Immittance Studies of DBP Plasticized Salicylic Acid Doped PMMA Based Gel Electrolytes

2006 ◽  
Vol 517 ◽  
pp. 97-100 ◽  
Author(s):  
M.I.N. Isa ◽  
S.R. Majid ◽  
A.K. Arof
Keyword(s):  
Activation Energy ◽  
Salicylic Acid ◽  
Room Temperature ◽  
Ethylene Carbonate ◽  
Gel Electrolyte ◽  
Electrolyte System ◽  
Conductivity Activation Energy ◽  
Gel Electrolytes ◽  
Tan Δ ◽  
Oxygen Site

A gel electrolyte system was prepared by dissolving poly(methyl methacrylate) in ethylene carbonate and propylene carbonate doped with salicylic acid and plasticized with dibutylphthalate (DBP). The gel was heated to 70 0C before it was cast into glass dishes. The composition of the electrolytes was 35 wt% EC, 30 wt% PC, 5 wt% SA, 5wt% DBP and 25 wt% PMMA. The gel electrolyte was sandwiched between two stainless-steel blocking electrodes and impedance measurements were conducted. The conductivity of the gel electrolyte was 2.03 x 10-4 S cm-1 at room temperature. The conductivity activation energy was obtained from the log σ versus 103/T graph. Loss tangent was calculated at every frequency for all temperatures. From the tan δ versus frequency plot, the activation energy of relaxation of the ion was calculated and plotted as ln τ versus 103/T. The conductivity activation energy value was (0.21 ± 0.04) eV and the activation energy of relaxation was (0.24±0.07) eV. The similarity between these activation energies imply that the protons ‘hop’ from one electronegative oxygen site in DBP to another.

Salicylic Acid and Dibuthyl Phatalate (DBP) Interaction in PMMA-Based Gel Electrolytes

2006 ◽  
Vol 517 ◽  
pp. 294-0
Author(s):  
M.I.N. Isa ◽  
A.K. Arof
Keyword(s):  
Salicylic Acid ◽  
Methyl Methacrylate ◽  
Propylene Carbonate ◽  
Dibutyl Phthalate ◽  
Ethylene Carbonate ◽  
Gel Electrolyte ◽  
Electrolyte System ◽  
Poly Methyl Methacrylate ◽  
Gel Electrolytes

A gel electrolyte system was prepared by dissolving poly(methyl methacrylate) (PMMA) in ethylene carbonate (EC) and propylene carbonate (PC) doped with salicylic acid (SA) and plasticized with dibutyl phthalate (DBP). The composition of the electrolyte was 35 wt% EC-30 wt% PC-5 wt% SA-5wt% DBP-25 wt% PMMA. The presence of a hump at ~760 cm-1 and a shoulder at 1155 cm-1 in the spectrum of SA-DBP indicate the protonation of DBP. The effect of these bands can also be observed in the spectrum of the gel. Hence, SA has dissociated producing H+ which then interacts datively at the oxygen sites of DBP.

Gel Electrolyte Based Supercapacitors with Higher Capacitances and Lower Resistances than Devices with a Liquid Electrolyte

MRS Advances ◽  
2018 ◽  
Vol 3 (22) ◽  
pp. 1261-1267 ◽  
Author(s):  
Belqasem Aljafari ◽  
Arash Takshi
Keyword(s):  
Polymer Electrolytes ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Liquid Electrolyte ◽  
Gel Electrolyte ◽  
Superior Performance ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Gel Electrolytes ◽  
Further Development

ABSTRACTRecently, gel polymer electrolytes (GPEs) have been drawn noteworthy attention for different applications, specifically, for supercapacitors. GPEs could become an excellent substitute to liquid electrolytes (LEs) for making flexible and more durable devices. The performance of two different electrolytes (GPEs and LEs) in multi-wall carbon nanotube based supercapacitors were investigated. In spite of significantly lower conductivity of GPEs than LEs, devices with the gel electrolyte presented a superior performance. More focused has been given in this work on demonstrating the performance of supercapacitors based on GPEs and LEs at different concentrations of the acids ranging from 1M to 3M. Both electrolytes have been characterized at room temperature by making supercapacitors and using cyclic voltammetry, charging-discharging, electrochemical impedance spectroscopy, and leakage tests. The experimental results showed that GPE devices had much better capacitances and resistances compare to the LE based devices. Moreover, the capacitances of all devices were increased proportionally with the increase in the concentration from 1M to 3M, and the resistances were increased inversely with the decreased of concentration. The promising results from the gel electrolytes is encouraging for further development of flexible and high capacitance energy storage devices.

scholarly journals Mechanical behavior and electrical conductivity of zinc-oxide ceramics

2020 ◽  
Vol 2020 (01) ◽  
pp. 46-54
Author(s):  
Y. M. Ostroverkh ◽  
◽  
I. O. Polishko ◽  
D. M. Brodnikovskyi ◽  
L. L. Kovalenko ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Zinc Oxide ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Type I ◽  
Type Ii ◽  
Conductivity Activation Energy ◽  
Zno Powder ◽  
Zno Ceramics

Ceramics sintered from zinc oxide powders, which differ in crystal structure, particle size and amount and type of impurities, have been studied for their mechanical behavior (strength and micromechanisms of biaxial bending at room temperature) and electrical conductivity depending on the purity of ZnO powder (99,9% byweight — type I and 99,5% byweight — type II) and its sintering temperature in the interval from 800 to 1250 ºC for 2 hours. It is found that the maximum values of strength and electrical conductivity are achieved in ZnO-ceramics sintered at temperatures of 1100—1200 and 1000—1150 ºC, respectively, and their micromechanism of fracture is the cleavage only. ZnO-powder developed (type II), being twice as large as the purchased (type I), 300—350 nm instead of 150—200 nm, provides close to 100% density at 1100 °C, the type II powder is sintering at almost 100 °C lower temperature than the purchased one. Type I ceramics provide biaxial strength at room temperature of 150—170 MPa; type II — 120—160 MPa. ZnO-ceramics from powders of both types provide maximum electrical conductivities of 8,54 10-3S/ cm and 1,6·10-3 S / cm at temperatures of 265 and 600 ºC, respectively. The activation energy of the electrical conductivity of ZnO-ceramics is dependent significantly on the properties of the powder and, accordingly, the structure of the ceramics and the test temperature. Type I ZnO ceramics have a lower conductivity activation energy than type II, 0,2—0,3 eVand 0,3—0,5 eV, respectively. The mechanism of electrical conductivity of ZnO-ceramics type I is practically unchanged in all the interval of testing temperatures, from the room one to 600 °C. In ZnO-ceramics of the type II, it changes at least twice. Keywords: zinc oxide, ZnO ceramics, sintering temperature, porosity, grain size, micromechanism of fracture, bending strength, electrical conductivity, activation energy.

A silica-based gel electrolyte system for improving the cycle performance of LiFePO4 batteries in an aqueous medium

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 2176-2182 ◽  
Author(s):  
J. L. Pan ◽  
Y. Yin ◽  
Y. H. Wen ◽  
S. L. Bai ◽  
J. Cheng ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Cycling Performance ◽  
Gel Electrolyte ◽  
Cycle Performance ◽  
Electrolyte System ◽  
Gel Electrolytes ◽  
P Cycling

Cycling performance of LiFePO4 electrodes in aqueous and gel electrolytes at a 0.5C rate.

Deposition and Characterization of Near “Intrinsic” μc-Si Films Deposited by Remote Plasma-Enhanced Chemical-Vapor Deposition - RPECVD

1991 ◽  
Vol 219 ◽  
Author(s):  
M. J. Williams ◽  
C. Wang ◽  
G. Lucovsky
Keyword(s):  
Activation Energy ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Boron Concentration ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Conductivity Activation Energy ◽  
Boron Doped ◽  
Si Films

ABSTRACTUndoped films of μc-Si deposited by RPECVD are n-type with a room temperature dark conductivity of ∼6×10-4 S/cm and an activation energy of ∼0.3 eV. This is due to native donor-like defects. We report on the conductivity and photoconductivity of boron-doped μc-Si, with emphasis on low doping levels that are designed to compensate exactly these native donor-like defects. We describe the dark conductivity and the photoconductivity as functions of dark conductivity activation energy and the average boron concentration, and present a model for the photoconductivity based on band off sets between the crystalline and amorphous regions of the μc-Si.

Effect of Different Filler Groups on Ionic Behavior of PVdF Gel Electrolyte System

2014 ◽  
Vol 1 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Mrigank Dwivedi ◽  
◽  
Nidhi Asthana ◽  
Kamlesh Pandey
Keyword(s):  
Gel Electrolyte ◽  
Electrolyte System

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

Insights into the synergistic role of metal–lattice oxygen site pairs in four-centered C–H bond activation of methane: the case of CuO

2016 ◽  
Vol 6 (11) ◽  
pp. 3984-3996 ◽  
Author(s):  
Jithin John Varghese ◽  
Quang Thang Trinh ◽  
Samir H. Mushrif
Keyword(s):  
Activation Energy ◽  
Copper Oxide ◽  
Bond Activation ◽  
Lattice Oxygen ◽  
Oxide Surfaces ◽  
Energy Barriers ◽  
Metal Lattice ◽  
Oxygen Site ◽  
Site Pair

Of the three mechanisms for activation of methane on copper and copper oxide surfaces, the under-coordinated Cu–O site pair mediated mechanism on CuO surfaces has the lowest activation energy barriers.

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