Abstract: Disclosed is an apparatus and method for forming an oxidation layer on a manifold block for a fuel cell stack, which forms an oxidation layer uniformly over the entire surface of a long and complicated internal flow field of a manifold block. In particular, the apparatus for forming an oxidation layer on a manifold block for a fuel cell stack includes: an electrolyte bath which contains an electrolyte required for the formation of the oxidation layer, an electrode for supplying a required electron flow for the formation of the oxidation layer from a power supply to the manifold block immersed in the electrolyte of the electrolyte bath and to the electrolyte, and an air supply for supplying oxygen to the electrolyte. Even more particularly, the electrode connected to the electrolyte is inserted into each internal flow field of the manifold block to provide an effective electron flow therein.

Abstract: The present invention provides a fuel cell separator with a gasket manufactured by integrally forming a gasket on one side of a separator; independently injection molding a frame gasket on a frame such that a first airtight portion covers the entire surface of the frame to maintain the shape of the frame gasket and a second airtight portion projects upward and downward from both ends of the first airtight portion; and bringing the first airtight portion of the frame gasket into contact with the other side of the separator with the gasket formed on one side thereof. To create a fuel cell stack in certain embodiments, the invention stacks the second airtight portion of the frame gasket on another second airtight portion of an adjacent unit cell with a membrane-electrode assembly interposed therebetween.

Abstract: The present invention provides an apparatus and method for generating a virtual sound source for monitoring the operating state of a fuel cell stack, which monitors in real time the deviation and deterioration of a plurality of cells in a fuel cell stack during operation, and expresses the results as a chord or different sounds, thus allowing a driver to easily recognize the operating state of the fuel cell stack.

Abstract: A metal separator for a fuel cell and a manufacturing method thereof are provided, in which a graphite carbon layer with a minute thickness is formed on the surface of a substrate, to improve conductivity. The manufacturing method includes preparing a metal substrate; loading the metal substrate into a chamber with a vacuum atmosphere; coating a graphite carbon layer by depositing carbon ions ionized from a coating source on a surface of the metal substrate; and unloading the metal substrate having the graphite carbon layer coated thereon to an exterior of the chamber.

Abstract: A method and an apparatus using a power transistor in a fuel cell stack diagnostic system provides an apparatus using a power transistor in a fuel cell stack diagnostic system. The apparatus includes a regenerative braking detector that detects regenerative braking of a fuel cell vehicle equipped with a fuel cell stack diagnostic system; a voltage rise determiner that determines whether a voltage rise due to regenerative braking of a fuel cell vehicle is a predetermined value or more; and a power transistor controller that controls an AC signal generator so that the voltage due to the regenerative braking is discharged by the power transistor, when the voltage rise due to regenerative braking determined by the voltage rise determiner is a predetermined value or more.

Abstract: The present invention provides a fuel cell separator with a gasket manufactured by integrally forming a gasket on one side of a separator; independently injection molding a frame gasket on a frame such that a first airtight portion covers the entire surface of the frame to maintain the shape of the frame gasket and a second airtight portion projects upward and downward from both ends of the first airtight portion; and bringing the first airtight portion of the frame gasket into contact with the other side of the separator with the gasket formed on one side thereof. To create a fuel cell stack in certain embodiments, the invention stacks the second airtight portion of the frame gasket on another second airtight portion of an adjacent unit cell with a membrane-electrode assembly interposed therebetween.

Abstract: The present invention provides an apparatus and method for generating a virtual sound source for monitoring the operating state of a fuel cell stack, which monitors in real time the deviation and deterioration of a plurality of cells in a fuel cell stack during operation, and expresses the results as a chord or different sounds, thus allowing a driver to easily recognize the operating state of the fuel cell stack

Abstract: The present invention provides a method for manufacturing a composite separator for a fuel cell, which can reduce the electrical contact resistance by performing an additional post-treatment to remove residual resin remaining on the surface of the composite separator by plasma etching. In certain preferred embodiments, the present invention provides a method for manufacturing a composite separator for a fuel cell, in which a liquid phase resin for gasket is applied to the surface of the composite separator along a predetermined gasket pattern, or a semi-cured resin for gasket in the form of a film with a predetermined gasket pattern is stacked on the surface of the composite separator, and then plasma etching is performed to remove the residual resin and, at the same time, cure the resin for gasket, thus reducing the overall processing time to improve the productivity and preventing a composite material of the separator from being damaged.

Abstract: The present invention provides a fuel cell stack with a water drainage structure, which can effectively drain condensed water and prevent water from flowing into unit cells by combining an end anode plate (EAP) and an end cathode plate (ECP), which are formed by modifying an anode plate (AP) and cathode plate (CP) respectively. In doing so, the modified anode plate (AP) and cathode plate (CP) are converted into a dummy cell which is positioned at the end portions of the fuel cell stack.

Abstract: A method and system for measuring impedance of a fuel cell stack that can rapidly measure impedance of a plurality of frequencies of the fuel cell stack using a sine wave signal in which a different plurality of frequencies are synthesized as an impedance measurement input signal, for diagnosis of the state of a fuel cell stack includes: synthesizing a plurality of sine wave signals having different frequencies; applying the synthesized signal as an input signal for measuring to the fuel cell stack; measuring a current and a voltage of the fuel cell stack; transforming the measured current and voltage of the fuel cell stack with a predetermined method; and calculating impedance of the fuel cell stack of the different frequencies based on the current and voltage of the fuel cell stack that is transformed with the predetermined method.

Abstract: A diagnostic and heat management system for a fuel cell stack is provided herein that includes a diagnostic control analyzer that diagnoses and analyzes a state of the fuel cell stack by measuring a voltage and a current of the fuel cell stack. Also, an AC signal generator generates a diagnostic AC signal, and an AC component driving element that is included in an AC component in a current of the fuel cell stack. Additionally, a termoelement is driven as a heat absorbing device when a temperature of the AC component driving element is equal to or greater than a predetermined temperature and is driven as a heat emitting device when a temperature of the AC component driving element is less than a predetermined temperature, in order to manage heat generation in the AC component driving element.

Abstract: A diagnostic system and method for a fuel cell stack that diagnoses the state and/or failure of the fuel cell stack. More specifically, the diagnostic control analyzer diagnoses and analyzes the state of the fuel cell stack by measuring the voltage and the current received from the fuel cell stack. To do this, an AC signal generator cogenerates a diagnostic AC signal according to the control upon receiving a control command form the analyzer, and an AC component driving element is then driven upon receiving the AC signal that is output from the AC signal generator in order to include a diagnostic AC component within the current of the fuel cell stack. In particular, the diagnostic control analyzer diagnoses the fuel cell stack based on a voltage and a current received from the fuel cell stack that includes the AC component via a load.

Abstract: The present invention features a fuel cell stack that preferably includes an electricity generating assembly having a plurality of unit cells that are suitably disposed one after another; a pair of end plates pressedly disposed respectively at upper and lower ends of the electricity generating assembly; and a joining device suitably engaging the end plates by a rope, where pressure is applied to the electricity generating assembly by means of tension of the rope, and the length and tension of the rope is suitably controlled.

Abstract: To diagnose a fault of a fuel cell stack, an alternating current having a first optimal frequency of a first frequency domain to diagnose a drop in cell voltage and an alternating current having a second optimal frequency of a second frequency domain to diagnose a cause of the drop in cell voltage are supplied to the fuel cell stack are provided. A distortion rate is then calculated based on voltage of the fuel cell stack according to the alternating current of the first optimal frequency, and the drop in cell voltage is diagnosed based on the calculated distortion rate. Also, impedance is calculated based on voltage and a current of the fuel cell stack according to the alternating current of the second optimal frequency and amount of water is calculated based on the calculated in the fuel cell stack, and the cause of the drop in cell voltage is diagnosed based on the calculated impedance and amount of water.

Abstract: A method for manufacturing a manifold for a fuel cell with a multilayer structure by injection-molding individual manifolds, each having welding projections and welding guides, and bonding the injection-molded individual manifolds by vibration welding includes arranging welding projections of an upper individual manifold and welding guides of a lower individual manifold to be engaged with each other while maintaining a uniform gap between each other to bond a plurality of individual manifolds in an up and down stacking structure, pressing the lower individual manifold upward, and applying vibration to the upper individual manifold in the left and right direction, thus bonding the upper and lower individual manifolds. Among the welding projections of the upper individual manifold, a non-horizontal welding projection whose longitudinal direction does not coincide with the vibration direction of the individual manifold has a variable height.

Abstract: A failure diagnosis apparatus that includes an alternating current (AC) absorption unit that is connected to the fuel cell stack and switched based on an applied AC signal to enable a current from the fuel cell stack to flow. In addition, an AC signal generator is configured to generate the AC signal and supply the generated AC signal to the AC absorption unit. As the current from the fuel cell stack is absorbed by the AC absorption unit based on an alternating signal, a stack current input into a diagnosis processing unit includes an AC component, thus the diagnosis processing unit may diagnose fuel cell stack failure by analyzing a frequency of the AC component.

Abstract: Disclosed is a membrane electrode assembly with enhanced hydrophobicity and a method for manufacturing the same. In particular, a nano pattern with a high aspect ratio is formed in a catalyst support on the surface of a catalyst layer constituting the membrane electrode assembly using plasma etching. A hydrophobic thin film is then formed on the nano pattern formed in the catalyst support.

Abstract: The present invention provides a surface pressure controlling device for a fuel cell stack, in which an inflator capable of being expanded by pneumatic or hydraulic pressure is mounted in an end plate so as to control the surface pressure required for the assembly of the fuel cell stack to be maintained above a predetermined level.

Abstract: The present invention provides an apparatus and method for generating a virtual sound source for monitoring the operating state of a fuel cell stack, which monitors in real time the deviation and deterioration of a plurality of cells in a fuel cell stack during operation, and expresses the results as a chord or different sounds, thus allowing a driver to easily recognize the operating state of the fuel cell stack.

Abstract: Disclosed is a membrane electrode assembly with enhanced hydrophobicity and a method for manufacturing the same. In particular, a nano pattern with a high aspect ratio is formed in a catalyst support on the surface of a catalyst layer constituting the membrane electrode assembly using plasma etching. A hydrophobic thin film is then formed on the nano pattern formed in the catalyst support.