Battery Cell Casing Rounded-Corner Structure for Crack-Free Forming

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The case of a battery cell is prone to wrinkling and cracking due to material accumulation at rounded corners during integral forming, which affects the performance and manufacturing difficulty.

Innovation Solution

The case is designed with a specific yield strength (140 MPa ≤ Re ≤ 1000 MPa) and rounded corner diameter (2.5 mm ≤ R1 ≤ 20 mm) to balance strength and reduce material accumulation, thereby minimizing cracking and forming difficulty.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If high-strength material is used to reduce wall thickness, then capacity space is improved, but material accumulation and cracking at rounded corners occur during integral forming

Engineering Contradiction:
Improvecapacity spaceVSAvoidforming quality
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the rounded corner inner diameter to a specific range (2.5-20mm) that balances two conflicting requirements: it is large enough to prevent material accumulation and cracking during integral forming of high-strength materials, yet small enough to maintain compact battery cell dimensions and maximize capacity space. This parameter optimization resolves the contradiction between using high-strength materials for thin-walled designs and maintaining forming quality.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If rounded corner inner diameter is increased to prevent cracking, then forming difficulty is reduced, but capacity space is decreased

Engineering Contradiction:
Improveforming difficultyVSAvoidcapacity space
Core Design Contradiction:
Ease of manufactureVSVolume of moving object

Solution Approach 1:

The patent resolves this contradiction by establishing an optimized parameter range for the rounded corner inner diameter (2.5-20mm). Within this range, the corner radius is sufficiently large to reduce material accumulation and cracking during forming, improving ease of manufacture. Simultaneously, the radius remains constrained to prevent excessive space consumption, thereby preserving capacity space. This parameter optimization allows both forming difficulty to be reduced and capacity space to be maintained.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If wall thickness is reduced to increase capacity space, then energy density is improved, but case strength and resistance to deformation are compromised

Engineering Contradiction:
Improvecapacity spaceVSAvoidcase strength
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The patent applies parameter changes by specifying a yield strength range (140-1000 MPa) for the case material and optimizing the rounded corner inner diameter (2.5-20mm). This combination allows the use of high-strength materials that can maintain adequate case strength with reduced wall thickness, thereby increasing capacity space. The optimized corner radius further prevents stress concentration that would compromise strength, enabling thin-walled designs to achieve both high energy density and sufficient mechanical strength.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4683060A1Casing, battery cell, battery, and electric device
Publication Date: 2026.01.21 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP4683060A1 patent drawingFigure 1~2
  • EP4683060A1 patent drawingFigure 3
  • EP4683060A1 patent drawingFigure 4

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. According to the case, the battery cell, the battery, and the power consuming apparatus in the embodiments of the present application, the problem of wrinkling and cracking of the case caused by material accumulation at the rounded corner can be reduced in a process of integrally forming the case.