Li_1.3Al_0.3Ti_1.7(PO₄)₃ filler effect on (PEO)LiClO₄ solid polymer electrolyte

Abstract

Composite polymer electrolyte (CPE) films consisting of PEO, LiClO 4 , and Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 with fixed EO/Li ϭ 8 but different relative compositions of the two lithium salts were prepared by the solution casting method. The CPE films were characterized using SEM, DSC, electrical impedance spectroscopy (EIS), and ion transference number measurement. It was found that the incorporation of LiClO 4 and Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 into PEO by keeping EO/Li ϭ 8 reduced the crystallinity of PEO from 50.34% to the range of 3.57-15.63% depending upon the relative composition of the two salts. The room temperature impedance spectra of the CPE films all exhibited a shape of depressed semicircle in the high frequency range and inclined line in the low frequency range, but the high temperature ones were mainly inclined lines. The Li ϩ ionic conductivity of the CPE films mildly increased and then decreased with increasing Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 content, and the maximum conductivities were obtained at Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 content of 15 wt % for all measuring temperatures, for example, 1.378 ϫ 10 Ϫ3 S/cm at 100°C and 1.387 ϫ 10 Ϫ5 S/cm at 25°C. The temperature dependence of the ionic conductivity of the CPE films follows the Vogel-Tamman-Fulcher (VTF) equationThe pseudo activation energies (E a ) were rather low, 0.053-0.062 eV, indicating an easy migration of Li ϩ in the amorphous phase dominant PEO. The pre-exponent constant A and ion transference number t Liϩ were found to have a similar variation tendency with increasing Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 content and reached their maximums also at Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 content of 15 wt %.

Characterization of (PEO)LiClO4‐Li1.3Al0.3Ti1.7(PO4)3 composite polymer electrolytes with different molecular weights of PEO

“…Ceramic powders, such as Al 2 O 3 , SiO 2 , and Li 3 N, may be added as fillers to improve the ionic conductivity but to preserve the mechanical strength and stability of the electrode/electrolyte interface 11–13. Instead of nonconducting oxides, fast ionic conductors (FIC), e.g., Li 1.4 Al 0.4 Ge 1.7 (PO 4 ) 3 and 14Li 2 O‐9Al 2 O 3 ‐38TiO 2 ‐39P 2 O 5 used as fillers in the PEO‐based CPE films and their positive effects on both mechanical properties and ionic conductivity were reported by Leo et al and Zhang et al14–16 Recently, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 filler effect on (PEO)LiClO 4 solid polymer electrolyte was reported by the authors 17. The (PEO)LiClO 4 ‐Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 CPE films with overall EO/Li = 8 and 15 wt % Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 had the optimum ionic conductivity, i.e., 1.387 × 10 −5 S/cm at room temperature and 1.378 × 10 −5 S/cm at 373 K 17.…”

“…Instead of nonconducting oxides, fast ionic conductors (FIC), e.g., Li 1.4 Al 0.4 Ge 1.7 (PO 4 ) 3 and 14Li 2 O‐9Al 2 O 3 ‐38TiO 2 ‐39P 2 O 5 used as fillers in the PEO‐based CPE films and their positive effects on both mechanical properties and ionic conductivity were reported by Leo et al and Zhang et al14–16 Recently, Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 filler effect on (PEO)LiClO 4 solid polymer electrolyte was reported by the authors 17. The (PEO)LiClO 4 ‐Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 CPE films with overall EO/Li = 8 and 15 wt % Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 had the optimum ionic conductivity, i.e., 1.387 × 10 −5 S/cm at room temperature and 1.378 × 10 −5 S/cm at 373 K 17. This work extends the study to the investigation of (PEO)LiClO 4 ‐Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 CPE films with overall EO/Li = 8 and 15 wt % Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 but different molecular weight of PEO.…”

Characterization of [poly(ethylene oxide)]LiClO–Li1.3Al0.3Ti1.7(PO4)3 composite polymer electrolytes with poly(ethylene oxide)s of different molecular weights

“…Ceramic powders, such as Al 2 O 3 , SiO 2 , and Li 3 N, can be added as fillers to improve the ionic conductivity (σ) and preserve the mechanical strength and stability of the electrode/electrolyte interface 11–13. Instead of nonconducting oxides, fast ionic conductors, such as Li 1.4 Al 0.4 Ge 1.7 (PO 4 ) 3 and 14Li 2 O–9Al 2 O 3 –38TiO 2 –39P 2 O 5 , have been used as fillers in PEO‐based composite polymer electrolyte (CPE) films, and their positive effects on both the mechanical properties and σ were reported by Leo and coworkers14, 15 and Zhang et al16 Recently, we reported the Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 filler effect on (PEO)LiClO 4 SPE 17. (PEO)LiClO 4 –Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 CPE films with an overall ethylene oxide (EO)/Li ratio of 8 and 15 wt % Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 had optimum σ values, that is, 1.387 × 10 −5 S/cm at room temperature and 1.378 × 10 −5 S/cm at 373 K 17.…”

“…Instead of nonconducting oxides, fast ionic conductors, such as Li 1.4 Al 0.4 Ge 1.7 (PO 4 ) 3 and 14Li 2 O–9Al 2 O 3 –38TiO 2 –39P 2 O 5 , have been used as fillers in PEO‐based composite polymer electrolyte (CPE) films, and their positive effects on both the mechanical properties and σ were reported by Leo and coworkers14, 15 and Zhang et al16 Recently, we reported the Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 filler effect on (PEO)LiClO 4 SPE 17. (PEO)LiClO 4 –Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 CPE films with an overall ethylene oxide (EO)/Li ratio of 8 and 15 wt % Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 had optimum σ values, that is, 1.387 × 10 −5 S/cm at room temperature and 1.378 × 10 −5 S/cm at 373 K 17. This article extends the study to the investigation of (PEO)LiClO 4 –Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 CPE films with an overall EO/Li ratio of 8 and 15 wt % Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 but PEOs of different molecular weights.…”

PEGDA/PVdF/F127 gel type polymer electrolyte membranes for lithium secondary batteries

“…A significant drawback of this conventional electrolyte system is low conductivity at room temperature. Since various approaches involving the addition of ceramic fillers/additives and polar plasticizers in literatures [7][8][9][10][11][12][13][14], the fabrication of gel type polymer electrolyte (GPE) system becomes a promising approach to create high ionic conductivity with other desirable properties. Some polymers such as poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), poly(vinylidene fluoride) (PVdF), polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA) and poly(vinyl chloride) (PVC) have been employed in the fabrication of GPEs.…”