• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.67-68
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• 2006

Solid polymer electrolyte is very important in the applications to high energy density lithium batteries of high safety. In this work, solid polymer electrolytes based on PE non-woven matrix, hybrid salt, and anion receptor were successfully prepared. They could provide high ion conduction phase with maintaining mechanical strength. They also showed high electrochemical stability and lithium ion transference number. This new type of solid polymer electrolyte is expected to be a good candidate for rechargeable solid state lithium secondary batteries.

• 한국군사과학기술학회지
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• 제11권1호
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• pp.102-111
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• 2008

This paper describes the basic model and simulation results of thermal battery. Voltage and thermal analysis is a critical part of thermal-battery design because of the need to maintain the inner temperature above the electrolyte melting point. Traditionally, battery design has depended on an empirical approach, in which prototype batteries are outfitted with thermocouples and the design of subsequent batteries is refined accordingly. We have developed the basic model that allows the design engineer to configure or modify a battery, quickly conduct a thermal analysis, and efficiently review the results. Based on performance tests, the thermal-battery model was established and the effect of design parameters on battery performance was analyzed.

• Journal of Electrochemical Science and Technology
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• 제5권2호
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• pp.49-52
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• 2014

Graphene nanosheets (GNS), nitrogen-doped graphene nanosheets (N-GNS), and sulfur-doped graphene nanosheets (S-GNS) were successfully synthesized, and their catalytic effects on the oxygen reduction reaction (ORR) in $Li-O_2$ batteries were compared. The S-GNS electrode exhibited the highest ORR catalytic activity, resulting in enhanced discharge capacity and power capability. We attributed the enhanced ORR catalytic activity to the increased defect sites on graphene.

• 전기화학회지
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• 제10권2호
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• pp.88-93
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• 2007

Nano-sized Sn particles were coated with Ni-P layer using an electroless deposition method and their anodic performance was tested for lithium secondary batteries. Uniform coating layers were obtained, of which the thickness was controlled by varying the $Ni^{2+}$ concentration in the plating bath. It was found that the Ni-P layer plays two important roles in improving the anodic performance of Sn powder electrode. First, it prevents the inter-particle aggregation between Sn particles during the charge/discharge process. Second, it provides an electrical conduction pathway to the Sn particles, which allows an electrode fabrication without an addition of conductive carbon. A pseudo-optimized sample showed a good cyclability and high capacity ($>400mAh\;g^{-1}$) even without conductive carbon loading.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.571-575
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• 2011

Graphite-based electrodes were prepared using synthetic graphite (MCMB 1028) or natural graphite (NG) powder using a dimensionally stable anode (DSA) as a substrate. Their electrochemical properties were investigated in vanadiumbased electrolytes to determine how to increase the durability and improve the energy efficiency of redox flow batteries. Cyclic voltammetry (CV) was performed in the voltage range of -0.7 V to 1.6 V vs. SCE at various scan rates to analyze the vanadium redox reaction. The graphite-based electrodes showed a fast redox reaction and good reversibility in a highly concentrated acidic electrolyte. The increased electrochemical activity of the NG-based electrode for the $V^{4+}/V^{5+}$ redox reaction can be attributed to the increased surface concentration of functional groups from the addition of conductive material that served as a catalyst. Therefore, it is expected that this electrode can be used to increase the power density and energy density of redox flow batteries.

• Journal of Electrochemical Science and Technology
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• 제3권1호
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• pp.14-23
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• 2012

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.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.124-129
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• 2013

Electro-Mechanical Batteries have important advantages compared with chemical batteries, especially in Low Earth Orbit satellites applications. High speed, slotless, external rotor, brushless DC machines are proposed and used in these systems as Motor/Generator. A simplified analytic design method is given for this type of machines and, the optimization of machine in order to have maximum efficiency and minimum volume and weight are given in this paper. Particle swarm optimization (PSO) is used as the optimization algorithm and the finite element-based simulations are used to confirm the design and optimization process and show less than 6% error in parametric design.

• 전기화학회지
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• 제9권4호
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• pp.158-169
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• 2006

The present article is concerned with the overview of the chemically/surface modified cubic spinel $LiMn_2O_4$ as a cathode electrode far lithium ion secondary batteries. Firstly, this article presented a comprehensive survey of the cubic spinel structure and its correlated electrochemical behaviour of $LiMn_2O_4$. Subsequently, the various kinds of the chemically/surface modified $LiMn_2O_4$ and their electrochemical characteristics were discussed in detail. Finally, this article reviewed our recent research works published on the mechanism of lithium transport through the chemically/surface modified $Li_{1-\delta}Mn_2O_4$ electrode from the kinetic view point by the analyses of the experimental potentiostatic current transients and ac-impedance spectra.

• Journal of Electrochemical Science and Technology
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• 제7권2호
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• pp.115-131
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• 2016

Though battery chemistry and technology had been developed for over a hundred years back, increase in demand for storage energy, in the computer accessories, cell phones, automobile industries for future battery car and uninterrupted power supply, has made, the development of existing and new battery, as an emerging areas of research. With innovation of high energetic inexpensive Nano structure materials, a more energy efficient battery with lower cost can be competitive with the present primary and rechargeable batteries. Materials electrochemistry of electrode materials, their synthesis and testing have been explained in the present paper to find new high efficient battery materials. The paper discusses fundamental of electrochemistry in finding true cell potential, overvoltages, current, specific energy of various combinations of anode-cathode system. It also describes of finding the performance of new electrode materials by various experiments viz. i. Cyclic Voltammetry ii. Chronoamperometry iii. Potentiodynamic Polarization iv. Electrochemical Impedance Spectroscopy (EIS). Research works of different battery materials scientists are discussed for the development of existing battery materials and new nano materials for high energetic electrodes. Problems and prospects of a few promising future batteries are explained.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.549-550
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• 2006

Mobile fuel cell is highlighted in these days because mobile fuel cell can contain more energy than existing batteries. Nowadays mobile devices like cellular phone, PMP(portable multi-media player), notebook, and etc. need more energy, But existing batteries like Li-ion or Ni-MH batteries are not going to satisfy such demands. In this paper, mobile fuel cell is developed. Its size is 50*70*8mm and it is made of aluminium plates. The fuel cell type is PEM and the fuel is pure hydrogen and oxygen.