Battery Cell Vent Portion for Controlled Internal Pressure Release
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Solution Overview
Problem
Lithium secondary batteries experience swelling and pressure increases during charging and discharging, leading to potential explosions or fires, necessitating effective internal pressure control measures.
Innovation Solution
A battery cell design featuring a vent portion with a lower hardness than the rest of the case, including a notch portion recessed in the case surface, which is formed through heat treatment or laser etching, allowing controlled pressure release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the case is made with high strength and uniform hardness throughout, then the structural integrity and strength is improved, but the ability to control internal pressure and prevent swelling damage deteriorates
Solution Approach 1:
The case is designed with a vent portion that has different hardness characteristics from the rest of the case body. Specifically, the vent portion has lower hardness than the surrounding regions, creating a localized weak point that preferentially deforms or breaks under excessive internal pressure. This allows the majority of the case to maintain high strength while the specific vent area provides pressure relief functionality.
2Reliability
If a vent portion with lower hardness is introduced, then the pressure control and safety is improved, but the structural uniformity and manufacturing complexity deteriorates
Solution Approach 1:
The hardness parameter of the case material is changed locally in the vent portion to create a functional gradient. By modifying the hardness parameter in this specific region (making it lower than surrounding areas), the case gains pressure relief capability without fundamentally changing the overall structure or requiring complex multi-component assemblies.
3Reliability
If the vent portion is designed to break at low pressure, then the internal pressure adjustment capability is improved, but the overall strength and damage resistance deteriorates
Solution Approach 1:
The case is segmented into functionally distinct regions: a strong case body for structural support and a weaker vent portion for pressure relief. This segmentation allows each region to be optimized for its specific function - the case body maintains high strength for damage resistance, while the vent portion is designed with lower hardness to break at controlled low pressure, preventing catastrophic failure of the entire battery structure.
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 provides enhanced stability by adjusting internal pressure, preventing explosions and minimizing damage by disconnecting the electrode terminal when the vent portion breaks, thus maintaining safety.
Implementation Method 1
The vent portion may be formed by performing heat treatment on an area of the case
Implementation Method 2
The vent portion may include a notch portion recessed from an outer surface of the case toward an inside of the case
Data Source
AI summary
The present disclosure relates to a battery cell and manufacturing method thereof. The battery cell according to an embodiment of the present disclosure includes a case receiving an electrode assembly, and an electrode terminal electrically connected to the electrode assembly, wherein the case includes a vent portion having a lower hardness than other regions of the case.