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Cathode Material (cathode + material)
Selected AbstractsA Novel Cathode Material with a Concentration-Gradient for High-Energy and Safe Lithium-Ion BatteriesADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Yang-Kook Sun Abstract A high-energy functional cathode material with an average composition of Li[Ni0.72Co0.18Mn0.10]O2, mainly comprising a core material Li[Ni0.8Co0.2]O2 encapsulated completely within a stable manganese-rich concentration-gradient shell is successfully synthesized by a co-precipitation process. The Li[Ni0.72Co0.18Mn0.10]O2 with a concentration-gradient shell has a shell thickness of about 1,µm and an outer shell composition rich in manganese, Li[Ni0.55Co0.15Mn0.30]O2. The core material can deliver a very high capacity of over 200,mA h g,1, while the manganese-rich concentration-gradient shell improves the cycling and thermal stability of the material. These improvements are caused by a gradual and continuous increase of the stable tetravalent Mn in the concentration-gradient shell layer. The electrochemical and thermal properties of this cathode material are found to be far superior to those of the core Li[Ni0.8Co0.2]O2 material alone. Electron microscopy also reveals that the original crystal structure of this material remains intact after cycling. [source] Power Generation and Electrochemical Analysis of Biocathode Microbial Fuel Cell Using Graphite Fibre Brush as Cathode MaterialFUEL CELLS, Issue 5 2009S.-J. You Abstract To improve cathodic efficiency and sustainability of microbial fuel cell (MFC), graphite fibre brush (GFB) was examined as cathode material for power production in biocatalysed-cathode MFC. Following 133-h mixed culturing of electricity-producing bacteria, the MFC could generate a reproducible voltage of 0.4,V at external resistance (REX) of 100,,. Maximum volumetric power density of 68.4,W,m,3 was obtained at a current density of 178.6,A,m,3. Upon aerobic inoculation of electrochemically active bacteria, charge transfer resistance of the cathode was decreased from 188 to 17,, as indicated by electrochemical impedance spectroscopy (EIS) analysis. Comparing investigations of different cathode materials demonstrated that biocatalysed GFB had better performance in terms of half-cell polarisation, power and Coulombic efficiency (CE) over other tested materials. Additionally, pH deviation of electrolyte in anode and cathode was also observed. This study provides a demonstration of GFB used as biocathode material in MFC for more efficient and sustainable electricity recovery from organic substances. [source] LiFePO4 Nanoparticles Embedded in a Nanoporous Carbon Matrix: Superior Cathode Material for Electrochemical Energy-Storage DevicesADVANCED MATERIALS, Issue 25-26 2009Xing-Long Wu An optimized nanostructure design for high-power, high-energy lithium-ion batteries and supercapacitors is realized by fabricating a nanocomposite with highly dispersed nanoparticles of active materials in a nanoporous carbon matrix. A nano-LiFePO4/nanoporous carbon matrix nanocomposite forms a bridge between a supercapacitor and a battery electrode and offers a reasonable compromise between rate and capacity. [source] A Novel Inorganic Polymer as Cathode Material for Secondary Lithium BatteriesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2005Guo-Xiang Xu Abstract Summary: This paper introduces a new inorganic poly(phosphazene disulfide) material. With unique element composition and molecular structure, the polymer has noncombustible safety and preferable conductivity. When used as cathode material for rechargeable lithium batteries, the polymer's first discharge capacity is as high as 467.9 mAh,·,g,1, which can be retained at 409.9 mAh,·,g,1 after 60 repeated cycles. Therefore, it has a great application potential in the field of lithium batteries. Replacement of the Cl atoms by SS groups by refluxing Na2S2 and linear poly(dichloro-phosphazene). [source] Electroactive Organic Molecules Immobilized onto Solid Nanoparticles as a Cathode Material for Lithium-Ion Batteries,ANGEWANDTE CHEMIE, Issue 40 2010Dr. Bostjan Genorio Aktive Monomere: Indem man lösliche organische Moleküle an unlösliche Substrate bindet, z.,B. Calixchinone an Nanopartikel (siehe Bild), gelingt die Herstellung einer ganzen Reihe sehr stabiler Materialien für Anwendungen in Lithiumionenbatterien. Die Immobilisierung der organischen Moleküle vermeidet das zu Leistungsabfällen führende Problem der Dissolution. [source] LiMn0.8Fe0.2PO4: An Advanced Cathode Material for Rechargeable Lithium Batteries,ANGEWANDTE CHEMIE, Issue 45 2009Surendra Mit Kohlenstoff beschichtete LiMn0.8Fe0.2PO4 -Nanopartikel (siehe TEM-Bild) aus einer Festkörpersynthese erwiesen sich als hervorragendes Kathodenmaterial für Lithiumionenbatterien: Neben einer stabilen reversiblen Kapazität von 165,mA,h,g,1 wurden ein hervorragendes Zyklusverhalten, schnelles Ansprechverhalten, eine hohe Temperaturbeständigkeit und sehr geringe Oberflächenreaktivität beobachtet. [source] ChemInform Abstract: Structure and Electrochemical Performance of FeF3/V2O5 Composite Cathode Material for Lithium-Ion Battery.CHEMINFORM, Issue 5 2010Wen Wu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Ag4V2O6F2 (SVOF): A High Silver Density Phase and Potential New Cathode Material for Implantable Cardioverter Defibrillators.CHEMINFORM, Issue 50 2008Frederic Sauvage Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Cu-Doped V2O5 as a High-Energy Density Cathode Material for Rechargeable Lithium Batteries.CHEMINFORM, Issue 37 2008Yingjin Wei Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Structural and Electrical Characterization of the Novel SrCo0.9Sb0.1O3-, Perovskite: Evaluation as a Solid Oxide Fuel Cell Cathode Material.CHEMINFORM, Issue 10 2008A. Aguadero Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] An Aqueous Reduction Method to Synthesize Spinel-LiMn2O4 Nanoparticles as a Cathode Material for Rechargeable Lithium-Ion Batteries.CHEMINFORM, Issue 4 2004V. Ganesh Kumar Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A New MnOx Cathode Material for Rechargeable Lithium Batteries.CHEMINFORM, Issue 29 2002Arno Perner Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] In Situ Time-Resolved Neutron Diffraction Investigation during Oxygen Exchange in Layered Cobaltite Cathode Materials,ANGEWANDTE CHEMIE, Issue 45 2009Lorenzo Malavasi Dr. Man achte auf den Sauerstoff: Mit dem im Titel genannten Verfahren können die beim Sauerstoffaustausch in einem Material auftretenden Strukturänderungen untersucht werden (siehe Diagramm für die Zunahme des Sauerstoffgehalts, wenn der Gasfluss von Ar auf O2 umgestellt wird). Die Methode wird an einem schichtförmigen Cobaltit demonstriert, einem vielversprechenden Kathodenmaterial für Brennstoffzellen. [source] ChemInform Abstract: Low Thermal Expansion MBa(Co,M,)4O7 Cathode Materials Based on Tetrahedral-Site Cobalt Ions for Solid Oxide Fuel Cells.CHEMINFORM, Issue 31 2010Jung-Hyun Kim Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Ru-Pyrochlores: Compositional Tuning for Electrochemical Stability as Cathode Materials for IT-SOFCs.CHEMINFORM, Issue 10 2009G. Ehora Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Performance of LiM0.05Co0.95O2 Cathode Materials in Lithium Rechargeable Cells When Cycled up to 4.5 V.CHEMINFORM, Issue 23 2005Meijing Zou Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Electrochemical Characteristics of Li0.7[Ni1/6Mn5/6]O2 Cathode Materials.CHEMINFORM, Issue 51 2002K. S. Park Abstract For Abstract see ChemInform Abstract in Full Text. [source] High-Performance Carbon-LiMnPO4 Nanocomposite Cathode for Lithium BatteriesADVANCED FUNCTIONAL MATERIALS, Issue 19 2010Seung-Min Oh Abstract A cathode material of an electrically conducting carbon-LiMnPO4 nanocomposite is synthesized by ultrasonic spray pyrolysis followed by ball milling. The effect of the carbon content on the physicochemical and electrochemical properties of this material is extensively studied. A LiMnPO4 electrode with 30 wt% acetylene black (AB) carbon exhibits an excellent rate capability and good cycle life in cell tests at 55 and 25 °C. This electrode delivers a discharge capacity of 158 mAh g,1 at 1/20 C, 126 mAh g,1 at 1 C, and 107 mAh g,1 at 2 C rate, which are the highest capacities reported so far for this type of electrode. Transmission electron microscopy and Mn dissolution results confirm that the carbon particles surrounding the LiMnPO4 protect the electrode from HF attack, and thus lead to a reduction of the Mn dissolution that usually occurs with this electrode. The improved electrochemical properties of the C-LiMnPO4 electrode are also verified by electrochemical impedance spectroscopy. [source] A Novel Cathode Material with a Concentration-Gradient for High-Energy and Safe Lithium-Ion BatteriesADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Yang-Kook Sun Abstract A high-energy functional cathode material with an average composition of Li[Ni0.72Co0.18Mn0.10]O2, mainly comprising a core material Li[Ni0.8Co0.2]O2 encapsulated completely within a stable manganese-rich concentration-gradient shell is successfully synthesized by a co-precipitation process. The Li[Ni0.72Co0.18Mn0.10]O2 with a concentration-gradient shell has a shell thickness of about 1,µm and an outer shell composition rich in manganese, Li[Ni0.55Co0.15Mn0.30]O2. The core material can deliver a very high capacity of over 200,mA h g,1, while the manganese-rich concentration-gradient shell improves the cycling and thermal stability of the material. These improvements are caused by a gradual and continuous increase of the stable tetravalent Mn in the concentration-gradient shell layer. The electrochemical and thermal properties of this cathode material are found to be far superior to those of the core Li[Ni0.8Co0.2]O2 material alone. Electron microscopy also reveals that the original crystal structure of this material remains intact after cycling. [source] Intermediate Temperature Anode-Supported Fuel Cell Based on BaCe0.9Y0.1O3 Electrolyte with Novel Pr2NiO4 CathodeFUEL CELLS, Issue 1 2010G. Taillades Abstract A proton conducting ceramic fuel cell (PCFC) operating at intermediate temperature has been developed that incorporates electrolyte and electrode materials prepared by flash combustion (yttrium-doped barium cerate) and auto-ignition (praseodymium nickelate) methods. The fuel cell components were assembled using an anode-support approach, with the anode and proton ceramic layers prepared by co-pressing and co-firing, and subsequent deposition of the cathode by screen-printing onto the proton ceramic surface. When the fuel cell was fed with moist hydrogen and air, a high Open Circuit Voltage (OCV,>,1.1,V) was observed at T,>,550,°C, which was stable for 300,h (end of test), indicating excellent gas-tightness of the proton ceramic layer. The power density of the fuel cell increased with temperature of operation, providing more than 130,mW,cm,2 at 650,°C. Symmetric cells incorporating Ni-BCY10 cermet and BCY10 electrolyte on the one hand, and Pr2NiO4,+,, and BCY10 electrolyte on the other hand, were also characterised and area specific resistances of 0.06,,,cm2 for the anode material and 1,2,,,cm2 for the cathode material were obtained at 600,°C. [source] Power Generation and Electrochemical Analysis of Biocathode Microbial Fuel Cell Using Graphite Fibre Brush as Cathode MaterialFUEL CELLS, Issue 5 2009S.-J. You Abstract To improve cathodic efficiency and sustainability of microbial fuel cell (MFC), graphite fibre brush (GFB) was examined as cathode material for power production in biocatalysed-cathode MFC. Following 133-h mixed culturing of electricity-producing bacteria, the MFC could generate a reproducible voltage of 0.4,V at external resistance (REX) of 100,,. Maximum volumetric power density of 68.4,W,m,3 was obtained at a current density of 178.6,A,m,3. Upon aerobic inoculation of electrochemically active bacteria, charge transfer resistance of the cathode was decreased from 188 to 17,, as indicated by electrochemical impedance spectroscopy (EIS) analysis. Comparing investigations of different cathode materials demonstrated that biocatalysed GFB had better performance in terms of half-cell polarisation, power and Coulombic efficiency (CE) over other tested materials. Additionally, pH deviation of electrolyte in anode and cathode was also observed. This study provides a demonstration of GFB used as biocathode material in MFC for more efficient and sustainable electricity recovery from organic substances. [source] Reactivity in LaGaO3/Ni and CeO2/Ni SystemsFUEL CELLS, Issue 2 2006N. Solak Abstract The reactivity in CeO2/Ni and LaGaO3/Ni systems, which are constituents of intermediate temperature solid oxide fuel cell (IT-SOFC) anodes, has been investigated both computationally and experimentally. The CALPHAD-method (CALculating of PHAse Diagrams), employing BINGSS and THERMOCALC software, was used to obtain a self-consistent set of Gibbs energy functions describing the systems. Interactions in the LaGaO3/Ni system were predicted using a thermodynamic database developed for the La-Ga-Ni-O system. Similarly, to analyze the CeO2/Ni system, the Ce-Ni-O ternary phase diagram was calculated using known thermodynamic data for binary Ce-O, Ni-O, and Ce-Ni systems. The experimental work was designed based on the calculated phase diagrams. While the La-Ga-Ni-O system experiments were conducted in air, the Ce-Ni-O system was also investigated in a reducing atmosphere. The calculated Ce-Ni-O diagram is in good agreement with the experimental results. It has been found that NiO does not react with CeO2. Extended solid solutions of La(Ga,Ni)O3, La2(Ni,Ga)O4, and La4(Ni,Ga)3O10 were found in the La-Ga-Ni-O system. Additionally, the compound LaNiGa11O19, with magnetoplumbite-type structure, has been found, which has not been reported in the literature so far. It is concluded that La2NiO4 is not chemically compatible, as a cathode material, with the LSGM electrolyte. [source] Synthesis of Nanohole-Structured Single-Crystalline Platinum Nanosheets Using Surfactant-Liquid-Crystals and their Electrochemical CharacterizationADVANCED FUNCTIONAL MATERIALS, Issue 4 2009Tsuyoshi Kijima Abstract Nanohole-structured single-crystalline Pt nanosheets have been synthesized by the borohydride reduction of Na2PtCl6 confined to the lyotropic liquid crystals (LLCs) of polyoxyethylene (20) sorbitan monooleate (Tween 80) with or without nonaethylene-glycol (C12EO9). The Pt nanosheets of around 4,10,nm in central thickness and up to 500,nm or above in diameter have a number of hexagonal-shaped nanoholes ,1.8,nm wide. High-resolution electron microscope images of the nanosheets showed atomic fringes with a spacing of 0.22,nm indicating that the nanosheets are crystallographically continuous through the nanoholed and non-holed areas. The inner-angle distributions for the hexagonal nanoholes indicate that the six sides of the nanoholes are walled with each two Pt (111), Pt (11) and Pt (010) planes. The formation mechanism of nanoholed Pt nanosheets is discussed on the basis of structural and compositional data for the resulting solids and their precursory LLCs, with the aid of similar nanohole growth observed for a Tween 80 free but oleic acid-incorporated system. It is also demonstrated that the nanoholed Pt nanostructures loaded on carbon exhibit fairly high electrocatalytic activity for oxygen reduction reaction and a high performance as a cathode material for polymer-electrolyte fuel cells, along with their extremely high thermostability revealed through the effect of electron-irradiation. [source] Cover Picture: Nanostructured Electrodes and the Low-Temperature Performance of Li-Ion Batteries (Adv. Mater.ADVANCED MATERIALS, Issue 1 20051/2005) Abstract The cover image shows a scanning electron micrograph of a commercially available track-etch polycarbonate filter. This porous membrane serves as the host for the template-synthesis of V2O5 nanowires of various diameters. Nanowires that are 70,nm in diameter are shown in the inset. Because V2O5 reversibly intercalates Li-ions, it has potential for use as a cathode material in Li-ion batteries. On p.,125, Sides and Martin report the use of these V2O5 nanowires as tools to investigate the poor low-temperature performance of Li-ion batteries. [source] Synthesis and Electrical Properties of Stabilized Manganese Dioxide (,-MnO2) Thin-Film ElectrodesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2008Do-Kyun Kwon Manganese dioxide (,-MnO2) thin films have been explored as a cathode material for reliable glass capacitors. Conducting ,-MnO2 thin films were deposited on a borosilicate glass substrate by a chemical solution deposition technique. High carbon activities originated from manganese acetate precursor, (Mn(C2H3O2)2·4H2O) and acetic acid solvent (C2H4O2), which substantially reduced MnO2 phase stability, and resulted in Mn2O3 formation at pyrolysis temperature in air. The ,-MnO2 structure was stabilized by Ba2+ insertion into a (2 × 2) oxygen tunnel frame to form a hollandite structure. With 15,20 mol% Ba addition, a conducting ,-MnO2 thin film was obtained after annealing at 600,650°C, exhibiting low electrical resistivity (,1 ,·cm), which enables application as a cathode material for capacitors. The hollandite ,-MnO2 phase was stable at 850°C, and thermally reduced to the insulating bixbyte (Mn2O3) phase after annealing at 900°C. The phase transition temperature of Ba containing ,-MnO2 was substantially higher than the reported transition temperature for pure MnO2 (,500°C). [source] A Novel Inorganic Polymer as Cathode Material for Secondary Lithium BatteriesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2005Guo-Xiang Xu Abstract Summary: This paper introduces a new inorganic poly(phosphazene disulfide) material. With unique element composition and molecular structure, the polymer has noncombustible safety and preferable conductivity. When used as cathode material for rechargeable lithium batteries, the polymer's first discharge capacity is as high as 467.9 mAh,·,g,1, which can be retained at 409.9 mAh,·,g,1 after 60 repeated cycles. Therefore, it has a great application potential in the field of lithium batteries. Replacement of the Cl atoms by SS groups by refluxing Na2S2 and linear poly(dichloro-phosphazene). [source] Highly localized ion focusing effects in PBIIDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2008Frank Haberkorn Abstract Plasma Based Ion Implantation and Deposition (PBIID) is characterized by a complex interaction of a supersonic plasma flux, a plasma sheath expanding and receding on a timescale of microseconds and a substrate which can be of an arbitrary complex shape. It is shown that ions impinging on the substrate in the wake region consist of two groups with strongly differing incidence angles. At the same time, localized ion focusing is observed only for very long pulses of 50 µs and intermediate voltages of 2.5 , 3.5 kV, independent of the cathode material , Ti or Al , and the Ar background pressure. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Biomimetic Synthesis of Metal Ion-Doped Hierarchical Crystals Using a Gel Matrix: Formation of Cobalt-Doped LiMn2O4 with Improved Electrochemical Properties through a Cobalt-Doped MnCO3 PrecursorCHEMISTRY - AN ASIAN JOURNAL, Issue 4 2010Takao Kokubu Abstract We have synthesized spinel type cobalt-doped LiMn2O4 (LiMn2,yCoyO4, 0,y,0.367), a cathode material for a lithium-ion battery, with hierarchical sponge structures via the cobalt-doped MnCO3 (Mn1- xCoxCO3, 0,x,0.204) formed in an agar gel matrix. Biomimetic crystal growth in the gel matrix facilitates the generation of both an homogeneous solid solution and the hierarchical structures under ambient condition. The controlled composition and the hierarchical structure of the cobalt-doped MnCO3 precursor played an important role in the formation of the cobalt-doped LiMn2O4. The charge,discharge reversible stability of the resultant LiMn1.947Co0.053O4 was improved to ca. 12,% loss of the discharge capacity after 100,cycles, while pure LiMn2O4 showed 24,% loss of the discharge capacity after 100,cycles. The parallel control of the hierarchical structure and the composition in the precursor material through a biomimetic approach, promises the development of functional materials under mild conditions. [source] Evaluating Carrier Accumulation in Degraded Bulk Heterojunction Organic Solar Cells by a Thermally Stimulated Current TechniqueADVANCED FUNCTIONAL MATERIALS, Issue 24 2009Kenji Kawano Abstract Here, the initial photo-degradation of encapsulated P3HT:PCBM bulk heterojunction organic solar cells is investigated. The degraded device is recovered by thermal annealing treatment. Thermally stimulated current measurements reveal that the cause of photo-degradation is carrier accumulation and that the degraded organic solar cell has two broad trap levels, of 0.71 and 0.81,eV. These traps are independent of the thickness of the photoactive layers, the mixing ratio of the photoactive materials and the cathode materials. In addition, it is confirmed that there is a close relationship between the degree of degradation and the amount of accumulated charge carriers. [source] Power Generation and Electrochemical Analysis of Biocathode Microbial Fuel Cell Using Graphite Fibre Brush as Cathode MaterialFUEL CELLS, Issue 5 2009S.-J. You Abstract To improve cathodic efficiency and sustainability of microbial fuel cell (MFC), graphite fibre brush (GFB) was examined as cathode material for power production in biocatalysed-cathode MFC. Following 133-h mixed culturing of electricity-producing bacteria, the MFC could generate a reproducible voltage of 0.4,V at external resistance (REX) of 100,,. Maximum volumetric power density of 68.4,W,m,3 was obtained at a current density of 178.6,A,m,3. Upon aerobic inoculation of electrochemically active bacteria, charge transfer resistance of the cathode was decreased from 188 to 17,, as indicated by electrochemical impedance spectroscopy (EIS) analysis. Comparing investigations of different cathode materials demonstrated that biocatalysed GFB had better performance in terms of half-cell polarisation, power and Coulombic efficiency (CE) over other tested materials. Additionally, pH deviation of electrolyte in anode and cathode was also observed. This study provides a demonstration of GFB used as biocathode material in MFC for more efficient and sustainable electricity recovery from organic substances. [source] | |||||||||||||||||||||||||