exTTF Polymers for High-Capacity Redox Storage

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Solution Overview

Problem

Existing organic redox-active polymers for electrical charge storage devices have limited theoretical capacity due to one-electron processes and multi-electron processes that result in undesirable charging/discharging plateaus and low cell voltages.

Innovation Solution

Development of 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene polymers with pendant groups that facilitate a reversible two-electron redox process, allowing for high cell voltage, long service life, and a flat charge/discharge plateau without the need for expensive catalysts or additional monomers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multi-electron redox processes are used (e.g., quinones, dicyanodiimides), then theoretical capacity increases, but cell voltage decreases and multiple charging/discharging plateaus appear

Engineering Contradiction:
Improvetheoretical capacityVSAvoidcell voltage
Core Design Contradiction:
Quantity of substanceVSPower

Solution Approach 1:

The patent segments the redox process into two independent one-electron steps within a single stage. The exTTF unit undergoes sequential one-electron oxidations at the same potential, dividing the multi-electron process into manageable segments that maintain high voltage while achieving high capacity (2 electrons per unit).

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the fundamental parameter of redox mechanism from multi-electron transfer to sequential one-electron transfer. This parameter change allows the system to achieve high theoretical capacity (2 electrons per exTTF unit) while maintaining high cell voltage and a single-stage charging/discharging profile.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If multi-electron redox processes are used (e.g., quinones, dicyanodiimides), then theoretical capacity increases, but multiple charging/discharging plateaus appear

Engineering Contradiction:
Improvetheoretical capacityVSAvoidcharging/discharging profile
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent segments the redox process into two independent one-electron steps that occur at the same potential. This segmentation results in a single-stage charging/discharging plateau with a flat profile, eliminating the multiple plateaus that would otherwise appear with dependent multi-electron processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the redox mechanism parameter to sequential one-electron transfer with identical potentials for both steps. This parameter change produces a stable, single-stage charging/discharging profile with high theoretical capacity, resolving the contradiction between capacity and profile stability.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If known redox-active polymers are used, then ease of manufacture is maintained, but theoretical capacity is limited by one-electron processes

Engineering Contradiction:
Improvesynthesis simplicityVSAvoidtheoretical capacity
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent changes the redox capacity parameter from one-electron to two-electron per monomer unit by using the exTTF structure. The synthesis remains straightforward using standard polymerization methods, achieving double the theoretical capacity without complicating the manufacturing process.

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

The new polymers achieve a high theoretical capacity with a simple and cost-effective synthesis method, providing a flat charging/discharging profile and extended service life in electrical charge storage devices.

Implementation Method 1

These new secondary batteries are characterized in particular by high cell voltages, high power densities and a long service life as well as simple and scalable processing and manufacturing methods. The new 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (exTTF) structures of these new polymers show a special electrochemical behavior. This is characterized by a reversible two-electron redox process

Methodology Applied
Scientific EffectRedox reactions: Redox Reactions

Data Source

PatentEP3122789B19,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene polymers and use thereof
Publication Date: 2019.05.08 EVONIK OPERATIONS GMBH
  • EP3122789B1 patent drawingFigure 1~2
  • EP3122789B1 patent drawingFigure 3~4
  • EP3122789B1 patent drawingFigure 5~6

AI summary

The problem addressed by the invention is that of creating new polymers, which can be produced with little complexity, wherein the chemical-physical properties of said polymers can be influenced in a specific manner within wide limits during the synthesis, and which can be used as active media in electrical charge storage elements for high storage capacity, long service life, and stable charging/discharging plateaus. 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene polymers, consisting of an oligomeric or polymeric compound of general formula (I), were discovered.