scholarly journals Scalable Synthesis of Iron Oxide–Based Composite Films As Freestanding Negative Electrodes With Ultra-High Areal Capacitances For High-Performance Asymmetric Supercapacitors

2021 ◽  
Author(s):  
Jincy Parayangattil Jyothibasu ◽  
Ruei-Hong Wang ◽  
Kenneth Ong ◽  
Juping Hillary Lin Ong ◽  
Rong-Ho Lee
Keyword(s):  
High Performance ◽  
Active Material ◽  
Composite Films ◽  
Negative Electrode ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Precipitation Process ◽  
Electrochemical Performances ◽  
Scale Production ◽  
Negative Electrodes

Abstract This paper reports a simple, cost-effective, and environmentally friendly procedure for the synthesis of cellulose/functionalized carbon nanotube (f-CNT)/Fe2O3 (CCF) composite films and their performance as freestanding negative electrodes in supercapacitors. A facile chemical precipitation process was performed at room temperature within a short reaction time without requiring any of the special processing conditions used in the conventional hydrothermal synthesis, making it the most cost-efficient method for the bulk-scale production of sustainable supercapacitors. The binder-free negative electrode with ultra-high active material loading exhibited outstanding areal (9107.1 mF cm–2) and volumetric (314 F cm–3) capacitances, which were much greater than the values reported previously in the literature for negative electrodes. Moreover, an asymmetric supercapacitor cell featuring cellulose/f-CNT/MnO2 (CCM) and CCF as its positive and negative electrodes, respectively, achieved superior electrochemical performances. Therefore, on account of the economic and environmental superiority of this method and its bulk scalability, this paper provides a simple, eco-friendly, and cost-effective approach for the development of sustainable supercapacitors for practical use.

Azo (Hydrazone) pigments: general principles

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Christie
Keyword(s):  
High Performance ◽  
Metal Salt ◽  
Low Cost ◽  
Cost Effective ◽  
Precipitation Process ◽  
Ambient Temperatures ◽  
Technical Performance ◽  
Chemical Structures ◽  
General Chemical ◽  
Physical Form

Abstract This paper presents an overview of the general chemical principles underlying the structures, synthesis and technical performance of azo pigments, the dominant chemical class of industrial organic pigments in the yellow, orange, and red shade areas, both numerically and in terms of tonnage manufactured. A description of the most significant historical features in this group of pigments is provided, starting from the discovery of the chemistry on which azo colorants are based by Griess in the mid-nineteenth century, through the commercial introduction of the most important classical azo pigments in the early twentieth century, including products known as the Hansa Yellows, β-naphthol reds, including metal salt pigments, and the diarylide yellows and oranges, to the development in the 1950s and 1960s of two classes of azo pigments that exhibit high performance, disazo condensation pigments and benzimidazolone-based azo pigments. A feature that complicates the description of the chemical structures of azo pigments is that they exist in the solid state as the ketohydrazone rather than the hydroxyazo form, in which they have been traditionally been illustrated. Numerous structural studies conducted over the years on an extensive range of azo pigments have demonstrated this feature. In this text, they are referred to throughout as azo (hydrazone) pigments. Since a common synthetic procedure is used in the manufacture of virtually all azo (hydrazone) pigments, this is discussed in some detail, including practical aspects. The procedure brings together two organic components as the fundamental starting materials, a diazo component and a coupling component. An important reason for the dominance of azo (hydrazone) pigments is that they are highly cost-effective. The syntheses generally involve low cost, commodity organic starting materials and are carried out in water as the reaction solvent, which offers obvious economic and environmental advantages. The versatility of the approach means that an immense number of products may be prepared, so that they have been adapted structurally to meet the requirements of many applications. On an industrial scale, the processes are straightforward, making use of simple, multi-purpose chemical plant. Azo pigments may be produced in virtually quantitative yields and the processes are carried out at or below ambient temperatures, thus presenting low energy requirements. Finally, provided that careful control of the reaction conditions is maintained, azo pigments may be prepared directly by an aqueous precipitation process that can optimise physical form, with control of particle size distribution, crystalline structure, and surface character. The applications of azo pigments are outlined, with more detail reserved for subsequent papers on individual products.

scholarly journals Influence of Multivector Field on Paste Preparation and Formation of Negative Electrodes of Lead Batteries

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 24
Author(s):  
Boris Shirov ◽  
Vesselin Naidenov ◽  
Urii Markov
Keyword(s):  
Active Material ◽  
Negative Electrode ◽  
Limiting Factors ◽  
Skeletal Structure ◽  
Experimental Result ◽  
External Application ◽  
Electrochemical Processes ◽  
Depth Of Discharge ◽  
Negative Electrodes ◽  
Positive Effect

During the operation of the negative electrode, some critical processes take place, which are limiting factors for the operation of lead–acid batteries. To improve the efficiency of the negative active material and minimize these processes, external application of multivector field is proposed. Two applications of the multivector field are studied: during negative paste preparation and during formation. It is established that, when applying multivector field during negative paste preparation, the chemical processes proceed more efficiently. The results are better phase composition and crystallinity of the cured paste, thus increasing the capacity of the consequently built lead batteries by 12% on average. The application of a multivector field during the formation of negative active materials in lead batteries has a positive effect on the skeletal structure, the size and shape of the Pb crystals. This ensures longer service life, which is confirmed by the 17.5% Depth of Discharge continuous tests on 12 V/75 Ah batteries. The batteries formed under the influence of external multivector field showed 20% longer cycle life. Based on the experimental result, a most probable mechanism of the influence of the multivector field on the chemical and electrochemical processes in lead batteries during negative paste preparation and formation of negative active masses is proposed.

scholarly journals Nanostructured intermetallic InSb as a high-capacity and high-performance negative electrode for sodium-ion batteries

2021 ◽  
Author(s):  
Irshad Mohammad ◽  
Lucie Blondeau ◽  
Eddy Foy ◽  
Jocelyne Leroy ◽  
Eric Leroy ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
High Performance ◽  
High Capacity ◽  
Negative Electrode ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Negative Electrodes ◽  
First Time

Following the trends of alloys as negative electrodes for Na-ion batteries, the sodiation of the InSb intermetallic compound was investigated for the first time. The benefit of coupling Sb with...

scholarly journals Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5558
Author(s):  
Dimitra Vernardou ◽  
Charalampos Drosos ◽  
Andreas Kafizas ◽  
Martyn E. Pemble ◽  
Emmanouel Koudoumas
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Large Scale ◽  
Electrode Materials ◽  
Low Cost ◽  
Aqueous Media ◽  
Chemical Vapour ◽  
Cost Effective ◽  
Scale Production ◽  
Environmentally Safe

The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials.

Study of Carbon Nanotubes for Lithium-Ion Batteries Application

2010 ◽  
Vol 72 ◽  
pp. 299-304
Author(s):  
Alberto Varzi ◽  
Corina Täubert ◽  
Margret Wohlfahrt-Mehrens ◽  
Martin Kreis ◽  
Walter Schütz
Keyword(s):  
Carbon Nanotubes ◽  
Active Material ◽  
Chemical Vapour ◽  
Rate Capability ◽  
Lithium Ion ◽  
Electrochemical Performances ◽  
Negative Electrodes ◽  
Multi Walled Carbon Nanotubes ◽  
Li Ion ◽  
Walled Carbon Nanotubes

The potential use of multi-walled carbon nanotubes (MWCNTs) produced by chemical vapour deposition (CVD) as a conductive agent for electrodes in Li-ion batteries has been investigated. LiNi0.33Co0.33Mn0.33O2 (NCM) has been chosen as active material for positive electrodes, and a nano-sized TiO2-rutile for the negative electrodes. The electrochemical performances of the electrodes were studied by galvanostatic techniques and especially the influence of the nanotubes on the rate capability and cycling stability has been evaluated. The addition of MWCNTs significantly enhanced the rate performances of both positive and negative electrodes and improved the capacity retention upon cycling. The obtained results demonstrated that the addition of MWCNTs in low amounts to the electrode composition enables an increase in both energy and power density of a Li-ion battery.

Ultrathin and porous NiCo2O4 nanosheets based 3D hierarchical electrode materials for high-performance asymmetric supercapacitor

2021 ◽  
pp. 1-11
Author(s):  
Fuyong Ren ◽  
Zhixiang Tong ◽  
Shufen Tan ◽  
Junnan Yao ◽  
Lijun Pei ◽  
...  
Keyword(s):  
Energy Storage ◽  
Active Sites ◽  
High Performance ◽  
Electrode Materials ◽  
Negative Electrode ◽  
Cost Effective ◽  
High Energy ◽  
Porous Nanosheets ◽  
High Area ◽  
Nico2o4 Nanosheets

Abstract It is well-known that designing unique morphology and structure of electrode materials is an effective strategy to achieve high performance supercapacitors. Herein, the ultrathin and porous NiCo2O4 nanosheets based 3D hierarchical electrode materials were synthesized via a simple and cost effective solvothermal method and subsequent annealing prosses. Since the ultrathin and porous nanosheets could accelerate the transmission of ions and provide numerous active sites, the obtained NiCo2O4 nanosheets based electrode exhibited excellent electrochemical performance with a high area capacity of 5.38 F cm−2 (2690 F g−1) at a current density of 10 mA cm−2 and a good rate performance of 41% capacitance retention at 50 mA cm−2. Furthermore, the corresponding asymmetry supercapacitor was assembled by using the resulted NiCo2O4 nanosheets and active carbon as positive electrode and negative electrode respectively. As expected, the corresponding supercapacitor delivered superior energy density of 52.6 Wh kg−1 at power density of 1.1 kW kg−1 and an extraordinary capacitive retention of 80.9% after 3,000 cycles at 20 mA cm−2. The high energy storage performances suggested that the obtained ultrathin and porous NiCo2O4 nanosheets based 3D hierarchical electrode materials could be prospective candidate in the field of energy storage.

Fe3O4 nanoparticles embedded in cellulose nanofibre/graphite carbon hybrid aerogels as advanced negative electrodes for flexible asymmetric supercapacitors

2018 ◽  
Vol 6 (36) ◽  
pp. 17378-17388 ◽  
Author(s):  
Liaoyuan Xia ◽  
Xiangling Li ◽  
Xian Wu ◽  
Le Huang ◽  
Yu Liao ◽  
...  
Keyword(s):  
Electrode Material ◽  
Fe3o4 Nanoparticles ◽  
High Performance ◽  
Rational Design ◽  
Negative Electrode ◽  
Asymmetric Supercapacitors ◽  
Bottom Up ◽  
Negative Electrodes ◽  
Hybrid Aerogels ◽  
Negative Electrode Material

A simple and scalable bottom-up strategy is developed for the rational design and preparation of a high-performance 3-D CNF/MWCNT/RGO/Fe3O4 negative electrode material for assembly of flexible asymmetric supercapacitors.

scholarly journals Uprooting defects to enable high-performance III–V optoelectronic devices on silicon

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Youcef A. Bioud ◽  
Abderraouf Boucherif ◽  
Maksym Myronov ◽  
Ali Soltani ◽  
Gilles Patriarche ◽  
...  
Keyword(s):  
Dislocation Density ◽  
High Performance ◽  
Optoelectronic Devices ◽  
Cost Effective ◽  
Deposition Process ◽  
Scale Production ◽  
Luminescence Efficiency ◽  
Low Dislocation Density ◽  
Mismatched Heteroepitaxy ◽  
Industrial Scale Production

Abstract The monolithic integration of III-V compound semiconductor devices with silicon presents physical and technological challenges, linked to the creation of defects during the deposition process. Herein, a new defect elimination strategy in highly mismatched heteroepitaxy is demonstrated to achieve a ultra-low dislocation density, epi-ready Ge/Si virtual substrate on a wafer scale, using a highly scalable process. Dislocations are eliminated from the epilayer through dislocation-selective electrochemical deep etching followed by thermal annealing, which creates nanovoids that attract dislocations, facilitating their subsequent annihilation. The averaged dislocation density is reduced by over three orders of magnitude, from ~108 cm−2 to a lower-limit of ~104 cm−2 for 1.5 µm thick Ge layer. The optical properties indicate a strong enhancement of luminescence efficiency in GaAs grown on this virtual substrate. Collectively, this work demonstrates the promise for transfer of this technology to industrial-scale production of integrated photonic and optoelectronic devices on Si platforms in a cost-effective way.

scholarly journals SMA-Assisted Exfoliation of Graphite by Microfluidization for Efficient and Large-Scale Production of High-Quality Graphene

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1653 ◽  
Author(s):  
Yuzhou Wang ◽  
Xianye Zhang ◽  
Haihui Liu ◽  
Xingxiang Zhang
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Cost Effective ◽  
Scale Production ◽  
Polyamide 66 ◽  
High Quality ◽  
Uniform Size ◽  
Large Scale Production ◽  
Maleic Anhydride Copolymer ◽  
Few Layer Graphene

In this paper, the sodium salt of styrene-maleic anhydride copolymer (SMA) was used as a stabilizer in the process of graphite exfoliation to few-layer graphene using the technique of microfluidization in water. This method is simple, scalable, and cost-effective, and it produces graphene at concentrations as high as 0.522 mg mL−1. The generated high-quality graphene consists of few-layer sheets with a uniform size of less than 1 μm. The obtained graphene was uniformly dispersed and tightly integrated into a polyamide 66 (PA66) matrix to create high-performance multifunctional polymer nanocomposites. The tensile strength and thermal conductivity of 0.3 and 0.5 wt% EG/PA66 composites were found to be ~32.6% and ~28.8% greater than the corresponding values calculated for pure PA66, respectively. This confirms that the new protocol of liquid phase exfoliation of graphite has excellent potential for use in the industrial-scale production of high-quality graphene for numerous applications.

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