Battery Casing Isolation Wall for Jelly-Roll Swelling
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Solution Overview
Problem
Jelly-roll type battery electrode assemblies experience deformation due to expansion and contraction during charging and discharging, leading to stress accumulation and potential internal short-circuits, which results in rapid performance degradation and increased defective rates in battery manufacturing, particularly in cylindrical batteries where casing design does not account for electrode expansion.
Innovation Solution
Incorporating an isolation wall within the battery casing to create a buffer space between the electrode assembly and the casing, which accommodates the deformation of the electrode assembly during expansion, thereby preventing deformation of the battery casing and reducing defective rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a jelly-roll type electrode assembly is used to achieve high energy density, then energy density is improved, but stress accumulation and deformation occur during charging and discharging
Solution Approach 1:
The battery cell is divided into multiple compartments by isolation walls, separating the electrode assembly from the battery casing. This segmentation allows the electrode assembly to expand and contract independently within its compartment, preventing stress accumulation and deformation while maintaining the high energy density benefits of the jelly-roll structure.
Solution Approach 2:
Isolation walls are introduced as intermediary structures between the electrode assembly and the battery casing. These walls act as mediators that absorb and distribute the stress generated during charging and discharging, preventing direct transmission of forces to the casing and eliminating deformation issues.
2Ease of manufacture
If the battery casing is designed without considering electrode expansion, then manufacturing simplicity is improved, but casing deformation occurs due to electrode assembly expansion
Solution Approach 1:
The battery casing design is segmented with isolation walls that create independent compartments. This allows the casing to maintain its original simple shape while the electrode assembly expands within the compartment, preventing casing deformation without complicating the overall manufacturing process.
Solution Approach 2:
Isolation walls are pre-installed in the battery casing to create buffer spaces before electrode expansion occurs. These walls provide beforehand cushioning that accommodates electrode assembly expansion, preventing casing deformation while maintaining manufacturing simplicity.
3Reliability
If isolation walls are added to provide buffer space, then casing deformation is prevented, but device complexity increases
Solution Approach 1:
The isolation walls are designed as thin, flexible barriers that provide the necessary buffer space while minimizing structural complexity. These thin film structures effectively prevent casing deformation without adding significant complexity to the battery cell design.
Solution Approach 2:
Isolation walls are strategically placed only at critical locations where electrode expansion would cause casing deformation, rather than uniformly throughout the entire battery structure. This localized approach prevents deformation while minimizing the increase in device complexity.
Data Source
AI summary
A battery cell is configured such that a jelly-roll type electrode assembly is accommodated in a battery casing, and includes: the battery casing including upper, lower, and side surfaces, wherein the side surface of the battery casing includes an isolation wall providing a buffer space between the battery casing and the electrode assembly. The buffer space accommodates deformation of the electrode assembly when the electrode assembly is expanded, such that deformation of the side surface of the battery casing is prevented from occurring.