Pouch Battery Cell Rupture Induction for Pressure Relief
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Solution Overview
Problem
Pouch-shaped battery cells lack reliable safety mechanisms to prevent thermal runaway, which can lead to fires or explosions due to their thin and soft case structure, and there is a need to easily distinguish between the front and rear surfaces during manufacturing.
Innovation Solution
Incorporating a rupture induction portion within the cell case that can induce a controlled rupture when pressure increases, using a nonconductive resin and metal core, and strategically placing these portions between the electrode assembly and the case surfaces to facilitate rapid case rupture and surface differentiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a pouch-shaped battery cell uses a thin and soft case structure, then the battery cell achieves compactness and flexibility, but the safety mechanism becomes unreliable and cannot prevent thermal runaway
Solution Approach 1:
The case is segmented into a main case body and a separate rupture induction portion. The rupture induction portion is specifically designed with lower mechanical strength to rupture first under pressure, segmenting the safety function from the structural function of the main case.
Solution Approach 2:
Different parts of the case have different mechanical properties. The rupture induction portion has locally reduced strength compared to the main case body, allowing it to rupture preferentially under pressure while the main case maintains its structural integrity.
2Ease of manufacture
If the battery case is made with uniform structure, then manufacturing is simplified, but the front and rear surfaces cannot be easily distinguished during assembly
Solution Approach 1:
The rupture induction portion is placed asymmetrically on the case, creating a physical difference between the front and rear surfaces. This asymmetric feature allows workers to easily identify the front surface during assembly without complicating the manufacturing process.
3Strength
If pressure builds up inside the battery cell during thermal runaway, then the case remains intact initially, but secondary accidents like fire or explosion occur
Solution Approach 1:
The rupture induction portion is pre-designed to rupture at a specific pressure threshold before thermal runaway can cause catastrophic failure. This preliminary action releases pressure and prevents the conditions necessary for fire or explosion.
Solution Approach 2:
The potential harm of case rupture is converted into a benefit by designing a controlled rupture mechanism. The rupture induction portion intentionally fails under pressure to release harmful gases and prevent uncontrolled thermal runaway, transforming a potential safety hazard into a safety feature.
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 safety by preventing secondary accidents like fires or explosions by inducing rapid case rupture and improves manufacturing efficiency by allowing easy identification of the front and rear surfaces through distinct disposition structures.
Implementation Method 1
a rupture induction portion configured to induce rupture of the cell case when pressure in the cell case increases
Data Source
AI summary
The present invention relates to a pouch-shaped battery cell with improved safety, and more particularly to a pouch-shaped battery cell including an electrode assembly, a cell case constituted by an upper case and a lower case configured to define a space portion configured to receive the electrode assembly, and a rupture induction portion. The electrode assembly including a negative electrode, a separator, and a positive electrode. Whereby the rapture induction portion is configured to induce rupture of the cell case when the pressure in the cell case increases is provided in the space portion of the cell case.