• Membrane Journal
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• v.27 no.2
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• pp.109-120
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• 2017

The reverse electrodialysis (RED) is an energy generation system to convert chemical potential of saline water directly into electric energy via the combination of current derived from a redox couple electrolyte and ionic potential obtained when cation ($Na^+$) and anion ($Cl^-$) pass through cation exchange membrane (CEM) and anion exchange membrane (AEM) into fresh water, respectively. Ion exchange membrane, a key element of RED system, should satisfy requirements such as 1) low swelling behavior, 2) a certain level of ion exchange capacity, 3) high ion conductivity, and 4) high perm-selectivity to achieve high power density. In this paper, research trends and prospects of ionomer materials and ion exchange membranes are dealt with.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.02a
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• pp.169-169
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• 1997

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.163.2-163
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.23-23
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• 1998

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.151.2-151
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• 1998

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.33.1-33.1
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• 2011

Strontium doped lanthanum manganite (LSM) with perovskite structure for SOFC cathode material shows high electrical conductivity and good chemical stability, whereas the electrical conductivity at intermediate temperature below $800^{\circ}C$ is not sufficient due to low oxygen ion conductivity. The approach to improve electrical conductivity is to make more oxygen vacancies by substituting alkaline earths (such as Ca, Sr and Ba) for La and/or a transition metal (such as Fe, Co and Cu) for Mn. Among various cathode materials, $LaSrMnCuO_3$ has recently been suggested as the potential cathode materials for solid oxide fuel cells (SOFCs). As for the Cu doping at the B-site, it has been reported that the valence change of Mn ions is occurred by substituting Cu ions and it leads to formation of oxygen vacancies. The electrical conductivity is also affected by doping element at the A-site and the co-doping effect between A-site and B-site should be described. In this study, the $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_{3{\pm}{\delta}}$ ($0{\leq}x{\leq}0.4$) systems were synthesized by a combined EDTA-citrate complexing process. The crystal structure, morphology, thermal expansion and electrical conductivity with different Sr contents were studied and their co-doping effects were also investigated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.26-26
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• 2003

Lithium storage electrodes for rechargeable batteries require mixed electronic-ionic conduction at the particle scale in order to deliver desired energy density and power density characteristics at the device level. Recently, lithium transition metal phosphates of olivine and Nasicon structure type have become of great interest as storage cathodes for rechargeable lithium batteries due to their high energy density, low raw materials cost, environmental friendliness, and safety. However, the transport properties of this family of compounds, and especially the electronic conductivity, have not generally been adequate for practical applications. Recent work in the model olivine LiFePO$_4$, showed that control of cation stoichiometry and aliovalent doping results in electronic conductivity exceeding 10$^{-2}$ S/cm, in contrast to ~10$^{-9}$ S/cm for high purity undoped LiFePO$_4$. The increase in conductivity combined with particle size refinement upon doping allows current rates of >6 A/g to be utilized while retaining a majority of the ion storage capacity. These properties are of much practical interest for high power applications such as hybrid electric vehicles. The defect mechanism controlling electronic conductivity, and understanding of the microscopic mechanism of lithiation and delithiation obtained from combined electrochemical and microanalytical techniques, will be discussed

• Journal of the Korean institute of surface engineering
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• v.30 no.4
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• pp.255-261
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• 1997

Thin film batteries can be used as a micro power source for electronic in which minute power is needed. In this study, lithium phosphorous oxynitride(LIPON) thin films were deposited as an eletrolyte for lithium ion batteries using RF magentron sputtering of lithium phosphate in N2. Ti was also added into the LIPON films as a second network former to enhance the ioinc conductivity of the films. The optimum conditions for LIPON film deposition were sought and the electrolyte with the conductivity of $2.5 \times 10^{-6}$S/cm was obtained at the condition of RF power 4.4 W/$\textrm{cm}^2$, process pressure 10 mtorr and pure nitrogen ambience. Furthermore, the conductivity of LIPON films was increased from $2.5 \times 10^{-6}$S/cm to $8.6 \times 10^{-6}$S/cm by the doping of 2.4at.% Ti. It was also found that by adding Ti to LIPON films, Li content was increased and nitrogen content that reported having the cross-linking effect on LIPON films was also increased as confirmed XPS.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.4
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• pp.306-311
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• 2000

The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li polymer battery. The temperature dependence of conductivity impedance spectroscopy and electrochemical properties of PDF/PAN electrolytes as a function of a mixed ratio were reported for PVDF/PAN based polymer electrolyte films which were prepared by thermal gellification method of preweighed PVDF/PAN plasticizer and Li salt. The conductivity of PVDF/PAN electrolytes was 10$\^$-3/S/cm. 20PVDF5PEN LiCiO$\_$4//PC$\_$10//EC$\_$10/ electrolyte has the better conductivity compared to others. 20PVDF5PANLICIO$\_$4//PC$\_$10//EC$\_$10/ electroylte remains stable up to 5V vs. Li/Li$\^$+/. Steady state current method and ac impedance were used for the determination of transference numbers in PVDF/PAN electrolyte film. The transference number of 20PVDF5PANLiCO$\^$4//PC$\_$10//EC$\_$10/ electrolyte is 0.48.

• Journal of the Korean Ceramic Society
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• v.54 no.5
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• pp.406-412
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• 2017

$70V_2O_5-10Fe_2O_3-13P_2O_5-7B_2O_3$ glasses were prepared to study the electrical conductivity and catalytic properties of the structural change with crystallization. The structural changes were analyzed by determining the molecular volume from the sample density; using X-Ray Diffraction (XRD) analysis, which indicated that $V_2O_5$, $VO_2$ and $B_2O_3$ crystals in heat-treated more than 1h samples. Especially a new crystalline phase of non-stoichiometric $Fe_{0.12}V_2O_5$ was formed after 6 h heat treatment. The V-O bonding change after crystallization was analyzed by Fourier Transform Infrared Spectroscopy (FTIR); V ion change from $V^{5+}$ to $V^{4+}$ was shown by XPS. Conductivity and catalytic properties were examined based on the polaronic hopping of V and Fe ions, which exhibited different valence states with crystallization.