochemical performance of NiO/TiO2 nanocomposites as an electrode material for supercapacitor were extensively studied. Methods: NiO/TiO2 nanocomposites were synthesized by sol-gel method. The as-prepared nanocomposites were characterized by high-resolution TEM, field emission SEM and XRD. The electrochemical behaviors of the electrode using nanocomposites were assessed by means of cyclic voltammetry (CV) and galvanostatic charge-discharge tests. Results: The maximum specific capacitance of the nanocomposites based electrode witnessed through CV test was 405 F g-1 at the scan rate of 5 mV s-1 in 1M Na2SO4 electrolyte. The capacitance retention after 5000 charge-discharge cycles was estimated as 92.32%. The energy and power densities at current density of 1 A g-1 were found to be 5.67 Wh kg-1 and 210.52 W kg-1, respectively. Conclusion: NiO/TiO2 nanocomposites synthesized via sol-gel technique appeared to be flake-like structure. NiO incorporated into TiO2 increased higher electronic conductivity while comparing to pure TiO2. Also, an introduction of NiO into TiO2 improved the specific capacitance, power density, energy density and cycle stability. Due to these facts, combining NiO with TiO2 could be considered to be an efficient way of enhancing the electrochemical performance of electrodes of the supercapacitor.

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