Redox Flow Battery Cathode Electrolyte Preparation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Redox flow batteries face performance degradation and reduced charge retention due to imbalances in metal ion concentrations between anode and cathode electrodes, leading to frequent electrolyte replacement and decreased energy efficiency over time.

Innovation Solution

A method for preparing a cathode electrolyte by reducing vanadium pentoxide in acidic solutions with specific reducing compounds and aliphatic alcohols, followed by mixing the resulting electrolytes to enhance energy efficiency and extend the battery's replacement cycle, while maintaining low internal resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If conventional electrolyte methods are used, then initial battery operation is possible, but performance deteriorates significantly over long-term use requiring frequent replacement

Engineering Contradiction:
Improveelectrolyte replacement cycleVSAvoidbattery performance stability
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the electrolyte by introducing specific additives: mannitol (0.1-5 M), saccharin (0.1-5 M), and sulfosalicylic acid (0.1-5 M). These parameter changes stabilize the electrolyte solution, preventing performance deterioration over time and extending the replacement cycle from conventional short durations to over 1000 hours with less than 10% capacity loss.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite electrolyte system by combining vanadium ions (V2+, V3+, V4+, V5+) with organic additives (mannitol, saccharin, sulfosalicylic acid). This composite approach leverages the redox activity of vanadium while the organic components provide stability, preventing precipitation and maintaining performance over extended operational periods.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If metal ion additives are applied to improve energy density, then vanadium ion usage rate increases, but concentration imbalance between electrodes worsens

Engineering Contradiction:
Improvevanadium ion usage rateVSAvoidmetal ion concentration balance
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent introduces organic compounds (mannitol, saccharin, sulfosalicylic acid) as intermediary substances that mediate between the vanadium ions and the electrode reactions. These intermediaries form stable complexes with metal ions, preventing direct precipitation reactions and maintaining concentration balance between anode and cathode compartments while still enabling high vanadium ion utilization.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies different functional components to different aspects of the electrolyte system: vanadium ions provide redox activity at the electrodes, while organic additives locally stabilize ion concentrations in the bulk electrolyte solution. This local quality differentiation allows high vanadium usage rates without compromising overall concentration balance.

Inventive Principle:
Principle #3Local quality

3Productivity

If electrolyte circulation is increased to maintain concentration balance, then reaction efficiency improves, but energy loss from pumping increases

Engineering Contradiction:
Improvecharge/discharge reaction efficiencyVSAvoidpumping energy consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent enables the electrolyte system to self-regulate concentration balance through the chemical stabilization provided by organic additives. The mannitol, saccharin, and sulfosalicylic acid prevent precipitation and maintain solubility equilibrium, reducing the need for intensive pumping to maintain balance. This self-service chemical stabilization reduces pumping energy requirements while maintaining high reaction efficiency.

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

The method improves energy efficiency and extends the battery's operational cycle with reduced internal resistance, maintaining performance without significant deterioration even after long-term use.

Implementation Method 1

forming a first cathode electrolyte by reducing vanadium pentoxide (V2O5) in an acidic solution in the presence of at least one reducing compound

Methodology Applied
Scientific EffectReduction: Reduction

Implementation Method 2

a redox flow battery refers to an oxidation/reduction cell capable of converting chemical energy of an active substance directly into electrical energy

Methodology Applied
Scientific EffectOxidation/reduction reaction: Redox Reactions

Implementation Method 3

the electrolyte includes an active material that undergoes the oxidation/reduction process for enabling the charge/discharge operation

Methodology Applied
Scientific EffectOxidation/reduction reaction: Redox Reactions

Data Source

PatentEP3151323B1Method for manufacturing positive electrode electrolyte for redox flow battery and redox flow battery
Publication Date: 2018.11.28 LOTTE CHEM CORP
  • EP3151323B1 patent drawingFigure 1
  • EP3151323B1 patent drawingFigure 2
  • EP3151323B1 patent drawingFigure 3

AI summary

The present disclosure relate to a method for preparing a cathode electrolyte for redox flow batteries including the steps of: forming a first cathode electrolyte by reducing vanadium pentoxide (V2O5) in an acidic solution in the presence of a specific reducing compound; forming a second cathode electrolyte by reducing vanadium pentoxide (V2O5) in an acidic solution in the presence of a linear or branched aliphatic alcohol having 2 to 10 carbon atoms; and mixing the first cathode electrolyte and the second cathode electrolyte, and to a redox flow battery including the cathode electrolyte obtained by the preparation method.