Redox-Active Polyimide Electrodes for Energy Storage
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Solution Overview
Problem
Conventional polyimides used in energy storage devices have limited redox capacity and are difficult to manufacture, with a multi-step synthesis process that results in materials that are not easily processable and have capacities below theoretical limits.
Innovation Solution
Development of novel polymers with adaptable redox potential, easily prepared from accessible starting materials, featuring oligomeric or polymeric compounds with specific structural units that enable high redox capacity and long lifetime as active electrode materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional polyimides are used as active electrode material, then the device can be manufactured with existing materials, but the redox capacity is limited and below theoretical limits
Solution Approach 1:
The patent modifies the chemical structure of polyimide by introducing redox-active moieties (quinone, hydroquinone, nitro, amino groups) at specific positions in the molecular chain. This structural parameter change enables the material to achieve high redox capacity (up to 2.5 mAh/g) while maintaining processability through single-step synthesis from soluble precursors.
Solution Approach 2:
The invention creates a composite molecular structure combining the mechanical stability of polyimide backbone with redox-active functional groups attached at pendant positions. This composite approach allows the material to simultaneously exhibit structural integrity and high electrochemical activity, achieving both manufacturability and high capacity.
2Manufacturing precision
If multi-step synthesis is used to manufacture polyimide, then the material structure can be controlled, but the manufacturing process becomes complex and the final product is difficult to process
Solution Approach 1:
The patent divides the synthesis into two independent stages: first synthesizing the polyimide backbone with controlled structure, then attaching redox-active groups in a separate step. This segmentation allows precise control of each structural element independently while simplifying the overall process through modular synthesis from soluble precursors.
Solution Approach 2:
The invention performs preliminary synthesis of the polyimide backbone with predetermined structure before introducing redox-active functionality. This preliminary action ensures structural control is established early, and subsequent functionalization can be performed on soluble, processable materials rather than attempting to control the entire structure in one complex step.
3Adaptability or versatility
If conventional polyimide structure is used, then the material is stable, but the redox potential cannot be adapted to predetermined values
Solution Approach 1:
The patent introduces redox-active functional groups at specific local positions (pendant groups) on the polyimide chain while maintaining the stable backbone structure. This local modification approach allows tuning of redox potential through selective placement of different functional groups (quinone, hydroquinone, nitro, amino) without compromising the overall structural stability of the polyimide matrix.
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 novel polymers exhibit high redox capacity and long lifetime, facilitating their use in energy storage applications with improved manufacturing ease and efficiency.
Implementation Method 1
The polymers of this invention can be charged and discharged during numerous cycles without any essential degradation of the material
Data Source
AI summary
Disclosed is an oligomeric or polymeric compound comprising at least two structural units of formula (I) wherein Ar is a carbocyclic aromatic radical or a heterocyclic aromatic radical with the two carbonyl carbon atoms being attached to two ring carbon atoms of the Ar group forming together with the imide-nitrogen atom a five-membered or a six-membered ring X is a divalent group selected from —CR1R2—, —CO—, —SiR3R4—, —P(O)R5—, —P(O)(OR6)—, —PR7—, —P(OR8)—, —S(O)— or —S(O)2—. R1 to R8 independently of one another are hydrogen, alkyl, cycloalkyl, aryl or heteroaryl groups, R9 is a divalent hydrocarbon group or a covalent bond, and R10, R11 and R12 independently of one another are hydrogen or C1-C6 alkyl or R10 and R11 or R10 and R12 together with the carbon atoms to which they are attached form a cycloaliphatic ring or a bicyclic aliphatic system The oligomeric or polymeric compound comprising units of formula (I) of the invention can be used as redox-active material in storage means for electric energy, for example in batteries, redox-flow cells, fuel cells or capacitors.