Pore sealing method for powder metallurgy chromium alloy fuel cell connector

Abstract

The invention relates to a pore sealing method for a powder metallurgy chromium alloy fuel cell connector. The method sequentially incudes the steps that a suspension containing conductive particles is prepared, the connector is placed in the suspension and subjected to standing in a vacuum environment at the room temperature, the soaked connector is taken out and cleaned, and the cleaned connector is cured. The pore sealing method is simple and convenient to operate; pores of the connector can be sealed through soaking, cleaning and curing, the airtightness of the connector is improved, and the cost is reduced; and besides, as a filler in the pores contains a certain quantity of conductive particles, the pore part has certain electroconductibility without changing the performance of a matrix, then, the airtightness and electroconductibility of the connector are effectively improved, and the method has good application prospects.

Description

technical field [0001] The invention belongs to the technical field of energy production, and in particular relates to a hole sealing method for a powder metallurgy chromium alloy fuel cell connector of a solid oxide fuel cell stack. Background technique [0002] The working principle of the solid oxide fuel cell is to continuously feed fuel gas on the anode side, such as hydrogen (H2), methane (CH4), city gas, etc., and the catalytic anode surface adsorbs fuel gas, and passes through the porous structure of the anode Diffusion to the interface between the anode and the electrolyte; Oxygen or air is continuously introduced on the cathode side, and the surface of the cathode with a porous structure absorbs oxygen. Due to the catalytic effect of the cathode itself, O2 obtains electrons and becomes O2-, under the action of chemical potential , O2- enters the solid oxygen ion conductor that acts as an electrolyte, diffuses due to the concentration gradient, and finally reaches t...

AI Technical Summary

Problems solved by technology

However, porosity is an inherent feature of powder metallurgy products. Due to the existence of pores, the airtightness of the connecting parts cannot be guaranteed, and the oxidizing gas and fuel gas cannot be isolated. Therefore, it is necessary to seal the holes of the powder metallurgy connecting parts to obtain good airtightness. While ensuring the electrical conductivity of the connector

The working temperature of the connectors is 800-1000°C, which leads to the impregnation of powder metallurgy products with resin or inorganic sodium silicate and other sealing agents, which cannot be applied to battery connectors.

[0005] For example, the Chinese invention patent "A Method for Sealing Holes of Powder Metallurgy Chromium Alloy Fuel Cell Connectors" previously applied by the applicant, the patent number is ZL201410554424.2, and the authorized announcement number is CN 105562698B, which discloses a powder metallurgy chromium alloy The hole sealing method of alloy fuel cell connectors uses carburizing atmosphere to oxidize and carbonize the chromium-based connecting plate to seal the holes, but it needs to be treated at a high temperature above 800 degrees Celsius for 1 to 8 hours, which increases the cost and seals the holes. Conductivity needs to be improved

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