Pouch Battery Seal Insulation with Curable Resin
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Solution Overview
Problem
Pouch-shaped batteries face challenges with moisture permeation and electrolyte leakage due to contamination of thermally welded portions and insulation breakdown, especially during charge and discharge cycles, and existing solutions like UV curable agents are difficult to apply effectively.
Innovation Solution
A method involving perpendicularly bending sealed portions and mounting the battery case in a jig with a depressed part, followed by injecting a curable material between the outer and inner walls of the jig, which is then cured, to stabilize the application of the curable material at the sealed portions and enhance sealability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal welding is used to seal the battery case, then sealing is achieved, but contamination of the thermally welded portions occurs leading to moisture permeation and electrolyte leakage
Solution Approach 1:
The patent applies a curable material (such as UV-curable resin) to the thermally welded portions, creating a composite structure that combines the thermal weld seal with the curable material's protective properties. This composite approach prevents moisture permeation and electrolyte leakage by adding an additional protective layer that compensates for contamination issues in the thermal weld areas.
Solution Approach 2:
The curable material acts as an intermediary substance applied to the thermally welded portions. It serves as a protective barrier between the contaminated weld areas and the electrolyte, preventing harmful interactions while maintaining the sealing function.
2Reliability
If UV curable agents are applied to prevent moisture permeation, then sealability is improved, but the application process becomes difficult and effective coverage is hard to achieve
Solution Approach 1:
The battery case is designed with protruding sealed portions that extend beyond the receiving part's outer side wall before assembly. This preliminary structural preparation ensures that when the battery case is assembled, the sealed portions are already in the optimal position to receive and retain the curable material, making the subsequent application process much easier and more effective.
Solution Approach 2:
The patent extends the sealed portions in a perpendicular direction outward from the battery case's outer side wall, creating a three-dimensional structure. This dimensional change provides additional surface area and creates a reservoir-like structure that facilitates easier application and ensures better coverage of the curable material.
3Ease of manufacture
If the battery case structure is simplified for low manufacturing cost, then production efficiency is improved, but insulation breakdown occurs at the end of the laminate sheet
Solution Approach 1:
The patent applies curable material to the end portions of the laminate sheet where insulation breakdown occurs. This creates a composite protective layer that maintains the simple laminate structure while adding insulation protection at critical areas, preserving both manufacturing simplicity and electrical insulation integrity.
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 method effectively prevents moisture ingress and electrolyte leakage, improves sealability, and simplifies the manufacturing process while maintaining high quality and yield rates.
Implementation Method 1
injecting a curable material into a space defined between the outer side wall of the receiving part of the battery case and an inner side wall of the depressed part of the jig and curing the injected curable material
Implementation Method 2
forming sealed portions at an outer edge of the receiving part by thermal welding
Data Source
AI summary
Disclosed herein is a method of manufacturing a battery cell having a structure in which an electrode assembly including a positive electrode, a separator, and a negative electrode is mounted in a battery case, and the battery case is sealed by thermal welding, the method including (a) mounting the electrode assembly in a receiving part of the battery case and forming sealed portions at an outer edge of the receiving part by thermal welding, (b) perpendicularly bending the sealed portions and bringing the bent sealed portions into contact with an outer side wall of the receiving part, (c) mounting and fixing the battery case processed at step (b) in a jig provided with a depressed part having a size corresponding to that of the battery case, and (d) injecting a curable material into a space defined between the outer side wall of the receiving part of the battery case and an inner side wall of the depressed part of the jig and curing the injected curable material.