Redox-Active Eutectic Liquid Reactant for Flow Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flow batteries have a low energy density, limiting their application beyond grid-scale storage due to the low concentration of redox-active species, which is difficult to achieve with existing nonaqueous solutions, hybrid concepts, and deep eutectic solvents, resulting in higher costs and limited scalability.
Innovation Solution
A eutectic mixture of two or more redox-active substances is used to create a high-energy density liquid reactant, omitting the need for solvents, by selecting substances like quinones and quinoxalines that reduce melting points below room temperature, allowing for a higher concentration of redox-active components, thereby increasing energy density up to 5-10 times that of traditional flow batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional nonaqueous solutions or deep eutectic solvents are used in flow batteries, then the battery can operate, but the energy density remains low (10-50 Wh/kg) due to low concentration of redox-active species
Solution Approach 1:
The patent changes the physical state parameter of redox-active compounds from solid to liquid by forming eutectic mixtures. This phase change enables the redox-active species to be in liquid form at room temperature without requiring traditional solvents, thereby achieving high concentration (at least 70% by weight) and high energy density (5-10 times that of traditional flow batteries).
Solution Approach 2:
The patent creates composite liquid reactants by mixing multiple redox-active compounds (organic and/or inorganic) in specific ratios to form eutectic compositions. This composite approach allows the mixture to exhibit liquid properties at room temperature while maintaining high concentrations of electrochemically active species, resolving the contradiction between concentration and energy density.
2Quantity of substance
If high concentration of redox-active species is achieved, then energy density increases, but the melting point of the mixture increases, causing it to solidify at room temperature
Solution Approach 1:
The patent exploits the eutectic phase transition phenomenon where mixing specific ratios of redox-active compounds creates a composition with a melting point below room temperature. This phase behavior allows the high-concentration mixture to remain liquid at operating temperatures, simultaneously achieving high concentration and low melting point.
Solution Approach 2:
By adjusting the compositional parameters of the redox-active compound mixture, the patent achieves a eutectic composition that lowers the melting point while maintaining high concentration of active species. This parameter optimization resolves the trade-off between concentration and melting temperature.
3Adaptability or versatility
If traditional flow battery designs are used, then scalability is achieved for grid-scale storage, but energy density remains too low for transportation applications
Solution Approach 1:
The patent changes the fundamental parameter of the liquid reactant from solvent-based to eutectic mixture-based, achieving energy density (5-10 times higher than traditional flow batteries) that enables transportation applications while preserving the scalable flow battery architecture for grid-scale storage.
Solution Approach 2:
The high-energy-density eutectic liquid reactant enables the flow battery to serve multiple applications - both grid-scale energy storage and transportation applications - by achieving energy density levels comparable to Li-ion batteries while maintaining the scalability and long cycle life advantages of flow battery architecture.
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 eutectic mixture achieves a high-energy density, enabling flow batteries to approach the energy density of Li-ion batteries, facilitating their use in electric vehicles and enhancing their scalability and cost-effectiveness for storing wind and solar energy.
Implementation Method 1
a eutectic mixture of two or more different redox-active substances... a melting temperature of the liquid reactant is below room temperature
Implementation Method 2
two or more different redox-active compounds... account for at least 70% by weight of the liquid reactant
Data Source
AI summary
An electrochemical device includes: (1) a compartment; (2) a container including a liquid reactant; and (3) a conveyance mechanism fluidly connected to the container and the compartment and configured to convey the liquid reactant from the container into the compartment, wherein the liquid reactant is a eutectic mixture of two or more different redox-active substances.