Towards the application of carboxymethyl chitin/ionic liquid blend as polymer electrolyte membrane for aqueous batteries.

Carboxymethyl chitin (CMChit) has the potential to be used as a solid polymer electrolyte (SPE) based on its ionic conductivity value of the order of 10-6 S·cm-1 in self-standing membranes. In controlled humidity of 65RH%, carboxymethyl chitin based membrane blended with 1-Butyl-3-methylimidazolium acetate (BMIM[Ac]) ionic liquid (IL) (40 wt%) showed a threshold value of ionic conductivity in the order of 10-4 S·cm-1 and electrochemical stability was up to 2.93 V. The effects of the relative humidity and ionic liquid weight fraction on the ionic conductivity and structural changes were investigated in detail. Furthermore, the X-ray diffraction (XRD) diffractogram indicated a clear reduction of crystallinity of the CMChit. The Field-emission scanning electron microscopy (FESEM) observation of the cross-sections confirmed the homogeneity of the prepared blend. This electrolyte was tested in symmetric cells based on Zn//SPE//Zn and showed good reversibility and potential for application in proton-conducting batteries.

The Influences of 1-Butyl-3-Methylimidazolium Tetrafluoroborate on Electrochemical, Thermal and Structural Studies as Ionic Liquid Gel Polymer Electrolyte.

After decades of development, ionic liquid gel polymer electrolytes (ILGPEs) are currently experiencing a renaissance as a promising electrolyte to be used in electrochemical devices. Their inherent tendency towards poor electrochemical properties have limited their applications and commercialization activities. Henceforth, gel polymer electrolyte (GPE) is being introduced to alleviate the abovementioned issues. In this work, the assessment of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] in poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) to form ILGPE was done. The relationship of [BMIM][BF4] towards the dielectric properties at different wt. % ratios and temperature was ascertained. The results indicated that [BMIM]BF4 is able to facilitate fast conduction. Moreover, it was found that [BMIM][BF4] could serve as an effective agent in reducing crystallinity and glass transition temperature of the polymer and thus enhanced the ionic conductivity of the samples. Notwithstanding, the ILGPE sample possessed a high thermal stability up to 300 °C and good electrochemical stability of 4.2 V which are beneficial for operation in electrochemical devices. All in all, the correlation between the ionic liquid chemistry and electrochemical performances could provide a valuable insight to rational selection and design for ILGPE electrolytes.