Lithium Battery Electrode Double-Layer Protection Against Deformation
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Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high mass productivity and stability, particularly in the electrodes, which are critical for high energy density and capacity requirements.
Innovation Solution
The electrodes incorporate a double-layer protection layer structure comprising a first acrylate-based binder and a second rubber-based binder, applied on the current collector, to enhance stability and reduce deformation, thereby improving mass productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer protection layer is used, then the structure is simple and manufacturing is easier, but the electrode stability and resistance to deformation are insufficient
Solution Approach 1:
The protection layer is divided into two distinct layers: a first protection layer containing a first binder and a second protection layer containing a second binder. This segmentation allows each layer to perform specific functions, with the first layer providing initial protection and the second layer enhancing stability, thereby resolving the contradiction between structural simplicity and electrode reliability.
Solution Approach 2:
The patent employs composite binder materials where the first binder and second binder have different compositions and properties. This composite structure combines the advantages of different materials to achieve both ease of manufacture and superior electrode stability, addressing the technical contradiction effectively.
2Reliability
If the protection layer is made thicker to improve stability, then electrode stability improves, but the active material layer thickness is reduced and mass productivity decreases
Solution Approach 1:
The protection layer is designed with non-uniform thickness distribution, being thicker at the edges and thinner at the center. This local quality approach provides enhanced stability where it is most needed (at the edges prone to deformation) while maintaining sufficient active material layer thickness in the center, thus resolving the contradiction between stability and productivity.
Solution Approach 2:
The patent uses thin film protection layers with optimized thickness (1-10 μm) that provide sufficient mechanical support and stability without significantly reducing the active material layer thickness. This allows mass productivity to be maintained while achieving the required electrode stability.
3Reliability
If different binders are used in the first and second protection layers, then electrode stability and resistance to deformation are improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent optimizes the thickness parameters and material composition parameters of the two protection layers to achieve the desired deformation resistance. By carefully controlling these parameters, the manufacturing process remains manageable while obtaining significant improvements in electrode reliability and resistance to deformation.
Data Source
AI summary
Examples of the disclosure include an electrode for a rechargeable lithium battery, and a preparation method of the electrode. The electrode includes a current collector, an active material layer on the current collector, and a protection layer on the current collector and in contact with one side surface of the active material layer. The protection layer includes a first protection layer having a first binder on the current collector, and a second protection layer having a second binder on the first protection layer, and the first binder and the second binder may be different from each other.