Structural characterization of new poly(ethylene oxide)-based alkaline solid polymer electrolytes

Abstract

ABSTRACT:A new class of alkaline solid polymer electrolytes (SPEs) based on poly(ethylene oxide) (PEO), potassium hydroxide (KOH), and water was investigated. The structure of the SPEs was studied by differential scanning calorimetry, thermogravimetric analysis (TGA), X-ray diffraction, and optical microscopy techniques. The existence of a crystalline complex between PEO, KOH, and H 2 O was evidenced for some compositions, depending on the O/K ratio. A possible structure was proposed, and a schematic phase diagram was established for this PEO-KOH-H 2 O system. The first conductivity measurements also revealed the great interest of these systems, with conductivity values up to 10 03 S/cm.

Investigating miscibility and lithium ion transport in blends of poly(ethylene oxide) with a polyanion containing precisely-spaced delocalized charges

“…Due to a wide variety of reported values of Δ H m 0 that range between 196 and 210 J g −1 , an average value of 203 J g −1 was taken to calculate the degree of crystallinity in PEO. 46–48 The degree of crystallinity reduced from 85% for pure PEO to 73% for EO 0.90 PhTFSI 0.10 and further to 52% for EO 0.70 PhTFSI 0.30 (Fig. 4d).…”

Nickel/Metal Hydride Secondary Batteries Using an Alkaline Solid Polymer Electrolyte

“…As we have mentioned above, the PEO/ KOH/H 2 O solid polymer electrolyte is not cross-linked. Its melting temperature is close to 60ЊC 24 ; that is the reason why the study of the cell behavior at temperatures exceeding 50ЊC was delicate to carry out. Some experiments at 60ЊC were conducted, which revealed problems, probably linked to softening of the solid polymer electrolyte membrane and to a change in the contact between the electrodes and solid polymer electrolyte.…”

Anion exchange membranes for alkaline fuel cells: A review

“…tivity can only be obtained above melting temperature, which limits the operating temperature range. This is why, in the last few years, many approaches have been attempted to reduce the crystallinity of PEO-based electrolytes [105].…”