Electrolyte-Responsive Battery Sealing Tape for Stable Electrode Fixing
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Solution Overview
Problem
The existing sealing tapes for lithium batteries fail to securely attach the electrode assembly to the battery case due to adhesive strength deterioration and shrinkage when exposed to electrolyte solutions, leading to increased internal resistance and potential damage from external vibrations.
Innovation Solution
A double-sided adhesive sealing tape with a (meth)acrylic copolymer and crosslinking agent, which expands in response to electrolyte solutions, ensuring secure attachment to both internal and external gaps between the electrode assembly and the battery case, preventing detachment and maintaining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing tape is placed in the gap between the inner wall of the battery case and the electrode assembly to fix the electrode assembly, then the electrode assembly can be secured against movement, but the adhesive strength of the sealing tape deteriorates or it shrinks through reaction with the electrolyte solution, causing detachment
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive layer by incorporating specific compounds: a carboxylic acid compound (proton donor), a basic compound (proton acceptor), and a hydroxyl group-containing compound. These compositional changes enable the adhesive to maintain strength through chemical interactions with the electrolyte solution rather than suffering deterioration.
Solution Approach 2:
The patent creates a composite adhesive system by combining multiple functional compounds: carboxylic acid compound, basic compound, and hydroxyl group-containing compound. This composite material approach allows the adhesive layer to exhibit multiple functions simultaneously: initial adhesion, chemical reaction with electrolyte to prevent deterioration, and shrinkage to maintain gap sealing.
2Ease of operation
If the electrode assembly is housed in the battery case with a predetermined gap, then the electrode assembly can be properly positioned, but the gap allows the electrode assembly to rotate or move due to external vibration or impact, increasing internal resistance and causing damage
Solution Approach 1:
The patent applies local quality by placing the sealing tape specifically in the gap region between the battery case inner wall and the electrode assembly. The adhesive layer is positioned locally where needed to provide securing function, while the rest of the battery structure maintains its original design for ease of assembly.
Solution Approach 2:
The sealing tape acts as an intermediary element between the battery case and the electrode assembly. It mediates the connection by adhering to both surfaces and providing the securing function, allowing the gap to remain for proper positioning while preventing harmful movement through the tape's adhesive and shrinking actions.
3Strength
If a conventional sealing tape is used to secure the electrode assembly, then initial adhesion is achieved, but the adhesive strength deteriorates or the tape shrinks when exposed to electrolyte solution, leading to detachment
Solution Approach 1:
The patent implements preliminary action by having the adhesive layer react with the electrolyte solution before detachment can occur. The carboxylic acid compound and basic compound are pre-positioned in the adhesive layer to chemically interact with the electrolyte, creating a protective effect that prevents adhesive deterioration and maintains strength over time.
Solution Approach 2:
The patent converts the harmful effect of electrolyte solution exposure (which normally causes adhesive deterioration) into a beneficial effect. The electrolyte solution triggers the chemical reaction between the carboxylic acid compound and basic compound in the adhesive, causing controlled shrinkage that enhances the sealing and securing functions while preventing detachment.
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 solution effectively reduces the risk of electrode assembly detachment, maintains battery performance, and suppresses internal resistance increases, ensuring reliable operation.
Implementation Method 1
a double-sided adhesive sealing tape with a (meth)acrylic copolymer and crosslinking agent, which expands in response to electrolyte solutions
Implementation Method 2
an adhesive layer having adhesiveness on both surfaces of the adhesive layer
Data Source
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AI summary
A sealing tape for a rechargeable lithium battery and a rechargeable lithium battery including the sealing tape are provided. The sealing tape for a rechargeable lithium battery includes a single-layer adhesive layer having adhesiveness on both opposite surfaces of the adhesive layer, wherein the adhesive layer includes a (meth)acrylic copolymer and a crosslinking agent, and the (meth)acrylic copolymer includes a moiety derived from a first substituted or unsubstituted C1 to C20 alkyl (meth)acrylate-based compound; a moiety derived from a second substituted or unsubstituted C3 to C20 cycloalkyl (meth)acrylate-based compound; a moiety derived from a third hydroxy group-containing compound; and a moiety derived from a fourth unsaturated morpholine-containing compound.