Water-Impermeable Solid Electrolyte Membrane for Selective Lithium Extraction
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Solution Overview
Problem
Current membrane technologies for separating and recovering alkali metals suffer from low ionic conductivity, durability, scalability, and selectivity, which limits their effectiveness in lithium extraction from various sources.
Innovation Solution
A water-impermeable membrane with a solid electrolyte embedded in a densely crosslinked hydrophobic matrix, allowing selective ion transport while preventing water and other substances from passing through, and capable of extracting lithium, sodium, or potassium ions for efficient recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If binders are used to hold the electrolyte membrane together, then the membrane can be formed into a desired shape, but the ionic conductivity and durability are reduced
Solution Approach 1:
The invention removes binders from the membrane structure entirely, using only sintered electrolyte particles to form the membrane. This extraction of the harmful binder component resolves the contradiction by eliminating the source of reduced ionic conductivity and durability while still achieving the desired shape through particle packing and sintering processes.
Solution Approach 2:
The membrane is constructed as a composite of sintered electrolyte particles with specific size distributions and compositions, creating a binder-free structure that maintains both mechanical integrity and high ionic conductivity. The composite particle arrangement enables shape formation without compromising durability.
2Ease of manufacture
If soft materials are used to easily process the membrane layer, then the membrane can be fabricated with ease, but the selectivity for alkali metals is reduced
Solution Approach 1:
The invention changes the physical and chemical parameters of the membrane material to specific electrolyte compositions and particle size distributions that provide both ease of processing and high selectivity. By controlling particle size, sintering temperature, and electrolyte composition, the membrane achieves manufacturing feasibility while maintaining precise alkali metal selectivity.
3Strength
If the membrane thickness is increased to improve durability, then the membrane strength is improved, but the voltage drop and energy consumption increase
Solution Approach 1:
The invention applies local quality optimization by creating a non-uniform particle size distribution within the membrane thickness, with finer particles in regions requiring higher strength and coarser particles in regions where ionic transport is prioritized. This localized variation in particle characteristics allows the membrane to achieve adequate strength at reduced thickness, minimizing voltage drop while maintaining durability.
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 membrane enhances lithium extraction efficiency, scalability, and durability, enabling the recovery of lithium from diverse sources with low energy demand, making it suitable for large-scale EV battery recycling.
Implementation Method 1
The solid electrolyte is ion-selective for the alkali metal and configured to extract ions of the alkali metal
Implementation Method 2
the layer is water impermeable... the matrix used may be densely crosslinked and hydrophobic, thereby preventing diffusion of water
Implementation Method 3
molecules of the matrix covalently may bond with particles of the solid electrolyte
Implementation Method 4
the ions of the alkali metal may pass through a single particle of the solid electrolyte of the layer
Data Source
AI summary
The presently disclosed concepts relate to improved techniques for alkali metal extraction (and in particular lithium), using a solid electrolyte membrane. By using a solid electrolyte embedded in a matrix, alkali metal (such as lithium) can be more effectively separated from feed solutions. Additionally, energy used to initially extract lithium from a feed solution may be stored as electrochemical energy, which in turn, may be discharged when lithium is depleted from the electrode. This discharged energy may therefore be reclaimed and reused to extract additional lithium.