Fuel cell bipolar plate for dehumidification and fuel cell stack

Abstract

The invention belongs to the related technical field of fuel cells, and discloses a fuel cell bipolar plate for dehumidification and a fuel cell stack. The bipolar plate comprises a substrate, a cathode flow field, an anode flow field and dehumidification holes, wherein the cathode flow field, the anode flow field and the dehumidification hole are formed in the substrate, grooves are formed in the front face and the back face of the upper half portion of the substrate and serve as gas flow channels to form the cathode flow field and the anode flow field respectively, and the dehumidification holes are formed in the lower half portion of the substrate, and cathode gas flows from the cathode flow field into the dehumidification holes. The invention also discloses a fuel cell stack which comprises an upper end plate, a lower end plate, bipolar plates, a membrane electrode and a dehumidifier, wherein a plurality of parallel bipolar plates are arranged between the upper end plate and the lower end plate, dehumidification holes below the plurality of parallel bipolar plates, the upper end plate and the lower end plate form a closed cavity, the dehumidifier is placed in the cavity, and the cathode gas is dehumidified in the cavity. According to the invention, the problem of water logging in the fuel cell is relieved, and good water management capability in the cell is maintained.

Description

technical field [0001] The invention belongs to the technical field related to fuel cells, and more specifically relates to a fuel cell bipolar plate for dehumidification and a fuel cell stack thereof. Background technique [0002] Water management is key to maintaining efficient and stable operation of PEM fuel cells. The battery flow channel is the only part of the battery system that undergoes mass exchange with the outside world, and it is also the only channel through which moisture in the battery is removed from the system. If the moisture in the flow channel cannot be removed in time, it will not only affect the transmission of the reaction gas, but also limit the contact between oxygen and the catalytic layer for reaction, increase the pressure drop of the system, make the battery current distribution uneven, reduce the battery performance, and even worse affect the safety of the battery. [0003] In view of the above problems, exhaust gas dehumidification is an ef...

AI Technical Summary

Problems solved by technology

Most of the existing dehumidification methods in fuel cell stacks use special dehumidification devices or special dehumidification systems. For the entire fuel cell stack, the structure is relatively complicated and the cost is high

At the same time, since the dehumidification device is far away from the outlet of the stack, the water vapor concentration gradient difference between the inside of the stack and the outlet gas is reduced, resulting in the ineffective effect of condensation dehumidification

And the outlet gas is collected together through the pipeline and then passed into the dehumidification device, which reduces the heat transfer area and reduces the heat transfer effect

Images