Multilayer Dry Electrode Prelithiation via Segmented Layers
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Solution Overview
Problem
Existing methods for prelithiation in lithium ion batteries face challenges such as non-uniform dispersion of lithium metal, adhesion issues during calendering, and reduced electrochemical utilization due to direct mixing of lithium with active materials, leading to inefficiencies and performance losses.
Innovation Solution
The introduction of a prelithiating layer laminated onto a dry free-standing active layer in multilayer dry electrode films, using materials like lithium foil, stabilized lithium metal powder (SLMP), or lithium-doped silicon oxide, allows for controlled prelithiation without mixing lithium with active materials, enhancing uniformity and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lithium metal is directly mixed with active materials for prelithiation, then the prelithiation process is simple, but non-uniform dispersion occurs and electrochemical utilization is reduced
Solution Approach 1:
The patent introduces a binder as an intermediary substance between lithium metal particles and active materials. The binder uniformly distributes lithium particles throughout the electrode structure, preventing direct contact between lithium and active materials while ensuring controlled lithium release. This resolves the dispersion uniformity issue without complicating the manufacturing process.
Solution Approach 2:
The patent segments the electrode into distinct functional layers: a prelithiation layer containing lithium particles embedded in binder, and an active material layer. This segmentation allows uniform lithium distribution within the prelithiation layer while preventing direct mixing with active materials, thereby maintaining both manufacturing simplicity and dispersion uniformity.
2Ease of manufacture
If lithium is directly mixed with active materials, then the fabrication process is straightforward, but adhesion issues occur during calendering
Solution Approach 1:
The binder serves as a mediating substance that provides adhesion between lithium particles, active materials, and the current collector during calendering. This intermediary layer prevents direct contact between lithium and active materials, eliminating adhesion issues while maintaining fabrication process simplicity.
3Device complexity
If lithium is directly mixed with active materials, then the electrode structure is simple, but electrochemical utilization is reduced due to direct contact
Solution Approach 1:
The patent divides the electrode into functionally distinct layers: a prelithiation layer with lithium particles in binder, and an active material layer. This segmentation prevents direct contact between lithium and active materials, improving electrochemical utilization by controlling lithium release, while adding only minimal structural complexity.
Solution Approach 2:
The binder acts as an intermediary that physically separates lithium particles from active materials while enabling controlled lithium release. This intermediary layer prevents premature direct contact that would reduce electrochemical utilization, while maintaining relatively simple electrode structure.
4Manufacturing precision
If a prelithiating layer is laminated onto dry free-standing active layer, then uniformity and performance are enhanced, but the manufacturing process becomes more complex
Solution Approach 1:
The patent combines the prelithiation function and active material function into a single integrated dry electrode structure with distinct layers. The binder matrix unifies lithium particles and active materials into a cohesive structure, achieving uniform lithium distribution without excessive structural complexity.
Data Source
AI summary
Provided herein are multilayer dry films for electrode film fabrication, and electrode films, electrodes, and energy storage devices that implement the multilayer dry films. The multilayer dry film for electrode film fabrication comprises a dry free-standing active layer comprising a first dry active material and a first dry binder, and a dry prelithiating layer comprising lithium, such that the first dry free-standing active layer and the dry prelithiating layer are laminated to each other to form a free-standing multilayer dry film.