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Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO2). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K2Pd(SO3)2) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.

Powerful sunlight, a high water temperature, and stagnation in the water flow induce eutrophication in rivers and lakes, which destroys the aquatic ecosystem and threatens the downstream water supply systems. Accordingly, it is very important to perform real-time measurements of nutrients that induce algal growth, especially total phosphorus, to preserve and manage the aquatic ecosystem. To conduct quantitative analysis of the total phosphorus in the aquatic ecosystem, it is essential to perform a pretreatment process and quickly separate the phosphorus, combined with organic and inorganic materials, into a phosphate. In this study, the sandblasting process was used for the physical etching of the wafer, and photocatalytic materials were deposited on the surface with various roughness in order to improve the photocatalytic reaction surface and efficiency. The photocatalytic reaction was applied to combine the pretreated sample with the coloring agent for color development, and the absorbance of the colored sample was analyzed quantitatively to compare and evaluate the characteristics, followed by the surface increase in the photocatalytic materials. In addition, the pretreatment and measurement parts were materialized in a single chip to produce a small and light total phosphorus analysis sensor.

In this study, pristine carbon nanotubes (CNTs) and the CNTs functionalized through heat treatment were fabricated, and their hydrogen (H2) gas sensing characteristics were evaluated at room temperature. Pristine CNTs exhibited relatively low reactivity toward H2 gas, whereas functionalized CNTs demonstrated linear electrical response characteristics with an increase in the gas concentration due to the presence of functional groups (such as COOH and OH) on the CNT surface, which reduced the activation energy for the adsorption of H2 molecules and provided additional reactive sites. Thus, functionalized CNTs can be potentially utilized in various fields because their operation does not require high-temperature environments (unlike the currently used metal oxide-based H2 sensors), while the power consumption and explosion risks of these materials are easily reduced through a simple heat treatment process.

Comparative properties of pin-type amorphous silicon (a-Si:H) thin-film solar cells with different PH3 flows for the i-layer and the presence of a buffer layer at the p–i interface were inv...

Squarylium-based colorimetric hydrogen sulfide (H2S) chemosensors (SQ1, SQ2, and SQ3) were developed, and their detection properties were systematically characterized. SQ1 exhibited rapid and high resolution H2S sensing properties through significant color changes detectable by naked-eye with limit of detection as low as 7.2 ppb. SQ1 also showed excellent selectivity for H2S detection over other relevant anions and nucleophiles. Sensing mechanisms of SQ1 were investigated based on spectroscopic and 1H NMR analyses with quantum calculations. Furthermore, SQ1 showed an efficient response to H2S under versatile conditions in the solution, solid, and dyed fabric states, which suggests applicability of SQ1 to simple, low-cost, and practical H2S sensors.

Si-Ti-Ni alloy (STN) is a promising active material for lithium ion batteries with high coulombic efficiency and stable cycleability since inactive matrix plays an important role in buffer action against large volume changes of Si during charge/discharge reactions. However, there still remain several challenges to apply to electric vehicles due to capacity fading and unstable cycle performances at high current density. In this study, to improve the properties of STN, we modified the surface of STN with poly(3,4-ethylenedioxythiophene) (PEDOT) by in-situ polymerization. The modified STN provides many advantages including stable cycleability, low charge transfer resistance, strong adhesion between active materials and active material and current collector, etc. Electrochemical performances are significantly improved after modification; especially under high current density conditions.

modified powder is almost same as that of the pristine NiOpowder. The existence of Ti is identified through energydispersive spectroscopy (EDS) and these data demonstratethe homogeneous distribution of Ti without severe agglome-ration after annealing.The structural change in the modified powders after surfacemodification was investigated by X-ray diffraction (XRD).Figure 2 shows XRD data of the samples annealed at 650

Temozolomide is the current first-line treatment for glioblastoma patients but, because many patients are resistant to it, there is an urgent need to develop antitumor agents to treat temozolomide-resistant glioblastoma. Gossypol, a natural polyphenolic compound, has been studied as a monotherapy or combination therapy for the treatment of glioblastoma. The combination of gossypol and temozolomide has been shown to inhibit glioblastoma, but it is not clear yet whether gossypol alone can suppress temozolomide-resistant glioblastoma. We find that gossypol suppresses the growth of temozolomide-resistant glioblastoma cells in both tumor sphere and adherent culture conditions, with tumor spheres showing the greatest sensitivity. Molecular docking and binding energy calculations show that gossypol has a similar affinity to the Bcl2 (B-cell lymphoma 2) family of proteins and several dehydrogenases. Gossypol reduces mitochondrial membrane potential and cellular ATP levels before cell death, which suggests that gossypol inhibits several dehydrogenases in the cell&rsquo, s metabolic pathway. Treatment with a Bcl2 inhibitor does not fully explain the effect of gossypol on glioblastoma. Overall, this study demonstrates that gossypol can suppress temozolomide-resistant glioblastoma and will be helpful for the refinement of gossypol treatments by elucidating some of the molecular mechanisms of gossypol in glioblastoma.

This paper proposes a simple and efficient method to develop a nanocomposite by depositing platinum (Pt) nanoparticles on a carbon nanotube (CNT) sheet, and experimentally verifies the applicability of the proposed nanocomposite as a reliable and sensitive carbon monoxide (CO) gas sensor that operates at room temperature. A Pt-CNT nanocomposite shows improved CO gas sensing properties compared with the pristine CNT sheet. Owing to its large surface area and high conductivity, a CNT sheet exhibits improved sensitivity and fast response and recovery times. Based on the Pt-CNT nanocomposite implemented by the proposed method, we fabricated a Pt-CNT sheet-based CO gas sensor operating at room temperature and experimentally verified its stable and reliable room temperature sensing properties and excellent structural flexibility.

The proton exchange membrane fuel cell (PEMFC) has received a great attention as a clean power generator to convert the chemical energy of hydrogen to electric energy electrochemically. It has major advantages for the portable electronic devices and transportation/stationary power systems such as the high power density and high energy efficiency, rapid start-up, etc. One of the most widely used proton exchange membrane is perfluorosulfonic acid (Nafion, DuPont Co.). It has excellent thermal and chemical stability and high proton conductivity below 80 C. However, PEMFC with Nafion membrane shows the poor performance at higher temperature due to the dehydration and low proton conductivity of the membrane. Recently, many studies have been performed to develop proton conducting membrane for operation above 100 C because the high temperature operation of PEMFC has the advantages of low CO poisoning of Pt catalyst and simple thermal and water management. Even if the Nafion composite membranes with incorporation of water retentive and inherent proton conductive fillers have been studied extensively under elevated temperature and low humidity conditions, the proton conductivity of the composite membrane is occasionally lower than the pristine Nafion because the wellconnected ionic domain of the Nafion is deformed by the inorganic fillers. In this paper, we report the physico-chemical and electrochemical properties of the phosphoric acid-functionalized mesoporous silica/Nafion composite membrane. The mesopore of silica increases the water retention capacity more effectively, and the phosphor-silicate has thermally and chemically stable silica networks and the surface-terminated phosphate interacts strongly with the water molecules. Therefore, the phosphoric acid-functionalized mesoporous silica/Nafion composite membrane shows the higher proton conductivities and cell performance than the pristine Nafion at high temperature and low humidity. The morphology and particle size of the prepared inorganic materials were investigated by TEM, and the data are shown in Figure 1. The shape of mesoporous SiO2 is spherical with a diameter of ~45 nm and their pore size is ~5 nm as shown in Figure 1(a). The specific surface area and the mean pore size of the mesoporous SiO2 are 560 m ·g and 4.82 nm, respectively. However, the morphology of the phosphoric acid-functionalized mesoporous SiO2 was quite different from that of pristine one. As shown in Figure 1(b)-(d), the porous structure is destructed and particle size increases as the annealing temperature increases after the mixing of mesoporous SiO2 with phosphoric acid. Figure 1(b) shows the sample heated at 80 C in the vacuum, and the result shows that the porosity of the sample is slightly reduced. With an annealing at 200 C, the morphology change is significant in that the mesopore disappears and large pore is formed. Interestingly, the further annealing above 200 C, the pore completely disappears and their particle size also increases, because of the formation of phosphor silicate through the reaction of silica and phosphoric acid, and the bulk-like phosphor silicate phase is confirmed by XRD (not shown for brevity). In order to elucidate the chemical structure of the prepared

The layered lithium-manganese oxide () as a cathode material of lithium ion secondary batteries was prepared and characterized the physico-chemical and electrochemical properties. The morphological and structural changes of MnO(OH) and are closely connected to the changes of electrochemical properties. The crystallinity of is enhanced as the annealing temperature increase, but its capacity is reduced due to the easier structural changes of less crystalline than highly crystalline one. Moreover, the addition of buffer material such as MnO(OH) into cathode causes to reduce the morphological and structural changes of layered and increase the discharge capacity and cycleability.

In this study, a cDNA microarray was developed from over 60,000 mRNA readings to analyze the expression profiles of transcriptomes of Haematococcus lacustris under astaxanthin-inducing culture conditions, high irradiance and nitrate starvation. Among 20,033 genes on the cDNA microarray, 2,675 genes exhibited a twofold or greater difference in expression. Of these, 1,333 genes were up-regulated and 1,342 genes were down-regulated. A significant decrease in the expression of chlorophyll biosynthesis and light harvesting complex (LHC) related genes were observed under astaxanthin inducing conditions (forming red cyst cells). On the other hand, respirationrelated genes, lipid metabolism-related genes and stress response-related genes were activated in the red cyst cells under stress conditions. These results enabled a better understanding of the cell responses during stress induction of H. lacustris such as photosynthesis, respiration, and some biopathways.

Sulfonated poly(fluorinated arylene ether)s (SDF-F)/poly[(N-vinylimidazole)-co-(3-methacryloxypropyl-trimethoxysilane)] (poly(VI-co-MPS))/poly(tetrafluoroethylene) (PTFE) is prepared for a high temperature proton exchange membrane fuel cell (PEMFC). The reaction of the membrane with phosphoric acid forms silicate phosphor, as a chemically bound proton carrier, in the membrane. Thus-formed silicate phosphor, nitrogen in the imidazole ring, and physically bound phosphoric acid act as proton carriers in the membrane. The physico-chemical and electrochemical properties of the membrane are investigated by various analytical tools. The phosphoric acid uptake and proton conductivity of the SDF-F/poly(VI-co-MPS)/PTFE membrane are higher than those of SDF-F/PVI/PTFE. The power densities of cells with SDF-F/poly(VI-co-MPS)/PTFE membranes at 0.6 V are 286, 302, and 320 mW at 150, 170, and 190 , respectively. Overall, the SDFF/poly(VI-co-MPS)/PTFE membrane is one of the candidates for anhydrous HT-PEMFCs with enhanced mechanical strength and improved cell performance.

LiMn 1.5 Ni 0.5 O 4 materials coated with AlPO 4 are prepared by a sol–gel method with citric acid to improve their electrochemical performance; the physical and electrochemical properties are characterized by various analytical techniques. The coated AlPO 4 layer completely covers the surfaces of the LiMn 1.5 Ni 0.5 O 4 particles and the thickness of the coated layer is ∼15 nm. 1 wt.% AlPO 4 -coated LiMn 1.5 Ni 0.5 O 4 has much lower surface and charge-transfer resistances and shows a higher lithium diffusion rate in comparison with the pristine sample. The modified material demonstrates dramatically enhanced electrochemical reversibility and stability under elevated temperature conditions. This is because the coated AlPO 4 layer reduces the contact area between the electrode and electrolyte and suppresses the formation of undesirable solid electrolyte interface films.

C의 용융탄산염과 산소 분위기조건에서 안정하고 높은 전기 전도도를 가지는 장점이 있다. 그러나, 장시간 운전 시 양극에서전해질로의 Ni dissolution은 전지 내부의 단락을 초래하여 전지의 수명을 단축시킨다. 본 연구에서는 대체 전극물질로서 코발트와 나이오븀을 코팅시킨 NiO 전극을 제조하였으며, 이렇게 제조된 전극은 기존 NiO전극과 비교하여 낮은 Ni dissolution과 안정되고 우수한 전기화학 성능을보임을 확인하였다.Abstract: NiO is commonly used as the cathode for the molten carbonate fuel cell due to itsstability and high electrical conductivity in molten carbonates and oxygen atmosphere. However,long-term operation of MCFC has a serious problem which is the degradation of cathode material,the so-called Ni dissolution. In the present study, we have attempted to synthesize a new alter-native cathode material as Co/Nb-coated NiO cathode. The results obtained in this study suggestthat the Co/Nb-coated NiO cathode can be utilized as having lower dissolution and higher cellperformance than those of the pure NiO cathode.Keyword: MCFC, Cathode, Ni dissolution

Nafion®–silica nanocomposite membranes are successfully prepared by adding hydrophobic silica nanoparticles to a Nafion® solution. To distribute these nanoparticles evenly in the Nafion® matrix, various fluorosurfactants of different ionic character are employed. Fluorosurfactants with acid groups such as phosphonic acid and sulfonic acid play an important role in simultaneously increasing the homogeneous dispersion of silica nanoparticles, enhancing proton conductivity, and reducing the methanol permeability of the nanocomposite membranes. Therefore, the dispersion properties of inorganic fillers such as silica can significantly affect nanocomposite performance in direct methanol fuel cell (DMFC) applications, whereas surfactants, if used properly, can improve the nanocomposite membrane properties. In particular, a commercial fluorosurfactant containing a sulfonic acid group (Zonyl® TBS) at the end of the surfactant chain exhibits better miscibility with the Nafion® ionomer. This feature results in a reduction in the dimensional change of the nanocomposite membrane due to relatively lower water swelling and significantly reduced methanol permeability through the membrane. A membrane–electrode assembly (MEA) prepared from a Nafion®–silica nanocomposite membrane with TBS shows the highest DMFC performance in terms of voltage vs. current density (V–I) and power density vs. current density (P–I). The current densities at 0.4 V and 90 °C are 342, 508, and 538 mA cm−2 with 1, 3 and 5 M methanol being fed at the anode side, respectively.

Polymer electrolyte nanocomposite membranes were prepared by using a commercial perfluorinated sulfonic acid ionomer (Nafion ® ), nonporous hydrophilic fumed silica (Aerosil 380 ® ), and anionic fluorosurfactant (Zonyl ® TBS). The fluorosurfactant-containing an acid group, which includes sulfonic acid, contributes to well-dispersion of the silica nanoparticles and simultaneously enhances the proton conductivity of the nanocomposite membrane. Hence, the addition of inorganic fillers such as silica to the fluorosurfactant can significantly improve the properties of the Nafion ® -based polymer electrolyte nanocomposite membrane. The membranes were characterized in terms of their mechanical properties ( e.g. , dimensional change and tensile strength) and fundamental electrochemical properties ( e.g. , proton conductivity and current–voltage ( I – V ) curve). Zonyl ® TBS, a commercial anionic fluorosurfactant with sulfonic acid groups at the end of the surfactant chain, added to the Nafion ® matrix showed improved mechanical and electrochemical properties. The sulfonic acid groups in Zonyl ® TBS allowed for the additional transport of protons. As a result, the nanocomposite membrane with surfactant exhibited an improved performance. In a single cell test on a proton exchange membrane fuel cell (PEMFC), a membrane electrode assembly (MEA) prepared from the Nafion ® –silica nanocomposite membrane with TBS exhibited the highest PEMFC performance. The cell was fed with H 2 and O 2 humidified at 75 °C for 80 °C, respectively at ambient pressure. The current density of this membrane was 1600 mA cm −2 at 0.6 V and 80 °C, superior to 999 mA cm −2 for Nafion ® 112.

Trioctylphosphine (TOP)/Pd composites have been synthesized and used as a methanol-barrier material to modify the surface of Nafion 115. The TOP/Pd composites have been applied to the surface of Nafion instead of being incorporated into the Nafion matrix, to provide the best chance of maintaining the inherent proton conductivity of Nafion. The properties of the TOP/Pd-modified membrane, in terms of its conductivity and methanol permeability, as well as the performance of the membrane electrode assembly (MEA) in direct methanol fuel cell (DMFC), have been analyzed and compared with those of bare Nafion. The DMFC performance of the TOP/Pd-modified membrane is somewhat better than that of the bare Nafion one at methanol concentration of 2 M and significantly better at a high concentration of 5 M. The TOP/Pd-modified membrane is able to operate the DMFC using a high concentration of methanol, which can satisfy the requirement to reduce the reactant volumes for portable applications as well as to achieve high performance. In contrast to bare Nafion, the TOP/Pd-modified membrane with its well-adhering and crack-free modified surface shows effect on reducing the methanol loss.

The consolidation process of ultra fine Si powders, generated as by-product during the decomposition process of silane gases, was systematically investigated for use as economical solar-grade feedstock. Si powder compacts were tried to fabricate by a consolidation process without a binding agent and then their density ratio and strength were evaluated. The Si powders in as-received state were not pure enough to be used alone as solar grade feedstock material. After the adequate chemical treatments, a sufficiently high purity above solar-grade was able to be achieved.

Nafion is modified by incorporating poly(1-vinylimidazole)/Pd composites into the ion cluster channels of the membrane. The poly(1-vinylimidazole)/Pd-impregnated (PVI/Pd-impregnated) membranes is characterized by means of X-ray photoelectron spectroscopy (XPS), proton conductivity and methanol permeability measurements and compared with those of the untreated Nafion. The dependence of the membrane proton conductivity and methanol permeability on the poly(1-vinylimidazole) (PVI) and palladium contents in the PVI/Pd-impregnated Nafion is studied. The performance of the cells employing the PVI/Pd-impregnated Nafion is evaluated using a direct methanol fuel cell (DMFC) unit cell. It is found that the best cell performance is obtained when Nafion is impregnated with the PVI/Pd composite solution for 20 h. This result suggests that there exists an optimum content of palladium and PVI in the modified membrane to obtain a high-proton conductivity and low-methanol permeability that result in a high-cell performance.

We prepared a novel phosphoric acid-doped sulfonated poly(fluorinated arylene ether)s/poly(N-vinylimidazole) blend polymer and poly(tetrafluoroethylene) (PTFE) layered membrane. The thermal and electrochemical properties of the new layered membrane were investigated by thermogravimetric analysis (TGA), electrochemical impedance spectroscopy (EIS), as well as the performance of its membrane electrode assembly (MEA). The morphology of membrane was observed with field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The fabricated membrane shows good mechanical property comparable to PBI membrane. The conductivity of new layered membrane was similar to that of polybenzimidazole (PBI) at high temperature. The single cell test showed that new PTFE layered membrane had a good performance over 150 °C. The PTFE layered membrane can be an alternative approach for PEMFC applications at high temperature.

The surface of Nafion was modified by applying palladium nanoparticles as methanol barrier materials to decrease methanol crossover and improve the performance of fuel cells. The properties of the Pd-modified membrane, in terms of conductivity, methanol permeability, percentage of liquid uptake as well as the performance of its membrane electrode assembly (MEA) in the direct methanol fuel cell, were analyzed and compared with those using bare Nafion. The modified membrane showed considerable improvement on reducing methanol loss without decreasing proton conductivity. The DMFC performance of modified membrane was superior to that of bare Nafion both at a typical fuel state of 2 M and at high concentration of 5 M, implying that the palladium-modified Nafion can be a good alternative approach for DMFC applications.

More than 1800 hundreds of millions of beverage cans are manufactured yearly over the world, which will pollute the globe environment without recycle. The recycle and regeneration estates of used beverage cans are highly profitable enterprises. Vacuum technologies are mature on a large scale today, and therefore, the re-melting process of used beverage cans (UBCs) does not have to use flux. Furthermore, the coating on UBCs becomes the key factor causing poor product quality. The present paper concerns removing the coating of UBCs and compares two different kinds of methods to remove the coating: a thermal method and a chemical reagent method. A new kind of reagent, thick sulfuric acid, was employed in the chemical reagent de-coating process. The de-coating ratio in the thermal method reached 93% at most, but the de-coating ratio reached 100% within 30 min in the chemical reagent method by using thick sulfuric acid. Recycling the used thick sulfuric acid was also supplied. A titanium yellow product can be simultaneously obtained. The experiments show that the chemical reagent method is more available than the thermal method, which will enhance the purity of the regeneration product enormously.

CeO 2 -coated LiMn 2 O 4 spinel cathode was synthesized using two-step synthesis method. All the samples exhibited a pure cubic spinel structure without any impurities in the XRD patterns. The results of the electrochemical performances on CeO 2 -coated electrode are compared to those of electrodes based on LiMn 2 O 4 spinel without CeO 2 coating. CeO 2 -coated LiMn 2 O 4 cathode improved the cycling stability of the electrode. The capacity retention of 2 wt% CeO 2 -coated LiMn 2 O 4 was more than 82% after 150 cycles between 3.0 and 4.4 V at room temperature and 82% after 40 cycles at elevated temperature of 60 °C. The amounts of dissolved manganese-ions in CeO 2 -coated LiMn 2 O 4 significantly are smaller than pristine LiMn 2 O 4 systems especially at elevated temperatures. Surface-modified LiMn 2 O 4 can suppress the dissolution reaction of manganese-ions at elevated temperature and clearly improve the cyclability of the spinel LiMn 2 O 4 cathode materials.

Olivine structure LiFePO 4 /C composite powders are synthesized as cathode materials for Li-ion batteries via a conventional solid-state reaction. Improvement in electrochemical performance has been achieved by using poly(vinyl alcohol) as the carbon sources for the as-prepared materials. The influence of the heat treatment on the physical and the electrochemical properties of LiFePO 4 /C materials is investigated. To examine the effect of added carbon content on the properties of materials, a one-step heat treatment has been employed with control of the PVA content in the precursor. Six samples were prepared with 0, 1, 3, 5, 10 and 30 wt.% PVA added to the raw materials. The particle size of LiFePO 4 decreases as the carbon content increases. Materials with medium carbon contents have a small charge-transfer resistance and thus exhibit superior electrochemical performance. Interestingly, for a LiFePO 4 /C composite with a low PVA content, an unusual plateau at 4.3 V is observed. It is considered that this is due to the Fe 3+ /Fe 4+ redox reaction of Fe 3+ compounds that are present as an impurity. For samples with a high PVA amount, a thicker carbon coating provides an obstacle to improve the electrochemical properties.

Investigations on alternative material for bipolar plates of PEMFC (polymer electrolyte membrane fuel cell) are becoming a research hotspot for many fuel cell researchers. In this paper, LF11 Al alloy bipolar plates via a surface plasma Au plating preparation were applied as bipolar plates. Performances and duration times of PEMFC single cells using graphite; Au-coated LF11 Al bipolar (ALABP) and Au-coated 316L stainless steel plates were compared. It was shown that ALABP exhibited preferable properties. Based on the preparations illustrated above, a kilowatt class proton exchange membrane fuel cell stack consisting of 30 cells was successfully assembled. Pure hydrogen and air were used as the fuel and oxidant, respectively, in the stack. External humidification was employed and cycle cooling water was used to remove the heat from the reaction in order to maintain a constant temperature. A Nafion 1135 membrane and Johnson-Matthy platinum on carbon with a Pt loading of 0.4 mg/cm2 were adopted as the electrolyte and catalyst, respectively. The working temperature of the stack ranged from 25 to 100°C. The stack typically worked well under conditions in which the pressure ratio of H2/air was 0.2/0.22 MPa. The output power, current and voltage were 1–1.3 kW, 40–80 A, and 26–20 V, respectively. The normal current density of the electrode was 200–800 mA/cm2, and the energy efficiency of the stack was 51%.

Organic–inorganic hybrid composite membranes have been prepared and evaluated for polymer electrolyte membrane fuel cells (PEMFCs) at 100–140 °C. A series of synthesized poly (fluorinated arylene ether)s was sulfonated by fuming sulfuric acid (20% SO3). The zirconium phosphate composite membrane was prepared by soaking the sulfonated poly (fluorinated arylene ether)s stepwise in 1 M zirconyl chloride solution and 1 M phosphoric acid solution. The chemical, thermal, and electrochemical properties of the composite membrane were investigated by thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and unit cell test. The cell performance of the zirconium phosphate sulfonated poly (fluorinated arylene ether)s composite membrane was superior to that of the starting membrane at intermediate temperature, 100–140 °C. And the cell performance with composite membrane indicated stable behavior during experimentation when operating temperature maintained at 120 °C, whereas sulfonated poly (fluorinated arylene ether)s membrane was irreversible degradation under the same condition.

The properties of a new cathode material of nano-sized TiO 2 -coated Ni powder for application in molten carbonate fuel cells (MCFCs) are investigated. The material is prepared by a sol–gel method. X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) with energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM) and Raman spectroscopy are employed to characterize the cathode material. The nano-sized TiO 2 particles are homogenously coated on the surface of the Ni powder. A stable LiTi 1− x Ni x O 2 phase is formed on the surface of the Ni powder during immersion in molten carbonate at 650 °C. The solubility of the TiO 2 -coated Ni cathode is about 50% lower compare with that of a pure Ni cathode.

Submicron-sized Li(Ni1/3Co1/3Mn1/3)O2 particles were prepared by spray pyrolysis. A polymeric precursor solution containing citric acid and ethylene glycol enabled the formation of submicron-sized Li(Ni1/3Co1/3Mn1/3)O2 spherical particles with narrow-sized distribution and non-aggregation characteristics in the spray pyrolysis. The mean sizes of the particles post-treated at temperatures of 800 and 900∘C were 380 and 770 nm. On the other hand, the Li(Ni1/3Co1/3Mn1/3)O2 particles obtained from the aqueous solution had irregular morphology and broad-sized distribution. The discharge capacity of the particles prepared from polymeric precursor solution decreased from 88 mAh/g to 135 mAh/g after 50 cycles. The particles prepared from polymeric precursor solution had high discharge capacity and good cyclic properties than those of the particles prepared from the aqueous solution.

Fluorine-doped nanocrystalline tin dioxide materials (F:SnO 2 ) have been successfully prepared by the sol–gel process from a single molecular precursor followed by a thermal treatment at 450–650 °C. The resulting materials were characterized by FTIR spectroscopy, powder X-ray diffraction, nitrogen adsorption porosimetry (BET) and transmission electron microscopy (TEM). The mean particle size increased from 5 to 20 nm and the specific surface area decreased from 123 to 37 m 2 /g as the temperature of heat treatment was risen from 450 to 650 °C. Fluorine-doped nanocrystalline SnO 2 exhibited capacity of 560, 502, and 702 mA h/g with 48%, 50%, and 40% capacity retention after 25 cycles between 1.2 V and 50 mV at the rate of 25 mA/g, respectively. In comparison, commercial SnO 2 showed an initial capacity of 388 mA h/g, with only 23% capacity retention after 25 cycles.

Layered Li[Ni0.5−xMn0.5−xZr2x]O2 (x = 0, 0.025) have been prepared by the mixed hydroxide and molten-salt synthesis method. The individual particles of synthesized materials have a sub-microsize range of 200–500 nm, and LiNi0.475Mn0.475Zr0.05O2 has a rougher surface than that of LiNi0.5Mn0.5O2. The Li/Li[Ni0.5−xMn0.5−xZr2x]O2 (x = 0, 0.025) electrodes were cycled between 4.5 and 2.0 V at a current density of 15 mA/g, the discharge capacity of both cells increased during the first ten cycles. The discharge capacity of the Li/LiNi0.475Mn0.475Zr0.05O2 cell increased from 150 to 220 mAh/g, which is 50 mAh/g larger than that of the Li/LiNi0.5Mn0.5O2 cell. We found that the oxidation of oxygen and the Mn3+ ion concerned this phenomenon from the cyclic voltammetry (CV). Thermal stability of the charged Li[Ni0.5−xMn0.5−xZr2x]O2 (x = 0, 0.025) cathode was improved by Zr doping.

Ordinary graphite plate was impregnated by PTFE (polytetrafluoroethylene) scattering solution to make it suitable for fuel cell collector. The feasibility of impregnation process was investigated, and the process was optimized. SEM analysis showed that the depth of impregnation process was 2.50 mm. Porosity of graphite dropped from 18.20 percent to 3.29 percent after impregnation. There is no detectable leakage of H2, even at a pressure of 0.3 MPa after impregnation with PTFE. The impregnation process has no effect on graphite resistivity. Impregnation process successfully met the requirements for fuel cell graphite collector.

A high-performance LiNi 0.8 Co 0.2 O 2 cathode was successfully fabricated by a sol–gel coating of CeO 2 to the surface of the LiNi 0.8 Co 0.2 O 2 powder and subsequent heat treatment at 700 °C for 5 h. The surface-modified and pristine LiNi 0.8 Co 0.2 O 2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), slow rate cyclic voltammogram (CV), and differential scanning calorimetry (DSC). Unlike pristine LiNi 0.8 Co 0.2 O 2 , the CeO 2 -coated LiNi 0.8 Co 0.2 O 2 cathode exhibits no decrease in its original specific capacity of 182 mAh/g (versus lithium metal) and excellent capacity retention (95% of its initial capacity) between 4.5 and 2.8 V after 55 cycles. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries.

Co/Mg solid solution coated Ni powder, where Mg-doped LiCoO2 is coated on NiO in molten carbonate, has been used as a new cathode material to reduce the solubility of NiO and to maintain the advantages of NiO cathode. The (Co/Mg)-coated NiO cathode was prepared by a coating Co/Mg solid solution on the surface of the Ni powder using a PVA assisted sol–gel method. The phase changes of the (Co/Mg)-coated Ni powder after immersed into Li/K eutectic carbonate mixtures at 550 °C ∼ 850 °C for 48 h was performed by XRD and Raman. SEM was used to study the particle morphologies. Co/Mg solid solution was coated on the surface of the Ni powder and Li(NiCoMg)O2 is formed on NiO in molten carbonate. It is expected that the Li(NiCoMg)O2 phase will reduce the solubility of NiO cathode in molten carbonate.

Preparation of catalyst layer in PEMFC electrodes was investigated. Toray carbon paper was used as diffusion layer, and Johnson–Matthey 20% Pt/C was employed as catalyst. Electrode contains neither PTFE nor carbon powder. The optimal catalyst layer composition was discovered by orthogonal test method, with the use of cell voltage–current curve and cyclic voltammogram curve. The optimal amount of the Nafion (ionomer) in the catalyst layer was found to be 1.4 mg / cm 2 when Pt loading was kept at 0.4 mg / cm 2 . Power density of PEMFC achieved 0.37 W / cm 2 with air and H 2 were used at the outlet pressure of 0.1 MPa.

A Li-sulfur cell with a high discharge capacity of over 1300 mAh g(-1) at a C/10 rate, and a controlled overcharge amount less than 1%, was manufactured by synthesizing a carbon-sulfur nano-composite via a wet milling process, and suppressing polysulfide dissolution using an electrolyte with a highly concentrated lithium salt.

New proton exchange membranes were prepared and evaluated as polymer electrolytes for a proton exchange membrane fuel cell (PEMFC). Two types of fluorinated poly(arylene ether)s (FPAEs) were synthesized by nucleophilic aromatic substitution of decafluorobiphenyl (DFBP) with 4,4′-(hexafluoroisopropylidene)diphenol (HFDP) and bisphenol-A (BPA). The FPAEs so prepared were converted into proton exchange polymers by sulfonation with fuming sulfuric acid (30% SO3). The FPAEs and sulfonated-fluorinated poly(arylene ether)s (S-FPAEs) with various sulfonation levels were characterized using 1 H NMR, thermogravimetric analysis (TGA) and back titration, and then successfully evaluated as proton exchange membranes (PEM) with unit cell operation. power output measurements of S-DFBP-HFDP carried out at a cell temperature of 80 °C. They exhibited a maximum power density of 425.5 mW/cm2 at 1150 mA/cm2.

In this study, we made a novel alternative cathode material of molten carbonate fuel cell (MCFC) using electroless deposition of Co on the surface of the Ni powder. Using this manufacturing method, we expect that economical and large-scale cathode can be made easily. The cathode prepared by this method formed LiCo 1− y Ni y O 2 phase in molten (Li 0.62 K 0.38 ) 2 CO 3 at 650 °C under CO 2 :O 2 =66.7:33.3% atmosphere, its solubility is 40% lower than that of NiO cathode. In the unit cell test, the performance of the cell composed of Co-coated Ni cathode was same as that of the cell composed of NiO cathode. Thus the cathode made by Co-coated Ni powder used as an alternative cathode can maintain the advantages of NiO cathode and lengthen the lifetime of MCFC.

Iodine-containing, cation-deficient, lithium manganese oxides (ICCD-LMO) are prepared by reaction of MnO2 with LiI. The MnO2 is completely transformed into spinel-structured compounds with a nominal composition of Li1−δMn2−2δO4Ix. A sample prepared at 800 °C, viz. Li0.99Mn1.98O4I0.02, exhibits an initial discharge capacity of 113 mA h g−1 with good cycleability and rate capability in the 4-V region. Iodine-containing, lithium-rich lithium manganese oxides (ICLR-LMO) are also prepared by reaction of LiMn2O4 with LiI, which results in a nominal composition of Li1+xMn2−xO4Ix. Li1.01Mn1.99O4I0.02 shows a discharge capacity of 124 mA h g−1 on the first cycle and 119 mA h g−1 a on the 20th cycle. Both results indicate that a small amount of iodine species helps to maintain cycle performance.

To elucidate the mechanism of gas generation during charge–discharge cycling of a lithium-ion cell, the generated gases and passive films on the carbon electrode are examined by means of gas chromatography (GC) and Fourier transform infrared (FTIR) spectroscopy. In ethyl carbonate/dimethyl carbonate and ethyl carbonate/diethyl carbonate 1 M LiPF 6 electrolytes, the detected gaseous products are CO 2 , CO, CH 4 , C 2 H 4 , C 2 H 6 , etc. The FTIR spectrum of the surface of the carbon electrode shows bands which correspond to Li 2 CO 3 , ROCO 2 Li, (ROCO 2 Li) 2 , and RCO 2 Li. These results suggest that gas evolution is caused by electrode decomposition, reactive trace impurities, and electrolyte reduction. The surface of the electrode is composed of electrolyte reduction products. When 0.05 M Li 2 CO 3 is added as an electrolyte additive, the total volume of generated gases is reduced, and the discharge capacity and the conductivity of lithium-ions are increased. These results can be explained by a more compact and thin ‘solid electrolyte interface’ film on the carbon electrode formed by Li 2 CO 3 , which effectively prevents solvent co-intercalation and carbon exfoliation.

The influences of Sr/(Ti+Nb) ratios on the electrical properties of Nb-doped SrTiO 3 ceramics have been investigated. Regardless of Sr/(Ti+Nb) ratios, the appearance of non-linearity in the current-voltage characteristics was observed. When Sr/(Ti+Nb) ratio is lower than 1.000, the results acquired from impedance analysis revealed that the activation energies for carrier conduction were determined to be 0.83 eV in grains and 1.67 eV in grain boundaries. Otherwise, the specimens with Sr/(Ti+Nb) S 1.004 showed energies of 0.80 eV in grains and 1.27 eV in grain boundaries. From these measured results, it was suggested that the activation energies, about 0.80 eV, measured in grains were originated from oxygen vacancies and the activation energies, 1.27 and 1.67 eV, measured in grain boundaries were from titanium and strontium vacancies, respectively.

The n = 3 Dion-Jacobson phases, NaLn2Ti2NbO10·xH2O (Ln = La, Pr, Nd, Sm), have been prepared by the ion-exchange reaction of CsLn2Ti2NbO10. Their crystal structures were determined by the Rietveld analysis of powder X-ray diffraction patterns, and they were found to keep the new-type ordering sequence of (Ti1/2Nb1/2)O6-TiO6-(Ti1/2Nb1/2)O6 in the tripled BO6 octahedra. The interlayer Na cations and H2O molecules were proposed for the first time to be situated at the 8g and 4e sites in the space group I4/mmm, forming face-shared octahedra along the (110) direction. Upon firing, they were dehydrated into new intermediate hydrates with P4/mmm symmetry at around 100 oC, and then NaLn2Ti2NbO10 with I4/mmm symmetry at above 200 oC.

Lithium cobalt oxide powders have been successfully prepared by a molten-salt synthesis (MSS) method using a eutectic mixture of LiCl and Li 2 CO 3 salts. The physico-chemical properties of the lithium cobalt oxide powders are investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), particle-size analysis and charge–discharge cycling. A lower temperature and a shorter time (∼700°C and 1 h) in the Li:Co=7 system are sufficient to prepare single-phase HT-LiCoO 2 powders by the MSS method, compared with the solid-state reaction method. Charge–discharge tests show that the lithium cobalt oxide prepared at 800°C has an initial discharge capacity as high as 140 mA h g −1 , and 100 mA h g −1 after 40 cycles. The dependence of the synthetic conditions of HT-LiCoO 2 on the reaction temperature, time and amount of flux with respect to starting oxides is extensively investigated.

A new series of pyrochlore phases in the ternary oxide Tl–Sb–O have been prepared at 650 °C in air and characterised by XRD, FT-IR, EDX, XPS, and density measurements. The unit cell parameters were continuously decreased from 10.3073(1) A for Tl/Sb = 1/4 to 10.28204(8) A for Tl/Sb = 1/2 as the content of Tl3+ cations was increased. The Rietveld analysis shows that Tl+, Tl3+, Sb3+, and Sb5+ cations were positioned in the 32e, 16d, 96g, and 16c sites, respectively. The Tl3+ cations progressively incorporated into the 16d sites in the space group Fd3m, substituting for Sb3+ cations in the 96g sites. The FT-IR absorption band at around 570 cm−1, corresponding to the Sb3+–O′ stretching vibrational mode, confirmed the existence of Sb3+ cations in the asymmetric 96g sites. These Tl–Sb–O phases are formulated with the composition (Tl+2/3 − 2δ)[Sb3+1 − yTl3+y]2/3Sb5+2O6.33 − δ (δ ∼ 0.05) and exhibit quite unique structural features with three types of A/A′ cations in the 16d, 32e, and 96g sites.

Lithiated NiO cathode dissolution has been a major problem for the development of molten carbonate fuel cells (MCFCs). Many studies have been contributed to find new alternative cathodes; here, lithium cobalt oxide, LiCoO2, was coated onto the commonly used NiO cathode by the electroplating method and the resulting cathode showed much reduced solubility compared with that of the common nickel oxide cathode. Thin film lithium cobalt oxide was prepared by the oxidation of Co metal deposited on a nickel plate in molten (Li,K)2CO3 at 650 °C under a CO2–O2 (2 ∶ 1 vol%) atmosphere. When this coated nickel plate was oxidized, the open circuit potential (OCP) decayed gradually, indicating two well-defined potential plateaux; the oxide films produced at each potential plateau were identified by X-ray diffraction methods. The surface product at the first plateau was CoO. LiCoO2 was formed at the second OCP plateau [around −0.47 V vs. CO2–O2 (2 ∶ 1 vol%) reference electrode]. By the same method, LiCoO2 was coated onto a porous nickel cathode in order to produce a MCFC. For 300 h steady operation of the cells, the mean voltages of the cells were 0.80 V using a NiO cathode and 0.85 V for a LC-NiO(EP) cathode at a current density of 150 mA cm−2. In addition to the cell efficiency improvement, the solubility of the LC-NiO(EP) cathode was much lower than that of the NiO cathode.

because it has high electrical conductivity, good thermal and chemical stability, high specific capacity, and the promotion of the reduction reaction of the cathode. Hence, it is expected that the use of the highly conductive PEDOT may serve as an outer layer to assist the transportation of Li ions.The pristine LiFePO

The prepolymers of polyether urethane acrylate (PEUA) were synthesized from polyether polyol (polyethylene glycol (PEG) or polypropylene glycol (PPG)), diisocyanate (hexamethylene diisocyanate (HMDI) or toluene 2,4-diisocyanate (TDI)), and the caprolactone-modified hydroxyethyl acrylate (FA2D) using the catalyst (dibutyltin dilaurate (DBTDL)) by stepwise addition reaction. Lithium triflate (LiCF3SO3) was dissolved in PEUA prepolymers, and plasticizer (propylene carbonate (PC)) was added into prepolymer and salt mixtures. Then photoinitiator (Irgacure 184) was also dissolved in the mixtures. Thin films were prepared by casting on the glass plate, and then by curing the plasticized prepolymer and salt mixtures under UV radiation. Electrochemical and electrical properties of PEUA–LiCF3SO3-based polymer electrolytes were evaluated and discussed to be used in lithium batteries.

Trifluoroacylated, trimethylsilylated and methylated mesocarb (3-(1-methyl-2-phenylethyl)-5-[[(phenylamino) carbonyl]amino]-1,2,3-oxadiazolium) were analyzed by gas chromatography/mass spectrometry (GC/MS). In trifluoroacylation, N-trifluoroacylated sydnophen (SP-NTFA), where the exocyclic nitrogen atom of the sydnonimine ring attacks N-methylbis(trifluoroacetamide), was identified by GC/MS. However, in trimethylsilylation, C-trimethylsilylated sydnophen (SP-CTMS), where the C-4 atom of the sydnonimine ring attacks N-methyl-N-trimethylsilyltrifluoroacetamide, was detected. SP-NTFA and SP-CTMS are intermediates of mesocarb in pyrolysis, and retain an intact sydnonimine ring. In methylation, a ketene form of mesocarb reacts as a nucleophile with methyl iodide to produce methylated N-nitroso-N-cyanomethylamphetamine. Thus, depending on the reaction substituents, the intermediate of mesocarb in pyrolysis was identified to be either an intact sydnonimine ring skeleton or an open-ring compound using GC/MS. Copyright © 1999 John Wiley & Sons, Ltd.

The solubility of a nickel oxide cathode in molten carbonate fuel cell (MCFC) electrolyte is one of the major technical obstacles to the commercialization of such fuel cells. Lithium cobalt oxide, LiCoO 2 , has been selected as a candidate material for MCFC cathodes because its solubility is small and the rate of dissolution into the melt is slower than that for nickel oxide. On the other hand, the electrical conductivity of LiCoO 2 is lower than that of nickel oxide. Thus, nickel oxide has been coated with stable LiCoO 2 in carbonate by a PVA-assisted sol–gel method to give a LiCoO 2 -coated NiO (LC-NiO) cathode. Raman spectra show that the structure of LC-NiO is different from that of nickel oxide, and that a LiCo 1− y Ni y O 2 phase is formed during heat-treatment of the LC-NiO cathode. The coating of LiCoO 2 on NiO electrode increases with increase in the dipping and heating times. The performance of unit cells show that the mean voltage of the cells is 0.80 V using a NiO cathode and 0.85 V with a LC-NiO cathode at a current density of 150 mA cm −2 . The solubility of the LC-NiO cathode in molten carbonate electrolyte is half that of NiO cathode after 300 h at 650°C.