Rechargeable Battery Gasket Rivet Structure Infiltration Prevention
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Solution Overview
Problem
Rechargeable batteries face issues with electrolyte solution infiltration between the electrode terminal and cap plate, leading to electrical shorts and leakage, which compromises their performance and safety.
Innovation Solution
A rechargeable battery design featuring a gasket and rivet structure with specific flange configurations and cross-sectional area ratios to prevent electrolyte infiltration, including a gasket with through holes and flanges that enhance adhesion and increase the path length for electrolyte permeation, thereby reducing the risk of electrical shorts and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional gasket structure is used, then the battery structure is simple, but the electrolyte solution infiltrates between the electrode terminal and cap plate causing electrical shorts
Solution Approach 1:
The gasket is divided into multiple segments (first gasket, second gasket, third gasket) arranged in sequence around the rivet flange. Each gasket segment creates a separate barrier layer, forcing the electrolyte solution to traverse multiple interfaces and increasing the infiltration path length. This segmentation approach enhances reliability without requiring a single overly complex structure.
Solution Approach 2:
The gasket flange extends radially outward from the rivet flange in a direction perpendicular to the rivet axis, creating a multi-dimensional barrier structure. The gasket flange presents a lateral obstacle that the electrolyte solution must navigate around or through, adding a radial dimension to the infiltration path beyond the simple axial path in conventional designs.
2Reliability
If the gasket contacting area is increased to prevent infiltration, then the adhesion improves, but the cross-sectional area for current conduction may be reduced
Solution Approach 1:
The gasket structure exhibits local quality differentiation: the gasket flange provides a large contacting area (Ac ≥ 3*Ath) for strong adhesion to the rivet flange at the interface, while the through-hole maintains a sufficient cross-sectional area (Ath ≥ 1.2*Agb) for electrolyte conduction. Different regions of the gasket serve different functions - the flange for mechanical bonding and the through-hole for fluid passage.
Solution Approach 2:
Specific parameter relationships are established to balance adhesion and conduction: the contacting area Ac is required to be at least 3 times the through-hole area Ath, while the through-hole area Ath is required to be at least 1.2 times the gasket flange cross-sectional area Agb. These parameter changes ensure both strong mechanical bonding and adequate electrolyte flow paths.
3Reliability
If multiple gasket flange parts are used to extend the infiltration path, then the leakage prevention improves, but the manufacturing complexity increases
Solution Approach 1:
Multiple functional elements are merged into a single integrated gasket component: the first, second, and third gaskets are formed as one piece with integrated flanges and through-holes. This merging approach achieves the leakage prevention benefits of multiple barriers while avoiding the assembly complexity of separate components, as the entire multi-layer barrier is installed as a single unit.
Solution Approach 2:
The single gasket component performs multiple functions simultaneously: it provides mechanical adhesion through the gasket flange, creates multiple infiltration barriers through sequential gasket layers, maintains electrolyte flow paths through the through-hole, and positions the rivet assembly through the central opening. This multi-functionality reduces the number of separate parts needed.
Data Source
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AI summary
A rechargeable battery includes: an electrode assembly in a case; a cap plate coupled to an opening of the case; a rivet electrically connected to the electrode assembly, the rivet including: a first rivet flange; and a second rivet flange; and a gasket between the rivet flange and the cap plate, the gasket including: a first gasket flange configured to be coupled with the first rivet flange; and a second gasket flange configured to be coupled with the second rivet flange.