Integrated metal-graphite composite bipolar plate fuel cell light electric stack and manufacturing method thereof

Abstract

The invention relates to an integrated metal-graphite composite bipolar plate fuel cell light electric stack. An integrated metal-graphite composite bipolar plate is used for the integrated metal-graphite composite bipolar plate fuel cell light electric stack, the integrated metal-graphite composite bipolar plate comprises a metal corrugated plate and a graphite plate, the metal corrugated plate is a negative pole plate, a raised ridge inner chamber is an oxygen flow field, and meanwhile a raised ridge takes a heat-radiating rib into consideration; the graphite plate is a positive pole plate, the surface of one side of the graphite plate body is provided with a hydrogen flow field, the edge of the surface of one side of the graphite plate body is provided with a sealing groove, and the other side of the graphite plate body is provided with a graphite plate corrugated structure; and the graphite plate is embedded into the metal corrugated plate by the graphite plate corrugated structure, and the graphite plate and the metal corrugated plate are connected as a whole. The performance and the stability of the electric stack are remarkably improved. Because a negative temperature coefficient thermistor material is added in the graphite plate material, the cold starting time can be remarkably reduced, and the electric stack can be used normally at a higher temperature above 60 DEG C.

Description

technical field [0001] The invention belongs to the technical field of fuel cell light stacks, in particular to an integrated metal-graphite composite bipolar plate fuel cell light stack and a manufacturing method thereof. Background technique [0002] The proton exchange membrane fuel cell (PEMFC) can directly convert the chemical energy in the fuel into electrical energy without burning. It has received widespread attention and is convenient for providing power systems for the transportation and aviation fields. The bipolar plate is the core component of PEMFC, its weight accounts for 70%-80% of the entire electric stack, and its cost accounts for more than 50% of the electric stack. At the same time, the bipolar plate also plays the role of separating the reactant gas and introducing the reactant gas into the fuel cell through the flow field, collecting and conducting current, supporting the membrane electrode, supporting the membrane electrode assembly, and evenly distr...

AI Technical Summary

Problems solved by technology

In order to pursue the specific power density of the battery, the thickness of the metal plate is reduced, and the thinning of the metal plate also brings a series of problems: the thinning of the metal plate greatly increases the processing cost of the metal plate; The plane of the metal plate is generally uneven, which increases the contact resistance and reduces the performance output of the stack; the metal bipolar plate made of thinned metal plate is also uneven, which not only increases the resistance between the bipolar plate and the membrane electrode, but also increases the resistance between the bipolar plate and the membrane electrode. When the stack is assembled, the force will be uneven, which will affect the consistency and stability of the stack; the metal plate is thinned, and its strength is low, which brings many difficulties to the assembly of the stack; the thinner metal plate, the stack If the strength is not enough, it loses the function of supporting the electric stack and anti-vibration, which reduces the reliability of the entire electric stack

The polymer electrolyte membrane fuel cell light stack and its manufacturing method mentioned in the patent CN104157895A are characterized in that a metal bipolar plate is formed by welding a metal corrugated plate and a metal flat plate, and the side of the bipolar plate is in contact with the anode of the membrane electrode. The corrugated surface is in contact with the cathode of the membrane electrode. The flat metal plate of the metal bipolar plate air-cooled fuel cell described in this patent has no flow field, and there are many problems. First, it affects the diffusion of the anode gas between the carbon papers in the flow field; Secondly, there is no flow field on the anode plate, which is easy to accumulate water and cause anode flooding; finally, the anode contact area between the metal plate and the membrane electrode is large, which is easy to corrode

Therefore, there are certain technical defects in the design of the bipolar plate air-cooled reactor belonging to CN104157895A

[0005] In addition, another major bottleneck of fuel cells is the difficulty of cold start

When the battery is at a temperature below zero, the liquid water generated by the electrochemical reaction inside the battery and the water in the anode will freeze. During the freezing process, the membrane electrode material will be damaged and the catalyst will fall off, making the fuel cell unable to start normally. Affects the efficiency of the fuel cell

At present, in order to solve the cold start of the fuel cell, most designs tend to embed electric heating elements between the membrane electrode and the bipolar plate. This method solves the cold start problem of the fuel cell and makes the battery design become more complex, adding weight to the fuel cell

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