Fuel Cell Stack Servo Assembly Line:the Sealing and Assembly of Hydrogen Fuel Cell Stack

Usually, a fuel cell stack has dozens or even hundreds of sealing surfaces or sealing parts, which are divided into disposable sealing surfaces and active sealing surfaces. Disposable sealing mainly uses resin adhesive, active sealing mainly uses rubber elastomer. At present, elastomer seals are commonly used for the sealing between single cells in fuel cell stacks, namely the so-called static seal. An appropriate assembly pressure is required to act on the contact surface of each component of the cell stack, and the movement of the components is restrained by static friction force to achieve the sealing effect. The sealing structure of fuel cell stack is closely related to the structure of MEA. The main function of sealing is to ensure the isolation and external sealing of the gas in each chamber under operating pressure during the operation of the battery stack.
1.1 Sealing Requirements
Fuel cell stacks require high seal reliability and do not allow any leakage, especially in automotive and military applications. In order to achieve a better sealing effect, it is necessary to choose the appropriate sealing structure and sealing material. Generally speaking, the seal of the battery stack should meet the following requirements:
(1) Reaction gas, coolant leakage, fuel, oxidizer and coolant do not channeling.
(2) The sealing assembly is safe and reliable with long service life.
(3) Compact structure of sealing components, convenient manufacturing and maintenance.
1.2 Sealing Materials
(1) General requirements for sealing materials
The sealing material should meet the requirements of sealing function. Due to the different media being sealed and the different working conditions of the equipment, the sealing material is required to have different applicability. The general requirements for sealing materials are as follows:
(1) Good density of the material, not easy to leak media.
(2) Appropriate mechanical strength and hardness.
(3) Good compressibility and resilience, small permanent deformation.
(4) No softening or decomposition at high temperature, no hardening or cracking at low temperature.
(5) Good corrosion resistance, in acid, alkali, oil and other media can work for a long time, its volume and hardness change is small, and does not adhere to the sealing surface, do not pollute other parts of the fuel cell.
(6) Small friction coefficient, good wear resistance; It has the softness combined with the sealing surface; Good aging resistance and durability.
(7) Convenient processing and manufacturing, cheap price, easy materials.
Although few materials can fully meet these requirements, materials with excellent sealing properties can generally meet most of these requirements.