Battery Cell Cap Plate Support Structure for Lower Cell Height
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The height of secondary battery cells is increased due to the thickness of the cap and the welding bead, which can lead to stress concentration and reduced durability.
Innovation Solution
A battery cell design that includes a support portion within the case to support the cap plate, forming a fixing space that allows the cap plate to be spaced apart from the case, and a welded portion within this space to secure the cap to the case, without the welding bead protruding outward.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cap and welding bead are used to seal the battery cell case, then the sealing reliability is improved, but the overall height of the battery cell increases
Solution Approach 1:
The cap plate is inserted into the case and nested within the internal accommodation space rather than being mounted externally. This nesting approach allows the cap plate to be positioned inside the case boundaries, eliminating the need for external welding beads and reducing the overall cell height while maintaining sealing integrity through internal positioning.
Solution Approach 2:
The sealing structure transitions from a external welding approach (adding height in the vertical dimension) to an internal insertion approach. The cap plate is inserted through the case opening and positioned internally, changing the spatial arrangement from external attachment to internal integration, thereby reducing the height dimension without compromising sealing reliability.
2Strength
If a thick cap and welding bead are used to secure the cap to the case, then the structural strength is improved, but the stress concentration increases and durability decreases
Solution Approach 1:
Instead of using a uniformly thick cap with external welding, the support portion is strategically positioned at specific locations inside the case to provide localized reinforcement. This localized support structure distributes stress more evenly across the cap plate and case interface, preventing stress concentration points while maintaining adequate structural strength for sealing integrity.
Solution Approach 2:
The support portion acts as an intermediary element between the cap plate and the case interior. It provides a transition structure that distributes the mechanical stress from the cap plate across a larger area of the case, preventing direct stress concentration at the welding interface and improving overall durability through stress distribution.
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
This design reduces the overall height of the battery cell and distributes stress evenly, enhancing durability and reducing the risk of impact vulnerability.
Implementation Method 1
a welded portion at least partially disposed in the fixing space to fix the case to the cap plate
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A battery cell includes a case accommodating an electrode assembly in an internal accommodation space and having an opening formed therein, a cap plate at least partially inserted into the accommodation space through the opening and coupled to the case, and a support portion disposed in the accommodation space and supporting a lower surface of the cap plate, wherein a side surface of the cap plate facing the internal surface of the case is spaced apart from the internal surface of the case by a predetermined distance to form a fixing space, and the support portion is disposed below the cap plate so that at least a portion thereof forms a lower surface of the fixing space.