Method for producing multi-layer nano composite proton exchange membrane with self-humidifying function

Abstract

The present invention is the preparation process of multilayer nanometer composite proton exchange film with self-humidifying function, and features that porous PTFE film is first soaked in mixture of proton conducting resin and nanometer SiO2 or TiO2 to form water maintaining proton conducting layer, and then soaked in in mixture of proton conducting resin and nanometer Pt or Pd grain to form self-humidifying proton conducting layer. The composite film as the proton conducting film in proton exchanging film fuel cell has excellent self-humidifying and water-maintaining capacity.

Description

technical field [0001] The invention relates to a preparation method of a proton exchange membrane with self-humidification ability and water retention ability during battery operation. It specifically relates to a preparation method of a multilayer nanocomposite proton exchange membrane with self-humidification function. Background technique [0002] Since hydrogen fuel cells are of great significance to solving the two major world problems of "energy shortage" and "environmental pollution", the international energy community generally believes that hydrogen energy is a sustainable energy source. The 21st century is the hydrogen energy century, and mankind will bid farewell Fossil energy has entered the era of hydrogen energy economy. Proton exchange membrane fuel cell (PEMFC) is a new generation of energy power system with energy revolution after the steam engine and internal combustion engine. During the operation of PEMFC, the conductivity and water content of the proto...

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Problems solved by technology

[0003] Some scholars use an additional catalyst layer in the middle of the proton exchange membrane or on one side to solve the self-humidification problem of the membrane, such as SangHee Hwak (Journal of Power Sources, 2003, 118, 200-204) et al. Inject a layer of 0.05~0.2mg / cm 2 Pt, so that the membrane has a self-humidification function, FuQiang Liu (Journal of Power Sources, 2003, 124, 81-89) and others sandwiched a layer of Pt black or Pt / C between two layers of Nafion membrane to solve this problem, The performance of the battery after compounding has been significantly improved; Mao Zongqiang et al. (Chinese patent CN1442913A) of Tsinghua University coated the inorganic particles with moisturizing function on both sides of the proton exchange membrane to prepare a composite membrane with self-humidifying function , but these methods inevitably increase the contact interface of the film in the battery, and also bring about the problem of cracking of the inorganic particle layer, which improves the ohmic resistance of the battery itself, and when the noble metal catalyst Pt is used, the amount of precious metal used is large, which greatly reduces the Increased battery cost

[0004] Other researchers use chemical deposition to form nano-scale Pt particles inside the proton exchange membrane to catalyze the H entering the membrane. 2 with O 2 Combination, so as to realize the humidification of the membrane, such as watanabe et al. (J. Electrochem. Soc., 1996, 143, 3847; J. Electrochem. Soc., 1998, 145, 1137) uniformly doped Pt particles in In the proton exchange membrane, this method can realize the self-humidification of the membrane, but the cross network formed by the Pt particles in the membrane will form a continuous electron channel, which may cause the self-discharge phenomenon of the battery and cause the battery to fail.

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