Effects of different inorganic nanoparticles on the structural, dielectric and ion transportation properties of polymers blend based nanocomposite solid polymer electrolytes

Plasticised chitosan: Dextran polymer blend electrolyte for energy harvesting application: Tuning the ion transport and EDLC charge storage capacity through TiO2 dispersion

This study investigates the performance of biopolymer electrolytes based on chitosan and dextran for energy storage applications. The optimization of ion transport and performance of electric double-layer capacitors EDCL using these electrolytes, incorporating different concentrations of glycerol as a plasticizer and TiO2 as nanoparticles, is explored. Impedance measurements indicate a notable reduction in charge transfer resistance with the addition of TiO2. DC conductivity estimates from AC spectra plateau regions reach up to 5.6 × 10-4 S/cm. The electric bulk resistance Rb obtained from the Nyquist plots exhibits a substantial decrease with increasing plasticizer concentration, further enhanced by the addition of the nanoparticles. Specifically, Rb decreases from ∼20 kΩ to 287 Ω when glycerol concentration increases from 10 % to 40 % and further drops to 30 Ω with the introduction of TiO2. Specific capacitance obtained from cyclic voltammetry shows a notable increase as the scan rate decreases, indicating improved efficiency and stability of ion transport. The TiO2-enriched EDCL achieves 12.3 F/g specific capacitance at 20 mV/s scan rate, with high ion conductivity and extended electrochemical stability. These results suggest the great potential of plasticizer and TiO2 with biopolymers in improving the performance of energy storage systems.

Demonstration of a Gel-Polymer Electrolyte-Based Electrochromic Device Outperforming Its Solution-Type Counterpart in All Merits: Architectural Benefits of CeO2 Quantum Dot and Nanorods

For years, solution-type electrochromic devices (ECDs) have intrigued researchers' interest and eventually rendered themselves into commercialization. Regrettably, challenges such as electrolyte leakage, high flammability, and complicated edge-encapsulation processes limit their practical utilization, hence necessitating an efficient alternate. In this quest, although the concept of solid/gel-polymer electrolyte (SPE/GPE)-based ECDs settled some issues of solution-type ECDs, an array of problems like high operating voltage, sluggish response time, and poor cycling stability have paralyzed their commercial applicability. Herein, we demonstrate a choreographed-CeO2-nanofiller-doped GPE-based ECD outperforming its solution-type counterpart in all merits. The filler-incorporated polymer electrolyte assembly was meticulously weaved through the electrospinning method, and the resultant host was employed for immobilizing electrochromic viologen species. The filler engineering benefits conceived through the tuned shape of CeO2 nanorod and quantum dots, along with the excellent redox shuttling effect of Ce3+/Ce4+, synchronously yielded an outstanding class of GPE, which upon utilization in ECDs delivered impressive electrochromic properties. A combination of features possessed by a particular device (QD-NR/PVDF-HFP/IL/BzV-Fc ECD) such as exceptionally low driving voltage (0.9 V), high transmittance change (ΔT, ∼69%), fast response time (∼1.8 s), high coloration efficiency (∼339 cm2/C), and remarkable cycling stability (∼90% ΔT-retention after 25,000 cycles) showcased a striking potential in the yet-to-realize market of GPE-based ECDs. This study unveils the untapped potential of choreographed nanofillers that can promisingly drive GPE-based ECDs to the doorstep of commercialization.

Analysis of Dielectric Parameters of Fe2O3-Doped Polyvinylidene Fluoride/Poly(methyl methacrylate) Blend Composites

In this paper, we report the effect of metal oxide (Fe2O3) loading in different weight ratios (0.5%, 1%, 2%, and 4%) on the structural and electrical parameters, viz., the complex dielectric constant, electric modulus spectra, and the AC conductivity, of polymeric composites of PVDF/PMMA (30/70 weight ratio) blend. The structural and geometric measurements have been analyzed with the help of peak location, peak intensity, and peak shape obtained from XRD as well as from FTIR spectra. The electrical properties have been investigated using an impedance analyzer in the frequency range 100 Hz to 1 MHz. The real parts of the complex permittivity and the dielectric loss tangent of these materials are found to be frequency independent in the range from 20 KHz to 1 MHz, but they increase with the increase in the concentration of nano-Fe2O3. The conductivity also increases with an increased loading of Fe2O3 in PVDF/PMMA polymer blends. The electric modulus spectra were used to analyze the relaxation processes associated with the Maxwell-Wagner-Sillars mechanism and chain segmental motion in the polymer mix.

Datura metel L. leaf extract mediated sodium alginate polymer membrane for supercapacitor and food packaging applications

Datura metel L. leaf extract mediated sodium alginate polymer membrane was successfully made using the solution casting technique. Electric, electrochemical, physicochemical and antimicrobial analyses of the prepared film were investigated. Functional groups of polysaccharides are identified in FTIR analysis and crystallinity/amorphous of the prepared samples was studied using XRD analysis. The prepared polymer membrane (DmMSA2) exhibits the ionic conductivity of 2.18 × 10^-4 Scm^-1, maximum specific capacitance of 131 F/g at a current density of 0.2 A/g and also exhibits a significant effect of antimicrobial activity against human pathogens. Hence, Datura metel L. leaf extract mediated polymer membranes are promising candidates for solid-electrolyte in supercapacitor devices and antimicrobial agents in food packaging applications.

Regression Analysis of the Dielectric and Morphological Properties for Porous Nanohydroxyapatite/Starch Composites: A Correlative Study

This paper aims to investigate the dielectric properties, i.e., dielectric constant (ε′), dielectric loss factor (ε″), dielectric tangent loss (tan δ), electrical conductivity (σ), and penetration depth (Dp), of the porous nanohydroxyapatite/starch composites in the function of starch proportion, pore size, and porosity over a broad band frequency range of 5 MHz−12 GHz. The porous nanohydroxyapatite/starch composites were fabricated using different starch proportions ranging from 30 to 90 wt%. The results reveal that the dielectric properties and the microstructural features of the porous nanohydroxyapatite/starch composites can be enhanced by the increment in the starch proportion. Nevertheless, the composite with 80 wt% of starch proportion exhibit low dielectric properties (ε′, ε″, tan δ, and σ) and a high penetration depth because of its highly interconnected porous microstructures. The dielectric properties of the porous nanohydroxyapatite/starch composites are highly dependent on starch proportion, average pore size, and porosity. The regression models are developed to express the dielectric properties of the porous nanohydroxyapatite/starch composites (R2 > 0.96) in the function of starch proportion, pore size, and porosity from 1 to 11 GHz. This dielectric study can facilitate the assessment of bone scaffold design in bone tissue engineering applications.

Effect of MWCNT nanofiller on the dielectric performance of bio-inspired gelatin based nanocomposites

In this work, multi wall carbon nanotube (MWCNT) reinforced bio-derived gelatin-based polymer nanocomposites were synthesized following an easy and affordable solution-casting method. The effects of different concentrations of MWCNTs on the structural, surface morphological, and dielectric properties of the nanocomposites were studied. A four-fold increase in the dielectric constant is observed due to the incorporation of just 0.02 wt% of MWCNT nanofiller into the polymer matrix. The modified Cole-Cole model was used to analyze the effect of nanofiller concentrations on the different dielectric parameters of the nanocomposite. The incorporation of MWCNTs was found to increase the dielectric strength and reduce the relaxation time of the nanocomposite. The AC conductivity of the nanocomposites was found to be improved due to the incorporation of the MWCNT nanofiller. A quantitative study based on the simulation of the complex impedance spectra demonstrates that the addition of MWCNTs into the nanocomposite decreases the grain barrier resistance from 5935 kΩ to 261 kΩ and increases the capacitive component from 0 to 23.25 μF. The improved dielectric performance of the nanocomposites can be attributed to the space charge polarization effect and is illustrated with a charge transport mechanism model. This biopolymer-based nanocomposite material with a large dielectric constant together with a small loss tangent may offer a potential route for the fabrication of fully biocompatible electrostatic capacitors and energy storage devices.

Ionic Conductivity of Hybrid Composite Solid Polymer Electrolytes of PEOnLiClO4-Cubic Li7La3Zr2O12 Films

Ionic conductivity of the polyethylene oxide-LiClO4 (PEOnLiClO4) solid polymer electrolyte (SPE) films with an EO:Li ratio (n) of 10, 12, 15, as well as the hybrid composite solid polymer electrolyte (CSPE) films of PEOnLiClO4 containing 50 wt% of cubic-Li7La3Zr2O12 (LLZO) sub-micron sized particles, have been studied by varying Li-salt content in the films. The complex AC dielectric permittivity and conductivity data obtained from electrical impedance measurements were fitted using a generalized power-law, including the effects of electrode polarization applied at low AC frequencies to obtain various relaxation times. In addition to increased mechanical and thermal robustness, the CSPE films show higher values of ionic conductivity, >10−4 S/cm at room temperature compared to those of SPE films with n = 12 and 15. On the contrary, the ionic conductivity of CSPE with n = 10 decreases by a factor of three compared to the corresponding SPE film due to increased polymer structural reorientation and Li-ion pairing effects. The Vogel–Tammann–Fulcher behavior of the temperature-dependent conductivity data indicates a close correlation between the ionic conductivity and polymer segmental relaxation. The PEO12LiClO4-LLZO film shows the lowest activation energy of ~0.05 eV.

Development on Solid Polymer Electrolytes for Electrochemical Devices

Electrochemical devices, especially energy storage, have been around for many decades. Liquid electrolytes (LEs), which are known for their volatility and flammability, are mostly used in the fabrication of the devices. Dye-sensitized solar cells (DSSCs) and quantum dot sensitized solar cells (QDSSCs) are also using electrochemical reaction to operate. Following the demand for green and safer energy sources to replace fossil energy, this has raised the research interest in solid-state electrochemical devices. Solid polymer electrolytes (SPEs) are among the candidates to replace the LEs. Hence, understanding the mechanism of ions' transport in SPEs is crucial to achieve similar, if not better, performance to that of LEs. In this paper, the development of SPE from basic construction to electrolyte optimization, which includes polymer blending and adding various types of additives, such as plasticizers and fillers, is discussed.

Development of Waste Polystyrene-Based Copper Oxide/Reduced Graphene Oxide Composites and Their Mechanical, Electrical and Thermal Properties

The current study reports the effect of different wt. ratios of copper oxide nanoparticle (CuO-NPs) and reduced graphene oxide (rGO) as fillers on mechanical, electrical, and thermal properties of waste polystyrene (WPS) matrix. Firstly, thin sheets of WPS-rGO-CuO composites were prepared through solution casting method with different ratios, i.e., 2, 8, 10, 15 and 20 wt.% of CuO-NPs and rGO in WPS matrix. The synthesized composite sheets were characterized by Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The electrical conductance and mechanical strength of the prepared composites were determined by using LCR meter and universal testing machine (UTM). These properties were dependent on the concentrations of CuO-NPs and rGO. Results display that the addition of both fillers, i.e., rGO and CuO-NPs, collectively led to remarkable increase in the mechanical properties of the composite. The incorporation of rGO-CuO: 15% WPS sample, i.e., WPS-rGO-CuO: 15%, has shown high mechanical strength with tensile strength of 25.282 MPa and Young modulus of 1951.0 MPa, respectively. Similarly, the electrical conductance of the same composite is also enhanced from 6.7 × 10-14 to 4 × 10-7 S/m in contrast to WPS at 2.0 × 106 Hz. The fabricated composites exhibited high thermal stability through TGA analysis in terms of 3.52% and 6.055% wt. loss at 250 °C as compared to WPS.

Effect of ZnO Nanoparticle Content on the Structural and Ionic Transport Parameters of Polyvinyl Alcohol Based Proton-Conducting Polymer Electrolyte Membranes

Proton conducting nanocomposite solid polymer electrolytes (NSPEs) based on polyvinyl alcohol/ammonium nitrate (PVA/NH4NO3) and different contents of zinc oxide nanoparticles (ZnO-NPs) have been prepared using the casting solution method. The XRD analysis revealed that the sample with 2 wt.% ZnO-NPs has a high amorphous content. The ionic conductivity analysis for the prepared membranes has been carried out over a wide range of frequencies at varying temperatures. Impedance analysis shows that sample with 2 wt.% ZnO-NPs has a smaller bulk resistance compared to that of undoped polymer electrolyte. A small amount of ZnO-NPs was found to enhance the proton-conduction significantly; the highest obtainable room-temperature ionic conductivity was 4.71 × 10-4 S/cm. The effect of ZnO-NP content on the transport parameters of the prepared proton-conducting NSPEs was investigated using the Rice-Roth model; the results reveal that the increase in ionic conductivity is due to an increment in the number of proton ions and their mobility.

CNTs/LiV3O8/Y2O3 Composites with Enhanced Electrochemical Performances as Cathode Materials for Rechargeable Solid-State Lithium Metal Batteries

Solid-state lithium metal battery (SSLMB) is regarded as a safer energy storage system compared to the liquid one. The performance of the SSLMB depends on the cathode performance and the side reactions derived from the interface of the cathode and the electrolyte, which becomes much severe at high temperatures. Herein, we carried out a facile spray-drying route to prepare a CNTs/LiV₃O₈/Y₂O₃ (M-LVO-Y) composite. The synthesized cathode material exhibits an outstanding Li⁺ storage performance with a high reversible capacity of 279.9 mA h g^-1 at 0.05 A g^-1, excellent power capability (182.5 mA h g^-1 at 2 A g^-1), and a long cycle lifespan of 500 cycles with a capacity retention of 66.5% at a current density of 1 A g^-1. The fabricated rechargeable solid-state Li/M-LVO-Y-2 lithium metal battery (LMB) with a poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE) achieves a high discharge capacity of 302.1 mA h g^-1 at 0.05 A g^-1 and a stable cycling performance with the highest capacity of 72.1% after 100 cycles at 0.2 A g^-1 and 80 °C. The above battery performance demonstrates that SSLMBs with the CNTs/LiV₃O₈/Y₂O₃ cathode and the PEO-based SPE film can provide high energy density and are suitable for applying in a high-temperature environment.

Green synthesis of nano-Al2O3, recent functionalization, and fabrication of synthetic or natural polymer nanocomposites: various technological applications

Environmentally friendly fabrication of nano-Al₂O₃, recent functionalization, and preparation of polymer nanocomposites including natural and man-made polymers with various industrial applications are reviewed.

Hydroxyapatite Nanowire-Reinforced Poly(ethylene oxide)-Based Polymer Solid Electrolyte for Application in High-Temperature Lithium Batteries

Hybrid polymer electrolytes with excellent performance at high temperatures are very promising for developing solid-state lithium batteries for high-temperature applications. Herein, we use a self-supporting hydroxyapatite (HAP) nanowire membrane as a filler to improve the performance of a poly(ethylene oxide) (PEO)-based solid-state electrolyte. The HAP membrane could comprehensively improve the properties of the hybrid polymer electrolyte, including the higher room-temperature ionic conductivity of 1.05 × 10^-5 S cm^-1, broad electrochemical windows of up to 5.9 V at 60 °C and 4.9 V at 160 °C, and a high lithium-ion migration of 0.69. In addition, the LiFePO₄//Li full battery with a solid electrolyte possesses good rate capability, cycling, and Coulomb efficiency at extreme high temperatures, that is, after 300 continuous charge and discharge cycles at 4 C rate, the discharge capacity retention rate is 77% and the Coulomb efficiency is 99%. The use of the flexible self-supporting HAP nanowire membrane to improve the PEO-based solid composite electrolyte provides new strategies and opportunities for developing rechargeable lithium batteries in extreme high-temperature applications.

A polycarboxylic/ether composite polymer electrolyte via in situ UV-curing for all-solid-state lithium battery

A polycarboxylic/ether composite polymer electrolyte derived from two-arm monomer and polyethylene oxide (PEO) was in situ synthesized on the cathode. The composite electrolyte exhibits a high ionic conductivity of 3.6 × 10^-5 S cm^-1, high oxidation stability, excellent stability towards Li metal and makes Li/LiFePO₄ present good cyclic and rate performance at 25°C.

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

To date high ionic conducting polymer electrolytes are of great interest because of their potential applications in various electrochemical devices such as batteries, fuel cells, solar cells and super capacitors etc., as electrolytes. Ion conduction through polymer electrolytes can occur mostly in amorphous environment exists above their glass transition temperature (T_g). In order to improve ionic conductivity, many approaches such as addition of plasticizer, blending of polymers, nano composite have been employed. This paper reviews the influence of different plasticizers/additives on the ion transport mechanism of Poly(vinyl alcohol) (PVA)-LiClO₄ polymer electrolytes since poly vinyl alcohol is a semi crystalline, synthetic biodegradable polymer and lithium perchlorate is one of the most moisture resistant lithium salts. This review also reveals the relation between dynamical disorder in polymer electrolyte with ionic conductivity.