A novel flexible, high performing chitosan-based gel electrolyte with poly (vinyl alcohol) (PVA) and potassium hydroxide (KOH) additives is prepared, using an optimized energy and time efficient method. Incorporation of a gelbased electrolyte in batteries aims to eliminate safety hazards present within conventional liquid-based electrolyte constructions. The ionic conductivity values obtained at room temperature are in the range of 5.32-105 mS/cm depending on composition. Optical, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectra studies are conducted to understand morphological and structural changes in the films with additives.Thermogravimetric analysis, manual bending and tensile tests, linear scan and cyclic voltammetry analysis are also conducted to study the physical and electrochemical stability of the films. Also, the prepared electrolytes are incorporated to form Zn-MnO 2 batteries and tested. Results reveal no physical damage of the films under continuous bending over 250 cycles. Mechanical properties for CPK0.3 suggest a strong and ductile material well suited for the intended application. Additionally, the novel electrolyte exhibits excellent physical stability up to 50 ο C, electrochemical stability until 2 V for zinc electrodes and prove to successfully accommodate redox reactions involved in the Zn-MnO 2 alkaline system.
A high-performing flexible chitosan-based gel electrolyte with poly(vinyl alcohol) (PVA) additive was prepared and swelled in varying concentrations of potassium hydroxide (KOH) solutions. A highest ionic conductivity of 457 mS/cm was recorded for the sample with a 2.1 swelling ratio, obtained by soaking in a 5 M KOH solution for 45 min. Stability test results demonstrated the prepared electrolyte to be strong and ductile along with stability under 50 °C and 2 V. Zn-EMD batteries were constructed with the prepared electrolyte using an optimized assembly technique employed to achieve good interfacial contact between the layers. Continuous charge–discharge tests were performed on the batteries at a current density of 0.1 A/g in specific limited and extended potential regions (low: 0.4–1.2 V and high: 0.4–1.6 V) to explore their performance and reversibility. Results indicated that the batteries cycled in the low region had higher capacity retention due to lower δ-MnO2 formations when compared to those in the high region cycling. To fully understand its performance capability, the battery was further tested extensively. Results indicated a good rate and initial bending performance of the battery with a maximum specific capacity of 310 mAh/g at 0.1 A/g. Additionally, the battery tested at 0.5 A/g showed an average specific capacity of 175 mAh/g over 300 cycles with a 96.5% Coulombic efficiency. Attaining energy densities between 150.4 and 252.4 Wh/kg (w.r.t. active cathode mass) is possible for these batteries, thus encouraging their use in varied applications. Utilizing chitosan gel electrolyte and limited voltage window testing, the prepared Zn-EMD alkaline batteries are among the first reported polymer-based alkaline electrolyte Zn rechargeable batteries with no cathode additives.
Thermoelectric generators (TEGs) fabricated using additive manufacturing methods are attractive because they offer the advantages of scalability, lower cost, and potentially higher power density than conventional TEGs. Additive manufacturing of TEGs requires active thermoelectric particles to be dispersed in a polymer binder to synthesize printable slurries, and printed films to be subsequently subjected to a long and high temperature curing to enhance their thermoelectic properties. A large amount of polymer binder present in composite films results in a sizable loss in the electrical conductivity. In addition, a long and high-temperature film curing results is a slow and energy intensive fabrication process. In this work, we demonstrate the feasibility of using a small amount (≤10 −3 wt ratio) of novel nanofiber cellulose (NFC) as a binder to provide sufficient adhesion strength to hold the TE particles together in the composite films. We also demonstrate a pressure induced densification process to enhance the thermoelectic properties of printed composite films. This novel approach has the potential to fundamentally transform the manufacting method for printing TEGs by eliminating the need of long-duration and high-temperature curing. A higher applied pressure leads to a compact packing and densification of films resulting in an improvement in the electrical conductivity. The highest power factor achieved for best performing p-type thermoelectric-NFC composite film subjected to pressure induced densification is 611 μW/m-K 2 .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.