Energy Storage Device Fitting Structure for Positional Deviation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In energy storage devices, particularly nonaqueous electrolyte secondary batteries used in vehicles, the current collector's physical fixation to the cover member using rivets can lead to deviation and distortion of the electrode assembly due to the force applied during assembly, which may cause adverse effects under vibrations.
Innovation Solution
The implementation of a fitting system where the cover member and current collector are securely connected via a first and second fitting portion, either projections or holes, that resist deviation forces, allowing for precise positioning and increased electrode assembly volume without requiring additional insulating treatments, thus maintaining a compact and insulated state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the current collector is physically fixed to the cover member using a rivet, then the current collector can be securely attached to the cover member, but the current collector and cover member may deviate from each other due to forces generated during rivet crushing
Solution Approach 1:
The fitting portions (projection and recess) are pre-formed on the current collector and cover member before assembly. This preliminary positioning structure ensures that the components are correctly aligned before the riveting process begins, preventing deviation during the subsequent rivet crushing operation.
Solution Approach 2:
The fitting portion acts as an intermediary positioning mechanism between the current collector and cover member. The projection-recess interface serves as a mediator that guides and stabilizes the relative positions of the two components during assembly, preventing the deviation that would otherwise occur during rivet installation.
2Manufacturing precision
If the current collector is fixed using an insulating member, then the current collector can be positioned relative to the cover member, but the insulating member may not be able to resist the forces generated during rivet crushing
Solution Approach 1:
The connection structure combines the metallic current collector with the metallic cover member through a metal-to-metal fitting interface (projection and recess). This composite metallic structure provides both the positioning precision needed for alignment and the mechanical strength to resist forces during rivet crushing, eliminating the weakness of using insulating members.
3Reliability
If additional insulating treatments are applied to maintain the insulating state, then the insulating requirement is satisfied, but the device complexity increases
Solution Approach 1:
The fitting portion structure serves dual functions: it provides mechanical positioning and alignment between the current collector and cover member, and it maintains the insulating state through the inherent design. By merging these functions into a single structural feature rather than adding separate insulating treatments, the device complexity is reduced while reliability is maintained.
Data Source
AI summary
An energy storage device includes an electrode assembly, a container that contains the electrode assembly therein, a metallic cover member that closes the opening of the container and has a first fitting portion, and a current collector having a second fitting portion that is fitted to the first fitting portion in a fitted state. Thus, the compact energy storage device having a large capacity can suppress the positional deviation between the cover member and the current collector.