Catalyst-Coated Membrane Layout to Limit Platinum Precipitation
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Solution Overview
Problem
The precipitation of platinum in the electrolyte membrane of a fuel cell leads to a decrease in output and increases production costs, as existing platinum trapping layers are disadvantageous in terms of cost and performance.
Innovation Solution
A catalyst coated membrane with specific ratios of hydrogen and oxygen permeability, platinum distribution, and catalyst layer thicknesses, along with a controlled relative humidity, to inhibit platinum precipitation and maintain output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a platinum trapping layer is arranged between the electrolyte membrane and the catalyst layer to prevent platinum precipitation, then platinum loss is reduced, but production cost increases and power generation performance decreases
Solution Approach 1:
The patent removes the platinum trapping layer from the structure and instead optimizes the electrolyte membrane's inherent hydrogen permeability properties to prevent platinum precipitation, thereby eliminating the need for additional trapping layers and reducing production costs
Solution Approach 2:
The patent changes the hydrogen permeability parameter of the electrolyte membrane by controlling its water content and physical state, transforming it from a passive membrane into an active platinum prevention system that maintains platinum in the catalyst layer without additional trapping structures
2Reliability
If a platinum trapping layer is arranged between the electrolyte membrane and the catalyst layer to prevent platinum precipitation, then platinum loss is reduced, but power generation performance decreases
Solution Approach 1:
The patent extracts and eliminates the platinum trapping layer that was causing performance degradation, relying instead on the optimized hydrogen permeability of the electrolyte membrane to achieve platinum retention while maintaining full power generation performance
Solution Approach 2:
The electrolyte membrane performs the dual function of both separating reactants and preventing platinum precipitation through its controlled hydrogen permeability, eliminating the need for separate trapping layers that would interfere with power generation
3Ease of manufacture
If the amount of platinum in the catalyst layer is decreased to reduce cost, then production cost decreases, but output and durability decrease due to platinum precipitation
Solution Approach 1:
The patent changes the hydrogen permeability parameter of the electrolyte membrane to create a protective environment that prevents platinum precipitation, enabling the use of lower platinum amounts while maintaining output and durability
Solution Approach 2:
The electrolyte membrane acts as an intermediary system that mediates between the platinum catalyst layer and the external environment, using its controlled hydrogen permeability to prevent platinum loss and enable cost-effective low-platinum designs
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively inhibits platinum loss from the catalyst layer, maintaining high output and reducing production costs by optimizing the permeability and platinum distribution in the catalyst layers.
Implementation Method 1
the permeability ratio TR50 (TH50/TO50) of the hydrogen permeability (TH50) to the oxygen permeability (TO50) of the electrolyte membrane at 65°C and 50% RH is 3.0 or more
Data Source
Figure 1
AI summary
The present invention provides a catalyst coated membrane capable of inhibiting a decrease in the output of a fuel cell, and simultaneously decreasing the production cost. The present invention is a catalyst coated membrane including: an electrolyte membrane; a cathode catalyst layer arranged on one surface of the electrolyte membrane; and an anode catalyst layer arranged on the other surface of the electrolyte membrane, wherein the cathode catalyst layer and the anode catalyst layer each contain platinum; the permeability ratio TR50 (TH50/TO50) of the hydrogen permeability (TH50) to the oxygen permeability (TO50) of said electrolyte membrane at 65°C and 50% RH is 3.0 or more; and the catalyst coated membrane satisfies the following condition 1 and/or condition 2. <condition 1> the ratio (CPt/APt) of the amount of platinum per unit area (CPt) of said cathode catalyst layer to the amount of platinum per unit area (APt) of said anode catalyst layer is 2.0 or more; <condition 2> the ratio (TAn/TCa) of the thickness (TAn) of said anode catalyst layer to the thickness (TCa) of said cathode catalyst layer is less than 0.40.