Bipolar Electrode Polygonal Protrusions Gas Management

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Solution Overview

Problem

Existing bipolar electrodes for electrolysis cells face a challenge in balancing active area for electrolysis with the need to prevent gas entrapment, which can inhibit the reaction and lead to process halts.

Innovation Solution

A bipolar electrode design with polygonal protrusions oriented in specific directions to facilitate gas mobility, avoiding the use of forced convection, and featuring a pattern of channels that widen along the flow direction to accommodate growing gas bubbles, ensuring efficient gas flow and maintaining active surface area for electrolysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the active area of the bipolar electrode is maximized to increase electrolysis capacity, then the productivity is improved, but gas bubbles are more likely to be trapped in the enlarged active area, causing harmful factors to increase and potentially halting the process

Engineering Contradiction:
Improveelectrolysis capacityVSAvoidgas entrapment
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The active surface of the bipolar electrode is segmented into multiple protrusions distributed across the surface. Each protrusion creates a localized active area while the spaces between them facilitate gas bubble escape. This segmentation allows the electrode to maintain large total active area for high productivity while preventing gas entrapment through the distributed geometry.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode surface is given non-uniform local quality through the protrusion geometry. The protrusions have specific height, width, and spacing characteristics that optimize both electrolysis activity at their surfaces and gas bubble release in the inter-protrusion spaces. This local quality variation resolves the contradiction by making different regions serve different functions: protrusion tops for electrolysis, inter-protrusion regions for gas escape.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If forced convection is used to improve gas mobility and prevent entrapment, then the harmful factors are reduced, but the device complexity increases due to the need for moving parts such as pumps

Engineering Contradiction:
Improvegas entrapmentVSAvoidmoving parts
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The electrode geometry itself provides the gas mobility function without requiring external forced convection systems. The protrusion design creates natural flow paths and pressure gradients that enable gas bubbles to self-propel away from active areas and toward collection regions. This self-service approach eliminates pumps and moving parts while maintaining effective gas management.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The mechanical forced convection system (pumps, moving parts) is replaced by a geometrically-driven natural convection system. The protrusion geometry creates pressure differentials and flow patterns that naturally move gas bubbles without mechanical intervention. This substitution reduces device complexity while achieving the same gas mobility objective.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Object-generated harmful factors

If the protrusions are made with complex shapes to optimize gas flow paths, then the object-generated harmful factors are reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvegas flow efficiencyVSAvoidprotrusion geometry
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The protrusion geometry is defined by a limited set of controllable parameters (height, base width, spacing, pattern arrangement) rather than complex free-form shapes. These parameters can be precisely controlled during manufacturing using standard techniques. The gas flow efficiency is achieved through optimized values of these parameters rather than through geometric complexity, thereby reducing manufacturing precision requirements while maintaining harmful factor reduction.

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

This design achieves high yield and efficient hydrogen gas mobility without the need for forced convection, resulting in a compact, reliable, and low-maintenance electrolysis unit with improved gas flow and reaction efficiency.

Implementation Method 1

a high yield can be achieved while the produced hydrogen gas retains adequate mobility without the need for forced convection

Methodology Applied
Scientific EffectNatural convection: Free Convection

Implementation Method 2

Bipolar electrodes for use in electrolysis cells are known in the art

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 3

the polygonal shape has at least one side that is oriented in a direction substantially normal (ideally, normal) to the intended direction of flow

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP2865038B1Bipolar electrode and method for producing same
Publication Date: 2019.06.05 SOLVAY SA
  • EP2865038B1 patent drawingFigure 1
  • EP2865038B1 patent drawingFigure 2a~2b
  • EP2865038B1 patent drawingFigure 3a~3c

AI summary

Bipolar electrode (100) for use in an electrolysis unit, said bipolar electrode (100) comprising a planar main body having a first side and a second side, each of said first side and said second side being provided with a corresponding pattern of protrusions (125), wherein each of said protrusions has a geometrical base within the plane of said planar main body and a substantially planar top side (129), the orthogonal projection of said top side onto said main body being contained in said geometrical base, and wherein the top sides (129) of the respective protrusions (129) of said first side and said second side lie in two planes parallel to said planar main body, the electrode being further characterized by specific shape and orientation requirements. Method for producing the bipolar electrode as above described, which includes an embossing step.