Effect of acid dopants in biodegradable gel polymer electrolyte and the performance in an electrochemical double layer capacitor

Abstract

Proton-conducting biodegradable gellan gum gel polymer electrolytes (GPEs) have been prepared using three different dopants, namely ortho-phosphoric (o-H 3 PO 4 ), sulfuric (H 2 SO 4 ) and hydrochloric acids (HCl). The GPEs were cross-linked using borax. The polymeric gels were characterized by spectroscopic, thermal, ionic conductivities and dielectric measurements. Proton conductivity was in the range of 5.1×10 −3 to 3.7×10 −4 s cm −1 and activation energies were between 0.14 meV and 0.19 meV, at different temperatures. Among the doped acids, the H 3 PO 4 doped GPE exhibited thermal stability at varying temperature. Electrochemical double layer capacitors (EDLCs) were fabricated using activated carbon as electrode material and GPEs. The EDLCs were tested using cyclic voltammetry, ac impedance spectroscopic and galvanostatic charge-discharge techniques. The maximum specific capacitance value was 146 F g −1 at a scan rate of 2 mV s −1 . Quite stable values were obtained at a constant current density up to 1000 cycles.

Water-in-Acid Gel Polymer Electrolyte Realized through a Phosphoric Acid-Enriched Polyelectrolyte Matrix toward Solid-State Supercapacitors

“…It is worth mentioning that the water-in-acid PGPEs reported in this work exhibit a far higher ionic conductivity (9.8 × 10 –2 S cm –1 ) value than the conventional quasi-solid-state and many other free-standing solid-state GPEs reported in the literature (summarized in Table S1, Supporting Information). ,,,− Compared to the other GPEs mentioned in Table S1, the presence of a high degree of functional group moieties which can favor hydrogen bonding along with a high concentration of the encapsulated proton-conducting species in P­(HEMA- co -AOETMA) facilitates high ionic conductivity of the He-Ao-Ac-sw GPE. This is in accordance with the hydrogen-bonding interactions proved from the FTIR spectra provided in Figure b and Figure S4 (Supporting Information).…”

Bacterial-Polymer-Based Electrolytes: Recent Progress and Applications

“…Singh et al used KI salt (40 wt %) in a simple casting method with gellan, which exhibited 2.5 × 10 –2 S cm –1 conductivity . Lastly, Sudhakar et al prepared borax-cross-linked gellan-based electrolytes with different acid dopants (H 3 PO 4 , H 2 SO 4 , and HCl) The maximum conductivity of 5.1 × 10 –3 S cm –1 was obtained by adding H 3 PO 4 at 35 °C.…”