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Lithium Air Battery: Alternate Energy Resource for the Future
Zahoor, Awan,Christy, Maria,Hwang, Yun-Ju,Nahm, Kee-Suk The Korean Electrochemical Society 2012 Journal of electrochemical science and technology Vol.3 No.1
Increasing demand of energy, the depletion of fossil fuel reserves, energy security and the climate change have forced us to look upon alternate energy resources. For today's electric vehicles that run on lithium-ion batteries, one of the biggest downsides is the limited range between recharging. Over the past several years, researchers have been working on lithium-air battery. These batteries could significantly increase the range of electric vehicles due to their high energy density, which could theoretically be equal to the energy density of gasoline. Li-air batteries are potentially viable ultra-high energy density chemical power sources, which could potentially offer specific energies up to 3000 $Whkg^{-1}$ being rechargeable. This paper provides a review on Lithium air battery as alternate energy resource for the future.
Jang, Hosaeng,Zahoor, Awan,Kim, Yongbin,Christy, Maria,Oh, Mi Young,Aravindan, Vanchiappan,Lee, Yun Sung,Nahm, Kee Suk Elsevier 2016 ELECTROCHIMICA ACTA Vol.212 No.-
<P><B>Abstract</B></P> <P>We have synthesized three dimensional architectural α–MnO<SUB>2</SUB>/RuO<SUB>2</SUB> hybrid nanostructures with three different compositions of (75:25), (69:31) and (50:50) by hydrothermal approach and evaluated their bifunctional electrocatalytic activity for Li–O<SUB>2</SUB> battery applications. The morphology of the α–MnO<SUB>2</SUB>/RuO<SUB>2</SUB> nanostructures changed from sharp sea urchins to solid nanospheres with increasing RuO<SUB>2</SUB> content in the composition. The variations observed in physical, structural, morphological and electrochemical properties were characterized with respect to the MnO<SUB>2</SUB>/RuO<SUB>2</SUB> concentrations by step by step analyses. MnO<SUB>2</SUB> exhibited better ORR catalytic activity, while RuO<SUB>2</SUB> revealed superior OER catalytic activity. Among the concentrations investigated, α–MnO<SUB>2</SUB>:RuO<SUB>2</SUB> (75:25) exhibited superior catalytic activity for oxygen reduction and evolution reactions in aqueous media. This excellent catalytic activity logically led us to apply it as air-cathode catalyst in Li–O<SUB>2</SUB> cell, which produced a maximum capacity of >8100mAhg<SUP>−1</SUP> with high columbic efficiency and cyclability. The superior performance of the hybrid nanostructure is mainly attributed to its structural and compositional design which favors the electrochemical activity. Based on a careful investigation on the structural characterizations, the growth mechanism of the 3D nanostructured α–MnO<SUB>2</SUB>/RuO<SUB>2</SUB> mixed oxides is discussed in detail.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three dimensional α–MnO<SUB>2</SUB>/RuO<SUB>2</SUB> hybrids are studied as bifunctional electrocatalysts. </LI> <LI> Morphology of the hybrids changed from nanourchin to spheres as RuO<SUB>2</SUB> loading increased. </LI> <LI> The growth mechanisms of the hybrids have been systematically studied. </LI> <LI> The catalytic activity (ORR/OER) was significantly improved by α–MnO<SUB>2</SUB>/RuO<SUB>2</SUB> hybrids. </LI> <LI> α–MnO<SUB>2</SUB>/RuO<SUB>2</SUB> (75:25) exhibited superior Li–O<SUB>2</SUB> battery profile. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
K. Ramachandran,Awan Zahoor,T. Raj Kumar,남기석,A. Balasubramani,G. Gnana Kumar 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.46 No.-
The tetragonal a-phase structured manganese dioxide nanorods were densely grown over the nitrogendoped graphite nanofibers (NGNF/MnO2) via a facile and one-pot hydrothermal technique. Theamperometric results depicted that NGNF/MnO2 composite exhibited a high sensitivity of1096 mAmM 1 cm 2 and a wide linear range from 0.1 to 11 mM with the lower detection limit of1.25 mMtoward the non-enzymatic hydrogen peroxide (H2O2) detection, owing to the synergistic effectsof NGNF and MnO2. In the prospect of excellent selectivity, real sample analysis and other strikingadvantages, the developed non-enzymatic sensors hold promising potential for the tight monitoring ofH2O2 in the food and clinical diagnosis fields.
Babu, Kaliyamoorthy Justice,Zahoor, Awan,Nahm, Kee Suk,Aziz, Md. Abdul,Vengadesh, Periasamy,Kumar, Georgepeter Gnana The Royal Society of Chemistry 2016 NEW JOURNAL OF CHEMISTRY Vol.40 No.9
<P>Manganese dioxide (MnO2)-vulcan carbon (VC)@silver (Ag) (core@shell) nanocomposites were synthesized through a simple wet chemical method without using hazardous organic reagents, polymeric micelles, templates or catalysts. The synthesized MnO2-VC@Ag exhibited a MnO2-VC core and Ag shell, and the thickness of shell was found to be 23 nm. The obtained diffraction patterns confirmed that the prepared nanocomposite consists of tetragonal and face-centred cubic structures of MnO2 and Ag nanostructures, respectively. Cyclic voltammetry and amperometric techniques were adopted to electrochemically characterize the MnO2-VC@Ag nanospheres for hydrazine oxidation in phosphate buffer solution. Under the optimized conditions, the fabricated sensor exhibited a good electrochemical performance toward hydrazine oxidation, offering a broad linearity of 0.1 to 350 mM, with a relatively low detection limit of 100 nM and a high sensitivity of 0.33 mA mM(-1) cm(-2). In addition, anti-interference properties, good reproducibility, long term performance, good repeatability and real sample analysis were achieved for the constructed sensor, owing to the synergetic effects of the Ag and MnO2-VC nanostructures. The aforesaid attractive analytical performance and facile preparation of the MnO2-VC@Ag core-shell nanospheres are new features for electrocatalytic materials and may hold promise for the design and development of effective hydrazine sensors.</P>
Role of solvents on the oxygen reduction and evolution of rechargeable Li-O<sub>2</sub> battery
Christy, Maria,Arul, Anupriya,Zahoor, Awan,Moon, Kwang Uk,Oh, Mi Young,Stephan, A. Manuel,Nahm, Kee Suk Elsevier 2017 Journal of Power Sources Vol.342 No.-
<P><B>Abstract</B></P> <P>The choice of electrolyte solvent is expected to play a key role in influencing the lithium-oxygen battery performance. The electrochemical performances of three electrolytes composed of lithium bis (trifluoromethane sulfonyl) imide (LiTFSI) salt and different solvents namely, ethylene carbonate/propylene carbonate (EC/PC), tetra ethylene glycol dimethyl ether (TEGDME) and dimethyl sulfoxide (DMSO) are investigated by assembling lithium oxygen cells. The electrolyte composition significantly varied the specific capacity of the battery. The choice of electrolyte also influences the overpotential, cycle life, and rechargeability of the battery. Electrochemical impedance spectra, cyclic voltammetry, and chronoamperometry were utilized to determine the reversible reactions associated with the air cathode.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The choice of electrolyte solvent influences the lithium/O<SUB>2</SUB> battery performance. </LI> <LI> Three solvents; TEGDME, ECPC and DMSO exhibit proper reversible reaction. </LI> <LI> TEGDME demonstrate a comparatively suitable electrode – electrolyte combination. </LI> </UL> </P>