Battery Electrode Tap Fracture Structure for Rapid Current Cutoff
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Solution Overview
Problem
Existing fuse devices in secondary batteries, such as PTC thermistors and TCOs, fail to promptly cut off current flow in response to abnormal conditions like internal pressure increases, leading to potential safety issues like fire or explosion, especially in high-output battery packs used in vehicles.
Innovation Solution
A battery design featuring a vulnerable portion on the electrode tap with a reduced cross-sectional area, coupled to a current collector, which fractures under increased internal pressure or temperature, along with a cap that ruptures to relieve pressure and a pressurizing member to accelerate fracture, ensuring rapid current cutoff.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PTC thermistors or TCOs are used as fuse devices, then current can be blocked when temperature rises due to overcharge, but the resistance increases as they are repeatedly operated, thereby increasing the overall resistance of the circuit
Solution Approach 1:
The patent extracts the fuse function from traditional PTC/TCO devices and implements it through a mechanical fracture mechanism of the electrode tap. The electrode tap includes a vulnerable portion that fractures under excessive force or temperature, cutting off current flow without relying on resistance changes, thereby eliminating the energy loss issue while maintaining current blocking capability.
2Reliability
If PTC thermistors or TCOs are used, then current blocking occurs when temperature rises, but they cannot block overcurrent immediately after the occurrence of a cause that may increase the temperature
Solution Approach 1:
The patent applies preliminary action by pre-positioning the vulnerable portion at a specific location on the electrode tap where stress concentration occurs first during abnormal conditions. This pre-designed weak point ensures that the electrode tap fractures at the vulnerable portion before the temperature rises to dangerous levels, enabling immediate current cutoff upon detection of abnormal force or temperature conditions.
3Reliability
If traditional fuse devices are used in high-output battery packs, then they operate depending on temperature, but they may operate too early when disposed in high-temperature environments
Solution Approach 1:
The patent applies local quality by creating a vulnerable portion with specifically reduced cross-sectional area at a localized position on the electrode tap. This localized weak point has lower fracture strength compared to other parts, ensuring it fractures first under abnormal conditions. The vulnerable portion's dimensions are carefully designed to be weaker than the electrode tap but stronger than the separator, enabling reliable current cutoff without premature operation in high-temperature environments while maintaining high output capability.
4Loss of time
If a vulnerable portion with reduced cross-sectional area is created on the electrode tap, then current can be quickly cut off when the vulnerable portion fractures, but the electrode tap becomes a potential weak point
Solution Approach 1:
The vulnerable portion is designed with locally reduced cross-sectional area to create a controlled weak point that fractures first under abnormal conditions. The dimensions are carefully optimized so that the vulnerable portion is weaker than the electrode tap but stronger than the separator, ensuring it serves as the intended failure point without compromising the overall structural integrity during normal operation. This localized weakness enables rapid current cutoff while maintaining sufficient strength for normal battery 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
The design enables quick and reliable disconnection of the current path in response to abnormal conditions, preventing thermal events and enhancing safety in high-output battery applications.
Implementation Method 1
a vulnerable portion formed on an electrode tap... configured such that a cross-sectional area of the electrode tap is partially reduced... fractures under increased internal pressure or temperature
Implementation Method 2
a pressurizing member disposed between the current collector and the electrode assembly, and configured to be deformed in its shape toward a core of the electrode assembly according to an increase in internal temperature of the battery, thereby pressurizing the vulnerable portion
Data Source
Figure 1
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AI summary
A battery according to an embodiment of the present disclosure may include: an electrode assembly comprising an electrode tap having a vulnerable portion formed thereon; a battery housing configured to receive the electrode assembly through an opening formed on one side thereof; a current collector comprising a tap coupling portion electrically coupled to the electrode tap and a housing coupling portion electrically coupled to the battery housing; and a cap configured to cover the opening.