37results about How to "Improve cathode performance" patented technology

The present invention provides electrochemical cells providing good electronic performance at low temperatures. Electrochemical cells of the present invention include lithium batteries capable of providing useful specific capacities under significant discharge rates for temperatures as low as −60 degrees Celsius. The present invention also provides methods for making electrochemical cells including a room temperature predischarge step preceding low temperature operation that enhances the performance of batteries having subfluorinated carbonaceous positive electrode active materials at low temperatures.

A method of producing Li_y[Ni_xCo_1−2xMn_x]O₂ wherein 0.025≦x≦0.5 and 0.9≦y≦1.3. The method includes mixing [Ni_xCo_1−2xMn_x]OH₂ with LiOH or Li₂CO₃ and one or both of alkali metal fluorides and boron compounds, preferably one or both of LiF and B₂O₃. The mixture is heated sufficiently to obtain a composition of Li_y[Ni_xCo_1−2xMn_x]O₂ sufficiently dense for use in a lithium-ion battery cathode. Compositions so densified exhibit a minimum reversible volumetric energy characterized by the formula [1833-333x] measured in Wh/L.

The invention discloses a Pdx@Pt/C core-shell structure cathode catalyst for a fuel cell and a preparation method of the Pdx@Pt/C core-shell structure cathode catalyst. The method comprises the following steps: (1) adding a palladium precursor and a conductive carrier to N,N-dimethyl formamide or ethanol, carrying out ultrasonic mixing, and then adding borane.N,N-diethyl aniline or sodium borohydride, reacting at a room temperature for 0.5-1.5h, carrying out centrifugal washing and vacuum drying and then obtaining a carbon-supported Pd catalyst, namely Pd/C; and (2) ultrasonically dispersing the Pd/C prepared in the step (1) into a formic acid solution with the concentration of 1-5ml formic acid/20ml water, adding a water solution of a platinum compound at the atomic ratio of Pt to Pd being 1 to 1 or 1 to 2 or 1 to 3, reacting at the room temperature for 2-6h, and carrying out centrifugal washing and vacuum drying to obtain the product. The catalyst with high catalytic activity and stability is prepared by a primary cell reaction principle; the catalyst is lower than a pure Pt catalyst in cost; the preparation method is simple, convenient, mild in condition and easy to operate; and the problem that a high temperature and a surfactant are required for preparation of the core-shell structure catalyst by a conventional chemical reduction method is solved.

Subfluorinated carbonaceous materials obtained through direct fluorination of graphite or coke particles are provided. One set of subfluorinated carbonaceous materials has an average chemical composition CF_x in which 0.63<x≦0.95, 0.66<x≦0.95 or 0.7<x≦0.95. The subfluorinated carbonaceous materials are capable of electrochemical performance superior to commercial CF at relatively high rates of discharge.

The invention discloses a Pt-based fuel cell cathode catalyst of a transition metal element doped with TiO2 and a carbon compound with high specific surface area as a carrier, and a preparation method of the Pt-based fuel cell cathode catalyst. The method comprises the steps of adding a Ti compound and a transition metal M precursor to water, adding carbon with high specific surface area, carrying out ultrasonic mixing evenly and then obtaining a composite oxide carbon carrier C-Ti<x>M<1-x>O<2> by using a hydrothermal method; and mixing a platinum compound water solution with the C-Ti<x>M<1-x>O<2> and obtaining a composite oxide carbon carrier-loaded nano Pt catalyst, namely a Pt/C-Ti<x>M<1-x>O<2> catalyst by adopting an impregnation method. Compared with commercial Pt/C, the prepared Pt/C-Ti<x>M<1-x>O<2> catalyst has higher catalytic activity and stability due to interaction between a metal and the carrier; the preparation method is simple and convenient, mild in condition and easy to operate; the problems of high surface Pt agglomeration degree and poor stability of the catalyst prepared by adopting a conventional impregnation method are solved; and the composite oxide carbon carrier-loaded nano Pt catalyst is a powder catalyst suitable for a proton exchange membrane fuel cell.

The invention relates to a novel mixed super capacitor which adopts a nano MnO2 electrode as a positive electrode, an activated carbon electrode as a negative electrode and alkaline lithium hydroxide water solution as electrolyte. The positive electrode stores energy by a Faraday oxidation reduction mechanism, and the negative electrode stors energy by a double electrode layer mechanism. When the lithium hydroxide electrolyte is adopted, the reaction mechanism of the nano MnO2 electrode is different from the reaction mechanism in potassium hydroxide electrolyte or neutral water solution. Therefore, the nano MnO2 electrode has higher specific capacitance. The super capacitor has the advantages of perfect high energy intensity, high power intensity, high-rate charge and discharge performance, long circulation service life, low cost and no environmental damages and can be applied to large power charge and discharge occasions.

A novel lithium battery cathode, a lithium ion battery using the same and processes and preparation thereof are disclosed. The battery cathode is formed by force spinning. Fiber spinning allows for the formation of core-shell materials using material chemistries that would be incompatible with prior spinning techniques. A fiber spinning apparatus for forming a coated fiber and a method of forming a coated fiber are also disclosed.

The present invention discloses a method for preparing a high-performance fuel cell nanocomposite cathode material, and belongs to the technical field of fuel cell catalytic material preparation. Thefeed stocks comprise: doped bismuth oxide, a complexing agent, La(NO3)3.6H2O, Sr(NO3)2, Mn(NO3)2 and ammonium hydroxide. The molar ratio of La(NO3)3.6H2O, Sr(NO3)2, and Mn(NO3)2 is (0.4-0.9): (0.1-0.6): (0.8-1.2); and the complexing agent is a mixture of citric acid and EDTA. The high-performance fuel cell nanocomposite cathode is successfully obtained by modifying the doped bismuth oxide by usinga sol-gel method. The composite cathode particles obtained by using the method disclosed by the present invention can reach a nanometer size and can exhibit remarkable high catalytic activity; and the feed stocks in the present invention is simple and available, the process is stable, and the industrialized conditions are achieved.

The present application relates to a metal oxide and synthesis of a lithium ion battery. Specifically, the present application selects a cobalt oxide compound, which uses Co₃O₄ as a main body, as a precursor of lithium cobalt oxide, and anion doping is performed in particles of Co₃O₄ to obtain a doped precursor for lithium cobalt oxide. The general formula of the precursor can be expressed as Co₃(O_1-yM_y)₄, where about 0<y<about 0.2, and wherein the anion M comprises at least one of F, P, S, Cl, N, As, Se, Br, Te, I or At. The lithium ion battery with a cathode made of lithium cobalt oxide material prepared by using the precursor presents good cycle stability in a high voltage charge-discharge environment.

A novel method to produce ALD films disposed on powders is disclosed. Examples include the formation of a cobalt doped zirconia (CDZ), hafnia, and cobalt doped hafnia (CDH) films on lanthanum strontium cobalt iron oxide (LSCF) powder for solid oxide fuel cell cathodes. The coated powders are sintered into porous cathodes that have utility for preventing the migration of cations in the powder to the surface of the sintered cathode and/or other performance enhancing attributes.

The invention belongs to the field of solid oxide fuel cells, in particular relates to a solid oxide fuel cell structure and a preparation method thereof. The cell structure comprises a cell cathode layer, an electrolyte layer and a cell anode layer in sequence from top to bottom, wherein the cell cathode layer is divided into a PrBaCo2O5 layer and an LSM (La0.8S0.2MnO3) layer from top to bottom; the electrolyte layer is YSZ (Yttria Stabilized Zirconia); the cell anode layer is Ni-YSZ; and the thickness of the PrBaCo2O5 layer is 2-4 microns. Because PrBaCo2O5 has higher catalytic performance, oxygen diffusion coefficients, surface exchange coefficients and oxygen ion migration capability, the oxygen adsorbing capability and oxygen dissociating capability of a cathode can be improved by adopting a PrBaCo2O5-LSM/YSZ/Ni-YSZ structure and material system; and the solid oxide fuel cell structure has the characteristic of improving the cathode performance of the solid oxide fuel cells.

The invention discloses a stacked passive paper-based microfluidic fuel cell with opposite arrangement of cathode and anode. The stacked passive paper-based microfluidic fuel cell comprises an air self-breathing cathode, an electrolyte flow channel, a fuel flow channel, an anode and a bottom plate. The stacked passive paper-based microfluidic fuel cell is characterized in the electrolyte flow channel and the fuel flow channel are formed by stacking double-layer or multi-layer paper bases, and a certain gap is left among the paper bases as a flow channel for electrolyte or fuel. The electrolyteflow channel is located above the fuel flow channel. The air self-breathing cathode and the anode are arranged opposite in a vertical direction, and the air self-breathing cathode is arranged above and in contact with the electrolyte flow channel. The air self-breathing cathode is composed of a hydrophobic porous electrode, and a catalytic layer is arranged at the contact part with the electrolyte flow channel. The anode is embedded in the fuel flow channel in a horizontal direction and forms a wedge-shaped gap with the fuel flow channel. The anode is composed of a hydrophilic electrode, anda catalytic layer is arranged at the part overlapping the fuel flow channel. The stacked passive paper-based microfluidic fuel cell can be widely applied in the fields of power supply and the like.

A method for producing a cathode active material which produces a spinel type lithium manganese oxide expressed by a general formula: Li1+xMn2-x-yMeyPO4, as the cathode active material, (here, x is expressed by a relation of 0<=x<=0.15 and y is expressed by a relation of 0 C01D 15/02 H01M 4/04 1 19 31 2001/10/23 1350339 2002/5/22 1189959 2005/2/16 2005/2/16 2005/2/16 Sony Corp. Japan Sakai Hideki Fukuba Shigeshi Takahashi Kimio wang jie 11038 The Patent Agency of the Chinese Council for the Promotion of International Trade (CCPIT) No.1 Waidajie, Fuxingmen, Beijing 100086 Japan 2000/10/23 323214/2000

The invention provides an iron-carbon micro-electrolysis filler as well as a preparation method and application thereof, and belongs to the technical field of new energy and environmental engineering.The method comprises the following steps: firstly, preparing an iron-carbon micro-electrolysis filler, and then constructing a CW-MFC system by taking the iron-carbon micro-electrolysis filler as a matrix of a coupling system. The system has the dual functions of sewage treatment and biological power generation, chemical energy is recycled in the form of electric energy while sewage is treated, and the win-win situation of environment-friendly ecological improvement and energy conservation is achieved.