Bipolar plate for fuel cell stacks, composite material and preparation process

A technology of fuel cell stacks and composite materials, which is applied in the field of fuel cells and can solve problems such as difficult diffusion bonding and high density

Inactive Publication Date: 2019-06-25
JIEXING ENVIRONMENTAL PROTECTION TECH INVESTMENT SHANGHAI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Gold-plated stainless steel outperforms traditional graphite and is cheaper than titanium, but it is dense and difficult to diffusion bond because its passivated surface layer is stable at bonding temperatures

Method used

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  • Bipolar plate for fuel cell stacks, composite material and preparation process
  • Bipolar plate for fuel cell stacks, composite material and preparation process
  • Bipolar plate for fuel cell stacks, composite material and preparation process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0073] see figure 1 , the present invention discloses a bipolar plate for a fuel cell stack, the bipolar plate includes: a cathode flow field plate, an anode flow field plate, and the cathode flow field plate and the anode flow field plate are joined together, using The bonding process joins the edges of the cathode flow field plate and the anode flow field plate. A coolant channel is left between the cathode flow field plate and the anode flow field plate.

[0074] The cathode gas inlet 3 flows through the S-shaped gas channel to the cathode gas outlet 4, and the cross-sectional area of ​​the gas channel changes from wide to narrow.

[0075] The cathode cooling liquid inlet 2 and the cathode cooling liquid outlet 5 communicate with each other from inside the bipolar plate, and the cooling liquid flows from the inside of the bipolar plate.

[0076] The anode gas inlet 1 and the anode gas outlet 6 are connected by an anode flow field, and the flow direction of the anode gas i...

Embodiment 2

[0093] The bipolar plate is made of composite material, and the composite material contains conductive aggregate with a weight ratio of 75% to 84%, 16% to 25% of adhesive and curing agent; the conductive aggregate is processed by potassium permanganate solution Treatment changes surface chemistry;

[0094] The conductive aggregate is formed by mixing flake graphite and powder graphite or carbon black, and the weight ratio of flake graphite to powder graphite is 16-5.4;

[0095] Described binder adopts thermoplastic polyimide resin or phenolic resin solution, wherein the solid content of thermoplastic polyimide resin or phenolic resin is 63%~70%; The weight ratio of crosslinking agent hexamethylenetetramine is 2-4%, and the weight ratio of filler silicon dioxide is 2-5%.

[0096] see figure 1 , the present invention discloses a bipolar plate for a fuel cell stack, the bipolar plate includes: a cathode flow field plate, an anode flow field plate, the cathode flow field plate a...

Embodiment 3

[0108] The invention discloses a composite material for preparing fuel cell stack bipolar plates, specifically as follows:

[0109] Conductive aggregate: In the composite material of the present invention, the conductive aggregate used is a mixed powder of flake graphite and graphite powder or carbon black. The particle size of flake graphite is generally 10000 mesh, and the particle size of graphite powder or carbon black is It is 800 mesh. The ratio of the two graphites in the bipolar plate composite material is: flake graphite / graphite powder is 16-5.4, the amount of conductive aggregate accounts for 85%-75% of the weight of the composite material, and the preferred value is 80%-84%. , The conductive aggregate is first treated with potassium permanganate solution, washed and then dried for use.

[0110] Binder resin: The binder resin not only plays the role of bonding other solid particles in the composite material together, but also affects the strength of the bipolar pla...

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Abstract

The invention discloses a bipolar plate for fuel cell stacks, a composite material and a preparation process. The bipolar plate includes a cathode flow field plate and an anode flow field plate, and acoolant channel is reserved between the cathode flow field plate and the anode flow field plate. The gas flow path of the bipolar plate is S-shaped. A flow field flow channel through which reaction gas reaches the center part of a flow field via a gas inlet changes from narrow to wide, and a flow field flow channel from the center part of the flow field to a gas outlet changes from wide to narrow. The composite material contains 75-84 wt% of conductive aggregate, 16-25 wt% of binder and curing agent, 2-5 wt% of filler and 2-4 wt% of cross-linking agent. The bipolar plate for fuel cell stacksdisclosed by the invention can improve the performance of stacks, reduces the size of the existing water-cooled reactor and increases the energy density of stacks. The conductivity, bending strength,gas permeability and other performance of the fuel cell bipolar plate made of the composite material of the invention are greatly improved. Moreover, the preparation process is simple, the productionefficiency is high and the cost is low.

Description

technical field [0001] The invention belongs to the technical field of fuel cells, and relates to a fuel cell stack, in particular to a bipolar plate for a fuel cell stack; at the same time, the invention also relates to a bipolar plate for preparing a fuel cell stack Composite material; In addition, the present invention also relates to a process for preparing the bipolar plate. Background technique [0002] A fuel cell is a device that directly converts chemical energy stored in fuel and oxidant into electrical energy through an electrochemical reaction. Its biggest feature is that its energy conversion efficiency is not limited by the "Carnot cycle", the energy conversion efficiency is high, the energy conversion rate is as high as 60% to 80%, and the actual use efficiency is twice that of ordinary internal combustion engines. In addition, it also has the advantages of diversified fuels, low environmental pollution, low noise, good reliability and maintainability, low te...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M8/0223H01M8/0258H01M8/0263
CPCY02P70/50Y02E60/50
Inventor 向华熊子昂黄平
Owner JIEXING ENVIRONMENTAL PROTECTION TECH INVESTMENT SHANGHAI
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