Electrolysis Cell Refurbishment With a Replaceable Flexible Anode

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Solution Overview

Problem

The refurbishment of anode electrodes in electrolysis cells is complex, costly, and logistically challenging due to the need for specialized workshops and milling, especially in large-scale operations, requiring high-quality personnel and materials.

Innovation Solution

A method is introduced where a flexible anode is interposed between the existing rigid anode and the separator, with the flexible anode taking over the main function while the rigid anode acts as a support, allowing on-site refurbishment without milling or specialized workshops, using spot-welding for improved conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rigid anode is welded onto webs and milled off in a specialized workshop, then superior electrical conductivity and even separator support are achieved, but the refurbishment process becomes time-consuming, expensive, and logistically complex

Engineering Contradiction:

Improveelectrical conductivityVSAvoidrefurbishment process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The anode system is divided into two functional parts: a rigid anode that remains welded to the webs for structural support and electrical conductivity, and a replaceable flexible anode layer that performs the electrochemical function. This segmentation allows the rigid anode to stay in place while only the flexible layer needs replacement, simplifying refurbishment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flexible anode is designed as a consumable, replaceable component that can be easily swapped out when worn. Instead of refurbishing the entire rigid anode assembly, only the flexible layer is replaced, reducing refurbishment complexity and cost while maintaining performance.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Stability of the object's composition

If the rigid anode is used to provide even separator support, then mechanical stability is achieved, but the refurbishment requires milling operations in a specialized workshop with high-quality personnel

Engineering Contradiction:

Improveseparator support stabilityVSAvoidrefurbishment ease

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of repair

If conventional refurbishment with milling is performed, then the anode can be refurbished, but large logistical effort is required to transport hundreds to thousands of half-cells to workshops

Engineering Contradiction:

Improveanode refurbishment capabilityVSAvoidlogistical time

Core Design Contradiction:

Ease of repairVSLoss of time

Solution Approach 1:

The flexible anode layer is extracted as a separate, easily replaceable component from the rigid anode assembly. This allows the flexible layer to be replaced in-situ without transporting the entire half-cell to a workshop, eliminating logistical time and effort.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The cell is designed to enable easy self-service replacement of the flexible anode at the operating location without requiring external workshop facilities or complex milling equipment, allowing operators to perform refurbishment on-site.

Inventive Principle:

Principle #25Self-service

4Ease of repair

If a dedicated workshop on-site is provided for refurbishment, then refurbishment can be performed without external transport, but the workshop requires large footprint and expensive machinery

Engineering Contradiction:

Improveon-site refurbishment capabilityVSAvoidworkshop space

Core Design Contradiction:

Ease of repairVSArea of stationary object

Solution Approach 1:

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Inventive Principle:

Principle #25Self-service

5Productivity

If the flexible cathode is replaced without welding, then quick and easy refurbishment is achieved, but the anode requires welding for superior electrical conductivity

Engineering Contradiction:

Improverefurbishment speedVSAvoidelectrical conductivity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Different attachment methods are applied to different electrodes based on their specific requirements: the cathode uses simple mechanical attachment for quick replacement, while the rigid anode uses welding for superior electrical conductivity and stability. Each component gets the treatment appropriate to its function.

Inventive Principle:

Principle #3Local quality

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

This method simplifies and reduces the maintenance effort, decreases downtime, and minimizes logistical and carbon footprints, while maintaining electrical conductivity, thus reducing costs and time.

Implementation Method 1

an elastic current distributor (34) compressing onto the cathode (35) in a planar fashion

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The second, opposite side of the sheet-like separator is supported by the rigid anode

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

using spot-welding for improved conductivity

Methodology Applied

Scientific EffectWelding: Welding

Data Source

PatentEP4707428A1Method for refurbishing an electrolysis cell and electrolysis cell

Publication Date: 2026.03.11 THYSSENKRUPP UHDE CHLORINE ENGINEERS GMBH

Figure 1A~1B
Figure 2

AI summary

The invention relates to a method for refurbishing an electrolysis cell for alkaline water electrolysis or chlor-alkali electrolysis, wherein at the start of the method the electrolysis cell is in a closed starting state with an elastic current distributor being in a compressed state, holding a cathode in planar contact with one side of a sheet-like separator, wherein a second, opposite second side of the sheet-like separator is supported by a rigid anode, and wherein the method comprises the steps of opening the electrolysis cell, while releasing the compression of the elastic current distributor, interposing a first flexible anode between the rigid anode and the separator, and closing the electrolysis cell, while compressing the elastic current distributor. The invention further relates to an electrolysis cell obtainable by the above method.