Dip angle hexagonal rib proton exchange membrane fuel cell bipolar plate

Abstract

The invention provides a hexagonal rib proton exchange membrane fuel cell bipolar plate with an inclination angle, which comprises a bottom plate, a groove is arranged in the bottom plate, and a plurality of hexagonal rib groups are sequentially arranged in the groove from top to bottom; the hexagonal rib group comprises a plurality of hexagonal ribs which are arranged at equal intervals, orthographic projections of the hexagonal ribs at the bottom of the groove are hexagonal, and the upper part of each hexagonal rib is provided with an inclined surface facing the upper part of the groove; the hexagonal ribs in two adjacent hexagonal rib groups are arranged in a staggered manner; and the plurality of hexagonal ribs form a flow field. According to the invention, reaction gas can be uniformly distributed in a flow field, the cell performance is improved, and liquid water can be discharged.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a bipolar plate, in particular to a proton exchange membrane fuel cell bipolar plate with inclined hexagonal ribs. Background technique [0002] Proton exchange membrane fuel cells (PEMFC) have the characteristics of low temperature operation, fast start, compact structure, high specific power and specific energy, long life, stable performance, etc., and are widely used in various fields such as automobiles, ships, and aviation. The bipolar plate is the main structure of the fuel cell, which has the function of collecting electrons and isolating the reaction gas, accounting for 60% of the weight of the stack and 30% of the cost. Flow fields are engraved on the bipolar plates, and the structure of the flow fields determines the distribution of reactant gases and products inside the fuel cell. The uniformity of the reaction gas distribution in the battery directly affects the u...

AI Technical Summary

Problems solved by technology

For example, the parallel flow field bipolar plate, although the pressure drop is small, but due to the low gas flow rate, the liquid water produced cannot be removed in time, which is likely to cause channel blockage, which will lead to battery performance degradation; due to the relatively short channel path of the parallel flow field, the gas in The residence time in the flow field is short and the gas utilization rate is low

Although the serpentine flow field can effectively remove liquid water, because it has only one path, the pressure drop is too large, the concentration loss near the outlet is large, and the current density distribution is uneven.

Although the multi-serpentine flow field can reduce part of the pressure drop, the overall current density distribution is still uneven

The interdigitated flow field uses closed channels to enhance convection under the ribs, enhance mass transfer, and improve gas utilization. At the same time, it can effectively remove water in the gas diffusion layer under the ribs, but because the flow channels are closed, a large pressure drop occurs; In addition, due to the closed flow field, the reaction gas is forced to pass through the gas diffusion layer. If the gas flow is too large, it will damage the membrane electrode and cause irreversible damage to the battery.

The point-like flow field uses point-shaped protrusions to form a flow field, which produces a small pressure drop, but due to the low gas flow rate, the generated water is not easy to drain, and the battery is prone to flooding; at the same time, it is easy to generate eddy currents, resulting in battery performance degradation

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