Power Storage Device Thin-Wall Side Wall Expansion Stress
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Solution Overview
Problem
Power storage devices experience mechanical stress at the joint between the exterior can and sealing plate due to expansion, which can lead to joint breakage, reducing the reliability of the device.
Innovation Solution
Incorporating a thin part in the side wall of the exterior can, which deforms prior to other parts during expansion, reducing mechanical stress at the joint and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing plate is joined to the opening of an exterior can, then the device structure is sealed and complete, but mechanical stress concentrates at the joint during expansion, causing joint breakage
Solution Approach 1:
The side wall portion is designed with non-uniform thickness, creating a thin part with different mechanical properties than the rest of the side wall. This local variation in quality allows the thin part to deform preferentially under stress, protecting the joint from excessive mechanical stress while maintaining overall structural integrity
2Ease of manufacture
If the side wall is made uniformly thick, then manufacturing is simple and strong, but expansion stress cannot be absorbed, leading to joint failure
Solution Approach 1:
Instead of uniform thickness throughout the side wall, a localized thin part is created at a specific position. This allows the majority of the side wall to maintain simple manufacturing processes while a specific local region provides the necessary stress-absorbing deformation capability
3Strength
If the sealing plate is rigidly joined to the exterior can, then the joint is strong, but expansion causes stress accumulation and joint breakage
Solution Approach 1:
The joint system is designed to be dynamically adaptive through the thin part's ability to change shape during expansion. The thin part acts as a compliant element that absorbs dimensional changes, allowing the joint to maintain strength while adapting to volume changes without breaking
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The configuration of a thin part in the exterior can's side wall allows it to deform and absorb expansion stress, preventing joint breakage and enhancing the reliability of the power storage device.
Implementation Method 1
the thin part formed in the exterior can deforms prior to other parts. This configuration reduces mechanical stress generated in a joint between the exterior can and a sealing plate
Data Source
AI summary
A power storage device includes an electrode assembly including a positive-electrode plate and a negative-electrode plate stacked with a separator interposed between the positive-electrode plate and the negative-electrode plate, an exterior can accommodating the electrode assembly and an electrolyte solution, and including a side wall portion having a tubular shape and an opening provided at least at one end of the side wall portion, and a sealing plate that closes the opening of the exterior can. The sealing plate is joined to the opening at a joint. Each of a pair of long walls of the side wall portion facing each other in a depth direction includes a thin part extending in a width direction.