Graphene BMC Bipolar Plates With Higher Through-Plane Conductivity

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Solution Overview

Problem

Current bipolar plates in fuel cell stacks face challenges in achieving high through-plane electrical conductivity while maintaining mechanical stability, corrosion resistance, and processability, which are essential for efficient and cost-effective manufacturing.

Innovation Solution

Incorporating graphene nanoplatelets into vinyl ester-based bulk molding compounds (BMCs) to enhance through-plane electrical conductivity, mechanical stability, and corrosion resistance, thereby improving the performance and durability of bipolar plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal materials such as stainless steel are used for bipolar plates, then electrical conductivity can meet DOE goals, but weight, cost, and corrosion resistance deteriorate

Engineering Contradiction:
Improveelectrical conductivityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent uses composite materials consisting of polymer matrices (thermoplastic or thermoset resins) filled with conductive additives such as graphite particles or fibers. This composite approach achieves electrical conductivity greater than 100 S/cm while maintaining the lightweight advantage of polymers, thereby resolving the contradiction between electrical conductivity and weight.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If machined graphite plates are used, then weight and corrosion resistance improve, but through-plane electrical conductivity deteriorates

Engineering Contradiction:
ImproveweightVSAvoidthrough-plane electrical conductivity
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent changes the physical and chemical parameters of the composite material by incorporating conductive additives with specific properties (graphite particles or fibers) into polymer matrices. This parameter modification enables the material to achieve through-plane electrical conductivity greater than 100 S/cm while maintaining low weight, resolving the contradiction between weight and electrical conductivity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If excessive amounts of conductive additives are incorporated into polymer resins, then electrical conductivity improves, but viscosity increases making processing difficult

Engineering Contradiction:
Improveelectrical conductivityVSAvoidprocessability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent optimizes the concentration parameter of conductive additives within a specific range (5-80 wt%) to achieve the desired electrical conductivity while maintaining acceptable viscosity for processing. This parameter optimization resolves the contradiction between electrical conductivity and processability.

Inventive Principle:
Principle #35Parameter changes

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 incorporation of graphene nanoplatelets increases through-plane electrical conductivity by up to 100% and maintains or improves mechanical properties such as strength and processability, making the BMCs suitable for thin, lightweight bipolar plates that meet the DOE's conductivity goals and retain dimensional stability.

Implementation Method 1

Incorporating graphene nanoplatelets into vinyl ester-based bulk molding compounds (BMCs) to enhance through-plane electrical conductivity

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS11807750B2Compositions with increased electrical conductivity
Publication Date: 2023.11.07 LYONDELLBASELL ADVANCED POLYMERS INC

AI summary

Thermoset bulk molding compounds (BMC) useful for making electrically conductive components such as bipolar plates for fuel cells are described. The thermoset bulk molding compounds incorporate graphene nanoplatelets to increase the through-plane electrical conductivity by at least 20% compared to BMCs without the graphene nanoplatelets. Additionally, these compositions have low shrinkage, low density for lightweight parts, and are easily processed. The compositions can be used to prepare a variety of electrically conductive components, including bipolar plates for fuel cells and chemical storage batteries that operate at temperatures of less than 100° C.