Sealed Current Interruption Device for Battery Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional current interruption devices in electricity storage systems, such as lithium ion batteries, face reliability issues due to contact portion deterioration within the electrolytic atmosphere, which can lead to reduced safety and operational difficulties during overcharging.
Innovation Solution
A current interruption device is designed with a sealed structure where the deforming plate inverts due to pressure differences, isolating contact portions from the electrolyte and external air, preventing deterioration and ensuring stable operation by maintaining a constant pressure difference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact portion is exposed to the electrolytic atmosphere to enable current flow, then electrical connectivity is achieved, but the contact portion deteriorates due to electrolyte exposure
Solution Approach 1:
A sealing plate is introduced as an intermediary component between the contact portion and the electrolyte. The sealing plate includes a sealing portion that contacts the inner wall of the current passage to seal the space, and a pressing portion that presses the deforming plate. This intermediary structure prevents direct contact between the electrolyte and the contact portion, thereby preventing deterioration while maintaining electrical connectivity.
Solution Approach 2:
The invention creates an inert environment by sealing the contact portion from the electrolytic atmosphere. The sealing plate forms a barrier that isolates the contact portion from the harmful electrolyte environment, effectively creating a protected zone where the contact portion can operate without exposure to deteriorating factors.
2Reliability
If the deforming plate is made to invert upon pressure increase to interrupt current, then safety is improved, but operational reliability may be reduced due to contact portion deterioration
Solution Approach 1:
The sealing plate serves as a mediator that protects the contact portion from electrolyte exposure while allowing the deforming plate to maintain its pressure-responsive inversion function. The sealing structure ensures that the contact portion remains intact and reliable throughout the operational lifecycle, including during pressure-induced inversion events.
Solution Approach 2:
The current passage is segmented into distinct functional zones: a sealed zone containing the contact portion protected from electrolyte, and an exposed zone where the deforming plate responds to pressure changes. This segmentation allows each component to perform its function optimally without interference from harmful environmental factors.
3Reliability
If the contact portion is isolated from electrolyte to prevent deterioration, then reliability is improved, but electrical connectivity may be compromised
Solution Approach 1:
The sealing plate acts as a mediator that simultaneously achieves isolation and connectivity. It seals the contact portion from electrolyte while maintaining the electrical pathway through the deforming plate and sealing structure, ensuring both durability and operational functionality.
Solution Approach 2:
The deforming plate functions as a flexible conductive element that maintains electrical connectivity while allowing for pressure-induced deformation. Its flexibility enables it to invert upon pressure increase to interrupt current, while its conductive nature ensures continuous electrical pathway when in the normal state.
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 solution effectively prevents contact portion deterioration and ensures reliable current interruption, enhancing safety and operational stability by maintaining a constant pressure difference and isolating the contact points from the electrolyte and hydrogen gas generation within the battery.
Implementation Method 1
When an internal pressure of the casing is increased, a deforming plate is inverted by a pressure difference between the inside of the current interruption device and the outside of the current interruption device
Data Source
AI summary
A current interruption device includes a deforming plate, a contact plate and a conducting plate which configure a current path. The deforming plate includes one surface on an opposite side from the contact plate facing a first space, a pressure of which is retained to a same pressure as the internal pressure of the casing and the other surface opposed to the contact plate facing a second space, a pressure of which is retained to a same pressure as an external pressure of the casing. When the internal pressure rises above the predetermined level, the second contact portion is separated from the conducting plate by deformation of the deforming plate toward the contacting plate.