Polypyrrole (PPy) is favoured in energy storage for its high pseudo-capacitive performance, notably as polypyrrole nanotubes (PPyNTs) due to their easy synthesis, cost-effectiveness and electrochemical solid properties. Metal-organic frameworks (MOFs) have also gained attention for enhancing supercapacitors (SCs). In this study, we fabricated aerogel composites with PPyNTs, MOFs and reduced graphene oxide (rGO) as SC electrode materials. Varying concentrations of PPyNTs and rGO were explored, with MOFs added to assess their impact. Electrochemical tests revealed that the composite with PPyNTs and Zn-MOF achieved the highest specific capacitance of approximately 270 F/g at 0.5 A/g.

This work focuses on the development of plasticized solid polymer electrolytes (SPEs) for electrochemical double-layer capacitors (EDLCs) application. The developed material, consisting of sodium carboxymethyl cellulose (NaCMC), pectin (PC), glycerol, and lithium perchlorate (LiClO4), 4 ) , was prepared using the solution casting method. To assess the performance of the prepared plasticized SPEs, several methods were employed, including Fourier transform infrared (FTIR) spectroscopy, X-Ray Diffraction (XRD), Electrical impedance spectroscopy (EIS), dielectric properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and linear sweep voltammetry (LSV). FTIR confirmed the successful interaction between the functional groups of the plasticized polymer blend and the cations (Li+) + ) of the salt. Similarly, EIS revealed that the sample containing the highest salt concentration (25 wt%) showed the highest ionic conductivity measured at 3.55 x 10-4-4 S cm-- 1 . According to LSV analysis, this sample demonstrated the capability to operate safely within a voltage limit of 3.3 V. The fabricated EDLC cell exhibited a nearly rectangular curve in cyclic voltammetry (CV) analysis and a triangular pattern in galvanostatic charge-discharge (GCD) tests. These curves confirm the capacitive behaviour of the EDLC cell. Finally, the electrochemical parameters of the EDLC cell including the specific discharge capacitance (Cspc), C spc ), energy density (Ed), d ), and power density (Pd) d ) were determined to be (4.2 F g-1),-1 ), (0.5 Wh kg-1 ), and (14 W kg-1 ) respectively.

Innovation in the design of Li-ion rechargeable batteries is necessary to overcome safety concerns and meet energy demands. In this regard, a new generation of Li-ion batteries (LIBs) in the form of all-solid-state batteries (ASSBs) has been developed, attracting a great deal of attention for their high-energy density and excellent mechanical-electrochemical stability. This review describes the current state of research and development on ASSB technology. To this end, study of the literature and patents as well as market analysis over the last two decades were carried out, highlighting how scientific achievements have informed the application of commercially profitable ASSBs. Analyzing the patents registered over the past 20 years revealed that the number of them had increased exponentially-from only few per year in early 2000 to more than 342 in 2020. Published literature and patents on the topic declare a solid-state electrolyte (SSE) to be the main component of ASSBs, and most patented examples are referred to as solid inorganic electrolytes (SIEs), followed by solid polymer electrolytes (SPEs) and solid hybrid electrolytes (SHEs) in popularity. Investigation of company websites, social media profiles, reports, and academic publications identified 93 companies associated with ASSBs. A list of leading businesses in the solid-state battery sector was compiled, out of which 36 provided information on the ASSB units in their product portfolio for detailed analysis.

Ti-based anode materials are considered to be an alternative to graphite anodes to accomplish high-rate application requirements. Ti2Nb10O29 (TNO15) has attracted much attention due to its high lithium storage capacity through the utilization of multiple redox couples and a suitable operating voltage window of 1.0 to 2.0 V vs Li/Li+. However, poor intrinsic electronic conductivity has limited the futuristic applicability of this material to the battery anode. In this work, we report the modification of TNO15 by introducing oxygen vacancies and using few-layered carbon and copper coatings on the surface to improve its Li+ storage property. With the support of the galvanostatic intermittent titration technique (GITT), we found that the diffusion coefficient of carbon/copper coated TNO15 is 2 orders of magnitude higher than that of the uncoated sample. Here, highly conductive copper metal on the surface of the carbon-coated oxygen-vacancy-incorporated TNO15 increases the overall electronic and ionic conductivity. The prepared TNO15-800-C-Cu-700 half-cell shows a significant rate capability of 92% when there is a 10-fold increase in the current density. In addition, the interconnected TNO15 nanoparticles create a porous microsphere structure, which enables better Li-ion transportation during charge/discharge process, and experiences an enhancement after the carbon and copper coating on the surface of the primary TNO15 nanocrystallites.

This study explores the structural and electrical properties of sodium carboxymethyl cellulose (NaCMC)-pectin (PC)-glycerol-NH4Br electrolyte films and investigates their potential applications in proton batteries. Plasticized solid polymer electrolyte (SPEs) films were fabricated using the solution casting method. The interaction between the salt and polymer blends was verified using Fourier-transform infrared (FTIR) analysis. Incorporation of various salt concentrations (up to 25 wt%) was found to enhance the amorphous phase of the polymer blend, as evidenced by X-ray diffraction (XRD) results. Additionally, the decrease in the glass transition temperature, as confirmed by DSC analysis, indicates that the inclusion of both plasticizer and salt contributed to this effect. An electrolyte with 25% wt. of NH4Br has the highest room temperature conductivity of 4.68 x 10-4 S cm- 1. This electrolyte was employed to fabricate the proton battery for energy storage application.

This work is focused on the optimization of electromagnetic and mechanical properties of magnetic polymer composites for EMI applications as radio absorbers (RAs). Polymer composites with a dual-phase polymer matrix, vinyl-terminated polydimethylsiloxane (PDMS) in epoxy (ER), were investigated for fabricating highlyfilled manganese zinc ferrite (MnZn) and carbonyl iron (CI) composites with respect to radio-absorption and mechanical properties. The dielectric and magnetic properties of the composites were determined by the type, concentration as well as the polymer matrix composition. Increase of the filler and the PDMS concentration leads to an increase in magnetic losses due to a decrease in the demagnetizing field. The electromagnetic properties of the composites were evaluated in the RF band using the impedance method (1 MHz–3 GHz). Based on the complex permittivity (ε*) and the complex permeability (μ*), the reflection loss RL (dB) of single-layer metal-backed RAs were calculated. The RAs with a MnZn ferrite demonstrated a larger bandwidth to thickness ratio in comparison with the CI-based RAs due to a proper ratio between ε* and μ* which leads to the better impedance matching conditions. According to the mechanical analyses (DMA, Charpy impact strength) the significant increase of stiffness up to 125% and the impact strength up to 150% was achieved due to the optimal composition of the polymer matrix and the filler.

Various oxidants used in the preparation of polyaniline are reviewed. Insoluble solid oxidant, manganese dioxide, has been investigated in the heterogeneous synthesis of polyaniline in detail. Aniline was oxidized in acidic aqueous medium at various oxidant-to-monomer mole ratios [MnO2]/[aniline]. At [MnO2]/[aniline] <= 1.25, i.e. at and below the stoichiometric composition, only polyaniline was produced, and the solid oxidant was absent in the product due to its reductive dissolution which took place during the reaction. Polyaniline prepared under such conditions did not differ with respect to conductivity from the standard polyaniline obtained with peroxydisulfate oxidant but fused polyaniline nanofibers have been produced instead of a common globular morphology. The composites of polyaniline/manganese dioxide resulted only at [MnO2]/[aniline] >1.25. Spectroscopic methods suggest that the oxidation with excess of manganese dioxide produced polyaniline at higher oxidation state. The presence of manganese dioxide in the products was confirmed by X-ray diffraction and EDAX. The results are important for the understanding of the preparation and properties of polyaniline/manganese dioxide composites that are currently used in supercapacitor electrodes. The present study also illustrates a new potential application, adsorption of organic dyes Reactive Black 5 and methylene blue, as an example of water-pollution treatment.

Benzendicarboxylic acid (BDC)-based metal-organic frameworks (MOFs) have been widely utilized in various applications, including supercapacitor electrode materials. Manganese and copper have solid diamond frames formed with BDC linkers among transition metals chosen for MOF formation. They have shown the possibility to enlarge capacitance at different combinations of MOFs and polyaniline (PANI). Herein, reduced graphene oxide (rGO) was used as the matrix to fabricate electrochemical double-layer SCs. PANI and Mn/Cu-MOF's effect on the properties of electrode materials was investigated through electrochemical analysis. As a result, the highest specific capacitance of about 276 F/g at a current density of 0.5 A/g was obtained for rGO/Cu-MOF@PANI composite.

The electrochemical parameters of a novel binder-free self-standing biomimetic cathode based on lithium manganese oxide (LMO) and carbon nanotubes (CNT) for rechargeable Lithium-ion aqueous batteries (ReLIAB) are improved using polyaniline (PANI) core-shell in situ polymerization and graphene (Gr). The fabricated cathode material exhibits the so-called “tectonic plate island bridge” biomimetic structure. This constitution is created by combining three components as shown by a SEM and a TEM analysis: the Gr substrates support an entangled matrix of conductive CNT which connect island of non-conductive inorganic material composed of LMO. The typical spinel structure of the LMO remains unchanged after modifying the basic structure with Gr and PANI due to a simplified hydrothermal method used for synthesis. The Gr and PANI core-shell coating improves the electric conductivity from 0.0025 S/cm up to 1 S/cm. The electrochemical performances of the LMO/CNT-Gr/PANI composite electrode are optimized up to 136 mA h g−1 compared to 111 mA h g−1 of the LMO/CNT. Besides that, the new electrode shows good cycling stability after 200 galvanostatic charging/discharging cycles, making this structure a future candidate for cathode materials for ReLIAB.

Polypyrrole was prepared by the oxidation of pyrrole with solid manganese dioxide. The present study concerns the chemistry of this process rather than materials properties of the products. The oxidant alone is insoluble in aqueous medium but the reductive dissolution takes place in the presence of pyrrole. Polypyrrole is the exclusive product below the stoichiometric mole ratio [MnO2]/[pyrrole] = 1.25, and polypyrrole/manganese dioxide composites result at higher ratios. Unlike with iron(III) chloride where protons are generated during the oxidation of pyrrole, with manganese dioxide they are consumed and water is a by-product. The sufficient acidity of the reaction medium is thus needed in order to obtain conducting materials. The presence of organic dyes in the preparation of polypyrrole improved the conductivity. One-dimensional morphology of polypyrrole was observed when methyl orange was introduced to the reaction mixture.

The study aims at the design of nanostructured hybrid materials that are both conducting and magnetic. Conducting polypyrrole nanotubes were prepared by the oxidation of pyrrole with iron(III) chloride stimulated by the organic dye, methyl orange. The excess of oxidant involved in the synthesis was used for the in situ generation of magnetite nanoparticles after addition of ammonia that coated the polypyrrole nanotubes. The resulting composites of varying composition were characterized with respect to the specific surface area and by X-ray diffraction and FTIR spectroscopy. The conductivity measurements revealed that polypyrrole nanotubes had a conductivity of approximate to 20 S cm(-1) and the composites with magnetite nanoparticles approximate to 1 S cm(-1) virtually independent of the composition. While polypyrrole nanotubes had marginal magnetic properties, the saturation magnetization of composites reached approximate to 50 emu g(-1), close to that of neat magnetite. The reprotonation of polypyrrole in composites increased the conductivity to approximate to 5 S cm(-1) at the expense of reduction of magnetic properties. The magnetorheological analysis was performed to illustrate their possible application exploiting the nanotubular morphology and requiring a magnetic response.

Conductive polymers, such as polyaniline (PANI) and polypyrrole (PPy), are widely used in the design of supercapacitors because of their high pseudo-capacitive performance as well as facile synthesis and low cost. In this study, hybrid aerogels based on reduced graphene oxide and ZnMn2O4 were modified by PANI and PPy. The 3D structure of the hybrid aerogels was obtained by using a one-step hydrothermal co-assembly method. Then, aniline and pyrrole were polymerized on and within the structure of the hybrid aerogel through in situ polymerization. The electrochemical properties of the hybrid aerogels were studied via cyclic voltammetry and galvanostatic charge–discharge testing to identify the effects of conductive polymers on the electrochemical properties of materials. It has been established that PANI and PPy facilitate an increase of the specific capacitance of rGO/ZnMn2O4 aerogels up to 297.8 F/g and 108.24 F/g at 0.2 A/g scan rate, respectively.

Metal-organic frameworks (MOFs) have lately obtained great attention of scientists as potential materials applied for supercapacitor electrodes. Due to their crystalline structure, MOFs show proper electrochemical double-layer capacitance at the enlarged specific surface area of the material and the mechanical supports for the composite materials. In this study, Zn-MOF was synthesized and composited with reduced graphene oxide (rGO) to be applied as a supercapacitor electrode material. To improve the electrodes working performance, polyaniline (PANI) was synthesized by different methods and added to the composite. The electrochemical properties of these materials were studied to identify the effect of PANI and Zn-MOF on the electrode materials. Among the composites obtained, the best specific capacitance of about 372 F/g was obtained at 0.1 A/g charge-discharge analysis of rGO/Zn-MOF@PANI sample due to its large surface with high pores sizes. The capacitance retentions of electrodes were also tested to decipher the effect caused by varied composites fabrication. (C) 2020 Elsevier Ltd. All rights reserved.

The different composites made of rGO, Ni-MOF, and PANI were synthesized via the hydrothermal method and used for the fabrication of electrodes for supercapacitors. The structure and morphology of composites obtained were characterized via SEM, XRD, and FTIR. The electrochemical properties of electrodes were studied using CV and galvanostatic charge/discharge methods, as well as by EIS. The results obtained demonstrated that the incorporation of rGO, Ni-MOF, and PANI significantly increase the specific capacitance of electrodes. It can be explained by the formation of a better specific surface area with a branched porous structure that enhances the contact between electrolyte ions with the electrode materials. The specific capacitance of rGO/Ni-MOF/PANI in 1 M H2SO4 electrolyte is 195.14 F/g at 0.2 A/g charge-discharge and the average capacitance retention remained 79.78% after 5,000 cycles at current density 1 A/g.

The binder-free technology is used to produce flexible self-standing cathodes for secondary Li-ion batteries containing commercial materials: lithium manganese oxide (LMO) and multiwall carbon nanotubes (CNT). The fragmentation of commercial LMO by short time ball-milling with low energy intensities, allows one to reduce the particle size from tens of microns to the micron and submicron level, while maintaining its spinel crystal structure. The electrode exhibits high electrical conductivity (46 S m(-1)) due to homogeneous distribution of LMO particles in the matrix of CNT. Electrochemical assessment of the electrode revealed good cyclic stability and a high reversibility of 93% after 120 galvanostatic charge/discharge cycles at 0.6C, with an initial specific discharge capacity of about 110 mA h-g(-1) and 80 mAh.g(-1) at high current rate of 2C.