• 한국세라믹학회지
• /
• 제51권4호
• /
• pp.248-259
• /
• 2014

Acceptor-doped cerium pyrophosphates have shown significant proton conductivity of > $10^{-2}Scm^{-1}$ in the range of $100-300^{\circ}C$ and are considered promising candidates for use as electrolytes in proton-conducting, ceramic electrolyte fuel cells (PCFCs). But, cerium pyrophosphates themselves do not have structural protons, and protons incorporate into their material bulk only as impurities on exposure to a hydrogen-containing atmosphere. However, proton incorporation and proton conduction in these materials are expected to be affected by factors such as the nature (ionic size and charge) and concentration of the aliovalent dopant, processing history (synthesis route and microstructure), and the presence of residual phosphorous phosphate ($P_mO_n$) phases. An exact understanding of these aspects has not yet been achieved, leading to large differences in the magnitude of proton conductivity of cerium pyrophosphates reported in various studies. Herein, we systematically address some of these aspects, and present an overview of factors affecting proton conductivity inacceptor-doped $CeP_2O_7$.

• 한국세라믹학회지
• /
• 제45권11호
• /
• pp.694-700
• /
• 2008

Proton conducting oxides based on the $BaCe_{0.9}M_{0.1}O_{3-{\delta}}$ (M = La, AL) were tested for the alternative electrolyte materials of fuel cell. The power density for single cell of Air |Pt| $BaCe_{0.9}M_{0.1}O_{3-{\delta}}$ |Pt| $H_2(3%H_2O)$ system was maximum $0.04W/cm^2$ at $1000^{\circ}C$. In this system, proton transport number was proved to depend on the lattice parameters and the distortion of $CeO_6$ octahedral as a function of the ionic radii of acceptor ions. This proton conducting oxide system requires developing the new electrode materials for application.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.75.2-75.2
• /
• 2010

Polymer electrolyte fuel cells (PEFCs) have received a lot of attention as a power source for both stationary and mobile applications due to their attractive feature. In general, the performance of PEFCs is highly affected by the property of the electrodes. A PEFC electrode essentially consists of a gas diffusion layer and a catalyst layer. The gas difusion layer is highly porous and hydrophobicized with PTFE polymer. The catalyst layer usually contains electrocatalyst, proton conducting polymer, even PTFE as additive. Particularly, the proton conducting ionomer helps to increase the catalytic activity at three-phase boundary and catalyst utilization. Futhermore, it helps to retain moisture, resulting in preventing the electrodes from membrane dehydration. The most widely used proton conducting ionomer is perfluorinated sulfonic acid polymer, namely, Nafion from DuPont due to its high proton conductivity and good mechanical property. However, there are great demands for alternative ionomers based on non-fluorinated materials in terms of high temperature availability, environmental adaptability and production cost. In this study, the electrodes with the various content of the sulfonated poly(ether sulfone) ionomer in the catalyst layer were prepared. In addition, we evaluated electrochemical properties of the prepared electrodes containing the various amount of the ionomers by using the cyclic voltammetry and impedance spectroscopy to find an optimal ionomer composition in the catalyst layer.

• 한국세라믹학회지
• /
• 제42권1호
• /
• pp.50-55
• /
• 2005

(3-Mercaptopropyl) trimethoxysilane(MPTS)의 thoil기(-SH)의 적절한 산화 및 (3-glycidoxypropyl) trimethooxysilane(GHS)와의 수화/중축합 반응을 통하여 얻어진 고분자 기질을 사용하여 새로운 고 프로톤 전도성 유기-무기 나노복합막을 성공적으로 합성하였다. 합성된 나노복합막으로부터 얻어진 프로톤 전도도는 $25^{circ}C$에서 $10^{-2} S/cm$ 이상의 높은 값을 나타내었으며, 온도와 상대습도를 $70^{circ}C$와 $100RH\%$로 증가시킴에 따라 전도도는 $3.6{\times}10^{-1}$ S/cm까지 증가하였다. 복합체의 높은 프로톤 전도도는 MPTS 말단의 thiol의 산화에 의해 얻어지는 아황산기$(-SO_{3}^{-})$가 프로톤 donor로서 작용하고, GHS로부터 유도된 'pseudo polyethylene oxide' 네트워크가 프로톤의 전도 path로 작용하고 있음을 나타낸다.

• 한국세라믹학회지
• /
• 제56권1호
• /
• pp.91-97
• /
• 2019

The effect of different Ni-containing additives on the sintering behavior and electric conductivity of the proton conducting electrolyte $BaCe_{0.35}Zr_{0.5}Y_{0.15}O_{3-{\delta}}$ (BCZY5) was investigated. Ni-doped, NiO-added, and $BaY_2NiO_5$(BYN)-added (all 4 mol%) BCZY5 samples were prepared by the solid state synthesis method and sintered at $1400^{\circ}C$ for 6 h. Among the three samples, the onset of densification was observed at the lowest temperature for NiO-added BCZY5, which is attributed to the formation of an intermediate phase at a low melting temperature. The BYN-added sample, where no consumption of the constitutional elements of the electrolyte was expected during sintering, exhibited the highest electrical conductivity whereas the doped sample had the lowest conductivity. The electrical conductivities at $500^{\circ}C$ under humid argon atmosphere were measured to be 2.0, 4.8, and $6.2mS{\cdot}cm^{-1}$ for Ni-doped and NiO- and BYN-added samples, respectively.

• 폴리머
• /
• 제26권2호
• /
• pp.179-184
• /
• 2002

양성자 전도도가 높으며 균일하고 또 기계적 강도가 우수한 양성자 전도체를 얻기 위하여 poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) 공중합체를 전해질의 지지체로 선택하고, $H_3PO_4$이 포함된 ethylene carbonate (EC)와 $\gamma$-butyrolactone (BL) 및 dimethyl carbonate (DMC)의 유기용매들을 혼합하여 겔-전해질을 제조하였다. 다양한 조성의 겔-전해질에 대하여 열분석과 전도도 측정 실험을 수행하였다. 상온에서 양성자 전도도는 30(PVdF-HFP) + 50EC/DMC + $20H_3PO_4$ 전해질에서 7.3$\times$$10^{-3}Sm^{-1}$/로 가장 높았다. 열분석 결과에서 거의 모든 시료는 대략 $80^{\circ}C$ 정도까지 안정하였으며, 특히 인산은 고분자 사슬과 민감하게 반응하여 고분자와 용매의 혼화성을 증대시키는 것을 확인하였다.

• Elastomers and Composites
• /
• 제47권4호
• /
• pp.292-296
• /
• 2012

폴리비닐알콜, 규소텅스텐산, 인산 및 수용액으로 구성된 $80{\mu}m$의 두께의 고분자겔 전해질 필름을 제조하여 활성탄소계 전기이중층 케페시터를 제조하였다. 제조한 고분자겔 전해질 필름은 상온에서 $10^{-2}S\;cm^{-1}$의 높은 이온전도도를 나타내었으며, 본 전해질 필름을 적용한 활성탄소계 전기이중층 케패시터는 100 mV/s에서 $58F\;g^{-1}$의 높은 캐패시턴스 특성과 우수한 수명특성을 나타내었다.

• 한국세라믹학회지
• /
• 제42권2호
• /
• pp.77-80
• /
• 2005

A series of proton conductive composite membranes based on poly(vinyl alcohol) and phosphosilicate gels powders were successfully prepared. The proton conductivity of these composite was attributed to the phosphosilicate gel, which derived from tetraethoxysilane and phosphoric acid by sol-gel process at a molar ratio of P/Si = 1.5. The proton conductivity increased with increasing both the content of phosphosilicate gel and relative humidity. Temperature dependence of conductivity showed a Vogel-Tamman-Fulcher type behavior, indicating that proton was transferred through a liquidlike phase formed in micropores of phosphosilicate gel. The high conductivity of 0.065 S/cm with a membrane containing 60 wt$\%$ of the gel was obtained at $60^{\circ}C$ at $90\%$ relative humidity.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2003년도 The 4th Korea-Italy Workshop
• /
• pp.37-40
• /
• 2003

Mesoporous zeolite - heteropolyacid-polymer hybrid membrane was prepared by sol-gel processes to make a proton conducting membrane. The crystallinity of mesoporous zeolite in composite membrane was increased with contents of heteropolyacid. Proton conductivity obtained from impedance measurements increases with contents of heteropolyacid, about 10$^{-3}$ S/cm in ca. 1.5 Wt% heteropolyacid.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2008년도 춘계 총회 및 학술발표회
• /
• pp.94-97
• /
• 2008