Battery Pack Cell Sealing Structure for Controlled Gas Release
Solution Overview
Problem
Conventional laminate cells are prone to series abnormalities due to random fractures in the sealing portion, which can lead to gas accumulation and increased temperature, causing adjacent cells to malfunction.
Innovation Solution
The battery pack design includes a module with cell pairs where the sealing portion is divided into regions, with a fracture promoting portion in the second region that is more likely to fracture under increased temperature or pressure, allowing gas to be issued safely and reducing the likelihood of series abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the sealing portion is made strong and uniform, then the exterior package maintains integrity, but gas accumulation can cause adjacent cells to heat up and malfunction
Solution Approach 1:
The sealing portion is divided into multiple regions with different fracture characteristics. The second region contains a fracture promoting portion that is intentionally designed to be weaker than other sealing regions, creating a predetermined fracture path that directs gas away from adjacent cells.
Solution Approach 2:
Different regions of the sealing portion are given different local properties. The first and third regions have normal sealing strength, while the second region has reduced strength due to the fracture promoting portion, creating localized weakness that serves a protective function.
2Ease of manufacture
If the sealing portion is made uniform throughout, then manufacturing is simpler, but fractures occur at random positions causing gas to accumulate between adjacent cells
Solution Approach 1:
The sealing portion incorporates a localized fracture promoting portion in the second region that has different properties from the rest of the sealing structure. This localized variation creates a predetermined fracture path that reliably directs gas away from adjacent cells during abnormal conditions.
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 effectively reduces the occurrence of series abnormalities in cells by safely releasing gas from the fracture promoting portion, thereby preventing gas accumulation and heat transfer to adjacent cells.
Implementation Method 1
when at least one of temperature and internal pressure of the first cell is increased
Implementation Method 2
internal pressure of the first cell is increased
Data Source
AI summary
A battery pack includes a module. The module includes one or more cell pairs. Each of the one or more cell pairs includes a first cell and a second cell. The first cell includes an exterior package, an electrode assembly, and an electrode terminal. The electrode terminal includes a first main surface and a second main surface. The first main surface is oriented in a direction of the second cell. A sealing portion is formed at a peripheral edge of the exterior package. The sealing portion includes a first region, a second region, and a third region. The first region is formed between the first main surface and the resin layer. The second region is formed between the second main surface and the resin layer. The third region is formed between portions of the resin layer. The second region includes a fracture promoting portion.