Thermally Stable Gel Polymer Electrolytes

Abstract

To prepare miscible polyethylene glycol diacrylate/polyvinylidene fluoride (PEGDA/PVdF) blend gel polymer electrolytes, low molecular weight false(M=742false) liquid PEGDA oligomer was mixed with PVdF-HFP dissolved in ethylene carbonate/dimethyl carbonate/ LiPF6 liquid electrolytes, and then cured under ultraviolet irradiation. Room temperature conductivity of PEGDA/PVdF blend films was found to be comparable to that of PVdF-HFP gel polymer electrolytes, and they were electrochemically stable up to 4.6 V vs. normalLi/Li+. Scanning electron micrographs revealed that PEGDA/PVdF blend electrolytes have pore size intermediate between dense PEGDA and highly porous PVdF-HFP. It was confirmed by weight change measurement that liquid electrolyte was likely to evaporate through large pores in PVdF-HFP at 80°C, while PEGDA/PVdF blend showed better liquid electrolyte retention ability. This result was in good agreement with more stable interfacial properties of PEGDA/PVdF blend at 80°C in ac impedance analysis. Consequently, both PVdF-HFP and PEGDA/PVdF gel polymer electrolytes delivered similar discharge capacity at room temperature, but PEGDA/PVdF blend gel polymer electrolyte showed much better cycle performance than pure PVdF-HFP at 80°C. © 2003 The Electrochemical Society. All rights reserved.

Synthesis and characterization of an electrolyte system based on a biodegradable polymer

“…The upper limit of the electrolyte stability was generally taken to be the point of intersection obtained by extrapolating the higher voltage linear current with the x-axis [30] which is found to be 3.7 V for the present case, which is fair enough to construct a zinc primary as well as rechargeable battery based on Zn 2+ intercalating/deintercalating &-MnO 2 electrode, since &-MnO 2 is an extensively used electrode to intercalate/deintercalate Zn 2+ in liquid electrolyte-based rechargeable batteries [31]. Further, cyclic voltammetry was also carried out with a view to obtain an evidence of the zinc plating/ stripping process.…”

Effective influences of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMIMTFSI) ionic liquid on the ion transport properties of micro-porous zinc-ion conducting poly (vinyl chloride) /poly (ethyl methacrylate) blend-based polymer electrolytes

“…As the applied anodic voltage further increases beyond 3.23 V, the anodic current begins to increase steadily which may be ascribed to the irreversible oxidation of anions followed by the degradation of polymeric chains resulting in electrolytic decomposition [38]. Hence the potential at which there is a irreversible onset of the current during the anodic scan establishes the breakdown voltage of the gel polymer electrolyte membranes and the point of intersection of the extrapolated linear current in the high voltage region with the voltage axis gives the breakdown voltage which may be an indication of the decomposition process of the gel polymer electrolyte sample coupled with the electrodes [39]. This suggests that the electrochemical stability window for the obtained GPEs (IL8) based on PVC/PEMA blend is 3.23 V. A very low steady background current prior to this decomposition voltage may be ascribed to the presence of water that could have oozed out of the sample or from the surrounding environment from which the hydroxyl functional groups could have attached to the surface of the stainless steel electrode thereby producing certain changes in the electrode morphology [40].…”

Synthesis and Rate Performance of Monolithic Macroporous Carbon Electrodes for Lithium-Ion Secondary Batteries

“…An alternating current (AC) perturbation of 10 mV was applied to the cell. The electrolyte resistance was determined from the high frequency intercept of the impedance spectrum with the real axis and converted first to resistivity by normalizing resistance to the area and thickness of electrolyte-infiltrated monolithic 3DOM carbon, and then to ionic conductivity, the reciprocal of ionic resistivity [76,77]. …”