Integral Battery Cell Case Geometry for Wrinkle- and Crack-Resistant Forming
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Solution Overview
Problem
The issue of wrinkling and cracking of battery cell cases due to material accumulation at rounded corners during integral forming, which affects the performance and manufacturing difficulty of the case.
Innovation Solution
The case is designed with a yield strength of 140 MPa ≤ Re ≤ 1000 MPa and an inner diameter of 2.5 mm ≤ R1 ≤ 20 mm for the rounded corner, balancing strength and forming difficulty, and a depth of 50 mm < H ≤ 250 mm to reduce cracking and improve space utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the wall thickness of the case is reduced to improve capacity space, then the strength of the case deteriorates
Solution Approach 1:
The patent employs high-strength materials with yield strength Re in the range of 140-1000 MPa for the case construction. This material selection enables the case to maintain adequate strength while using thinner walls, thereby increasing the internal capacity space for battery cells.
2Manufacturing precision
If the inner diameter of the rounded corner is reduced to improve forming precision, then the case is prone to cracking due to stress on high-strength material during integral forming
Solution Approach 1:
The patent specifies an optimal range for the inner diameter of rounded corners (R1) between 2.5-20 mm. This parameter optimization balances the competing requirements of forming precision and cracking resistance by preventing excessive stress concentration during the integral forming process of high-strength materials.
3Volume of moving object
If the yield strength of the case material is increased to reduce wall thickness, then the forming difficulty increases due to stress on high-strength material
Solution Approach 1:
The patent defines an optimal yield strength range (Re: 140-1000 MPa) for the case material. This parameter specification enables the use of high-strength materials that reduce wall thickness while maintaining manufacturability by avoiding excessively high strength levels that would cause forming difficulties.
4Volume of moving object
If the depth of the case is increased to improve capacity, then the structural stability deteriorates
Solution Approach 1:
The patent incorporates rounded corners with inner diameter R1 between 2.5-20 mm into the case structure. This curvature design distributes stress more evenly throughout the case body, enhancing structural stability while allowing for increased depth and capacity.
Data Source
AI summary
Embodiments of the present application provide a case, a battery cell, a battery, and a power consuming apparatus. The case has an opening, and the case is of an integrally formed structure. The case includes a first wall and at least two second walls opposite to the opening. The first wall and the second walls intersect with each other. Two of the at least two second walls are connected by using a first rounded corner. The first rounded corner has an inner diameter of R1. The case has a yield strength of Re at a temperature of 25° C., where Re and R1 satisfy: 140 MPa≤Re≤1000 MPa and 2.5 mm≤R1≤20 mm.