Double-layer cathode structure of direct methanol fuel cell for water collection and transportation

Abstract

The invention discloses a double-layer cathode structure of a direct methanol fuel cell for water collection and transportation. The double-layer cathode structure comprises a cathode collector plateand a cathode water collecting plate. A super-hydrophilic interface area and a super-hydrophobic interface area are arranged on the surface of the cathode water collecting plate. A drainage channel isformed at the junction of the super-hydrophilic interface area and the super-hydrophobic interface area. A cathode water collecting area is arranged at the position, corresponding to the cathode flowfield area, of the super-hydrophilic interface area. Holes are formed in the cathode water collecting area. The positions of the holes are the same as the positions of the holes of the cathode watercollecting plate. The interior of the drainage channel is a super-hydrophilic interface area and the exterior of the drainage channel is a super-hydrophobic interface area. The drainage channel is provided with an inlet and an outlet. The inlet side of the drainage channel is connected with the cathode water collecting area. According to the double-layer cathode structure, water drops which originally and uniformly cover the surface of a cathode can be gathered and discharged, so that the phenomenon that the cathode is flooded is prevented. The influence of cathode water gathering on oxygen transmission is eliminated. The working stability of the direct methanol fuel cell is improved.

Description

technical field [0001] The invention belongs to the technical field of passive direct methanol fuel cells, and relates to a double-layer cathode structure with water collection and directional transport. Background technique [0002] With the high integration and high performance of mobile computing and communication equipment, mobile equipment puts forward more stringent requirements on the corresponding power supply system. The new generation of mobile power system needs to have the characteristics of high energy density (that is, high energy storage, small volume and small weight), fast start-up speed and high output power. In this context, direct methanol fuel cells have become a new development direction for portable micro power systems due to their high energy conversion efficiency, high energy density, simple fuel storage, and easy replenishment. At present, there are still some problems restricting the application and development of direct methanol fuel cells. The c...

AI Technical Summary

Problems solved by technology

At present, there are still some problems restricting the application and development of direct methanol fuel cells. The cathode "water flooding" phenomenon is one of them: when the direct methanol fuel cell is working, the cathode of the battery will continuously react to form water. If it is discharged, there will be a "water flooding" phenomenon, that is, water droplets will condense and block the cathode air inlet, hindering the self-breathing process of the passive fuel cell, resulting in a decrease in the output capacity of the fuel cell

[0003] At present, the main solution to this problem is to improve the drainage capacity of the cathode by optimizing the opening ratio of the cathode plate to increase the diffusion of liquid water and the evaporation rate of gaseous water. However, in the traditional plate, the autonomy of liquid water The diffusion phenomenon is not obvious, and the evaporation of gaseous water mainly depends on the mass transfer of air, that is, the influence of the change of air velocity, and the influence of optimizing the opening ratio on the "water flooding" phenomenon is very limited

In recent years, there have been designs using porous media materials (such as copper or stainless steel fiber felt) as passive direct methanol fuel cell plates. This design greatly increases the contact area between water and air on the cathode plate and accelerates the evaporation of water. , but the distribution of water on the cathode has not been changed in essence, and there is still the problem of mutual obstruction of air and water transmission

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