Sloping Pouch Battery Case Minimizing Dead Volume
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Solution Overview
Problem
Conventional secondary battery cells, particularly pouch-shaped lithium batteries, face safety concerns due to deformation and reduced capacity caused by dead volumes between the electrode assembly and the battery case, which can lead to explosions or reduced performance upon impact.
Innovation Solution
The battery cell design features a battery case with an upward or downward sloping structure corresponding to the electrode assembly, minimizing dead volumes and ensuring tight contact, thereby enhancing safety and capacity by reducing the likelihood of internal short circuits and deformation upon impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional rectangular electrode assembly is used in a pouch-shaped battery case, then the battery can be manufactured with simple structure, but dead volumes are created between the electrode assembly and battery case causing deformation and safety issues upon impact
Solution Approach 1:
The battery case is designed with a curved inner surface that matches the outer surface curvature of the electrode assembly. This curvature adaptation eliminates dead volumes and ensures tight contact between the electrode assembly and battery case, preventing deformation and internal short circuits upon impact while maintaining manufacturing feasibility.
Solution Approach 2:
The inner surface of the battery case is designed with different geometric characteristics at different locations - specifically curved surfaces that correspond to the electrode assembly's outer surface. This local adaptation of geometry ensures optimal contact and safety without requiring complete redesign of the entire battery structure.
2Productivity
If dead volumes are present between the electrode assembly and battery case, then the battery structure is simpler, but the battery capacity is reduced due to inefficient space utilization
Solution Approach 1:
The curved inner surface of the battery case conforms to the curved outer surface of the electrode assembly, eliminating dead volumes and maximizing space utilization. This curvature matching allows the battery to achieve higher capacity by efficiently using all available space within the pouch structure.
Data Source
AI summary
Disclosed herein is a battery cell configured to have a structure in which an electrode assembly is mounted in a battery case formed of a laminate sheet including a resin layer and a metal layer in a state in which the electrode assembly are connected to electrode terminals protruding outward from the battery case. The electrode assembly is configured such that separators are respectively disposed between cathodes and anodes, each of which is formed by applying a compound including an electrode active material to a current collector. At least a portion of an inside of the battery case corresponding to an outer circumference of the electrode assembly has an upward sloping structure in which a width of the battery case increases upward in vertical section or a downward sloping structure in which the width of the battery case increases downward in vertical section.