Pouch Battery Cut-Edge Coating for Moisture-Blocked Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pouch-type secondary battery manufacturing methods expose metal layers during the cutting process, leading to reduced battery performance due to moisture and air exposure.
Innovation Solution
A method involving the formation of a conformal coating layer on the side surface of the sealing portion to prevent metal layer exposure, combined with a resin coating layer formed by melting parts of the outer or inner coating layers during heat sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the battery case is cut to assemble upper and lower cases, then the battery case can be manufactured with modular structure, but the metal layer is exposed to moisture and air causing battery deterioration
Solution Approach 1:
The patent applies preliminary action by forming a sealing coating layer on the battery case before assembly, and performing heat sealing treatment on the sealing portion after assembly. This preliminary protective coating prevents metal layer exposure during the cutting and assembly process, while the subsequent heat sealing ensures complete sealing. The sequence of coating → assembly → heat sealing resolves the contradiction by preparing protection in advance and completing it after modular assembly.
Solution Approach 2:
The patent introduces a sealing coating layer as an intermediary substance between the metal layer and the external environment (moisture and air). This coating layer, formed by applying resin material and subsequent heat sealing, acts as a mediator that allows modular assembly to proceed while blocking the harmful interaction between the exposed metal layer and moisture/air. The intermediary coating resolves the contradiction by decoupling the assembly process from the protection requirement.
2Reliability
If a thick inner coating layer is used to prevent metal layer exposure, then the metal layer is protected from moisture and air, but the overall volume of the battery case increases
Solution Approach 1:
The patent applies local quality by concentrating the protective function in a localized sealing coating layer applied specifically to the sealing portion where metal layer exposure occurs, rather than using a uniformly thick inner coating throughout the entire battery case. The coating is applied locally to the cut surfaces and sealing areas, providing targeted protection exactly where needed (at the sealing portion) without adding unnecessary volume elsewhere in the battery case structure.
3Reliability
If additional sealing portion is formed by pressing, then the exposed metal layer is protected from contact with pack unit metal, but inner resin layer material leaks and requires thicker layer increasing volume
Solution Approach 1:
The patent applies parameter changes by transitioning from a mechanical pressing process to a thermal heat sealing process. Instead of relying on mechanical pressure that causes material leakage and requires thicker layers, the patent uses heat sealing treatment that changes the physical state of the resin material (melting and re-solidifying) to create a sealed protective layer. This parameter change from mechanical to thermal processing achieves protection without the volume increase problem.
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 approach effectively blocks moisture and air from contacting the metal layers, enhancing battery performance and reducing the risk of corrosion and insulation resistance deterioration.
Implementation Method 1
forming an insulating coating layer including a conformal coating layer on the metal layer exposed to a cut surface of a battery case
Implementation Method 2
a resin coating layer formed by melting parts of the outer or inner coating layers during heat sealing
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a pouch-type secondary battery and a method of manufacturing the same. More particularly, disclosed is a pouch-type secondary battery and a method of manufacturing the same capable of completely protecting a metal layer from moisture or air by forming an insulating coating layer including a conformal coating layer on the metal layer exposed to a cut surface of a battery case, the method including a first step of preparing a battery case including an upper case and a lower case by cutting a laminate sheet including an outer coating layer, a metal layer, and an inner coating layer; a second step of receiving an electrode assembly between the upper case and the lower case; a third step of closely contacting a sealing portion provided at an outer periphery of the upper case and the lower case; a fourth step of forming a conformal coating layer on a side surface of the sealing portion so as to prevent the exposure of the metal layer; and further a fifth step of sealing the upper case and the lower case by heat sealing the sealing portion of the upper case and the lower case.