Battery Cell Vent Part Stress Concentration for Pressure Relief
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Solution Overview
Problem
Lithium secondary batteries, particularly pouch type batteries, are prone to explosion due to rapid increases in internal pressure and temperature from overcharge or short-circuit, leading to instability and potential accidents in battery packs, as existing solutions fail to effectively control the threshold pressure for safe gas discharge.
Innovation Solution
A battery cell design featuring a pouch form case with a sealing part and a vent part, where the vent part has a narrower bonding width than the sealing part, allowing stress concentration and controlled opening to prevent explosions by forming a predetermined region for gas discharge, thereby ensuring stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a safety plate is added to the battery cell to prevent explosion, then battery safety is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the safety function from a separate safety plate component and integrates it directly into the case structure through the vent part. The vent part is formed as an inherent feature of the case during the case forming process, eliminating the need for a separate safety plate component while maintaining the pressure relief function.
Solution Approach 2:
The patent merges the safety function with the case structure by forming the vent part as an integrated feature of the case. The vent part combines the structural role of the case with the safety function of pressure relief, eliminating the need for separate safety components and reducing overall device complexity.
2Reliability
If a separate safety component is added to control pressure release, then battery safety is improved, but productivity decreases due to additional manufacturing processes
Solution Approach 1:
The vent part is formed during the case forming process itself, before the battery assembly is completed. The pressure relief structure is prepared in advance as an inherent feature of the case, eliminating the need for separate safety component installation steps and improving manufacturing efficiency.
Solution Approach 2:
The case structure itself provides the safety function through the integrated vent part. The case serves dual purposes: containing the battery components and providing pressure relief when needed. This self-service approach eliminates the need for separate safety components and their associated manufacturing processes.
3Reliability
If the case is made fully sealed to maintain battery integrity, then battery reliability is improved, but the ability to release pressure safely is reduced
Solution Approach 1:
The patent applies local quality by creating a vent part with specific local characteristics (narrower bonding width) in a specific region of the case. The majority of the case maintains strong sealing for integrity, while the vent part has intentionally reduced bonding strength to enable controlled pressure release. This localized modification allows the case to simultaneously maintain overall integrity and provide safe pressure relief.
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 effectively prevents battery explosions by concentrating stress on the vent part, ensuring controlled pressure release and maintaining stability, even in conditions of rapid internal pressure or temperature increases, thus enhancing safety and productivity.
Implementation Method 1
the vent part having a bonding width narrower than that of the sealing part, and the bonding part bonding the first case and the second case to each other in a state in which the battery unit is received in the case
Data Source
AI summary
Provided are a battery cell and a battery module including the same. The battery cell is provided with a vent part, which is a predetermined region of a sealing part of a case having a width narrower than that of the other region thereof, thereby making it possible to easily discharge gas.