Sealed Battery Rough Surface Sealing Plug Leakage Prevention
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Solution Overview
Problem
Sealed batteries face liquid leakage issues due to degradation of resin-based sealing members, which can lead to gaps between the sealing plug, sealing member, and battery case, especially under high temperature conditions.
Innovation Solution
A sealed battery design featuring a battery case and sealing plug with a rough surface area (arithmetic average roughness Sa ≥ 1 μm) to enhance friction force between the sealing member and the case/plug, preventing deformation and subsequent liquid leakage, even when the sealing member degrades.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resin sealing member is used between the sealing plug and battery case, then liquid leakage is inhibited through pressure rebound coverage of microscopic gaps, but the sealing member degrades under high temperature and aging conditions causing gap formation and liquid leakage
Solution Approach 1:
The patent replaces the resin-based mechanical sealing system with a metal sealing plug that utilizes friction-based mechanical interlocking. The rough surface area (Sa ≥ 1 μm) on the sealing plug creates high friction force with the sealing member, preventing relative movement and maintaining sealing pressure without relying on resin elasticity that degrades over time.
Solution Approach 2:
The patent changes the surface roughness parameter of the sealing plug to have an arithmetic average roughness Sa of 1 μm or more. This parameter change creates increased surface friction that prevents the sealing member from degrading and forming gaps, thereby extending the sealing system's service life under high temperature conditions.
2Ease of manufacture
If a smooth surface is used for the sealing plug and battery case, then manufacturing is easier, but the sealing member deforms outward in the diameter direction when degraded, generating gaps and causing liquid leakage
Solution Approach 1:
The patent applies local quality by creating a rough surface area (Sa ≥ 1 μm) specifically on the portion of the sealing plug that contacts the sealing member. This localized surface treatment provides high friction force exactly where needed to prevent sealing member deformation, while not complicating the overall manufacturing process.
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 rough surface area effectively inhibits electrolyte leakage by regulating the deformation of the sealing member, maintaining the sealing structure's integrity and preventing liquid leakage, while being easily applicable to fine parts and enhancing manufacturing efficiency.
Implementation Method 1
a surface of a battery case and/or an opposed surface of a sealing plug includes a rough surface area on at least a part of a portion contacting with a sealing member, and an arithmetic average roughness Sa of a rough surface area is equal to or more than 1 μm
Data Source
AI summary
The herein-disclosed sealed battery includes a sealing plate, a sealing plug comprising a flange part opposed to an outer surface of the sealing plate, and a sealing member disposed between the sealing plate and the flange part of the sealing plug. Then, regarding the herein-disclosed sealed battery, the outer surface of the sealing plate and an opposed surface of the flange part include a rough surface area R on at least a part of a portion contacting with the sealing member and an arithmetic average roughness Sa of the rough surface area is equal to or more than 1 μm. By doing this, it is possible to suppress a liquid leakage of an electrolyte.