Secondary Battery Safety Vent With Staged Rupture Pressure
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Solution Overview
Problem
Existing secondary batteries face challenges in managing internal pressure fluctuations during high-temperature exposure or high-current charging/discharging, leading to potential electrode assembly damage and thermal runaway due to simultaneous vent rupture.
Innovation Solution
The safety vent in the secondary battery is designed with multiple vent plates of varying thicknesses, areas, and notches, allowing for sequential rupture at different pressures, thereby controlling the release of internal gases and reducing pressure spikes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single vent plate is used in the safety vent, then the structure is simple and manufacturing is easy, but the internal pressure cannot be controlled during venting leading to thermal runaway risk
Solution Approach 1:
The safety vent is divided into multiple vent plates (first vent plate, second vent plate, third vent plate) with different rupture pressures. Each vent plate ruptures at a specific pressure threshold, creating a staged venting process that controls internal pressure release and prevents thermal runaway while maintaining reasonable structural complexity.
2Reliability
If multiple vent plates with different rupture pressures are used, then pressure control and safety are improved, but the manufacturing precision requirements increase
Solution Approach 1:
Each vent plate is designed with specific local characteristics including different thicknesses (first vent plate thicker than second, which is thicker than third) and different rupture pressures. The connection portions between vent plates and notches have controlled minimum thicknesses to ensure consistent rupture behavior. This local differentiation enables precise pressure control while managing manufacturing precision through clear design specifications.
3Reliability
If the vent plates have different thicknesses and areas, then the rupture pressures are differentiated for staged venting, but the device complexity increases
Solution Approach 1:
The venting function is segmented across three distinct vent plates with progressively different thicknesses and rupture pressures. The first vent plate (thickest) ruptures at highest pressure, the second at medium pressure, and the third (thinnest) at lowest pressure. This segmentation creates a controlled staged venting sequence that enhances safety while the modular plate design keeps the overall structure manageable.
4Manufacturing precision
If connection portions between vent plates and notches have varying minimum thicknesses, then the rupture pressure precision is improved, but the manufacturing complexity increases
Solution Approach 1:
The connection portions between each vent plate and adjacent notches are designed with specific minimum thickness requirements that vary by location. This local quality control ensures that each vent plate ruptures at its intended pressure threshold. The first notches connect to the case, second notches connect between vent plates, and third notches provide additional connection points, creating a controlled complexity in the connection structure that enables precise rupture pressure control.
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 minimizes the risk of thermal runaway by allowing controlled venting, reducing the likelihood of electrode assembly damage and ensuring safe operation under extreme conditions.
Implementation Method 1
each of the plurality of vent plates has a different rupture pressure
Implementation Method 2
The safety vent includes a plurality of vent plates, and each of the plurality of vent plates has a different rupture pressure
Data Source
AI summary
A secondary battery including an electrode assembly including a first electrode, a separator, and a second electrode, a case accommodating the electrode assembly, and a safety vent at a side of the case, the safety vent including a plurality of vent plates, and each of the plurality of vent plates having a different rupture pressure.