Lithium Cation Exchange Membrane for Water Electrolysis

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Solution Overview

Problem

Conventional water electrolysis methods face challenges with low current density and high costs due to the use of noble metals in proton exchange membrane systems and low efficiency in alkaline systems, while high-temperature electrolysis systems are difficult to operate and commercialize.

Innovation Solution

A lithium cation exchange membrane with a monomer solution having a sulfonic acid group and a hydrophilic polymer solution is used to enhance lithium ion conductivity, increasing the current density and hydrogen production rate in a water electrolysis system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If noble metal catalysts are used in proton exchange membrane water electrolysis, then current density is improved, but system cost increases

Engineering Contradiction:

Improvecurrent densityVSAvoidsystem cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent changes the ionic conductivity parameter of the membrane by using lithium cation exchange membrane instead of conventional proton exchange membrane, enabling high current density without noble metals. The lithium ion conductivity of the membrane is optimized to achieve proton-level performance with low-cost catalysts.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive noble metal catalysts with low-cost alternative catalysts (such as nickel-based catalysts) that can be used effectively when combined with the lithium cation exchange membrane, significantly reducing system cost while maintaining acceptable performance.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Ease of manufacture

If low-cost catalysts are used in alkaline water electrolysis, then system cost is reduced, but current density decreases

Engineering Contradiction:

Improvesystem costVSAvoidcurrent density

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The lithium cation exchange membrane acts as an intermediary component that enables low-cost catalysts to achieve high current density. The membrane's high lithium ion conductivity facilitates efficient ion transport, allowing inexpensive catalysts to perform at levels previously only achievable with noble metals.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite system combining lithium cation exchange membrane with low-cost catalyst materials, where the membrane's unique properties enhance the catalytic activity and ion transport efficiency, achieving high current density without noble metals.

Inventive Principle:

Principle #40Composite materials

3Productivity

If high temperature operation is used in ceramic electrolysis, then current density is improved, but operational complexity and material durability requirements increase

Engineering Contradiction:

Improvecurrent densityVSAvoidoperational complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent changes the operating temperature parameter from high temperature (700°C or higher) to moderate temperature by using lithium cation exchange membrane, which maintains high ionic conductivity at lower temperatures, simplifying system operation and reducing material durability requirements.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the ceramic electrolyte system with a polymer-based lithium cation exchange membrane system, substituting the high-temperature ceramic mechanism with a lower-temperature polymer electrolyte mechanism that achieves similar current density with reduced operational complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 lithium cation exchange membrane system achieves a higher current density and improved hydrogen production efficiency compared to alkaline water electrolysis, while reducing system costs compared to proton exchange membrane systems, and operates effectively with a low-cost catalyst.

Implementation Method 1

lithium cation exchange membrane (LEM) for water electrolysis

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

water electrolysis method

Methodology Applied

Scientific EffectElectrolysis: Electrolysis

Data Source

PatentUS20230313396A1Lithium cation exchange membrane for water electrolysis, and water electrolysis system using same

Publication Date: 2023.10.05 BOYAZ ENERGY

AI summary

The present invention relates to a lithium cation exchange membrane, for water electrolysis, having high lithium cation conductivity, and a water electrolysis system using same, and a water electrolysis system using a lithium cation exchange membrane (LEM) for water electrolysis according to the present invention, comprising a hydrophilic polymer solution and a monomer solution having a sulfonic acid group, is an economically feasible water electrolysis system achieving lower costs than conventional proton exchange membrane (PEM) water electrolysis and a higher current density than alkali water electrolysis.