In-Situ Gravitational Separation of Electrolyte Slurries in Flow Redox Batteries

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Flow redox battery systems face inefficiencies due to the mixing of charged and discharged active materials within the anolyte and catholyte tanks, leading to electrochemical losses and reduced open-circuit voltage.

Innovation Solution

The implementation of carrier slurries with different densities and electronegativities within the anolyte and catholyte tanks, allowing for the separation and selective engagement of charged and discharged active materials, thereby optimizing the concentration of reactants within the electrochemical cell and reducing electrochemical losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If charged and discharged active materials are mixed within the anolyte and catholyte tanks, then the system structure is simple, but electrochemical losses increase and open-circuit voltage decreases

Engineering Contradiction:
Improveelectrochemical lossesVSAvoidsystem structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the electrolyte solution into distinct charged and discharged active material phases using density differences. Carrier slurries with different densities are introduced to selectively bind and separate charged and discharged species, creating physically distinct regions within the tank that prevent mixing and associated electrochemical losses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces carrier slurries as intermediary substances that mediate between the charged and discharged active materials. These carriers selectively bind to specific charge states through electronegativity differences, acting as transport vehicles that facilitate separation and prevent direct contact between oppositely charged species, thereby reducing electrochemical losses.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If carrier slurries with different densities and electronegativities are implemented, then open-circuit voltage and reactant concentration are enhanced, but system complexity increases

Engineering Contradiction:
Improveopen-circuit voltageVSAvoidslurry composition
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent systematically varies key parameters of the carrier slurries, specifically density and electronegativity, to achieve optimal separation and electrochemical performance. By adjusting these parameters, the system enhances open-circuit voltage and reactant concentration while maintaining controllable complexity through defined compositional variations.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If active materials are not separated, then the system operation is simple, but reactant concentration efficiency decreases

Engineering Contradiction:
Improvereactant concentration efficiencyVSAvoidsystem operation
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements a self-service separation mechanism where the carrier slurries automatically separate charged and discharged active materials based on their inherent density and electronegativity differences. This passive separation process occurs without external intervention, allowing the system to maintain high reactant concentration efficiency while requiring minimal operational complexity.

Inventive Principle:
Principle #25Self-service

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 approach increases the efficiency of the flow redox battery system by maximizing the concentration of reactant active materials, enhancing the open-circuit voltage and minimizing recirculation of non-reactant materials, thus improving overall system performance.

Implementation Method 1

The first anolyte carrier slurry includes a density that is less than a density of the second anolyte carrier slurry

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Implementation Method 2

the first anolyte carrier slurry includes an electronegativity that is greater than an electronegativity of the second anolyte carrier slurry such that the first anolyte carrier slurry electrochemically attracts a discharged anolyte active material

Methodology Applied
Scientific EffectElectronegativity: Ion Repulsion/Attraction

Implementation Method 3

The electrochemical cell includes an ion-exchange membrane positioned between and electrochemically engaged with an anode and a cathode

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Data Source

PatentEP3430668B1In-SITU gravitational separation of electrolyte solutions in flow redox battery systems
Publication Date: 2021.05.26 SAUDI ARABIAN OIL CO
  • EP3430668B1 patent drawingFigure 1
  • EP3430668B1 patent drawingFigure 2
  • EP3430668B1 patent drawingFigure 3

AI summary

A flow redox battery system including an electrochemical cell, an anolyte tank, a catholyte tank, a first anolyte carrier slurry, a second anolyte carrier slurry, a first catholyte carrier slurry, a second catholyte carrier slurry, and a power generation circuit. An ion-exchange membrane is electrochemically engaged with an anode and a cathode. The power generation circuit is electrically coupled to the anode and the cathode. The anolyte tank is fluidly coupled to the anode and the catholyte tank is fluidly coupled to the cathode. The first anolyte carrier slurry includes a density less than a density of the second anolyte carrier slurry and an electronegativity different than an electronegativity of the second anolyte carrier slurry. Further, the first catholyte carrier slurry includes a density less than a density of the second catholyte carrier slurry and an electronegativity different than an electronegativity of the second catholyte carrier slurry.