A microelectrode system and method for testing oxygen mass transfer coefficient of proton exchange membrane

Abstract

The invention discloses a microelectrode system and method for testing an oxygen mass transfer coefficient of a proton exchange membrane. The system comprises an electromagnetic shielding box, an on-off type temperature controller and an environment cavity formed in the electromagnetic shielding box; atmosphere can be continuously introduced into the environment cavity, and humidity can be monitored; a high-temperature-resistant clamping device, a platinum disc microelectrode with the effective diameter being 10 micrometers, a platinum sheet electrode, a silica gel heating plate and a temperature sensor are arranged in the environment cavity; the clamping device is used for sequentially superposing and clamping the proton exchange membrane to be detected, the platinum sheet electrode and the silica gel heating plate; the on-off temperature controller is connected with the silica gel heating plate, the temperature sensor is used for monitoring the temperature of the silica gel heating plate, the platinum disc microelectrode serves as a working electrode, and the platinum sheet electrode serves as a counter electrode and a reference electrode and is connected to the electrochemical workstation. According to the system and the method disclosed in the invention, the mass transfer coefficient of oxygen in various polymer electrolytes can be quantitatively and accurately characterized, and quantitative guidance is provided for optimization of a catalytic layer structure.

Description

Technical field[0001]The invention belongs to the field of fuel cells, and relates to a microelectrode system and method for testing the oxygen mass transfer coefficient of a proton exchange membrane. It is a method that can be used to quantitatively test the diffusion coefficient, solubility and permeability of oxygen in the proton exchange membrane under high temperature and low humidity conditions Equivalent microelectrode system and the corresponding electrochemical test technology method.Background technique[0002]With the progress and development of human industry, the massive use of fossil energy has caused serious environmental pollution and energy shortages. Therefore, the development of new and environmentally friendly renewable energy has become one of the current research hotspots. Among them, proton exchange membrane fuel cells (PEMFCs) are considered as a new type of energy conversion device with great potential. Its working principle is: hydrogen oxidizes at the anode,...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: ①It takes a lot of catalyst and membrane materials; ②Assembling the battery is time-consuming and laborious; ③The obtained battery performance data is a comprehensive result, and it is difficult to obtain the influence of the binder on the mass transfer of oxygen in it.

However, HT-PEMFCs generally operate at atmospheric pressure, and in the catalytic layer of HT-PEMFCs, oxygen electrochemically reacts at the interface between the platinum catalyst and the binder, resulting in the diffusion of oxygen molecules dissolved in the binder to the surface of the platinum catalyst. , the existing differential pressure gas transmission rate tester cannot simulate the electrochemical environment in which HT-PEMFCs operate

In addition, the operating temperature of HT-PEMFCs is generally 100-200°C, and the existing differential pressure gas transmission rate tester cannot achieve stable operation at such a high temperature

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