Open-Shell Polymer-Carbon Electrodes for High-Energy Supercapacitors
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Solution Overview
Problem
Conventional supercapacitors face limitations in energy density and power delivery, with trade-offs in cycling stability, making them unsuitable for high-frequency applications and large-scale IoT systems.
Innovation Solution
A synergistic combination of conjugated open-shell donor-acceptor polymers with carbon-based compounds, such as reduced graphene oxide, is used to create composite electrodes with a large potential window and high areal capacitance, achieved through electro-polymerization at room temperature, eliminating the need for inert solubilizing groups and enhancing charge transfer kinetics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional supercapacitors are used, then fast charging rate and high power density are achieved, but energy density is smaller compared to batteries
Solution Approach 1:
The patent employs composite materials combining conjugated open-shell donor-acceptor polymers with carbon-based compounds (graphene, carbon nanotubes, activated carbon) to create electrode structures that simultaneously achieve high energy density and high power density. The composite structure allows the polymer to provide high energy storage capacity while the carbon components ensure rapid charge transfer and high power delivery, resolving the trade-off between energy and power density.
2Use of energy by moving object
If batteries are used for energy storage, then high energy density is achieved, but cycle life is limited to hundreds of cycles
Solution Approach 1:
The patent changes the fundamental electrochemical parameters of the energy storage system by using open-shell donor-acceptor polymers with extended conjugation and specific HOMO-LUMO gaps that enable stable operation at high voltages (2.5-3.0V) with reversible redox reactions. This parameter change allows achieving battery-like energy density while maintaining supercapacitor-like cycle life exceeding 5,000 cycles, as the polymer structure resists degradation during repeated charging-discharging cycles.
3Productivity
If supercapacitors operate at high frequency, then fast charging rate is achieved, but capacitance retention decreases over cycles
Solution Approach 1:
The patent applies local quality by creating electrodes with heterogeneous structures where conductive carbon components (graphene, carbon nanotubes) are distributed throughout the polymer matrix. This local arrangement ensures that high-frequency charge transfer occurs at the conductive carbon interfaces while the polymer bulk maintains structural integrity and capacitance. The local quality of conductive pathways enables fast charging without sacrificing long-term capacitance retention.
4Ease of manufacture
If conventional polymers are used in supercapacitors, then ease of manufacture is improved, but charge transfer kinetics and power delivery are limited
Solution Approach 1:
The patent introduces carbon-based compounds (graphene, carbon nanotubes, activated carbon) as intermediary components that mediate between the polymer matrix and the electrolyte. These carbon intermediaries provide highly conductive pathways for charge transfer, enhancing power delivery and charge transfer kinetics. The intermediaries also facilitate easier manufacture by serving as scaffolds for polymer deposition and improving overall electrode processability.
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 composite electrodes exhibit exceptional stability and high energy density, capable of operating at 120 Hz with 85% capacitance retention after 5,000 cycles, offering a compact and durable energy storage solution for IoT devices.
Implementation Method 1
achieved through electro-polymerization at room temperature
Implementation Method 2
enhancing charge transfer kinetics
Implementation Method 3
high areal capacitance, capable of operating at 120 Hz with 85% capacitance retention after 5,000 cycles
Data Source
AI summary
Embodiments of the presently disclosed technology provide a synergistic combination of a conjugated open-shell donor-acceptor polymer with a carbon-based compound (e.g., reduced graphene oxide) to produce a composite electrode material which demonstrates state-of-the-art capacitance and potential window, with excellent kinetics and cycle life. The conjugated open-shell donor-acceptor polymer may comprise a plurality of alternating electron-rich monomers (i.e., donors) and electron-deficient monomers (i.e., acceptors) bonded together via a conjugated backbone. The conjugated backbone may comprise a connection of π-orbitals of the plurality of monomers in alternating single and double bonds that facilitates unpaired electron delocalization—thereby stabilizing charge for the polymer. The carbon-based compound of the composite electrode material may provide porous, conductive scaffolds for the composite electrode material, resulting in electrodes scalable to microns-thick films with fast kinetics.