Effect of incorporation of different plasticizers on structural and ion transport properties of PVA-LiClO4 based electrolytes

Zinc metal complexes synthesized by a green method as a new approach to alter the structural and optical characteristics of PVA: new field for polymer composite fabrication with controlled optical band gap

The current study employed a novel approach to design polymer composites with modified structural and declined optical band gaps. The results obtained in the present work for polymer composites can be considered an original method to make a new field for research based on green chemistry. Natural dyes extracted from green tea were mixed with hydrated zinc acetate (Zn(CH3COO)2·2H2O) to produce a metal complex. FTIR results comprehensively established the formation of the Zn-metal complex. The interaction among various components of PVA : Zn-metal complex composite was investigated using FTIR spectroscopy. The non-existence of anion bands of acetate in the Zn-metal complex spectrum confirms the formation of the Zn-metal complex. XRD analysis reveals that the Zn-metal complex improves the amorphous phase of the PVA-based composites. The absorption edge of the doped films shifted towards the lower photon energies. Optical dielectric properties were used to determine N/m*, ε ∞, τ, μ opt, ω p, and ρ opt; the W-D model was used to calculate E d, E o and n o parameters. The optical dielectric loss parameter was used to determine the optical band gap while the Tauc model was employed to identify various types of electron transitions. The optical energy band gap was 6.05 eV for clean PVA while it decreased to 1 eV for PVA inserted with the Zn-metal complex. The increase in Urbach energy from 0.26 eV to 0.45 eV is an evidence of the boost of amorphous phases in PVA : Zn-metal complex composites. The nonlinear refractive index and the first-order and second-order nonlinear optical susceptibilities were determined. The value of E o obtained from the W-D model closely matches the optical energy band gap obtained from the Tauc model, which indicates the precision of the analysis in the present study. The increase in SELF and VELF in the composite films establishes that new energy states assigned to the added Zn-metal complex amplify the probability of light-matter interaction.

Chitosan as a suitable host for sustainable plasticized nanocomposite sodium ion conducting polymer electrolyte in EDLC applications: Structural, ion transport and electrochemical studies

The challenge in front of EDLC device is their low energy density compared to their battery counter parts. In the current study, a green plasticized nanocomposite sodium ion conducting polymer blend electrolytes (PNSPBE) was developed by incorporating plasticized Chitosan (CS) blended with polyvinyl alcohol (PVA), doped with NaBr salt with various concentration of CaTiO3 nanoparticles. The most optimized PNSPBE film was subsequently utilized in an EDLC device to evaluate its effectiveness both as an electrolyte and a separator. Structural and morphological changes were assessed using XRD and SEM techniques. The PNSPBE film demonstrated a peak ionic conductivity of 9.76×10-5 S/cm, as determined through EIS analysis. The dielectric and AC studies provided further confirmation of structural modifications within the sample. Both TNM and LSV analyses affirmed the suitability of the prepared electrolyte for energy device applications, evidenced by its adequate ion transference number and an electrochemical potential window of 2.86 V. Electrochemical properties were assessed via CV and GCD techniques, confirming non-Faradaic ion storage, indicated by the rectangular CV pattern at low scan rates. The parameters associated with the designed EDLC device including specific capacitance, ESR, power density (1950 W/kg) and energy density (12.3 Wh/kg) were determined over 1000 cycles.

Enhancement of Electrochemical Stability Window and Electrical Properties of CNT-Based PVA-PEG Polymer Blend Composites

New polymer blend composite electrolytes (PBCEs) were prepared by the solution casting technique using poly(vinyl alcohol) (PVA)-polyethylene glycol (PEG), sodium nitrate (NaNO₃) as a doping salt and multiwalled carbon nanotubes (MWCNTs) as fillers. The X-ray diffraction pattern confirms the structural properties of the polymer blend composite films. FTIR investigations were carried out to understand the chemical properties and their band assignments. The ionic conductivity of the 10 wt % MWCNTs incorporated PVA-PEG polymer blend was measured as 4.32 × 10^-6 S cm^-1 at 20 °C and increased to 2.253 × 10^-4 S/cm at 100 °C. The dependence of its conductivity on temperature suggests Arrhenius behavior. The equivalent circuit models that represent the R _s(Q₁(R₁(Q₂(R₂(CR₃))))) were used to interpret EIS data. The dielectric behavior of the samples was investigated by utilizing their AC conductance spectra, dielectric permittivity, dielectric constant (εⁱ and ε^r), electric modulus (Mⁱ and M^r), and loss tangent tan δ. The dielectric permittivity of the samples increases due to electrode polarization effects in low frequency region. The loss tangent's maxima shift with increasing temperature; hence, the peak height rises in the high frequency region. MWCNTs-based polymer blend composite electrolytes show an enhanced electrochemical stability window (4.0 V), better transference number (0.968), and improved ionic conductivity for use in energy storage device applications.

Ion rectification based on gel polymer electrolyte ionic diode

Biological ion channels rely on ions as charge carriers and unidirectional ion flow to produce and transmit signals. To realize artificial biological inspired circuitry and seamless human-machine communication, ion-transport-based rectification devices should be developed. In this research, poly(methyl methacrylate) (PMMA) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) gel polymer electrolytes (GPEs) are assembled to construct a novel ionic diode, enabling ion rectification through ion-diffusion/migration that emulates biological systems. This ion rectification results from the different diffusion/migration behaviors of mobile ions transporting in the GPE heterojunction. The electrical tests of the GPE heterojunction reveal outstanding rectifying ratio of 23.11. The GPE ionic diode operates in wide temperature window, from -20 °C (anti-freezing) to 125 °C (thermal tolerance). The absence of redox reactions is verified in the cyclic voltammogram. The GPE ionic diodes are used to construct ionic logic gates for signal communication. Furthermore, rectification of a triboelectric nanogenerator and potential for synaptic devices are demonstrated.

Towards an All-Solid-State Electrochromic Device: A Review of Solid-State Electrolytes and the Way Forward

In order to curb high electricity usage, especially in commercial buildings, smart windows, also known as “switchable” or “smart” glasses, have attracted a significant amount of attention in an effort to achieve energy savings in eco-friendly buildings and transportation systems. Smart windows save energy by regulating the input of solar heat and light and hence cutting down air-conditioning expenses, while maintaining indoor comfort. This is achieved by electrochromism, which is defined as the reversible colour change in electrochromic (EC) materials from transparent to dark blue and vice versa under a small applied voltage. Recent state-of-the-art electrochromic devices (ECD) adopt liquid-based electrolytes as the main source of energy for basic operations. While this has resulted in much success in ECDs as reported in past studies, there remain several drawbacks to this aspect, such as liquid electrolyte leakage and evaporation, not to mention safety concerns related to the harmful nature of electrolyte materials. This paper aims to review the recent advances in various solid electrolytes that are potential solutions to the mentioned problems.

Recent Progress on Self-Healable Conducting Polymers

Materials able to regenerate after damage have been the object of investigation since the ancient times. For instance, self-healing concretes, able to resist earthquakes, aging, weather, and seawater have been known since the times of ancient Rome and are still the object of research. During the last decade, there has been an increasing interest in self-healing electronic materials, for applications in electronic skin (E-skin) for health monitoring, wearable and stretchable sensors, actuators, transistors, energy harvesting, and storage devices. Self-healing materials based on conducting polymers are particularly attractive due to their tunable high conductivity, good stability, intrinsic flexibility, excellent processability and biocompatibility. Here recent developments are reviewed in the field of self-healing electronic materials based on conducting polymers, such as poly 3,4-ethylenedioxythiophene (PEDOT), polypyrrole (PPy), and polyaniline (PANI). The different types of healing, the strategies adopted to optimize electrical and mechanical properties, and the various possible healing mechanisms are introduced. Finally, the main challenges and perspectives in the field are discussed.

Improving Cyclability of All-Solid-State Batteries via Stabilized Electrolyte-Electrode Interface with Additive in Poly(propylene carbonate) Based Solid Electrolyte

In this study, tetraethylene glycol dimethyl ether (TEGDME) is demonstrated as an effective additive in poly(propylene carbonate) (PPC) polymers for the enhancement of ionic conductivity and interfacial stability and a tissue membrane is used as a backbone to maintain the mechanical strength of the solid polymer electrolytes (SPEs). TEGDME in the PPC allows the uniform distribution of conductive LiF species throughout the cathode electrolyte interface (CEI) layer which plays a critically important role in the formation of a stable and efficient CEI. In addition, the high modulus of SPEs suppresses the formation of a protrusion-type CEI on the cathode. The SPE with the optimized TEGDME content exhibits a high ionic conductivity of 0.89 mS cm^-1 , an adequate potential stability of up to 4.89 V, and a high Li-ion transference number of 0.81 at 60 °C. Moreover, the Li/SPE/Li cell demonstrates excellent cycling stability for 1650 h, and the Li/SPE/LFP full cell exhibits an initial reversible capacity of 103 mAh g^-1 and improved stability over 500 cycles at a rate of 1 C. The TEGDME additive improves the electrochemical properties of the SPEs and promotes the creation of a stable interface, which is crucial for ASSLIBs.

Plasticizing effect on polyethylene oxide doped ammonium perchlorate

Plasticized polymer complex films of polyethylene oxide with ammonium perchlorate (NH4ClO4) are synthesized by using solution cast technique. Propylene carbonate (PC) used as dopant to enhance conductivity of polymer electrolyte. The prepared films are characterized in detail using X-ray diffraction, infrared spectral analysis, transient ionic current, and electrochemical impedance studies. Plasticized polymer electrolyte shows high ionic conductivity (∼10−4 S/cm) which appear as novel electrolyte for electrochemical devices.

Fiber‐Shaped Electronic Devices

Textile electronics embedded in clothing represent an exciting new frontier for modern healthcare and communication systems. Fundamental to the development of these textile electronics is the development of the fibers forming the cloths into electronic devices. An electronic fiber must undergo diverse scrutiny for its selection for a multifunctional textile, viz., from the material selection to the device architecture, from the wearability to mechanical stresses, and from the environmental compatibility to the end‐use management. Herein, the performance requirements of fiber‐shaped electronics are reviewed considering the characteristics of single electronic fibers and their assemblies in smart clothing. Broadly, this article includes i) processing strategies of electronic fibers with required properties from precursor to material, ii) the state‐of‐art of current fiber‐shaped electronics emphasizing light‐emitting devices, solar cells, sensors, nanogenerators, supercapacitors storage, and chromatic devices, iii) mechanisms involved in the operation of the above devices, iv) limitations of the current materials and device manufacturing techniques to achieve the target performance, and v) the knowledge gap that must be minimized prior to their deployment. Lessons learned from this review with regard to the challenges and prospects for developing fiber‐shaped electronic components are presented as directions for future research on wearable electronics.

A Review of the Use of GPEs in Zinc-Based Batteries. A Step Closer to Wearable Electronic Gadgets and Smart Textiles

With the flourish of flexible and wearable electronics gadgets, the need for flexible power sources has become essential. The growth of this increasingly diverse range of devices boosted the necessity to develop materials for such flexible power sources such as secondary batteries, fuel cells, supercapacitors, sensors, dye-sensitized solar cells, etc. In that context, comprehensives studies on flexible conversion and energy storage devices have been released for other technologies such Li-ion standing out the importance of the research done lately in GPEs (gel polymer electrolytes) for energy conversion and storage. However, flexible zinc batteries have not received the attention they deserve within the flexible batteries field, which are destined to be one of the high rank players in the wearable devices future market. This review presents an extensive overview of the most notable or prominent gel polymeric materials, including biobased polymers, and zinc chemistries as well as its practical or functional implementation in flexible wearable devices. The ultimate aim is to highlight zinc-based batteries as power sources to fill a segment of the world flexible batteries future market.

Metal Complex as a Novel Approach to Enhance the Amorphous Phase and Improve the EDLC Performance of Plasticized Proton Conducting Chitosan-Based Polymer Electrolyte

This work indicates that glycerolized chitosan-NH₄F polymer electrolytes incorporated with zinc metal complexes are crucial for EDLC application. The ionic conductivity of the plasticized system was improved drastically from 9.52 × 10⁻⁴ S/cm to 1.71 × 10⁻³ S/cm with the addition of a zinc metal complex. The XRD results demonstrated that the amorphous phase was enhanced for the system containing the zinc metal complex. The transference number of ions (t_ion) and electrons (t_e) were measured for two of the highest conducting electrolyte systems. It confirmed that the ions were the dominant charge carriers in both systems as t_ion values for CSNHG4 and CSNHG5 electrolytes were 0.976 and 0.966, respectively. From the examination of LSV, zinc improved the electrolyte electrochemical stability to 2.25 V. The achieved specific capacitance from the CV plot reveals the role of the metal complex on storage properties. The charge–discharge profile was obtained for the system incorporated with the metal complex. The obtained specific capacitance ranged from 69.7 to 77.6 F/g. The energy and power densities became stable from 7.8 to 8.5 Wh/kg and 1041.7 to 248.2 W/kg, respectively, as the EDLC finalized the cycles.

Influence of high and low dielectric constant plasticizers on the ion transport properties of PEO: NH4HF2 polymer electrolytes

Different composition ratio of polymer electrolytes based on poly(ethylene oxide) (PEO) as host polymer, ammonium bifluoride (NH4HF2) as salt, and propylene carbonate (PC), dimethyl acetamide (DMA), dimethyl chloride (DMC), and diethyl carbonate (DEC) as plasticizers has been prepared by solution casting technique. The influence of high dielectric constant plasticizers (PC and DMA) and low dielectric constant plasticizers (DMC and DEC) on the ion transport properties of PEO-NH4HF2 polymer electrolytes has been studied. The increase in ionic conductivity of polymer electrolytes containing PC and DMA is observed to be more as compared to those electrolytes containing DMC and DEC, which is due to an increase in both the amorphous phase and dielectric constant of PEO. X-ray diffraction study reveals the amorphous nature in case of plasticized polymer electrolyte. In the Fourier transform infrared study, the changes and shifting of the different characteristic peaks confirm the polymer–salt complex formation and the dissociation of ion aggregates present at higher concentration of salt with the addition of PC. Maximum ionic conductivity of 1.40 × 10−4 S cm−1 at room temperature has observed in case of plasticized polymer electrolytes containing optimum concentration of PC so that mechanical stability and flexibility be maintained. The variation of linewidth with temperature has also been studied by 1H and 19F nuclear magnetic resonance (NMR), which confirms that both cations and anions are mobile in these polymer electrolytes. Line narrowing associated with the glass transition temperature ( T g; low mobility region) and melting temperature ( T m; high mobility region) of PEO has also been observed for plasticized polymer electrolytes containing PC having optimum conductivity value. Conductivity versus temperature variation study reveals curved nature of plot in case of plasticized polymer electrolytes containing high dielectric constant plasticizers, which is significant for their amorphous nature. Smooth morphology observed in case of plasticized polymer electrolytes having optimum conductivity value is essential key factor for polymer electrolytes to be suitable for practical applications.