Pouch Battery Sealing Structure for Impact and Leakage Resistance
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Solution Overview
Problem
Pouch-type secondary batteries are vulnerable to external impacts, which can cause electrode separation and electrolyte leakage, compromising safety, especially in applications like electric vehicles where high impact resistance is crucial.
Innovation Solution
The design incorporates a pouch-type battery case with strategically positioned sealing parts and a gas pocket to absorb impacts, optimizing the ratio of sealing area to electrode assembly weight and distance to prevent electrode displacement and electrolyte leakage, while maintaining energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If pouch-type battery case is used to achieve light weight and high energy density, then weight and energy density are improved, but impact resistance deteriorates
Solution Approach 1:
The patent introduces a gas pocket part between the cup part and the first sealing part that can deform upon external impact. This gas pocket acts as a cushioning element that absorbs impact energy before it reaches the electrode assembly, preventing electrode separation and electrolyte leakage while maintaining the lightweight pouch-type structure
2Reliability
If sealing area is increased to improve impact resistance, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by concentrating the sealing function in specific critical areas rather than uniformly increasing sealing area throughout. The first sealing part is positioned at the location most susceptible to impact damage, and its area is optimized based on the electrode assembly weight (A/B ratio), providing targeted protection without unnecessary complexity elsewhere
3Reliability
If distance between sealing part and electrode assembly is increased to prevent electrode separation, then reliability is improved, but volume increases
Solution Approach 1:
The patent optimizes the distance parameter between the first sealing part and the electrode assembly based on the electrode assembly weight (A/B ratio of 0.29-0.37). This parameter optimization ensures sufficient distance to prevent electrode separation during impact while minimizing the volume increase, achieving a balance between reliability and compactness
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 solution enhances the impact resistance of pouch-type secondary batteries, reducing the risk of damage, electrolyte leakage, and maintaining energy density within safe limits, thus improving safety without sacrificing performance.
Implementation Method 1
a gas pocket part disposed between the cup part and at least one of the pair of first sealing parts
Data Source
AI summary
Provided is a pouch secondary battery. The pouch-type secondary battery may include an electrode assembly and a pouch-type battery case. The pouch-type battery case may include a cup part configured to accommodate the electrode assembly, a pair of first sealing parts disposed at both sides of the cup part perpendicular to a length direction, and a second sealing part configured to connect the pair of first sealing parts to each other and disposed at one side of the cup part perpendicular to a width direction. When an area of the first sealing part is A mm2, and a weight of the electrode assembly is B g, a ratio A/B may be about 0.29 or more.