Secondary Battery Case Stepped Sections for Tab Deviation
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Solution Overview
Problem
The deviation of electrode tabs in secondary batteries due to movement of the electrode assembly within the case leads to reduced production yield.
Innovation Solution
The use of a case with stepped sections, such as holes, grooves, or protrusions, at the inner contact surface with the electrode assembly to increase friction and minimize movement, maintaining the length of electrode tabs constant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the electrode assembly is allowed to move freely within the case, then the ease of assembly is improved, but the production yield decreases due to large deviation of electrode tabs
Solution Approach 1:
The case is designed with stepped sections at specific locations (bottom section and/or side wall section) rather than uniformly throughout. These localized stepped structures provide frictional engagement with the electrode assembly at critical positions to prevent movement, while leaving other areas smooth to maintain ease of assembly. This localized application of increased friction resolves the contradiction between ease of assembly and production yield.
Solution Approach 2:
The stepped sections are pre-formed on the case during manufacturing, creating predetermined engagement points that guide and constrain the electrode assembly during the assembly process. This preliminary structuring of the case ensures that when the electrode assembly is inserted, it automatically engages with the stepped sections, preventing excessive movement of electrode tabs without requiring additional assembly steps or complex mechanisms.
2Productivity
If stepped sections are added to the case to reduce electrode assembly movement, then the production yield is improved, but the device complexity increases
Solution Approach 1:
The stepped sections are implemented only at specific critical locations (bottom section and/or side wall section) rather than throughout the entire case. This localized approach provides the necessary frictional engagement to prevent electrode assembly movement and improve production yield, while minimizing the overall structural complexity and maintaining simplicity in other areas of the case.
Solution Approach 2:
The stepped sections modify the surface geometry parameter of the case at specific locations, creating small dimensional variations (steps) that increase frictional engagement. These parameter changes are minimal and localized, providing the necessary constraint on electrode assembly movement without significantly increasing the overall device complexity or requiring major structural modifications.
3Ease of manufacture
If the case is made with a single smooth layer, then the manufacturing process is simplified, but the electrode assembly moves excessively within the case
Solution Approach 1:
The case is segmented into multiple functional zones: smooth sections that facilitate easy assembly and stepped sections that provide frictional engagement to stabilize the electrode assembly position. This segmentation allows the case to perform multiple functions - maintaining manufacturing simplicity in most areas while providing position stability at critical locations through the stepped sections.
Solution Approach 2:
The case structure transitions from a uniform smooth surface to a differentiated structure with localized stepped sections. These stepped sections are positioned at the bottom section and/or side wall section where they provide the necessary frictional engagement to prevent electrode assembly movement, while the rest of the case remains smooth to maintain manufacturing simplicity.
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 enhances the production yield by reducing the deviation of electrode tabs and stabilizing their length, thereby improving the manufacturing efficiency of secondary batteries.
Implementation Method 1
a plurality of stepped portions for increasing a friction force between the electrode assembly and the case is formed at a bottom portion of the case in contact with the electrode assembly
Data Source
AI summary
A secondary battery including: an electrode assembly; a case receiving the electrode assembly and including a plurality of stepped sections at an inner side of the case in contact with the electrode assembly; and at least one electrode tab electrically connected with the electrode assembly and withdrawn toward an outside of the case. In the secondary battery, a friction force between the inner side of the case and the electrode assembly is increased due to the plurality of stepped sections, thereby minimizing or reducing movement of the electrode assembly within the case.