Amphoteric Electrolyte Membrane and a Redox Flow Battery Comprising an Electrolyte Membrane

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent discloses a novel amphoteric ion exchange membrane designed for use in redox flow batteries, particularly all-vanadium redox flow batteries. The membrane is engineered with a blend of anion and cation exchange groups in a precisely controlled ratio, providing high ion selectivity, suppressed crossover of vanadium ions, and improved chemical and mechanical stability. The membrane technology aims to balance ionic transport, reduce capacity fading, and can be produced at potentially lower cost through radiation-induced grafting onto robust polymer films.

Use CasesContent extracted from patent full text and abstract with AI.

• Stationary energy storage solutions for renewable energy integration, such as solar or wind farms
• Grid stabilization and peak-shaving in electrical utility networks
• Large-scale backup power systems
• Redox flow battery systems for commercial and industrial applications requiring high-capacity, long-duration energy storage
• Electrochemical processes requiring precise ion selectivity and stability in harsh chemical environments

BenefitsContent extracted from patent full text and abstract with AI.

• Enhanced ion selectivity reduces unwanted crossover of vanadium or other redox-active ions, maintaining battery efficiency
• Balances vanadium ion transport, significantly reducing capacity fading and maintenance requirements
• Improved mechanical and chemical robustness results in longer membrane life and lower replacement rates
• Potential for lower-cost production compared to incumbent materials (e.g., Nafion)
• Scalable manufacturing using radiation-induced grafting technology
• Higher round-trip energy efficiency over a broad range of current densities compared to standard membranes
• Customizable membrane properties by tuning ratio of anion to cation exchange functionalities

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

It is the objective of the present invention to provide a membrane with high ion selectivity, a balancing influence on the vanadium transport in all-vanadium redox-flow environment, high physicochemical stability and potentially low cost.These characteristics can be obtained from an amphoteric ion exchange membrane having selective ion transport properties due to a defined ratio of anion and cation exchange capacity, in particular for use in a redox flow battery, comprising:a) a mechanically robust and chemically resistant base polymer film;b) ion exchange groups covalently bound to the base polymer film, being a mixture of anion exchange groups and cation exchange groups;c) a ratio of the anion exchange groups to the cation exchange groups of 1.5 to 4 (50 - 300% excess of anion exchange groups over cation exchange groups) in order to balance the transport of positively charged redox-active ions;d) a quaternary bonded alpha-C atom in the repeating units of the polymer constituent bearing ion exchange groups used to protect the resulting polymer sterically against chemical degradation;e) optionally additional functional constituents, such as crosslinkers and/or antioxidants.