Hybrid Gel Electrolytes Derived from Keggin-Type Polyoxometalates and Imidazolium-Based Ionic Liquid with Enhanced Electrochemical Stability and Fast Ionic Conductivity

Abstract

New hybrid gel electrolytes, derived from synergetic self-assembling of inorganic polyoxometalates (POMs) and organic ionic liquid (IL) components, have been successfully prepared using Keggin-type heteropolyanions such as {PMo 11 VO 40 } 4− and {PW 11 MoO 40 } 3− and ionic liquid N-methyl imidazolium-1-(3sulfonic group) propyl (MIMPS). Powder X-ray diffraction study reveals that these hybrid gels possess lamellar structure and exhibit characteristic thermo-tropic liquidcrystalline behavior. Ionic conductivity (σ) of ∼0.1 S cm −1 under ambient conduction was observed at 93 °C for [MIMPS] 4 PMo 11 VO 40 (IL-PMo 11 V) and [MIMPS] 3 PW 11 MoO 40 (IL-PW 11 Mo) hybrid gels. The electrochemical stability window (ESW) of IL-PMo 11 V and IL-PW 11 Mo seem to be about 2 and 4 V, respectively, at room temperature. The POM-based IL gel electrolytes show super ionic conductivity and high ESW compared to other known IL-based electrolytes, including 1-dodecyl-3-methylimidazolium-bis(pentafluoro-ethylsolfonyl)imide (σ = 0.003 S cm −1 at 94 °C, ESW = 3.5 V), 1-dodecylimidazolium-bis(pentafluoroethylsolfonyl)imide (σ = 0.002 S cm −1 at 94 °C, ESW = 3 V), SiO 2 /1-methy-3-propylpiperidinium/bis(trifluoro methanesulphonyl)imide (σ = 0.014 S cm −1 at 85 °C, ESW = 1.5 V), and 1-ethyl-3-methylimidazolium tetracyanoborate/ poly(vinylidene fluride-co-hexafluoropropylene (σ = 0.027 S cm −1 at 90 °C, ESW = 3.8 V).

The synthesis and electrical properties of hybrid gel electrolytes derived from Keggin-type heteropoly acids and 3-(pyridin-1-ium-1-yl)propane-1-sulfonate (PyPs)

“…[17][18][19][20][21] Various hybrid gels were developed using POMs and ILs such as Nmethyl imidazolium-1-(3-sulfonic group) propyl (MIMPS), 3-(pyridine-1-ium-1-yl)propane-1-sulfonate (PyPs), 1-(3-sulfonic group) triethylamine (TEAPS) and N-propyl-N-methylpiperidinium hexauorophosphate. [22][23][24][25][26][27][28][29][30] Several heteropoly acids (HPAs) and polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) hybrids were also recently reported. 28 Herein, we report the synthesis and structural, chemical and electrochemical characterization of hybrid gel electrolytes based on recently developed 3-(pyridin-1-ium-1-yl)propane-1sulfonate (PyPs) 24 IL and H 3 PW 11 MoO 40 , H 4 PMo 11 VO 40 and H 5 PMo 11 V 2 O 40 for potential electrochemical energy conversion and storage applications.…”

Polyoxometalates: Tailoring metal oxides in molecular dimension toward energy applications

“…301 Novel structures are prepared by hybridizing polyoxometalates and other substrates, 302,303 while polyoxomolybdates are employed in a number of applications owing to their versatile properties. 4,49,89,228,[304][305][306][307][308][309][310][311] 7 | POLYOXOVANADATE Vanadium oxide enjoys high coefficient of thermal resistance and has been applied to vanadium redox batteries and various catalysts. [312][313][314] Vanadium-containing polyoxometalates have been used in dye-sensitized solar cells via as cosensitizers 84 and as precursors for solar conversion photoanode synthesis such as BiVO 4 .…”

Synthesis and Characterization of a Novel Polyoxometalate Gel Electrolyte

“…Some research in material science area pay more attention to the electrochemical performance of these compounds since they are perfect electron acceptors. [6][7][8][9][10] The electrochemical performance of polyoxometalate will provide insights into developing electrochemical electrolytes based on heteropolyacids or polyoxometalate, such as phase transformation electrolytes.…”