Button Cell Terminal Plate Structure for Short-Circuit Isolation
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Solution Overview
Problem
Ultra-small rechargeable batteries used in wearable devices are prone to short circuits, terminal damage, and explosion risks due to assembly errors, pressure, and unintended temperature and pressure increases.
Innovation Solution
A rechargeable battery design featuring an electrode assembly with a separator between electrodes, a case, a cap plate with a through-hole, and a terminal plate with a flange portion and protrusion that includes a curved and inclined surface, which are insulation-bonded using a thermal-fusion layer, to prevent short circuits, terminal damage, and explosions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the battery size is reduced to ultra-small dimensions for wearable devices, then the battery can be mounted on wearable devices, but short circuit between electrode terminals may occur due to assembly errors
Solution Approach 1:
The battery structure is segmented into distinct functional zones: the cap plate covers the outer area while the terminal plate with protrusion covers the central area through the through-hole. This segmentation ensures that even if assembly errors occur, the separated functional zones prevent short circuits between electrode terminals by maintaining proper spatial isolation of electrical components.
Solution Approach 2:
The protrusion acts as an intermediary element between the terminal plate and the electrode assembly. It extends through the through-hole to make controlled contact with the electrode terminal, ensuring proper electrical connection while preventing direct contact between opposing electrodes. This intermediary structure mitigates short circuit risks by controlling the interaction between electrical components.
2Strength
If pressure is applied to the battery, then the battery can withstand external forces, but damage to electrode terminal may occur
Solution Approach 1:
The curved surface on the protrusion serves as a pre-designed cushioning feature that absorbs and distributes applied pressure before it reaches the electrode terminal. This beforehand cushioning prevents concentrated stress that could damage the terminal, while still allowing the battery to withstand external forces. The curved geometry provides mechanical compliance to protect vulnerable components.
3Adaptability or versatility
If temperature and pressure increase inside the battery, then the battery can operate under varying conditions, but explosion risk may increase
Solution Approach 1:
The through-hole in the cap plate extracts the harmful function of pressure accumulation by providing a dedicated pathway for gas venting. When temperature and pressure increase inside the battery, gases can escape through the through-hole rather than accumulating to explosive levels. This extraction of the pressure management function separates the operating condition adaptability from the explosion hazard.
4Reliability
If the protrusion has a curved surface, then stress is dispersed to prevent terminal damage, but manufacturing complexity increases
Solution Approach 1:
The protrusion incorporates a curved surface that provides stress dispersion to protect the electrode terminal from damage. The curvature is integrated into the protrusion geometry in a way that can be manufactured using standard forming processes. The curved surface naturally distributes applied forces, reducing stress concentration points while maintaining manufacturability through conventional molding or machining techniques.
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 design effectively suppresses short circuits, terminal damage, and explosion risks by dispersing stress and providing a ventilation channel for gases, ensuring the battery's safety and reliability even under assembly errors and pressure increases.
Implementation Method 1
The thermal-fusion layer may melt at a predetermined temperature.
Data Source
AI summary
A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case configured to be connected to the first electrode to accommodate the electrode assembly, and including an opening to receive the electrode assembly; a cap plate configured to be coupled with the case to cover an outer area of the opening, and including a through-hole to expose a central area of the opening; and a terminal plate configured to be connected to the second electrode and to be insulation-bonded to the cap plate, and including a flange portion covering the through-hole, and a protrusion penetrating the through-hole from the flange portion.