Synthesis of self-healing polyurethane and its application in graphene/SnO2-pillared carbon anode materials

2019 ◽  
Vol 28 (5) ◽  
pp. 348-355
Author(s):  
Young Joon Kwon ◽  
Jeevan Kumar Reddy Modigunta ◽  
AM Shanmugharaj ◽  
Hyung Jin Mun ◽  
Sung Hun Ryu

Self-healing polyurethane (SHPU) containing disulfide was synthesized and used as a binder to investigate its effect on the performance of reduced graphene oxide–tin oxide electrodes compared to those of polyurethane (PU) and poly(vinylidene difluoride) (PVDF) binders in Li-ion battery (LIB). Structural and morphological characterization of the SHPU and electrode was performed using a tensile tester, Fourier transform infrared spectroscopy, X-ray diffractometer, and scanning electron microscopy. Electrochemical performance was investigated using Galvanostatic charge–discharge and electrochemical impedance measurements. The tensile properties and scanning electron microscopy photographs confirmed the self-healing characteristics of the synthesized SHPU. Electrochemical studies were conducted using an RGO-SnO2 electrode. The electrochemical measurements revealed that the SnO2-pillared carbon-based anode materials with SHPU binder showed improved cycling performances with an excellent reversible capacity retention compared to PU or PVDF. After 1000 cycles at 1C, the surface morphology of the electrode with SHPU showed no cracks or dendrites, while the PVDF-based electrode possessed some cracks and dendrites on its surface. The electrochemical results confirmed that SHPU binder improves the electrochemical performance of LIBs.

2021 ◽  
Vol 11 (5) ◽  
pp. 13019-13030

The extract of Justicia secunda (JS) leaves was investigated as an eco‐friendly corrosion inhibitor of aluminum in 0.5 M HCl using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and scanning electron microscopy (SEM) techniques. The inhibitor concentrations used ranged from 50 to 250 ppm at 30, 40, and 50oC. Results show that Justicia secunda acts as a good inhibitor for aluminum. Its efficiency increased with increasing inhibitor concentration but decreased with increasing temperature. Maximum inhibition efficiency as high as 94.3% was found at 30°C for 250 ppm of the inhibitor with the weight loss technique. Tafel polarization results show that the extract acts as a mixed-type inhibitor. The Nyquist plots indicated decreasing double-layer capacitance and increasing charge transfer resistance on increasing JS concentration. The inhibition action occurred through the physical adsorption of the extract on the aluminum surface. The adsorption process was found to follow Langmuir adsorption isotherm. The formation of a protective film on the metal surface was confirmed by scanning electron microscopy.


2011 ◽  
Vol 284-286 ◽  
pp. 1701-1704
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Gao Lin Li

The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.


2008 ◽  
Vol 47-50 ◽  
pp. 173-176 ◽  
Author(s):  
Tao Liu ◽  
Kin Tak Lau ◽  
Shou Gang Chen ◽  
Sha Cheng ◽  
Yan Sheng Yin

A novel super-hydrophobic film was prepared by myristic acid (CH3(CH2)12COOH) chemically adsorbed onto the polyethyleneimine (PEI) coated Fe3Al-type intermetallic wafer. The film character and structure were probed with contact angle measurement, scanning electron microscopy (SEM) and atomic force microscope (AFM). The results suggest that the structure of the film is similar to lotus and the seawater contact angle is larger than 150◦. Moreover, the corrosion resistances of untreated and modified samples in seawater were investigated by electrochemical impedance spectroscopy (EIS). Experimental results show that the corrosion rate of Fe3Al-type intermetallic with super-hydrophobic surface decreases dramatically because of its special microstructure.


2014 ◽  
Vol 633-634 ◽  
pp. 817-820
Author(s):  
Ping Liang ◽  
Yun Xia Zhang ◽  
Yan Hua Shi

To improve the corrosion resistance of Ni-P electroless coating, the KI was added in the electroless solution. The surface micrograph was observed using scanning electron microscopy (SEM), and the corrosion resistance of Ni-P coatings in 3.5%NaCl solution was examined by polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that KI reduced the amount of defects and the size of crystal grain of Ni-P coating, and the surface of Ni-P coating became more homogenous, smoother and compact by KI. In addition, the phosphorus content of Ni-P coating was increased by KI. These factors increased the ability to corrosion protection of Ni-P coating.


2021 ◽  
pp. 295-308 ◽  
Author(s):  
Jagdish C. Bhangoji ◽  
Srikant Sahoo ◽  
Ashis Kumar Satpati ◽  
Suresh S. Shendage

A simple and environment friendly protocol has been developed for the synthesis of Ag nanoparticles (AgNPs) supported on reduced graphene oxide (rGO) with copper metal foil as reductant. The prepared AgNPs-rGO, nanocomposite was characterized by various analytical techniques such as scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD). The electrochemical performance of the material has been evaluated using cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The average crystallite size of AgNPs is found to be 32.34 nm. The application of prepared electrocatalyst (AgNPs-rGO) as a non-enzymatic sensor is examined through the modified electrode with the synthesized AgNPs-rGO. The sensor showed excellent performance toward H2O2 reduction with a sensitivity of 12.73 µA.cm-2.mM-1, with a linear dynamic range of 1.5 µM – 100 mM, and the detection limit of 1.90 µM (S/N = 3). Furthermore, the sensor displayed high sensitivity, reproducibility, stability and selectivity for the determination of H2O2. The results demonstrated that AgNPs-rGO has potential applications as sensing material for quantitative determination of H2O2.


2015 ◽  
Vol 90 (4) ◽  
pp. 581-584 ◽  
Author(s):  
Hiram Larangeira de Almeida Jr. ◽  
Henrique Isaacsson ◽  
Isabelle Maffei Guarenti ◽  
Ricardo Marques e Silva ◽  
Luis Antônio Suita de Castro

2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Gianfranco DiGiuseppe ◽  
Li Sun

This paper reports a new study where relatively long-term tests of about a 1000 h are performed on several planar anode-supported solid oxide fuel cells. The cell electrochemical behaviors are studied by using voltage-current density measurement, electrochemical impedance spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The cell total polarization obtained from electrochemical impedance spectroscopy results is shown to be consistent with the area-specific resistance calculated from the voltage-current density curve over the course of the test. In addition, a four-constant phase element model is used to analyze the cell components resistances at different intervals over the lifetime of the test. Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used postmortem to determine if any damages occurred to the cells and to determine if any change in composition occurred to the lanthanum strontium cobalt ferrite cathode. This study shows that the tested cells remain stable with a relatively small increase in the cell total polarization but with no increase in ohmic resistance.


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