Secondary Battery Case Sealing Edge Reinforcement
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Solution Overview
Problem
Conventional secondary battery cases face issues with moisture exposure and electrical short circuits due to polyolefin-based resin layers being vulnerable, leading to rapid battery performance deterioration and venting phenomena when subjected to external impacts.
Innovation Solution
A secondary battery case design featuring a polymer resin layer and a reinforcing layer on the edge of the sealing part where the electrode terminal exists, which covers the polyolefin-based resin layers and enhances water resistance, insulation, and mechanical properties, preventing exposure and improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polyolefin-based resin layers are used for sealing the case edge, then the sealing structure is simple and easy to manufacture, but the resin layers are vulnerable to moisture and cause electrical short circuits
Solution Approach 1:
The patent applies composite materials by combining polyolefin-based resin layers with polymer resin layers (epoxy, polyester, or polyamide) and metal layers (aluminum foil). This multi-layer composite structure leverages the moisture resistance and insulation properties of the polymer resin layer and the barrier properties of the metal layer, while maintaining the ease of manufacture of the original polyolefin-based sealing structure.
Solution Approach 2:
The patent applies local quality by forming the polymer resin layer and metal layer specifically at the edge of the sealing part where the electrode terminal exists, rather than throughout the entire case. This targeted approach enhances moisture resistance and insulation exactly where needed (at the vulnerable edge region) without unnecessarily complicating the overall sealing structure or increasing manufacturing complexity.
2Reliability
If the sealing part coupling shape is changed to improve water resistance and insulation, then electrical characteristics improve, but the volume or weight of the case is deformed
Solution Approach 1:
The patent applies local quality by adding the polymer resin layer and metal layer only at the edge of the sealing part where the electrode terminal exists, rather than modifying the entire case structure. This localized enhancement improves water resistance and insulation without deforming the overall case volume or weight, as the modification is confined to a specific regional area.
3Strength
If the sealing part is subjected to external impact, then the case structure is tested for durability, but venting phenomenon occurs and battery performance deteriorates rapidly
Solution Approach 1:
The patent applies composite materials by combining polyolefin-based resin layers with polymer resin layers (epoxy, polyester, or polyamide) and metal layers (aluminum foil). This multi-layer composite structure enhances the overall strength and durability of the sealing part, providing better protection against external impacts while preventing venting phenomena and maintaining battery performance stability through improved moisture resistance and insulation.
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 effectively prevents moisture penetration and electrical short circuits, maintains battery performance over time, and delays the venting phenomenon by enhancing water resistance and mechanical properties without significantly affecting the case's volume or weight.
Implementation Method 1
a polymer resin layer formed on an edge of the first sealing part
Implementation Method 2
a reinforcing layer surrounding the polymer resin layer
Implementation Method 3
improve water resistance and insulation
Data Source
AI summary
Provided is a case for a secondary battery accommodating an electrode assembly, including a lower member, an upper member disposed above the lower member, and a sealing part to which the lower member and the upper member are fused to seal the case. The sealing part includes a first sealing part in which an electrode terminal connected to the electrode assembly exists and a second sealing part which is a remaining area except for the first sealing part. The case includes a polymer resin layer formed on an edge of the first sealing part and a reinforcing layer surrounding the polymer resin layer. The case for a secondary battery has improved water resistance, insulation and mechanical properties. Also provided is a secondary battery, a module, and a device including the same.