Redox Flow Battery Decoupling for Self-Discharge Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Redox flow batteries face high self-discharge and temperature increases due to transport phenomena and shunt currents, leading to energy loss and inefficiency, especially when not all stacks are needed, as existing solutions either require constant load or fail to address dynamic energy demands.
Innovation Solution
A device connects decoupled functional units to energy storage via a DC/DC converter, allowing selective discharge of inactive stacks to charge active subsystems, reducing self-discharge and enabling immediate energy supply during fluctuating demands without external inverter consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If stacks are shut down to reduce self-discharge, then energy efficiency is improved, but temperature increase occurs due to heat generation from self-discharge
Solution Approach 1:
The patent converts the harmful self-discharge heat generation into a beneficial process by electrically coupling idle stacks to active stacks. The electrical energy that would otherwise be lost as heat is instead transferred to active stacks, where it can be utilized. This transforms the waste heat problem into useful energy transfer, simultaneously reducing self-discharge losses and preventing temperature increase.
Solution Approach 2:
The patent merges idle stacks with active stacks through electrical coupling, creating a unified energy management system. Instead of operating stacks independently, the system combines them into a single electrical network where energy can flow between stacks. This merging allows idle stacks to contribute their residual energy to the overall system, improving overall efficiency while managing thermal characteristics.
2Loss of energy
If external inverter is used to discharge idle stacks, then self-discharge is reduced, but system complexity and energy loss increase
Solution Approach 1:
The patent extracts the inverter component from the system architecture and replaces it with direct electrical coupling between stacks. By removing the external inverter requirement, the system achieves the same self-discharge reduction function through a simpler configuration. The electrical energy from idle stacks is directly transferred to active stacks without needing external conversion equipment, thereby reducing both complexity and associated energy losses.
Solution Approach 2:
The patent makes the stack system multi-functional by enabling idle stacks to serve dual purposes: maintaining electrical neutrality and providing energy transfer capability. The same electrical coupling mechanism that prevents self-discharge also enables energy redistribution within the system, eliminating the need for separate discharge and charge management systems.
3Loss of energy
If electrolyte flow is stopped in idle stacks, then energy efficiency is improved, but rapid response to increasing demand cannot be achieved
Solution Approach 1:
The patent prepares idle stacks in advance by maintaining them in an electrically coupled state, ready to immediately contribute energy when needed. Rather than waiting for electrolyte flow to be re-established (which takes several minutes), the electrical coupling is already in place, allowing instantaneous energy transfer. This preliminary electrical connection enables rapid response to demand increases without requiring electrolyte circulation.
Solution Approach 2:
The patent replaces the mechanical electrolyte flow system with an electrical energy transfer system for rapid response. Instead of relying on mechanical pumping of electrolyte (which has inertia and startup time), the system uses electrical coupling to transfer energy almost instantaneously. This substitution of electrical for mechanical energy transfer enables rapid response while maintaining the energy efficiency benefits of stopped electrolyte flow.
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 minimizes self-discharge and irreversible cell fallout, providing efficient energy storage and immediate power supply, reducing energy loss and temperature increases while maintaining system reliability and efficiency.
Implementation Method 1
By means of a DC/DC converter, this energy can be used to charge a parallel battery or subsystems of the flow battery which are still active
Implementation Method 2
redox flow battery, in particular a vanadium redox flow battery
Data Source
AI summary
A redox flow battery, in particular a vanadium redox flow battery, with at least two functional units, for example at least two stages with at least one battery cascade, or at least two battery cascades, has a device for electrically decoupling at least one of these units. In order to ensure fault-free and functionally reliable operation of an energy supply system on the basis of such a redox flow battery alongside best-possible efficiency, a device for connecting a decoupled functional unit to at least one store for electrical energy is provided.