Enhanced ionic conductivity in nano-composite solid polymer electrolyte: (PEG) x LiBr: y(SiO2)

Abstract

In this paper, we report an enhancement in ionic conductivity in a new nano-composite solid polymer electrolyte namely, (PEG) x LiBr: y(SiO 2 ). The samples were prepared, characterized, and investigated by XRD, IR, NMR, and impedance spectroscopy. Conductivity as a function of salt concentration shows a double peak. Five weight percent addition of silica nanoparticles increases the ionic conductivity by two orders of magnitude. Conductivity exhibits an Arrhenius type dependence on temperature. IR study has shown that the existence of nanoparticles in the vicinity of terminal O-H group results in a shift in IR absorption frequency and increase in amplitude of vibration of the terminal O-H group. This might lead to an enhancement in conductivity due to increased segmental motion of the polymer. 7 Li NMR spectroscopic studies also seem to support this. Thus addition of nanoparticle inert fillers still seems to be a promising technique to enhance the ionic conductivity in solid polymer electrolytes.

Role of Dynamically Frustrated Bond Disorder in a Li+ Superionic Solid Electrolyte

“…In fact, the hypothesis that beyond Coulombic interactions in the cation–anion bond could be responsible for lowering diffusion barriers in alkali halides dates back to early theory studies (LiBr itself features a vacancy migration barrier of 0.35 eV, unusually low among those of ionic salts) . Moreover, there are several reports of LiBr-based fast ion conductors, further suggesting the Li–Br interaction can be leveraged for enhanced ionic conductivity. − …”

Studies on Composite PVA-CA-NH4CF3SO3-Al2O3 Polymer Electrolyte for Electrochemical Devices

“…7 shows the logarithm of conductivity with the reciprocal of absolute temperature for PVA-CA-AT-x Al 2 O 3 (x = 0, 0.06, 0.08, 01 and 0.3 mol) composite polymer electrolytes and the plots are not completely linear as predicted by Arrhenius equation. Usually, the polymer electrolyte exhibits one of the five behaviours [25,26], thus our system exhibits Arrhenius behaviour at low temperature and VTF behaviour at high temperature and our results are comparable with those obtained by Huang et al [25]. The enhancement of conductivity values with increasing temperature for all the nano-Al2O3 added composite electrolytes can be attributed to the increase in flexibility in the polymer chain due to the decrease in their viscosity and Lewis acidbase type of interaction between the migrating ions and the O/ OH groups on the Al2O3 surface; thus adsorption of anions on to the surface of Al2O3 reduces ion pairing, creating additional hopping sites for ionic motion [7].…”

Dielectric Relaxation Study on TiO₂ Based Nanocomposite Blend Polymer Electrolytes

“…Further improvement in ambient temperature ionic conductivity is achieved by dispersing inorganic nano-sized filler particles such as Al 2 O 3 [4], SiO 2 [5], TiO 2 [6], ZrO 2 [7] etc in the polymer matrices. The incorporated nano fillers hinder the crystallization kinetics and promote the retention of amorphous phase [8].…”