Button Cell Side-Welded Cap Structure for Short-Circuit Isolation
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Solution Overview
Problem
Conventional button cells face challenges in preventing short circuits between the cap plate and terminal plate due to the positioning of the welded portion, which makes it difficult to overlap the bonding layer effectively, leading to potential delamination and interference during the welding process.
Innovation Solution
The button cell design incorporates a side welded portion between the case and cap plate, with a bonding layer positioned between the cap plate and terminal plate, and includes welding grooves to prevent damage to the bonding layer, ensuring the side welded portion does not directly contact it, thus preventing short circuits and facilitating easy welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the welded portion is positioned at the upper portion of the button cell, then the case and cap plate can be connected, but the bonding layer cannot effectively overlap the welded portion, leading to potential short circuits
Solution Approach 1:
The welded portion is repositioned from the upper portion (vertical dimension) to the side portion (horizontal dimension) of the button cell. This dimensional change allows the bonding layer to be applied on the cap plate without interfering with the welded portion, as they are now separated in different spatial dimensions. The side welding configuration enables the bonding layer to overlap the cap plate surface effectively while maintaining electrical insulation between the cap plate and terminal plate.
2Strength
If the welded portion is positioned at the upper portion, then connection is achieved, but delamination of the bonding layer occurs due to interference from the welded portion
Solution Approach 1:
The button cell structure is segmented into distinct functional zones: the welded portion is separated and positioned at the side, while the bonding layer is applied on the upper surface of the cap plate. This spatial segmentation prevents the welded portion from interfering with the bonding layer adhesion, eliminating the delamination problem. The welding process and bonding process can be independently optimized without mutual interference.
3Reliability
If the welded portion is repositioned to the side, then short circuit prevention is improved, but welding interference may increase
Solution Approach 1:
The cap plate serves as an intermediary element that facilitates side welding between the case and itself. By positioning the welded portion at the side of the cap plate, the welding process is separated from the bonding layer application area. This intermediary configuration allows the welding to proceed without directly interfering with the bonding layer, while still achieving the electrical insulation function.
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 design effectively prevents short circuits and enhances structural stability by ensuring the bonding layer does not contact the side welded portion, allowing for reliable operation and easy welding between the case and cap plate, while suppressing interference from the side welded portion.
Implementation Method 1
a bonding layer between the cap plate and the terminal plate and insulatively bonding between the cap plate and the terminal plate
Implementation Method 2
a side welded portion between the step portion of the cap plate and the sidewall of the case
Data Source
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AI summary
A button cell includes an electrode assembly, a case including an opening exposing the electrode assembly, a cap plate coupled to the case to cover an outer region of the opening and including a through hole exposing a central region of the opening, and a step portion recessed to correspond to a sidewall of the case and in which the sidewall of the case is inserted, a terminal plate connected to the second electrode tab, insulatively bonded to the cap plate, and covering the through hole, a bonding layer between the cap plate and the terminal plate and insulatively bonding between the cap plate and the terminal plate, and a side welded portion between the step portion of the cap plate and the sidewall of the case.