Lithium-Sulfur Battery Polysulfide Confining Layer
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Solution Overview
Problem
Lithium-sulfur batteries face durability issues due to polysulfide loss during charge and discharge reactions, with existing solutions either causing electrical conduction deterioration, being costly, or requiring complex and costly nanostructure formation processes.
Innovation Solution
A porous hydrophilic membrane polysulfide confining layer is interposed between the positive electrode and separator to prevent polysulfide loss, utilizing a perforated structure that allows effective dispersion of materials during reactions and forming an electric barrier to confine lithium polysulfide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If adhesive materials (active carbon fiber, transition metal chalcogenide, alumina, silica) are added to the positive electrode to delay polysulfide outflow, then polysulfide loss is reduced, but electrical conduction deteriorates and side reactions occur
Solution Approach 1:
The invention divides the battery structure into distinct functional layers: a positive electrode layer and a separate polysulfide confining layer. This segmentation allows the confining layer to specifically address polysulfide retention without compromising the electrical conduction properties of the positive electrode, as the confining layer uses lithium hydroxide particles that maintain good electrical contact while physically confining polysulfides.
Solution Approach 2:
The polysulfide confining layer acts as an intermediary between the positive electrode and the electrolyte/negative electrode. It uses lithium hydroxide particles to adsorb and confine polysulfides, preventing them from migrating to the negative electrode while maintaining electrical conductivity through the use of conductive agents and proper particle size selection.
2Loss of substance
If surface treatment with coating materials (hydroxide, oxyhydroxide, oxycarbonate, hydroxycarbonate) is applied to sulfur, then polysulfide loss is reduced, but sulfur is lost during treatment and cost increases
Solution Approach 1:
Instead of treating the sulfur surface directly, the invention segments the functional requirements by creating a separate polysulfide confining layer containing lithium hydroxide particles. This layer is applied after sulfur synthesis, preserving the full sulfur content while providing polysulfide confinement through the confining layer's adsorption capacity.
3Loss of substance
If carbon material is formed into nanostructures to confine lithium polysulfide, then polysulfide loss is reduced, but manufacturing complexity increases, cost increases, and volume loss occurs
Solution Approach 1:
The invention uses a polysulfide confining layer containing lithium hydroxide particles with specific pore structures and surface properties to confine polysulfides. This approach avoids the need for complex carbon nanostructure formation processes, reducing manufacturing complexity while maintaining effective polysulfide confinement through the porous confining layer structure.
Solution Approach 2:
The invention changes the material parameter from carbon-based nanostructures to lithium hydroxide-based particles with specific size ranges (0.1-10 μm) and pore structures. This parameter change simplifies the manufacturing process while achieving effective polysulfide confinement through controlled particle morphology and surface chemistry.
4Reliability
If conventional methods are used to prevent polysulfide loss, then durability is improved, but cost increases significantly
Solution Approach 1:
The invention uses inexpensive lithium hydroxide particles as the primary confining material in the polysulfide confining layer. These particles provide effective polysulfide retention without requiring expensive materials or complex manufacturing processes, achieving cost-effective battery durability improvement.
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
This approach minimizes polysulfide loss, enhances sulfur utilization, and improves battery durability and safety by preventing polysulfide reaction with the lithium metal negative electrode, thus delaying capacity loss and maintaining reaction activity.
Implementation Method 1
a porous hydrophilic membrane is interposed between a positive electrode and a separator to prevent a polysulfide-based material from being lost from the surface of the positive electrode
Implementation Method 2
a porous hydrophilic membrane polysulfide confining layer is interposed between the positive electrode and separator to prevent polysulfide loss
Data Source
AI summary
The present invention provides a lithium-sulfur battery with a polysulfide confining layer, which can prevent loss of polysulfide formed on the surface of a positive electrode during charge and discharge reactions, thus improving the durability of the battery. For this purpose, the present invention provides a lithium-sulfur battery including a hydrophilic polysulfide confining layer interposed between a positive electrode and a separator to prevent a polysulfide-based material from being lost from the surface of the positive electrode during discharge.