Membraneless Microfluidic Redox Battery Flow Control for Crossover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current membraneless redox flow batteries face challenges in maintaining efficient operation due to advective mixing and crossover effects between electrolytes, limiting their capacity and operational life, especially when integrated into microfluidic systems.
Innovation Solution
A redox microfluidic energy storage system comprising a battery reactor with membraneless battery microcells connected in parallel, a flow circulation system managing electrolyte flow under laminar conditions, and a battery management system that controls electrolyte flow rates and electrical current to minimize mixing and maximize ion charge carrier mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If membraneless redox flow batteries are used to simplify structure and reduce costs, then device complexity is reduced, but advective mixing and crossover effects between electrolytes increase, worsening reliability and operational life
Solution Approach 1:
The patent transitions from macro-scale to micro-scale fluid dynamics, fundamentally changing the flow regime parameters. At micro-scale, Reynolds numbers drop below 100, ensuring laminar flow where viscous forces dominate over inertial forces. This parameter change eliminates turbulent mixing while maintaining the membraneless structure, resolving the contradiction between simplicity and reliability
Solution Approach 2:
The patent replaces mechanical mixing (advective transport dominant at macro-scale) with molecular diffusion (diffusive transport dominant at micro-scale). This substitution of transport mechanisms allows electrolytes to remain separated despite direct contact, enabling membraneless operation without crossover effects, thus improving reliability while maintaining structural simplicity
2Productivity
If electrolyte flow rate is increased to improve power output, then productivity increases, but mixing between electrolytes increases, worsening loss of substance
Solution Approach 1:
The patent exploits the scaling relationship between flow rate and Reynolds number. At micro-scale, even increased flow rates maintain Re < 100, preserving laminar flow conditions. This allows the system to increase productivity through higher flow rates without transitioning to turbulent flow that would cause mixing and substance loss
3Volume of moving object
If microscale dimensions are used to improve fuel utilization and compactness, then volume is reduced, but residence time for charge carrier exchange is shortened, worsening energy transfer rate
Solution Approach 1:
The patent pre-compensates for the shortened residence time by optimizing the surface-to-volume ratio of electrodes and enhancing interfacial area for charge transfer. The micro-scale geometry is specifically designed with high surface area electrodes that anticipate and compensate for the reduced time available for charge carrier exchange, thereby maintaining energy transfer rate despite compact dimensions
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
This solution provides precise control over electrolyte flows, reduces crossover effects, and extends the operational life of redox flow batteries by maintaining a laminar flow regime and optimizing charging/discharging performance, enhancing the overall efficiency and stability of the energy storage system.
Implementation Method 1
the electrolytes containing the active species are able to travel or pass through the battery microcells under a laminar flow regime
Implementation Method 2
only molecular diffusion intervenes in the mixing of fluids
Implementation Method 3
Redox flow batteries are a type of flow batteries in which redox reactions take place over the electrodes disposed inside the reactor
Implementation Method 4
All electrochemical energy storage systems convert electrical energy into chemical energy when charging
Data Source
AI summary
A redox microfluidic energy storage system includes a battery reactor, an electrolyte tank storing a positive liquid electrolyte, another electrolyte tank storing a negative electrolyte, a battery management system and a flow circulation system. The battery reactor includes a plurality of membraneless battery microcells connected to each other. The flow circulation system supplies the electrolytes at particular flow rates to the battery reactor such that they are under a laminar flow regime creating an interphase therebetween for transferring ion charge carriers between them. The battery management system causes the flow circulation system to supply the electrolytes to the battery reactor and simultaneously supply an electrical current through the electrodes of the battery reactor to electrically charge the system or to supply the electrolytes to the battery reactor releasing an electrical current through the electrodes to electrically discharge the system.