Defect-Engineered 2D Ion Transport Membranes for Selective Lithium Extraction
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Solution Overview
Problem
Existing lithium extraction technologies face challenges in efficiently extracting high-purity lithium from easily accessible sources like seawater and brine due to low extraction efficiency, economic viability, and difficulty in selectively separating lithium ions from other cations.
Innovation Solution
An ion transport structure comprising a two-dimensional nanomaterial membrane with defects and nanoflakes formed on its surface, creating primary and secondary ion channels for unidirectional transport of cations, particularly lithium ions, using materials like graphene and transition metal dichalcogenides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a porous membrane is used for lithium extraction, then lithium ions can be extracted from seawater, but the pore size cannot be precisely controlled making it difficult to selectively separate lithium ions from other cations
Solution Approach 1:
The patent replaces traditional porous membranes with two-dimensional nanomaterial membranes (graphene, MoS2, WS2) that have atomic-level thickness and precisely controllable defect sizes. These thin film structures enable precise control of ion transport pathways through defect engineering, allowing selective passage of lithium ions while blocking other cations based on their size differences.
Solution Approach 2:
The patent controls the size and distribution of defects in the two-dimensional nanomaterial membrane to precisely regulate ion channel dimensions. By adjusting defect parameters during membrane fabrication, the system achieves precise size control that enables selective lithium ion transport, resolving the pore size control issue of traditional porous membranes.
2Quantity of substance
If conventional adsorbent-based lithium extraction is used, then lithium can be adsorbed from seawater, but the extraction efficiency is low and economic viability is poor
Solution Approach 1:
The patent replaces the adsorption-based mechanical system with an electrochemical ion transport system. By applying an electric field across the two-dimensional nanomaterial membrane, lithium ions are driven through the membrane from the anode to the cathode compartment, enabling efficient and controllable lithium extraction that overcomes the low efficiency of adsorbent-based methods.
Solution Approach 2:
The patent uses two-dimensional nanomaterial membranes with engineered defects that create controlled nanoscale channels for ion transport. These defect-engineered porous structures provide high ion conductivity and selective transport pathways, enabling efficient lithium ion extraction while blocking other cations, thus improving both capacity and productivity.
3Adaptability or versatility
If lithium extraction is performed from sources containing various cations, then lithium can be obtained from accessible sources, but high-purity lithium is difficult to obtain
Solution Approach 1:
The patent creates local quality differences by engineering specific defect sites in the two-dimensional nanomaterial membrane that are optimized for lithium ion transport. The defect size, shape, and distribution are locally controlled to match the size of lithium ions, creating selective transport pathways that allow lithium ions to pass while blocking other cations, thus achieving high-purity lithium extraction from diverse sources.
Solution Approach 2:
The patent exploits the asymmetry in size between lithium ions and other cations present in seawater and brine. The two-dimensional nanomaterial membrane with controlled defect sizes creates asymmetric transport pathways that are permissive to lithium ions but restrictive to larger cations, enabling selective separation and high-purity lithium extraction from complex mixtures.
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 structure enables selective and efficient extraction of high-purity lithium ions by controlling ion channel sizes, allowing for effective lithium extraction from sources containing multiple cations with minimal energy input.
Implementation Method 1
a primary ion channel formed by the defects, and a secondary ion channel formed by the interlayer gap between the membrane and the nanoflake
Implementation Method 2
introducing a recovery device containing an adsorbent into seawater to selectively adsorb lithium
Data Source
AI summary
The present invention relates to an ion transport structure using a two-dimensional nanomaterial having defects, a method for preparing same, and a lithium extraction apparatus comprising same. According to the present invention, by using a structure in which nanoflakes covering defects are grown on a two-dimensional nanomaterial membrane with the defects, unidirectional transport of cations is possible and an ion channel with a controlled size can be formed. Therefore, the ion transport structure of the present invention has excellent ion transport properties and selectivity, and thus can be usefully applied to various fields that require selective transport of ions. In particular, when a lithium ion transport structure is prepared according to the present invention and applied to a separator of a lithium extraction device, high-purity lithium can be efficiently extracted.