Regenerative Fuel Cell Hydrogen Anode Volume Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Regenerative fuel cells face challenges such as high costs, large volumes of expensive electrolytes, low power density, and inefficient energy storage due to the use of hazardous materials and complex system designs, particularly in all-vanadium redox flow batteries, which limit their widespread industrial application.
Innovation Solution
A hydrogen gas/dissolved metal ion regenerative fuel cell system utilizing vanadium, cerium, or manganese, with a reversible redox couple, that replaces large liquid electrolyte storage with compressed gas storage, reducing costs and increasing output power by using a hydrogen gas anode and a catalysed porous carbon cathode, allowing for retro-fitting existing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If large volumes of electrolyte are used for large-scale energy storage, then energy storage capacity is improved, but storage costs and system size increase
Solution Approach 1:
The patent transitions the anode electrolyte from liquid phase to gas phase by using hydrogen gas instead of liquid vanadium electrolyte. This phase transition dramatically reduces the volume required for storing the same amount of electrochemical energy, as gases can be compressed to much higher energy densities than liquids, directly resolving the contradiction between energy storage capacity and system volume
Solution Approach 2:
The patent changes the physical state parameter of the anode electrolyte from liquid to gas, and modifies the chemical composition by using hydrogen instead of vanadium. This parameter change enables the system to achieve the same energy storage capacity with significantly reduced volume, addressing the contradiction between storage capacity and system size
2Volume of stationary object
If compressed gas storage is used instead of large liquid electrolyte storage, then physical space is reduced, but system pressure requirements increase
Solution Approach 1:
The patent employs pneumatic principles by using compressed hydrogen gas as the anode electrolyte. The system utilizes pressure vessels and compression equipment to store and deliver hydrogen gas at controlled pressures. This approach accepts the necessary pressure increase as a trade-off for achieving dramatic volume reduction, resolving the contradiction between storage volume and pressure requirements through engineered pneumatic systems
3Power
If hydrogen gas anode is used, then output power is enhanced, but hydrogen storage and handling complexity increases
Solution Approach 1:
The patent makes the hydrogen storage system multi-functional by using the same compressed hydrogen reservoir for both power delivery (fuel cell operation) and power generation (electrolysis mode). The system can operate bidirectionally, storing energy by producing hydrogen and delivering power by consuming hydrogen, thereby reducing overall system complexity despite the added hydrogen storage requirements
Solution Approach 2:
The system provides self-service by using the hydrogen produced during charging (electrolysis mode) directly for power delivery without requiring external hydrogen sources. The regenerative fuel cell system is self-sufficient, generating its own fuel during energy storage mode and consuming it during power delivery mode, which simplifies the overall hydrogen management complexity
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 system significantly reduces the amount of expensive vanadium required, decreases the physical space needed, enhances output power, and lowers capital costs by enabling the adaptation of existing vanadium/vanadium systems, thereby overcoming the limitations of current regenerative fuel cells.
Implementation Method 1
a membrane separating the anode compartment from the cathode compartment, which membrane is capable of selectively passing protons
Implementation Method 2
the redox reaction at the hydrogen gas anode will not produce any 'spent' species in the power delivery mode as the electrochemically active species (hydrogen gas) is transformed into protons that are dissolved in the electrolyte
Implementation Method 3
In the energy storage mode, electrical power is used to regenerate the electrochemically active species, which are stored
Implementation Method 4
The fundamental chemical process in these regenerative fuel cell (RFC) systems is characterised by a chemical equation where the action proceeds in one direction in the energy storage mode of the system and in the opposite direction during the power delivery mode by the system
Data Source
AI summary
The present invention provides a regenerative fuel cell comprising a reversible hydrogen gas anode, in an anode compartment and a reversible cathode in a cathode compartment, wherein the redox reaction at the cathode is selected from formula (i), formula (ii) and formula (iii).