Asymmetric-structure fuel cell positive and negative pole plates and galvanic pile formed by same

Abstract

The invention discloses asymmetric-structure fuel cell positive and negative pole plates and a galvanic pile formed by the same. The positive and negative pole plates are characterized in that the positive and negative pole plates are both in asymmetric structures, areas of oxidant, reducing agent and cooling agent outflow passages of the positive and negative pole plates are larger than or equalto areas of corresponding inflow passages, and a ratio range of a medium outflow passage area and a medium inflow passage area is 1-4. Reaction gases required by discharging of each cell of the galvanic pile can be distributed uniformly, flow differences in distribution of three fluid media including an oxidant, a reducing agent and a cooling agent in the galvanic pile from respective distributionpassages into each cell are reduced, current density distribution uniformity is guaranteed, local overheating is avoided, and accordingly output electrical performance uniformity of each cell is improved.

Description

technical field [0001] The invention relates to the field of fuel cells, more specifically, to an asymmetric fuel cell cathode and anode plate and an electric stack formed therefrom. Background technique [0002] A fuel cell (PEMFC) generates electricity through an electrochemical reaction between hydrogen as a fuel gas and oxygen (or air) as an oxidant gas. PEMFC has the characteristics of high efficiency, high current density, high power density, short start-up time, and fast response to load changes. [0003] However, due to the low output voltage of a single fuel cell, generally 0.6-0.8V, in practical applications, it is necessary to connect many single cells in series to form a stack. In the thickness direction of the stack, the fluid distribution on each single cell The channels form the fluid distribution conduits. When the fuel cell is working, the externally supplied reaction gas and coolant are distributed to each single cell through their respective fluid distri...

AI Technical Summary

Problems solved by technology

[0004] For high-power fuel cell stacks, the output power is usually around 100KW, and the number of stacked single cells is generally around 300. The flow rate to be supplied increases with the increase in the number of stacks. The principle of fluid mechanics often leads to uneven flow distribution of each battery

Moreover, with the enlargement of the stack thickness, the distribution uniformity difference in the fluid distribution pipe is also enlarged. Therefore, for a high-power fuel cell stack, the design of the fluid distribution pipe directly affects the overall output performance of the stack. In the absence of accurate design calculations, the flow rate may decrease in a certain direction in the distribution pipeline

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