Secondary Battery Case Curvature for Higher Energy Density
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Solution Overview
Problem
Existing secondary batteries have inefficiencies in space utilization within their cases, leading to reduced energy density.
Innovation Solution
The design incorporates a first case with a recess and a second case that is welded to form a coupling part, with a round part between the recess and extension part, where the curvature radius is equal to or greater than the thickness of the first case, reducing unnecessary space and increasing energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the case structure is simplified without optimization, then manufacturing is easier, but unnecessary space increases reducing energy density
Solution Approach 1:
The patent applies curvature by forming a round part at the corner of the first case where the extension part bends. The curvature radius is specifically designed to be equal to or greater than the thickness of the first case, allowing the extension part to bend smoothly without creating excessive empty space. This curved transition optimizes space utilization while maintaining structural integrity and reducing unnecessary voids in the case.
2Quantity of substance
If the extension part is bent tightly to reduce space, then energy density increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies that the curvature radius of the round part should be equal to or greater than the thickness of the first case, with a preferred range of 100% to 500% of the thickness. This parameter definition provides clear manufacturing guidelines that balance space optimization with manufacturability, ensuring the extension part bends smoothly without requiring excessive precision while still minimizing unnecessary space.
3Reliability
If the case thickness is increased to improve sealing, then reliability increases, but unnecessary space increases reducing energy density
Solution Approach 1:
The curved round part design allows for optimized sealing without requiring excessive case thickness. The curvature distributes stress more evenly and provides a better sealing surface geometry, enabling effective sealing with thinner case walls, thereby maximizing the internal space for electrode assemblies and improving energy density.
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 design enhances energy density by minimizing unnecessary space in the battery case, allowing for increased capacity in a given size.
Implementation Method 1
a coupling part coupling, by welding, the extension part of the first case to an edge of the second case
Data Source
AI summary
Embodiments relate to a secondary battery, in which an unnecessary space in a case is reduced to increase energy density, and a method for manufacturing the same. A secondary battery includes an electrode assembly provided with a first electrode plate and a second electrode plate, and a case accommodating the electrode assembly. The case includes a first case having a recess, in which the electrode assembly is accommodated, at a central area thereof, wherein the first case has one surface opened, and a second case configured to seal the one opened surface of the first case. The first case further includes an extension part extending from one end of the recess and coupled to the second case, and a round part between the recess and the extension part. A curvature radius of the round part is equal to or greater than a thickness of the first case.