Secondary Battery Case Vent Structure for Pressure Relief
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Solution Overview
Problem
Secondary batteries are prone to abnormal conditions such as gas generation and explosions due to internal pressure increases, necessitating improved stability and safety features.
Innovation Solution
A secondary battery design with a vent formed at a thinner portion of the case that opens in response to internal pressure or temperature thresholds, allowing gas release without additional components, and terminals positioned at opposite side-surfaces for improved insulation and space efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vent is formed by adding a separate component, then the gas release function is reliable, but the device complexity and manufacturing cost increase
Solution Approach 1:
The vent function is merged with the case structure by forming a localized thin portion directly on the case surface. This eliminates the need for separate vent components while maintaining the gas release function, thereby reducing device complexity and manufacturing cost without compromising reliability
Solution Approach 2:
The case structure itself provides the venting function through its thin portion that automatically opens under pressure. The case serves dual purposes: containing the electrolyte solution and providing a pressure-responsive venting mechanism, eliminating the need for external venting components
2Reliability
If the case thickness is reduced to form a vent, then the gas release function is activated, but the structural strength decreases
Solution Approach 1:
The case exhibits non-uniform thickness with a localized thin portion specifically positioned to serve as the vent. The majority of the case maintains its original thickness for structural strength, while only the specific vent region has reduced thickness to enable pressure-responsive opening
Solution Approach 2:
The thickness parameter of the case is selectively modified in the vent region to create a pressure-sensitive structure. The thin portion is designed with specific dimensional parameters that allow it to deform and open at predetermined pressure thresholds while the rest of the case retains sufficient strength
3Reliability
If terminals are positioned at opposite side-surfaces, then the insulation performance is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The terminals are positioned asymmetrically at opposite side-surfaces of the case rather than at adjacent surfaces. This asymmetric placement maximizes the insulation distance between terminals, improving electrical isolation performance while the case structure provides natural positioning references
4Speed
If the vent thickness is reduced, then the opening response to pressure is faster, but the manufacturing precision requirements increase
Solution Approach 1:
The vent thickness parameter is optimized to balance opening speed and manufacturability. The thin portion has controlled dimensions that enable rapid pressure-responsive opening while remaining within achievable manufacturing tolerances through conventional forming processes
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 enhances safety by preventing explosions and efficiently releasing gases while simplifying manufacturing and reducing costs by eliminating extra components.
Implementation Method 1
the vent may be configured to be opened in response to an internal pressure of the case exceeding a threshold pressure
Data Source
AI summary
A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case accommodating the electrode assembly, and including an open first side-surface and an open second side-surface that are opposite to each other; and a vent at a surface of the case. A thickness of the vent is smaller than a thickness of a portion of the surface of the case without the vent.