Polyacetylene Research Articles

Three-Dimensional hybrid structure loader type flexible supercapacitor based on Polyvinyl alcohol gel and Acetylene black

In order to overcome the structural drawbacks of layered electrodes in flexible supercapacitors, the construction of an electrode frame with high adaptability for the loading of different active materials makes the production of flexible supercapacitors simpler and more accurate. Herein, a novel loader type flexible supercapacitor with three-dimensional hybrid structure is built. In our design, the acetylene black and active material are enriched in the polyvinyl alcohol matrix, and the three-dimensional conductive network that can load different active material is formed. The active material can be selected on demand. The basic electrode (also a loader) formed by polyvinyl alcohol and acetylene black is an electronic conductor (∼1 Scm−1) with good electrochemical and mechanical performance. By loading active materials in this basic electrode, more powerful flexible electrodes can be built easily and accurately with the same steps according to the designed proportion. Electrodes constructed according to this method deliver nonnegligible surface capacity (e.g. 1.1 Fcm−2 in surface capacitance, polyaniline/carbon nanotube composite as active materials) with good response, rate performance, excellent durability (10000 times of charge-discharge), and good foldability (1000 times of folding). This pattern of carrier type electrodes provides a simple and universal strategy for manufacturing flexible supercapacitors.

Improved OER performance of an Anderson-supported cobalt coordination polymer by assembling with acetylene black

First report on POM based hybridi.e.Anderson cluster based solid for OER in a basic medium. Increased efficiencyviaassembly with acetylene black. The composite shows an overpotential of 330 mV to achieve a current density of 100 mA cm−2with a stability of 40 h.

Extremely High Thermal Conductivity of Aligned Polyacetylene Predicted using First-Principles-Informed United-Atom Force Field

Molecular simulations of polymer rely on accurate force fields to describe the inter-atomic interactions. In this work, we use first-principles density functional theory (DFT) calculations to parameterize a united-atom force field for polyacetylene (PA), a conjugated polymer potentially of high thermal conductivity. Different electron correlation functionals in DFT have been tested. Bonding interactions for the alternating single and double bonds in the conjugated polymer backbone are explicitly described and Class II anharmonic functions are separately parameterized. Bond angle and dihedral interactions are also anharmonic and parameterized against DFT energy surfaces. The established force field is then used in molecular dynamics (MD) simulations to calculate the thermal conductivity of single PA chains and PA crystals with different simulation domain lengths. It is found that the thermal conductivity values of both PA single chains and crystals are very high and are length-dependent. At 790 nm, their respective thermal conductivity values are ~480 Wm-1K-1 and ~320 Wm-1K-1, which are comparatively higher than those of polyethylene (PE), the most thermally conductive polymer fiber measured up-to-date.

Theoretical studies of conducting polymers: a mini review

The present short review discusses the computational studies carried out on polyacetylene (PAc), polyaniline (PANI), polypyrrole (PPy), and other conducting polymers for predicting their electronic, optoelectronic and structural properties.

Effect of Polymer-Coating on Acetylene Black for Durability of Polymer Electrolyte Membrane Fuel Cell

Effect of Polymer-Coating on Acetylene Black for Durability of Polymer Electrolyte Membrane Fuel Cell

Construction of Large Scale Defect Enriched Carbon: Cobalt, Nitrogen Co-Doped Acetylene Black for High Orr Efficiency and Zinc-Air Battery

Construction of Large Scale Defect Enriched Carbon: Cobalt, Nitrogen Co-Doped Acetylene Black for High Orr Efficiency and Zinc-Air Battery

Acetylene Black Interlayer Regulated Sulfur Deposition for Lithium-Sulfur Batteries with High Utilization and Long-Term Life

Acetylene Black Interlayer Regulated Sulfur Deposition for Lithium-Sulfur Batteries with High Utilization and Long-Term Life

The Stable 3D Zn Electrode for High-Power Density Zn Metal Batteries

A stable Zn metal electrode can develop rechargeable zinc metal batteries (RZMBs) which have the high theoretical capacity (820 mAh g−1), low redox potential, and intrinsic safety. However, the corrosion of Zn metal in aqueous electrolytes and Zn dendrite formation during the plating process lead to poor cycling and thus hinder the development of RZMBs. Here, we employed ionic liquid-based gel polymer (poly(vinylidene fluoride)-co-hexafluoropropylene, PVDF-HFP) and acetylene black (AB) to achieve a stable and flexible three-dimensional (3D) Zn/AB/PVDF-HFP film electrode with ionic and electronic conductive networks and high surface area, showing 26 times higher plating/stripping current than planar Zn plate. By developing a continuous structure between the ionic liquid-based gel polymer membrane and the flexible 3D Zn/AB/PVDF-HFP electrode, the low resistance, high rate capability and long cycle life (> 800 h) was obtained. Our work shows a flexible Zn film electrode and ionic liquid-based gel polymer electrolyte, could pave the path for rechargeable and high-cycle life thin-film RZMBs.

In Situ Synthesis of Surface-Mounted Novel Nickel(II) Trimer-Based MOF on Nickel Oxide Hydroxide Heterostructures for Enhanced Methanol Electro-Oxidation.

Engineering the heterogeneous interface fusing MOFs and inorganic active component is an effective strategy to improve the electrochemical performance. Herein, we report a new Ni3-based MOF (denoted as CTGU-24) with an infrequent two-fold interpenetrating 3D (3,8)-connected network constructed from Ni(II) trimer and mixed tripodal tectonics for the electrocatalytic methanol oxidation reaction (MOR). In order to improve its stability and activities, the heterogeneous hybrid CTGU-24@NiOOH has been fabricated successfully via the first preparation of the NiOOH nanosphere and then in situ formation of CTGU-24 decorated on the NiOOH surface. Moreover, the integration of CTGU-24@NiOOH and different additives [acetylene black (AB) and ketjen black (KB)], resulting in the optimized hybrid sample AB&CTGU-24@NiOOH (4:4). It attains better MOR performance with an area-specific peak current density of 34.53 mA·cm−2 than pure CTGU-24 (14.99 mA·cm−2) and improved durability in an alkali medium. The new findings indicate that the CTGU-24@NiOOH heterostructure formed in situ and the integration of moderate additives are critical to optimizing and improving electrocatalytic activity of pure MOF crystalline material.

Relation between Mixing Processes and Properties of Lithium-ion Battery Electrode-slurry

The mixing process of electrode-slurry plays an important role in the electrode performance of lithium-ion batteries (LIBs). The dispersion state of conductive materials, such as acetylene black (AB), in the electrode-slurry directly influences the electronic conductivity in the composite electrodes. In this study, the relation between the mixing process of electrode-slurry and the internal resistance of the composite electrode was investigated in combination with the characterization of the electrode-slurries by the rheological analysis and the alternating current (AC) impedance spectroscopy. Some of the electrode-slurries showed higher value and gentler slope of the dynamic storage modulus in the low-angular-frequency region and higher thixotropic index than the others depending on the way of the mixing process and the AB content, agreeing with the low electronic volume resistivities of the corresponding composite electrodes and the electrode-slurries, which indicates the AB network growth. The results suggested that the low-viscosity state when AB and active electrode material are mixed contributes to the dispersive AB network.

Influence of conductive additives on the electrochemical compatibility of cupper fluoride cathode for FSB

• The electrochemical performance of CuF 2 was studied for FSBs. • The influence of conductive additives on the CuF 2 performance was investigated. • Both SWCNT and AB were simultaneously incorporated into the CuF 2 electrode. • The addition of appropriate amount of AB provides a homogeneous distribution. • The inclusion of SWCNTs decreases the capacity fading during the cycling. • The combined effect of SWCNT and AB has a significant impact on battery performance. In this paper, the influence of conductive additives such as single-wall carbon nanotubes (SWCNTs) and acetylene black (AB) on the electrochemical performance of CuF 2 based electrodes in fluoride shuttle batteries are studied. CuF 2 based-electrodes with different SWCNT and AB concentrations, namely, CuF 2 /AB 4.5 /SWCNT 1.7 (85.4/4.5/1.7/8.4 in wt%) and CuF 2 /AB 3.8 /SWCNT 3.8 (73.4/3.8/3.8/19 in wt%), are prepared. Scanning electron and laser microscopy analyses show that the strong van der Waals (VdW) attractions in SWCNTs are reduced when an appropriate ratio between SWCNTs and AB is attained. This aids in the possible reduction of phase separation and aggregation of CuF 2 -based composite films. It is noticed that the contribution of AB in reducing the aggregation of CuF 2 is significantly high as it spreads the entire surface and acts as a bridge between SWCNTs and CuF 2 . Further, the electrochemical performance test results have revealed significant improvement in the capacity of CuF 2 at high C rates when appropriate concentrations of SWCNTs and AB are used. In addition, the recovery of the capacity at all C rates is also improved. The results show that the simultaneous inclusion of both AB and SWCNTs play a critical role to improve the performance of CuF 2 -based FSBs.

Semi-conducting cyclic copolymers of acetylene and propyne

Polyacetylene (PA) exhibits conductivities comparable to metals after doping, yet the extremely low solubility of PA limits its processing and utility. Introducing pendent groups can alter the properties of PA. Copolymerizing acetylene and propyne using Zieglar-Natta type catalysts affords linear poly(acetylene-co-propyne) as free-standing films. However, this process requires grams of catalysts and extensive workup. Cyclic polyacetylene is a unique topological isomer of linear polyacetylene. Herein, we report a facile synthesis of cyclic poly(acetylene-co-propyne) as thin, flexible films with extremely low catalyst loading (milligrams) and easy purification. Altering the feed ratio of acetylene and propyne produces copolymers with different acetylene/propyne incorporations. The films exhibit similar conductivities as linear copolymers after doping. The soluble portions of different cyclic copolymers exhibit low acetylene incorporation. TGA analysis reveals the cyclic copolymers are less thermally stable than cyclic PA, with the stability dependent on the ratio of acetylene and propyne incorporation.

Modified New Microporous Carbon Layer Structure for Improved PEM Fuel Cell Performance with Low-Pt Catalyst Loadings

Three types of commercial carbon black with different porosity and hydrophilicity were investigated at various conditions in a new architecture of microporous carbon layers where they are deposited directly on the low loading cathode catalyst layers (0.1 mgPt cm−2) of membrane electrode assemblies (MEAs) used in H2/O2 fuel cells. The benefits of this modified microporous layer (MPL) include reduced interfacial gaps present between the catalyst layer and the conventional MPL-coated gas diffusion layer of the MEAs, reduced water accumulation, and therefore, higher power densities. Acetylene Black and Vulcan XC72R based modified MPLs with mass loadings in the range of 0–1.0 mg cm−2 show improved fuel cell performance in the higher current density regions due to their lower porosity and higher hydrophobicity. The MPL optimum loading under wet and dry conditions is found to be around 0.8 mg cm−2 (∼20 μm), at which a power gain of up to ∼37% is possible as a result of the improved interlayer contact and mass transport under wet conditions as well as enhanced membrane and cathode catalyst layer hydration under dry conditions. Detailed performance characteristics and longer-term studies performed under different humidification levels were also examined and are discussed in this paper.

A dual-coated multifunctional separator for the high-performance lithium-sulfur batteries

The lithium-sulfur (Li-S) battery has received widespread attention because of the high theoretical energy density and inexpensive raw material. However, some issues still restrict its commercialization, including the shuttle effect, the lithium dendrite growth and low safety, etc. In this work, a PMMA-LLZO/PP/AB multifunctional separator was designed and facilely prepared to overcome these problems. A composite dense layer of the PMMA and LLZO sheets with excellent interface stability was coated on one side of the PP separator to face lithium metal anode, which can inhibit the lithium dendrites growth and increase the safety. Meanwhile, this composite coating possesses high affinity with the liquid electrolyte and the soluble polysulfides, which can improve the ionic conductivity, effectively adsorb the polysulfides. An acetylene black (AB) layer was further coated on the other side of the PP separator to not only act as an electron conductor but also adsorb and hinder the migration of lithium polysulfides. The co-modified PMMA-LLZO/PP/AB separator displays remarkable electrochemical performances and an excellent thermal stability. The cell with the co-modified separator exhibits high specific capacities of 1456 mAh g−1 at 0.1 C and 969 mAh g−1 at 1.0 C, and retains a capacity of 413 mAh g−1 after 500 cycles, corresponding to a retention of 42.6% as well as a low decay of 0.114%/cycle. Especially, the cell with the multifunctional separator also displays a high capacity and a low decay even for a high sulfur mass loading cathode of 2.5–3.0 mg cm−2 or at a high temperature of 60 °C. The co-modified multifunctional separator has great application potential in the high-performance Li-S battery.

Polymeric Energy Materials: Development and Challenges

The discovery of conjugated, conducting polymers (CPs) polyacetylene (PA) in 1977 opened up a new frontier in the field of polymer science for both academia and industries. CPs possess characteristics such as excellent tunability, ease of synthesis, eco-friendliness, processability etc. These features have enabled the exploration of its applicability in energy and electronics devices. It has also paved way for extensive research world over to develop novel methods for synthesizing CPs with required properties. An important area in the field of synthesis of CPs is to produce conducting nanocomposites with the combination of conducting polymers and inorganic materials in order to achieve high magnitude of electrical conductivity. Several polymeric materials such as, as poly(3,4ethylenedioxythiophene) (PEDOT), polypyrrole (PPy), and polyaniline (PANI) have exhibited potential in various applications such as, “energy harvesting”, “energy storage”, “light emitting”, and “sensing”. The objective of this review is to develop better understanding on conducting polymers used for energy and electronics application. The review presents the state of research in the development of CPs with a focus on general synthesis method, morphology and dependent properties along with the discussion on challenges with possible solutions.

Synthesis of Cyclic Polyacetylene

Synthesis of Cyclic Polyacetylene

Polyacetylenes and Flavonoids Isolated from Flowers of Carthamus tinctorius

Polyacetylenes and Flavonoids Isolated from Flowers of Carthamus tinctorius

Development of Si/C6 Negative Electrode for High Capacity Lithium-Sulfur Batteries

Recently, lithium-sulfur batteries are attracting attention as large-capacity energy storage devices for renewable energy. Lithium-sulfur battery uses elemental sulfur (S8) as positive electrode and Li metal as the negative electrode, respectively. Although large theoretical capacity (1,672 mAhg-1) of the sulfur active material is expected as advantage, formation of Li dendrites at the Li metal surface during charge process is concerned as serious problem. In this study, we applied a negative electrode with Si to suppress the precipitation of Li dendrites. The theoretical capacity of Si is extremely high at 4,200 mAhg-1 and high energy density can be expected. However, Si has low cycle performance owing to their volume changes with Li+ insertion and desorption. In this study, several cells ([Li | 1M-LiFSI EC/DEC(=3/7) | x wt%-Si/C6] ) using nano-Si mixed electrodes with C6 ( x wt%-Si/C6 (x=5,10,25,50) ) were prepared and evaluated.As example, showing how the 5wt%-Si/C6 electrode is fabricated. C6:Si:Acetylene Black:PVdF was mixed into the NMP solvent at a weight ratio of 81:4:7:8. The mixed slurry was applied onto copper foil and dried at 353 K. The 5wt%-Si/C6 electrode was punched to φ 16 mm and pressed with a uniaxial force. [Li| 1M-LiFSI EC/DEC(=3/7) | x wt%-Si/C6] cells were prepared and investigated by charge-discharge test at 303 K.Fig. 1 shows the charge-discharge profiles at the first cycle of the [Li| 1M-LiFSI EC/DEC(=3/7) |x wt%-Si/C6] (x=5,10,25,50) cells (a) and the relationship between the number of cycles and discharge capacity (b) . The initial discharge capacity was higher than the theoretical capacity of C6 (ca. 360 mAhg-1). However, remarkable decrease in discharge capacity is confirmed in accordance with an increase in the mixing amount of Si. Miniaturization might be occurred due to the volume change of Si during the charge-discharge reaction. As a result, the reaction at the electrode/electrolyte interface should be degraded. Irreversible reactions might be occurred after 2nd cycle. In addition, the lowest discharge capacity was obtained at 10wt%. As a result, isolation of active material was also suggested. Therefore, it is necessary to consider improving the cycle characteristics by the use of additives and improvement of the negative electrode itself. In the presentation, we will report for improvement methods of charge-discharge properties, such as new binder and composites with electric conductive additives. Figure 1

An in-situ electrodeposited cobalt selenide promotor for polysulfide management targeted stable Lithium–Sulfur batteries

Lithium–sulfur batteries (LSBs) have attracted much attention due to their high theoretical specific capacity, energy density and low cost. However, the commercial application of LSBs is hindered due to the lithium polysulfide (LiPS) shuttle as well as the sluggish reaction kinetics. Herein, cobalt selenide (Co0.85Se) nanowire arrays have been constructed on a carbon-modified separator by an in-situ electrodeposition technique without any other post-treatments such as coating with other ancillary materials. The introduced three-dimensional (3D) conductive carbon layer comprising of carbon nanotube (CNT) and acetylene black (AB) not only serves as the effective support for Co0.85Se (CS) but also builds a hierarchical structure to promote the e− transfer. The as-obtained CS-CNT/AB presents a strong anchoring effect on LiPSs and high electrocatalytic activity for sulfur reaction kinetics. As a result, the LSBs inserted with electrodeposition-enabled CS modified separator exhibit an outstanding rate capability (1560.4 mAh g−1 at 0.1 C) and relatively low capacity decay of only 0.068% per cycle over 500 cycles at 2.0 C. This study provides a promising strategy to realize the rational construction of high-efficiency and long-life LSBs.

Electrochemical Characteristics of Micrometer-sized Sn and Acetylene Black Composites Prepared by Mechanical Milling for Sodium-ion Battery Anodes

Five types of micrometer-sized Sn and acetylene black (AB) composite powders were prepared by mechanical milling for 1, 3, 6, 12, and 24 h. The Sn/AB powders obtained, in addition to Sn-only powders were added to a binder and conductive material, and then dried under vacuum to prepare negative electrodes (anodes) for sodium-ion batteries (SIBs). SIBs were fabricated with the anodes in the form of 2032-type coin cells, and were evaluated using charge-discharge tests up to 50 cycles within the cutoff voltage range of 0.005–0.65 V at a constant current of 50 mA g−1 at 25 °C. Maximum discharge capacities of 614 to 651 mAh g−1 were obtained with all the anodes prepared with both the Sn-only and the Sn/AB composites. However, the discharge capacities of the Sn-only and Sn/AB composites milled for 1 and 3 h were significantly decreased as the charge-discharge cycle increased. In contrast, the Sn/AB composites milled for 6 h or more exhibited improved cycle characteristics; capacities of 635, 619, and 584 mAh g−1 were maintained during 50 cycles of testing with the Sn/AB_6h, Sn/AB_12h, and Sn/AB_24h samples, respectively, which were significantly higher than the anode prepared with the Sn-only powder (135 mAh g−1).