Lithium Ion-Exchanged Zeolite Separator for Contaminant Removal
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Solution Overview
Problem
Lithium-ion batteries face degradation due to trace water, hydrogen ions, hydrofluoric acid, and polysulfides in the electrolyte, which lead to reduced cycle performance and capacity fade, as existing separators fail to effectively remove these contaminants without hindering lithium ion transport.
Innovation Solution
A porous separator with an active layer containing lithium ion-exchanged zeolite particles, which have a specific pore size and cation content, is used to selectively remove these contaminants while allowing lithium ion flow, thereby improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional separators are used, then lithium ion transport is maintained, but contaminants (trace water, hydrogen ions, hydrofluoric acid, polysulfides) are not effectively removed
Solution Approach 1:
The patent employs porous zeolite particles with specific pore sizes (0.3-1.0 nm) that allow selective transport of lithium ions while blocking larger contaminant molecules. The porous structure provides both ion conductivity and filtration capability, resolving the contradiction between maintaining lithium ion transport and removing contaminants.
Solution Approach 2:
The separator is constructed as a composite material combining conventional porous substrate (e.g., polyethylene or polypropylene) with lithium ion-exchanged zeolite particles. This composite structure integrates the mechanical strength and baseline ion transport of the substrate with the contaminant-trapping and selective ion transport properties of the zeolite layer.
2Reliability
If separator with contaminant removal capability is implemented, then cycle performance is improved, but manufacturing complexity increases
Solution Approach 1:
The zeolite particles are pre-synthesized and ion-exchanged with lithium ions before being incorporated into the separator structure. This preliminary preparation of the active material simplifies the overall manufacturing process by allowing modular assembly rather than requiring in-situ formation of the complex functional structure.
Solution Approach 2:
The patent optimizes specific parameters of the zeolite particles (pore size 0.3-1.0 nm, particle diameter 0.1-20 μm, lithium ion exchange capacity) to achieve the desired balance between contaminant removal and ion transport. By carefully controlling these parameters, the separator achieves high performance without requiring overly complex structural designs.
3Object-affected harmful factors
If zeolite particle pore size is reduced to trap contaminants, then contaminant removal improves, but lithium ion transport may be hindered
Solution Approach 1:
The patent identifies and optimizes the critical parameter of pore size, specifying a range of 0.3-1.0 nm that is small enough to trap contaminant molecules (water, HF, polysulfides) but large enough to allow efficient transport of lithium ions. This precise parameter control resolves the size-related transport-trapping contradiction.
Solution Approach 2:
The use of zeolite porous materials with well-defined pore structures enables size-selective transport. The uniform pore architecture provides predictable ion pathways that maintain high ion conductivity while the pore dimensions physically exclude larger contaminant species, achieving both trapping and transport functions simultaneously.
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 use of lithium ion-exchanged zeolite particles in the separator effectively traps trace water, hydrogen ions, and polysulfides, reducing corrosion and degradation, and enhancing cycle performance and Coulombic Efficiency of lithium-ion batteries.
Implementation Method 1
ion-exchanging precursor zeolite particles with Li+ ions to form lithium ion-exchanged zeolite particles
Implementation Method 2
The lithium ion-exchanged zeolite particles effectively traps trace water, hydrogen ions, and polysulfides
Implementation Method 3
The lithium ions travel from the negative electrode (anode) to the positive electrode (cathode), for example, through the ionically conductive electrolyte solution contained within the pores of an interposed porous separator
Implementation Method 4
The lithium ion-exchanged zeolite particles may have: (i) an average pore size diameter of less than or equal to about 1 nm; and (ii) an average particle diameter of less than or equal to about 20 μm
Data Source
AI summary
A porous separator for a lithium-containing electrochemical cell is provided herein. The porous separator includes a porous substrate and an active layer comprising lithium ion-exchanged zeolite particles. Methods of manufacturing the porous separator and lithium-containing electrochemical cells including the porous separator are also provided herein.