Fuel cell stack

Abstract

The invention provides a fuel cell stack, and belongs to the technical field of fuel cells. The fuel cell stack comprises a battery pack which is formed by stacking a plurality of single batteries, afront end plate and a rear end plate are separately arranged at the upper end and the lower end of the battery pack, a front end collector plate is arranged between the upper end of the battery pack and the front end plate, and a rear end collector plate is arranged between the lower end of the battery pack and the rear end plate; each single battery comprises an anode plate, a cathode plate and amembrane electrode, and the membrane electrode is sandwiched between the anode plate and the cathode plate; a first limiting boss is arranged on the periphery of the surface, which faces the corresponding membrane electrode, of each anode plate, and is used for fixing the position of the corresponding membrane electrode; a fuel flow field is arranged on the surface, which faces the correspondingmembrane electrode, of each anode plate; and a second limiting boss is arranged on the surface, which faces the corresponding membrane electrode, of each cathode plate, and an oxidizing agent flow field is arranged on the surface, which faces the corresponding membrane electrode, of each cathode plate. By the stack, the amount of compression of a gas diffusion layer of each membrane electrode canbe controlled accurately, the uniformity of the performance of the single batteries in the stack is good, and the service life of the stack is prolonged.

Description

technical field [0001] The invention provides a fuel cell stack, which belongs to the technical field of fuel cells. Background technique [0002] Proton exchange membrane fuel cell (PEMFC) is a clean and environmentally friendly electrochemical power generation device, due to its small size, light weight, mild operating conditions, high energy conversion rate, simple structure and rapid response, etc. It can be widely used in many aspects such as transportation, stationary power generation, material handling, backup power supply and portable power supply. Hydrogen energy and fuel cell technology provide a new way for the utilization of clean energy systems. Hydrogen comes from a wide range of sources, including both renewable and non-renewable energy sources. Hydrogen energy can become an energy carrier complementary to electricity, thereby effectively reducing the carbon emissions of the current energy system. Therefore, PEMFC is considered to be the preferred clean a...

AI Technical Summary

Problems solved by technology

[0004] The traditional electric stack is formed by stacking membrane electrodes and bipolar plates at intervals and then compacting them. During this process, the total compression of the gas diffusion layer is controlled by adjusting the pressing force or the total length of the electric stack. Due to the pressing process, The uneven distribution of preload inside the stack leads to different compression of the gas diffusion layer of each unit cell in the stack, that is, the compression of the gas diffusion layer of some single cells is too large, and the gas diffusion layer of some single cells If the compression amount is too small, the performance gap between the individual cells will become larger and larger during the operation of the stack, especially after a long time of operation, resulting in a "short plate effect" and affecting the life of the stack

[0005] For traditional electric stacks, when the airtightness test of the electric stack fails or the electric stack breaks down during operation, it is likely to dismantle the stack for inspection. Due to repeated disassembly and assembly of the electric stack, the gas diffusion layer is repeatedly squeezed, resulting in the gas diffusion layer The structure of the structure suffers irreversible damage, which hinders the transmission of reactive gases and water, thereby affecting the life of the stack

[0006] In addition, the sealing performance of the stack is also one of the key factors affecting the life of the stack. The gas sealing of the traditional stack is achieved by using a five-in-one combination of anode plate / anode side gasket / membrane electrode frame / cathode side gasket / cathode plate. It is realized by a compression structure, which requires high accuracy for the height of the anode side gasket and the cathode side gasket, and the cell stack with this structure is prone to misalignment between the plates in the environment of vibration and impact, so It is easy to cause air leakage, which will cause the stack to fail to operate and affect the life of the stack

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