Secondary Battery Can Corner Curvature for Controlled Deformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries face safety risks due to voltage surges from short circuits, overcharging, and physical stress, which can lead to fires or explosions during safety tests like longitudinal compression, where deformation of the electrode assembly can cause ignition.
Innovation Solution
The design of a secondary battery with a can that can be deformed in a predetermined manner during longitudinal compression tests, featuring specific curvature radii and notched regions at the corners, allowing controlled deformation and preventing short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the can is made with uniform thickness and smooth corners, then the manufacturing process is simple, but the can cannot be deformed in a predetermined manner during longitudinal compression tests
Solution Approach 1:
The can is designed with non-uniform wall thickness, featuring a thinner first region at the corner portions and a thicker second region at the side surfaces. This local variation in thickness allows the corner portions to deform preferentially during longitudinal compression tests while maintaining structural integrity of the side surfaces, thereby enabling predetermined deformation patterns for safety testing.
Solution Approach 2:
The corner portions of the can are designed with specific radius of curvature values (R1 for inner corner, R2 for outer corner) that differ from each other. This curvature design creates stress concentration points at the corners during compression, guiding the deformation to occur in a predetermined manner at these corner regions rather than uniformly across the entire can structure.
2Strength
If the can deforms uniformly during longitudinal compression, then the structural integrity is maintained, but short circuits may occur between electrode plates due to electrode assembly deformation
Solution Approach 1:
By creating localized thin regions at the corner portions with specific curvature radii, the can is designed to deform in a controlled manner at these specific locations during compression. This localized deformation strategy protects the central electrode assembly area from severe deformation that would cause short circuits, while still allowing the can to exhibit measurable deformation for safety testing purposes.
3Reliability
If the corner portions have different inner and outer radius of curvature, then the can deforms in a predetermined manner, but the manufacturing precision requirements increase
Solution Approach 1:
The invention specifies particular radius of curvature values for the inner corner (R1) and outer corner (R2) portions, creating an asymmetric curved geometry that enables predetermined deformation patterns. This curvature design allows the can to deform in a controlled and repeatable manner during longitudinal compression tests, with the different radius values creating specific stress distribution patterns that guide the deformation behavior.
Data Source
AI summary
A secondary battery including an electrode assembly and a case accommodating the electrode assembly, the case including a bottom surface, a first pair of parallel sidewalls and a second pair of parallel sidewalls, connected with the bottom surface, and a corner portion formed by an intersection of each of the first pair of parallel sidewalls and the bottom surface, the corner portion having a first radius of curvature at a first region, and a second radius of curvature different from the first radius of curvature at a second region.