Natural Polymer Electrolyte System Based on Sago: Structural and Transport Behavior Characteristics

A Review of Solid-State Proton-Polymer Batteries: Materials and Characterizations

The ever-increasing global population necessitates a secure and ample energy supply, the majority of which is derived from fossil fuels. However, due to the immense energy demand, the exponential depletion of these non-renewable energy sources is both unavoidable and inevitable in the approaching century. Therefore, exploring the use of polymer electrolytes as alternatives in proton-conducting batteries opens an intriguing research field, as demonstrated by the growing number of publications on the subject. Significant progress has been made in the production of new and more complex polymer-electrolyte materials. Specific characterizations are necessary to optimize these novel materials. This paper provides a detailed overview of these characterizations, as well as recent advancements in characterization methods for proton-conducting polymer electrolytes in solid-state batteries. Each characterization is evaluated based on its objectives, experimental design, a summary of significant results, and a few noteworthy case studies. Finally, we discuss future characterizations and advances.

Carboxymethyl cellulose-based materials as an alternative source for sustainable electrochemical devices: a review

In electrochemistry, bio-based materials are preferred over the traditional costly and synthetic polymers due to their abundance, versatility, sustainability and low cost. One of the bio-based polymers is carboxymethyl cellulose (CMC) which has become an overarching material in electrochemical devices pertaining to its amphiphilic nature with multi-carbon functional groups. Owing to its flexible framework with fascinating groups on its surface like hydroxide (-OH) and carboxylate (-COO-), CMC is able to be modified into conducting materials by blending it with other biopolymers, synthetic polymers, salts, acids and others. This blending has improved the profile of CMC by exploiting the ability of hydrogen bonding, swelling, adhesiveness and dispersion of charges and ions. These properties of CMC have made it possible to utilize this bio-sourced polymer in several applications as a conducting electrolyte, binder in electrodes, detector, sensor and active material in fuel cells, actuators and triboelectric nanogenerators (TENG). Thus, CMC based materials are cheap, environment friendly, hydrophilic, biodegradable, non-toxic and biocompatible which render it a desirable material in energy storage devices.

Bio-Based Polymer Electrolytes for Electrochemical Devices: Insight into the Ionic Conductivity Performance

With the continuing efforts to explore alternatives to petrochemical-based polymers and the escalating demand to minimize environmental impact, bio-based polymers have gained a massive amount of attention over the last few decades. The potential uses of these bio-based polymers are varied, from household goods to high end and advanced applications. To some extent, they can solve the depletion and sustainability issues of conventional polymers. As such, this article reviews the trends and developments of bio-based polymers for the preparation of polymer electrolytes that are intended for use in electrochemical device applications. A range of bio-based polymers are presented by focusing on the source, the general method of preparation, and the properties of the polymer electrolyte system, specifically with reference to the ionic conductivity. Some major applications of bio-based polymer electrolytes are discussed. This review examines the past studies and future prospects of these materials in the polymer electrolyte field.

Structural, Impedance, and EDLC Characteristics of Proton Conducting Chitosan-Based Polymer Blend Electrolytes with High Electrochemical Stability

In this report, a facile solution casting technique was used to fabricate polymer blend electrolytes of chitosan (CS):poly (ethylene oxide) (PEO):NH4SCN with high electrochemical stability (2.43V). Fourier transform infrared (FTIR) spectroscopy was used to investigate the polymer electrolyte formation. For the electrochemical property analysis, cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) techniques were carried out. Referring to the FTIR spectra, a complex formation between the added salt and CS:PEO was deduced by considering the decreasing and shifting of FTIR bands intensity in terms of functional groups. The CS:PEO:NH₄SCN electrolyte was found to be electrochemically stable as the applied voltage linearly swept up to 2.43V. The cyclic voltammogram has presented a wide potential window without showing any sign of redox peaks on the electrode surface. The proved mechanisms of charge storage in these fabricated systems were found to be double layer charging. The EIS analysis showed the existence of bulk resistance, wherein the semicircle diameter decreased with increasing salt concentration. The calculated maximum DC conductivity value was observed to be 2.11 × 10⁻⁴ S/cm for CS:PEO incorporated with 40 wt% of NH₄SCN salt. The charged species in CS:PEO:NH₄SCN electrolytes were considered to be predominantly ionic in nature. This was verified from transference number analysis (TNM), in which ion and electron transference numbers were found to be t_ion = 0.954 and t_el = 0.045, respectively. The results obtained for both ion transference number and DC conductivity implied the possibility of fabricating electrolytes for electrochemical double layer capacitor (EDLC) device application. The specific capacitance of the fabricated EDLC was obtained from the area under the curve of the CV plot.

Structural and Ionic Transport Properties of Protonic Conducting Solid Biopolymer Electrolytes Based on Carboxymethyl Cellulose Doped with Ammonium Fluoride

Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and transference number measurement (TNM) techniques were applied to investigate the complexation, structural, and ionic transport properties of and the dominant charge-carrier species in a solid biopolymer electrolyte (SBE) system based on carboxymethyl cellulose (CMC) doped with ammonium fluoride (NH₄F), which was prepared via a solution casting technique. The SBEs were partially opaque in appearance, with no phase separation. The presence of interactions between the host polymer (CMC) and the ionic dopant (NH₄F) was proven by FT-IR analysis at the C-O band. XRD spectra analyzed using Origin 8 software disclose that the degree of crystallinity (χ_c%) of the SBEs decreased with the addition of NH₄F, indicating an increase in the amorphous nature of the SBEs. Analysis of the ionic transport properties reveals that the ionic conductivity of the SBEs is dependent on the ionic mobility (μ) and diffusion of ions (D). TNM analysis confirms that the SBEs are proton conductors.

Ionic Conductivity and Dielectric Properties of CMC Doped NH4SCN Solid Biopolymer Electrolytes

In this work, solid biopolymer electrolytes (SBE) containing carboxymethyl cellulose (CMC) doped with ammonium thiocyanate (NH4SCN) were prepared via solution casting method. The ionic conductivity and dielectric properties of CMC-NH4SCN system were investigated by electrical impedance spectroscopy in the temperature range of 303-353 K. The dc conductivity shows that the highest ionic conductivity of 6.48 x 10-5 Scm-1 at ambient temperature was obtained when 25 wt.% of NH4SCN was incorporated. The temperature dependence of ionic conductivity revealed that CMC-NH4SCN system was discovered to obey Arrhenius law where the regression value is almost unity (R2≈1). Activation energy of CMC-NH4SCN system was found to decrease with the increment of NH4SCN concentration. The dielectric behaviour of the CMC-NH4SCN system have been analyzed using dielectric permittivity (ε*) and electrical modulus (M*) spectra. Results from dielectric studies showed a non-Debye behaviour of CMC-NH4SCN system.

Conductivity and Transport Properties Study of Plasticized Carboxymethyl Cellulose (CMC) Based Solid Biopolymer Electrolytes (SBE)

Solid biopolymer electrolytes (SBE) comprising carboxymethyl cellulose (CMC) with NH4Br-EC were prepared by solution casting method. The samples were characterized by impedance spectroscopy (EIS) and sample containing 25wt. % of NH4Br exhibited the highest room temperature conductivity of 1.12 x 10-4S/cm for salted CMC based SBE system. The ionic conductivity increased to 3.31 x 10-3S/cm when 8 wt. % of ethylene carbonate (EC) was added to the highest conductivity. The conductivity-temperature of plasticized SBE system obeys the Arrhenius relation where the ionic conductivity increases with temperature. The influence of EC addition on unplasticized CMC based SBE was found to be dependent on the number and the mobility of the ions. This results revealed that the influence of plasticizer (EC) which was confirmed play the significant role in enhancement of ionic conductivity for SBE system.