Battery Cell Case Thickening for Corner Crack Resistance
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Solution Overview
Problem
Existing battery cells face reliability issues due to cracking caused by stress concentration during the manufacturing process and impact, particularly at the corners and heat-affected zones formed by welding, which compromise the structural integrity and performance.
Innovation Solution
The battery cell design incorporates thickened portions on the walls and corner areas to enhance structural strength, with specific thickness ratios and dimensions to mitigate stress concentration and impact resistance, ensuring improved reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the case wall thickness is increased to improve impact resistance, then the strength is improved, but the stress concentration during manufacturing process worsens
Solution Approach 1:
The patent applies local quality by providing thickened portions only at specific locations (corner areas and wall portions corresponding to openings) rather than uniformly throughout the case. This localized thickening reinforces areas subject to impact while avoiding excessive material in other regions, and the gradual transition design prevents stress concentration during manufacturing processes like drawing and demolding
2Reliability
If thickened portions are added to the case to improve strength, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The case structure employs local quality by implementing thickened portions only where structurally necessary - specifically at corner areas and wall portions corresponding to openings - rather than uniformly throughout. This selective reinforcement maintains reliability while minimizing structural complexity and material usage
Solution Approach 2:
The patent resolves complexity by transitioning the thickened portions into a gradual transition area that extends along the thickness direction. This dimensional approach creates a smooth gradient from the thickened to normal wall thickness, eliminating stress concentration points without requiring complex multi-component assemblies
Data Source
AI summary
A battery cell includes a case. An opening is formed at an end of the case along a first direction. Along a circumference direction of the opening, the case includes a first wall, a corner area, and a second wall which are connected in sequence. The first wall includes a first body portion and a first thickened portion arranged along a first direction. The first body portion is farther away from the opening than the first thickened portion, and a maximum thickness of the first thickened portion is greater than a thickness of the first body portion. The corner area includes a second body portion and a second thickened portion arranged along the first direction. The second body portion is farther away from the opening than the second thickened portion, and a maximum thickness of the second thickened portion is greater than a thickness of the second body portion.