Abstract: A fuel cell stack enclosure is provided that includes side covers configured to be joined with each of end of a stack module respectively. A lower cover is also configured to be provided under the stack module and formed to partially cover a lower portion and a first side portion of an outer surface of the side cove. An upper cover may be provided over the stack module, and be formed to partially cover an upper portion and a second side portion of the outer surface of the side cover to enclose the stack module along with the lower cover while joining with the side covers.

Abstract: A fuel cell stack is provided that includes a fuel cell stack module and an enclosure. The fuel cell stack module includes end plates and coupling bars coupled to the end plates. The enclosure includes an upper enclosure covering a front surface, an upper surface, and a back surface of the fuel cell stack module, a lower enclosure covering the front surface, a lower surface, and the back surface of the fuel stack module, a left enclosure fixed to one of the end plates, and a right enclosure fixed to the other of the end plates. The upper enclosure and the lower enclosure are coupled to protruding portions of the left enclosure and the right enclosure and bent toward the surfaces of the fuel cell stack module so as to be in surface contact with the surfaces of the fuel cell stack module.

Abstract: A connector that may be prevented from detaching from separating plates of a stack even when vibrations or an external impact of a vehicle occurs by maintaining a locking state in which locking bosses of a CPA are inserted into lock grooves of terminals of separating plates. In addition, connecting points of connecting pieces of connecting terminals are spaced apart to not contact each other with respect to a contact line. The connecting terminals are not detached from the separating plates even when the separating plates is a ultra-slim film having a thickness of about 0.1 mm or less, making it possible to increase a reliability of a product.

Abstract: The present invention provides a local hydrophilic gas diffusion layer configured to enhance the water removal performance of a fuel cell For this purpose, the present invention provides a gas diffusion layer in which a region under each of a pair of lands, which receives a clamping pressure of the fuel cell stack, is subjected to local hydrophilic treatment by a simple process, thereby enhancing the water removal performance of the fuel cell stack. In particular, the local hydrophilic gas diffusion layer has a first region under each land of the separator which receives the clamping pressure; and a second region under the gas channel of the separator, wherein the first region is subjected to hydrophilic treatment.

Abstract: A technique is described herein for monitoring the operational state of a fuel cell stack by the detection of nonlinearity in such a manner that an external test signal for frequency response is generated and applied to the fuel cell stack during operation, the resulting signal output from the fuel cell stack is measured, and the harmonic content of the measured signal is analyzed, the method including: applying a multiple frequency test signal comprising at least two sinusoidal waves as the test signal for frequency response to the fuel cell stack; and analyzing the resulting current or voltage signal output from the fuel cell stack.

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: A manifold insert installed in a fuel cell having distribution guides is provided. The manifold insert is configured to form a flow field from an inlet port of fluid to an outlet port connected to a fuel cell stack. This manifold insert includes a plurality of distribution guides that divide the flow field from the inlet port to the outlet port such that the fuel cell stack is divided into a plurality of regions according to the distance from the inlet port. The distribution guides have surfaces that are at least partially curved such that the flow of the fluid from the inlet port to the outlet port is changed by the curved surfaces and form a plurality of guide flow fields such that the fluid is supplied to the divided regions of the fuel cell stack along the plurality of guide flow fields at different flow rates.

Abstract: An apparatus for insulating a plurality of exposed live parts of a fuel cell stack, includes a plurality of protectors. Each of the plurality of protectors is made of an insulating material and configured to insulate a corresponding one of the plurality of exposed live parts to which a corresponding one of current collector terminals disposed in an end plate of the fuel cell stack and a corresponding one of connections of a busbar are connected.

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: 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: 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: The present invention provides a local hydrophilic gas diffusion layer configured to enhance the water removal performance of a fuel cell For this purpose, the present invention provides a gas diffusion layer in which a region under each of a pair of lands, which receives a clamping pressure of the fuel cell stack, is subjected to local hydrophilic treatment by a simple process, thereby enhancing the water removal performance of the fuel cell stack. In particular, the local hydrophilic gas diffusion layer has a first region under each land of the separator which receives the clamping pressure; and a second region under the gas channel of the separator, wherein the first region is subjected to hydrophilic treatment.

Abstract: Disclosed is a hydrogen supply system for a fuel cell, which has an integrated manifold block in which components for hydrogen supply are integrated and modulated. In particular, a hydrogen supply line, a hydrogen discharge line, and a hydrogen recirculation line are formed in a manifold block mounted on the outside of a plurality of stack modules of a fuel cell stack. Additionally, components of the hydrogen supply system including components for supplying and discharging hydrogen and components for recirculating hydrogen are integrally mounted in predetermined positions of the hydrogen supply line, the hydrogen discharge line, and the hydrogen recirculation line to modularize the manifold block and the components of the hydrogen supply system.

Abstract: Disclosed is a manifold block for a fuel cell, which provides excellent electrical insulation for a coolant flow channel in an internal flow channel. More specifically, a manifold block for a fuel cell stack, includes a coolant interface formed of a polymer insulating material and coolant flow channels; and a reactant gas interface formed of a metal material and including reactant gas flow channels. In particular, the reactant and coolant interfaces are mounted to a stack module and, at the same time, are integrally bonded to each other.

Abstract: A humidifier includes an inlet assembly provided in an air exhaust pipe, through which water-supersaturated exhaust gas is discharged from a fuel cell stack, to supply water condensed from the exhaust gas to the fuel cell stack and an outlet assembly provided in an air supply pipe, through which a reactant gas to be humidified and supplied to the fuel cell stack passes, to supply the water transferred through a pumping pipe to the air supply pipe such that the reactant gas is humidified. A pumping pipe including a porous material disposed therein along with electrodes are disposed between the inlet assembly and the outlet assembly so that the water is transferred through a capillary path in the porous material via a pumping force by electroosmosis when the electrodes apply a voltage.

Abstract: The present invention provides a method of assembling a fuel cell stack, in which a fixing block and a fixing pin are used to assemble the fuel cell stack instead of a bolt, thereby reducing the time and process required for assembly of the fuel cell stack, enabling an assembly process using an automated device to be realized, and facilitating mass production.

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: 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 manifold block for a fuel cell stack, coupled to a fuel cell stack module and having a gas passage and a cooling water passage. The manifold block includes an insulating member and an insulating cover. The insulating member is inserted into the cooling water passage and contacts an inner surface of the cooling water passage. The insulating member has a tube-like shape and electrically insulates the inner surface of the cooling water passage. The insulating cover is inserted into the cooling water passage and contacts an inner surface of the insulating member. The insulating cover fixes and protects the insulating member.

Abstract: A technique is described herein for monitoring the operational state of a fuel cell stack by the detection of nonlinearity in such a manner that an external test signal for frequency response is generated and applied to the fuel cell stack during operation, the resulting signal output from the fuel cell stack is measured, and the harmonic content of the measured signal is analyzed, the method including: applying a multiple frequency test signal comprising at least two sinusoidal waves as the test signal for frequency response to the fuel cell stack; and analyzing the resulting current or voltage signal output from the fuel cell stack.