Low-contact-resistance fuel cell stack and fuel cell using same

Abstract

The invention discloses a low-contact-resistance fuel cell stack and a fuel cell using the same. Each fuel cell unit comprises an anode plate, a membrane electrode and a cathode plate which are sequentially stacked into a whole, wherein the membrane electrode is provided with gas diffusion layers on each of two sides; the cathode plate and the anode plate are silicon polar plates made of doped conductive crystalline silicon materials; the silicon polar plates are provided with front reducing agent runners and / or back oxidizing agent runners; an intermediate layer for reducing contact resistance is arranged between each silicon polar plate and the corresponding gas diffusion layer; the intermediate layer are deposition films formed by a deposition process; and each deposition film comprisesa carbon deposition film in contact with the corresponding gas diffusion layer. According to the low-contact-resistance fuel cell stack and the fuel cell using the same of the invention, the metal deposition film are adopted as the intermediate transition layers, so that the contact resistance between the carbon films and the surfaces of the silicon polar plates can be obviously reduced, so thatthe internal resistance of the fuel cell stack is obviously reduced.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a fuel cell stack with low contact resistance, and also relates to a fuel cell used in the fuel cell stack. Background technique [0002] A fuel cell is a chemical device that directly converts the chemical energy of fuel into electrical energy, also known as an electrochemical generator. Since the fuel cell converts the Gibbs free energy in the chemical energy of the fuel into electrical energy through an electrochemical reaction, it is not limited by the Carnot cycle effect, and the energy conversion rate is high; and the reaction product of the fuel cell using hydrogen as fuel is Water, environmentally friendly, theoretically can achieve zero pollution emissions; in addition, the fuel cell has no mechanical transmission parts, less moving parts, and low noise during operation; moreover, the fuel cell also has high specific energy, high reliability, wide fuel range, and easy to start ...

AI Technical Summary

Problems solved by technology

With the further industrial application of the silicon pole plate, it will be found that the contact resistance between the silicon pole plate and the gas diffusion layer is relatively large, causing the fuel cell stack to consume energy due to its own internal resistance when generating electricity. The internal resistance of the stack not only reduces the output power of the stack, increases the heat generation and cooling burden, but also affects the life of the fuel cell stack due to the increase in the heat generated in the local area of ​​the fuel cell stack

For the fuel cell stack, the contact resistance between the bipolar plate and the gas diffusion layer is one of the main sources of the internal resistance of the stack. Therefore, reducing the contact resistance between the silicon plate and the gas diffusion layer is a key to manufacturing high-efficiency , high durability and high power density fuel cell stack; at the same time, after the applicant has conducted a large number of patent searches and technical information research, no relevant information on reducing the interface contact resistance between the silicon plate and the gas diffusion layer has been found. technology research

In addition, the surface of the silicon material bipolar plate is easy to form a natural oxide layer, which is hydrophilic, which is not conducive to the discharge of water generated during the operation of the fuel cell

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