Nafion Coated Mg50Ni50 and (La,Mg)2Ni7 Negative Electrodes for NiMH Batteries

2018-01-01
Eyovge, Cavit
Öztürk, Tayfur
A study is carried out to develop a surface modified Mg based alloy with an improved discharge capacity that would be durable in alkaline environment. For this purpose, Mg50Ni50 alloy is synthesized via ball milling of elemental powders and tested electrochemically in both bare and nafion coated form. The study shows that the bare electrode yields an acceptable discharge capacity but subject to a fast capacity decay. Nafion coating is effective in reducing the capacity decay where the discharge capacity after 20 cycle is as high as 82% of the initial capacity. The study further shows that there is a substantial increase in the discharge capacity of the electrode with nafion coating. This is also investigated with a more traditional alloy of (La0.70Mg0.30)(2)(Ni0.85Co0.15)(7). The capacities which are 329 and 334 mAh/g in bare electrodes, in the first cycle, are increased to 498 and 448 mAh/g with nafion coating for Mg50Ni50 and La0.70Mg0.30)(2)(Ni0.85Co0.15)(7) respectively. It is proposed that the increase in discharge capacity is due to the increase in local hydrogen pressure at electrode-nafion interface made possible by the nafion envelope resulting in the increased hydrogen storage in the active powders. (C) 2018 The Electrochemical Society.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY

Suggestions

Micro processing by intense fast electron beam
Goktas, H; Kirkici, H; Oke, G; Udrea, M (2001-06-22)
Generation of intense electron beams by superposing two discharges, namely a low pressure do glow discharge and a high current pulsed discharge at pressures and voltages very similar to that of the pseudo-spark gap devices, has been reported previously [1, 2]. The small diameter, high peak current and short pulse length are the characteristics of the electron beam generated using this technique. In this technique, no high vacuum facilities are necessary, and many applications such as micro processing, X-ray...
Numerical modeling of visco-elasto-plastic hygro-thermal stresses and the effects of operating conditions on the mechanical degradation of PEFC membranes
Mehrtash, Mehdi; Tarı, İlker; YEŞİLYURT, SERHAT (2018-08-31)
Durability of membranes is one of the concerns for widespread commercialization of polymer electrolyte fuel cells. Effects of membrane swelling on the durability pose important challenges for the fabrication of the catalyst-coated membrane. This study provides insight into vulnerable locations of the membrane under hygrothermal loading, mechanical loading due to clamping and realistic conditions where a combination of both of these loadings are imposed. With a half rib-channel model, we simulate a polymer e...
Nafion/titanium silicon oxide nanocomposite membranes for PEM fuel cells
DEVRİM, YILSER; Erkan, Serdar; BAÇ, NURCAN; Eroğlu, İnci (2013-04-01)
In the present study, Nafion/Titanium Silicon Oxide (TiSiO4) nanocomposite membranes were prepared by recasting method for proton exchange membrane fuel cells. The composite membrane containing 10wt% TiSiO4 had a membrane thickness of 80 mu m. The membrane was characterized by thermogravimetric analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). SEM and XRD results have proven the uniform and homogeneous distribution of TiSiO4 in Nafion, and consequently, the crystalline character of ...
Anodization of 316L stainless steel for implant applications
Erdoğan, Yaşar Kemal; Ercan, Batur (2021-06-10)
316L stainless steel (SS) surfaces were modified via anodization to form nanopit structures with aim of improving its corrosion resistance, bone cell adhesion, proliferation and enhance its bioactivity. Surface characterization studies revealed that nanopit structures were composed of Fe2O3 and Cr2O3. The in vitro results showed that nanopit surfaces enhanced bone cell proliferation. Thus, we concluded that fabrication of nanostructures on 316L SS surfaces is a promising way to enhance bone cell functions f...
Electrochemical polymerization of 1-(4-nitrophenyl)-2,5-di(2-thienyl)-1 H-pyrrole as a novel immobilization platform for microbial sensing
Tuncagil, Sevinc; ODACI DEMİRKOL, DİLEK; Varis, Serhat; TİMUR, SUNA; Toppare, Levent Kamil (2009-09-01)
Two types of bacterial biosensor were constructed by immobilization of Gluconobacter oxydans and Pseudomonas fluorescens cells on graphite electrodes modified with the conducting polymer; poly(1-(4-nitrophenyl)-2,5-di(2-thienyl)-1 H-pyrrole) [SNS(NO2)]. The measurement was based on the respiratory activity of cells estimated by the oxygen consumption at -0.7 V due to the metabolic activity in the presence of substrate. As well as analytical characterization, the linear detection ranges, effects of electropo...
Citation Formats
C. Eyovge and T. Öztürk, “Nafion Coated Mg50Ni50 and (La,Mg)2Ni7 Negative Electrodes for NiMH Batteries,” JOURNAL OF THE ELECTROCHEMICAL SOCIETY, pp. 0–0, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32391.