Abstract: A fuel cell system and a control method thereof are capable of preventing anode flooding due to a temperature difference between a stack and reformate upon starting a fuel cell system. The method of controlling a fuel cell system including steps of detecting a temperature of a fuel cell stack, detecting a temperature of reformate that is generated in a fuel reformer and then is supplied to the fuel cell stack through a heat exchanger, and setting the temperature of the reformate to be lower than the temperature of the fuel cell stack during a starting time of the fuel cell system.

Abstract: A fuel cell stack for generating electrical energy by an electrochemical reaction of a fuel and an oxidizing gas including a plurality of electricity generating units and a fastening member is disclosed. The plurality of electricity generating units are configured for an electrochemical reaction between the fuel and the oxidizing gas to generate electrical energy, and the fastening member combines the plurality of electricity generating units into a stack. Each electricity-generating unit includes a membrane electrode assembly (MEA) and separators that are provided on each side of the MEA. Each separator comprises a channel on a surface facing the MEA. The channel is divided into a multiple of 2 sub-channels that is greater than 2 on a surface of the separator, and the sub-channels have substantially the same fluid passage length.

Abstract: The present invention relates to a fuel cell capable of transferring a power generation state and coupling information of the fuel cell to an external apparatus and relates to an information device capable of receiving power and information from the fuel cell. The fuel cell includes a fuel cell stack for generating electricity by an electrochemical reaction of a fuel and an oxidant; a fuel supplier for supplying the fuel to the fuel cell stack; a set of output terminals for outputting electricity generated from the fuel cell stack and for outputting information on a power generation state of the fuel cell; and a power supply information processing unit for applying a voltage level according to the information to any one of the set of output terminals.

Abstract: A process of manufacturing a positive active material for a lithium secondary battery includes adding a metal source to a doping element-containing coating liquid to surface-treat the metal source, wherein the metal source is selected from the group consisting of cobalt, manganese, nickel, and combination thereof; drying the surface-treated metal source material to prepare a positive active material precursor; mixing the positive active material precursor with a lithium source; and subjecting the mixture to heat-treatment. Alternatively, the above drying step during preparation of the positive active material precursor is substituted by preheat-treatment or drying followed by preheat-treatment.

Abstract: Disclosed is a separator for a fuel cell stack. The separator includes a plate having a first opening and a second opening on a surface thereof. A field or a channel is formed on the surface of the plate. The field has a first end and a second end. A field inlet is formed on the surface of the plate and connects the first end of the field to the first opening, and a field outlet is formed on the surface of the plate and connects the second end of the field to the second opening. An area of a cross-section of the field inlet, which is cut perpendicular to the surface of the plate, is smaller than an area of a cross-section of the field outlet, which is cut perpendicular to the surface of the plate.

Abstract: A positive active material composition for a rechargeable lithium battery includes at least one lithiated compound, and at least one additive compound selected from the group consisting of a thermal-absorbent element-included hydroxide, a thermal-absorbent element-included oxyhydroxide, a thermal-absorbent element-included oxycarbonate, and a thermal-absorbent element-included hydroxycarbonate.

Abstract: The present invention relates to a positive active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery comprising the same. The positive active material includes a lithium/nickel-based compound wherein primary particles having an average particle diameter ranging from 1 ?m to 4 ?m are agglomerated to form secondary particles. The positive active material of the present invention has excellent electrochemical performance and outstanding inhibition to swelling at high temperatures.

Abstract: A fuel cell stack has an electrical generator including at least one unit cell between a pair of opposing end plates having a length and a width, wherein an aspect ratio of the length of the end plate to the width of the end plate is between about 1 to about 4. A center fastener penetrates the electrical generator through generally central regions of the end plates and a plurality of edge fasteners penetrates the electrical generator through generally peripheral regions of the end plates. The center fastener and the plurality of edge fasteners are adapted to press the end plates together.

Abstract: A fuel cell stack including an electricity generating unit for generating electrical energy by electrochemically reacting a fuel and an oxidizing agent, the electricity generating unit including: a first separator; a second separator; a membrane electrode assembly (MEA) between the first separator and the second separator, each of the first and second separators including a channel on a surface facing the MEA and a manifold in the surface facing the MEA, the manifold communicating with the channel; and a gasket, positioned at an outer circumference portion of an area where the MEA is positioned, for sealing a space between the first and second separators and for covering an open area of a channel extension area of at least one of the first and second separators where the manifold communicates with the channel.

Abstract: An air-breathing fuel cell stack including: a membrane electrode assembly that includes an anode, a cathode, and an electrolyte disposed therebetween; a fuel supplier coupled to the anode, to supply fuel to the anode; a cathode current collector coupled to the cathode; a cathode end plate to support the cathode current collector; and a filter positioned between the cathode current collector and the cathode end plate, to control the moisture content of the membrane electrode assembly.

Abstract: A process of manufacturing a positive active material for a lithium secondary battery includes adding a metal source to a doping element-containing coating liquid to surface-treat the metal source, wherein the metal source is selected from the group consisting of cobalt, manganese, nickel, and combination thereof; drying the surface-treated metal source material to prepare a positive active material precursor; mixing the positive active material precursor with a lithium source; and subjecting the mixture to heat-treatment. Alternatively, the above drying step during preparation of the positive active material precursor is substituted by preheat-treatment or drying followed by preheat-treatment.

Abstract: A fuel cell stack includes a plurality of membrane electrode assemblies (MEAs) and a stamped metal separator. The metal separator is positioned between the membrane electrode assemblies. The separator includes at least one channel on both surfaces of the separator formed by a stamping process. The separator comprises a plurality of holes, each of which form a manifold communicating with each the channels.

Abstract: A fuel cell stack comprising a multitude of membrane-electrode assemblies stacked with a separator interposed therebetween is characterized in that an MEA of first a property having an anode and a cathode, and the MEA of second property having an anode electrode and a cathode electrode are stacked. Preferably the MEA of the first property is a hydrocarbon-based MEA and the MEA of the second property is a fluorine-based MEA.

Abstract: Disclosed is a fuel cell system wherein the flow of fuel and oxygen is optimized thereby improving the thermal efficiency of the entire system. The fuel cell system comprises at least one stack for generating electrical energy by an electrochemical reaction between hydrogen gas and oxygen, a fuel supply portion for supplying fuel to the stack, and an oxygen supply portion for supplying oxygen to the stack. The stack is formed in a stacked configuration with MEAs and separators. The separators are positioned on either surface of the MEAs. The separators have a plurality of ribs proximate to the MEAs which define a plurality of channels wherein the ratio of a width of the channels to the width of the ribs is from about 0.8 to 1.5.

Abstract: Disclosed is a method of preparing a positive active material for a rechargeable lithium battery including adding first and second compounds to a solvent to prepare an acidic solution with a pH from 0.

Abstract: A process of manufacturing a positive active material for a lithium secondary battery includes preparing a coating-element-containing organic suspension by adding a coating-element source to an organic solvent, adding water to the suspension to prepare a coating liquid, coating a positive active material with the coating liquid, and drying the coated positive active material.

Abstract: Disclosed is a positive active material for a rechargeable lithium battery, including a lithiated intercalation compound and an additive compound. The additive compound comprises one or more intercalation element-included oxides which have a charging voltage of 4.0 to 4.6V when 5-50% of total intercalation elements of the one or more intercalation element-included oxides are released during charging.

Abstract: The present invention relates to a negative active material for a lithium rechargeable battery and a method of preparing the same, and the negative active material prepared by coating a carbon source with a coating liquid, and drying the carbon source, and the negative active material comprises a core having a carbon source with surface-treatment layer formed on the surface of the core, the surface-treatment layer having at least one compound of coating element selected from the group cosnsisting of amorphous, semi crystalline, or crystalline hydroxides, oxyhydroxides, oxycarbonates, and hydroxidecarbonates.

Abstract: A membrane-electrode assembly for a mixed reactant fuel cell system is provided. The membrane-electrode assembly does not require a separator that physically separates the membrane-electrode assemblies from each other in a stack. The membrane-electrode assembly of the present invention instead includes an electrode substrate that is disposed on a surface of an anode or a cathode of the membrane-electrode assembly. The electrode substrate has a flow path, through which a fuel and an oxidant are supplied. The fuel and oxidant are absorbed into the electrode substrate and further into the anode and the cathode. The fuel and the oxidant are selectively oxidized and reduced in the anode and the cathode, respectively, to produce electricity.

Abstract: A positive active material includes a core including a lithiated compound, and at least two surface-treatment layers formed on the core. The surface-treatment layer includes at least one compound selected from the group consisting of a coating-element-included hydroxide, a coating-element-included oxyhydroxide, a coating-element-included oxycarbonate, and a coating-element-included hydroxycarbonate. The coating element is selected from the group consisting of Mg, Al, Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, and As.