Redox Flow Battery Unit Cell Furrow Design for Pressure Drop Reduction

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Solution Overview

Problem

Conventional redox flow batteries face high pressure drop issues due to the size of electrodes, leading to increased power consumption and reduced efficiency, with existing solutions either increasing costs or complicating assembly and material usage.

Innovation Solution

The design incorporates an outer frame with side support walls forming furrows and sub-flow paths that connect to the main flow paths, allowing the electrolyte to flow laterally through shorter distances within the electrodes, reducing the overall length of electrolyte passage and thus minimizing pressure drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the electrode size is increased to maintain high flow rates and power output, then the power output is improved, but the pressure drop increases significantly

Engineering Contradiction:
Improvepower outputVSAvoidpressure drop
Core Design Contradiction:
PowerVSStress or pressure

Solution Approach 1:

The flow frame is divided into multiple flow paths that segment the electrolyte flow. Instead of a single long flow path through the entire electrode, the electrolyte is distributed through multiple shorter parallel paths, reducing the flow length and pressure drop while maintaining the same total flow rate and power output capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a lateral flow dimension by creating flow paths that extend sideways along the electrode rather than only through it. This dimensional change allows the electrolyte to travel a shorter distance through the electrode material, reducing pressure drop while still achieving adequate contact for electrochemical reactions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If conventional flow path designs are used, then the structure is simple, but the pressure drop is high leading to increased power consumption

Engineering Contradiction:
Improveflow path structureVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The flow path is segmented into multiple sections with lateral flow channels that branch off from the main flow path. This segmentation creates shorter flow segments that reduce the overall pressure drop, thereby lowering the power consumption of the pump while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

3Stress or pressure

If the electrolyte flow path length is reduced to decrease pressure drop, then the pressure drop is improved, but the power output may be affected

Engineering Contradiction:
Improvepressure dropVSAvoidpower output
Core Design Contradiction:
Stress or pressureVSPower

Solution Approach 1:

Multiple flow paths are merged back together after passing through the electrode, allowing the electrolyte to collect and continue flowing. This merging of parallel flow paths maintains the beneficial short flow length for reduced pressure drop while ensuring adequate electrochemical reaction surface area is utilized for maintaining power output.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration significantly reduces pressure drop while maintaining high flow rates and power output, enhancing the system's efficiency and cost competitiveness by minimizing the use of expensive materials and simplifying assembly.

Implementation Method 1

reducing the overall length of electrolyte passage and thus minimizing pressure drop

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP3457480B1Unit cell for redox flow battery, for reducing pressure drop caused by electrolyte flow in stack
Publication Date: 2023.08.02 H2 INC
  • EP3457480B1 patent drawingFigure 1~2
  • EP3457480B1 patent drawingFigure 3~4
  • EP3457480B1 patent drawingFigure 5~6

AI summary

Provided is a redox flow battery stack comprising: an ion-exchange membrane (1000); two flow frames (2000A, 2000B) disposed on both sides of the ion-exchange membrane (1000), respectively; two bipolar plates (4000A, 4000B) disposed outside the flow frames (2000A, 2000B), respectively; and electrodes disposed in cavities inside outer frames of the flow frames (2000A, 2000B), respectively, in which at least two electrodes are disposed in the flow frames, respectively, and at least three furrows in which the electrolyte flows are formed between electrodes or between the electrode and the outer frame in the flow frame.