Alkaline Battery Sealing Unit Boss-Collar Ratio
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Solution Overview
Problem
Alkaline batteries with small negative electrode current collectors experience ineffective safety valve operation due to excessive pressure application, causing the collar part to be buried in the softened boss part, leading to inadequate breakage of the thin part and potential battery burst during short-circuit conditions.
Innovation Solution
Setting the ratio of the outer diameter of the boss part to the outer diameter of the collar part to 4.0 or smaller in the sealing unit of the alkaline battery, ensuring secure breakage of the safety valve even with a body diameter of the negative electrode current collector as small as 1.8 mm, thereby maintaining effective operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the body diameter of the negative electrode current collector is reduced to decrease cost, then the cost of the alkaline battery is reduced, but the safety valve operates ineffectively due to excessive pressure application causing the collar part to be buried in the softened boss part
Solution Approach 1:
The invention changes the geometric parameters of the sealing unit by specifying that the ratio of the outer diameter of the boss part to the outer diameter of the collar part should be 4.0 or smaller. This parameter change ensures that even with a reduced body diameter of the negative electrode current collector (1.8 mm or smaller), the collar part does not get buried in the softened boss part during short-circuit conditions, maintaining safety valve effectiveness while reducing cost
Solution Approach 2:
The invention applies preliminary anti-action by pre-configuring the boss part and collar part dimensions to prevent the burying phenomenon before it occurs. By setting the diameter ratio to 4.0 or smaller in advance, the design prevents excessive pressure application from causing the collar part to be buried in the softened boss part, ensuring the thin part can break effectively when needed
2Ease of manufacture
If the ratio of the outer diameter of the boss part to the outer diameter of the collar part is increased to allow smaller current collectors, then cost is reduced, but the distance between the negative electrode terminal plate and the annular part decreases leading to ineffective safety valve operation
Solution Approach 1:
The invention optimizes the ratio parameter between boss part outer diameter and collar part outer diameter, setting it to 4.0 or smaller. This parameter change maintains an appropriate distance between the negative electrode terminal plate and the annular part of the gasket, ensuring the thin part can break effectively while still allowing use of smaller current collectors for cost reduction
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
This configuration prevents excessive pressure application to the contact face between the boss and collar parts, ensuring the safety valve operates effectively by securing the distance between the negative electrode terminal plate and the annular part of the gasket, resulting in a low-cost and reliable alkaline battery.
Implementation Method 1
Upon abnormal rise in the internal pressure of the battery, the thin part 108 is broken to release gas generated in the battery outside the battery through a gas hole 109 formed in the negative electrode terminal plate 105, thereby preventing the battery from being burst
Implementation Method 2
the short-circuit current causes abrupt temperature rise of a battery itself to soften the gasket 107, which is made of resin, by the high temperature heat and to deform it by the pressure of gas generated inside the battery
Data Source
AI summary
An opening part of a battery casing is sealed by a sealing unit into which a negative electrode terminal plate, a negative electrode current collector joined to the negative electrode terminal plate, and a gasket are integrated. The gasket includes a boss part through which the negative electrode current collector passes, an outer peripheral part in contact with the opening part of the battery casing, and an annular part arranged between the boss part and the outer peripheral part, and a part of the annular part is formed into a thin part serving as a safety valve. The negative electrode current collector has a body diameter of 1.8 mm or smaller and includes at the end part thereof a collar part. The ratio of the outer diameter of the boss part to the outer diameter of the collar part is 4.0 or smaller.