External Terminal Raised Portion for Sealed Battery Riveting
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Solution Overview
Problem
The existing methods for attaching external terminals to battery cases using rivet joints often result in deformation of the terminals, leading to gaps and poor welding quality when high pressing forces are applied, which compromises the hermeticity and electrical insulation of sealed batteries.
Innovation Solution
The design incorporates a raised portion on the external terminal around the insertion hole, allowing the internal terminal's shaft to be fastened without deforming the terminal, and a bus bar is welded to the flat plate portion of the external terminal, ensuring high welding quality and maintaining hermeticity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the external terminal is pressed with a large pressing force to fasten the rivet portion, then the hermeticity is improved, but the external terminal deforms
Solution Approach 1:
The external terminal is designed with a localized reinforcement structure (raised portion or rib) specifically at the pressing area where the rivet is fastened. This local reinforcement increases the structural strength and rigidity at the critical pressing zone, allowing the terminal to withstand the large pressing force (e.g., 3000 N) without deforming, while maintaining hermeticity through proper gasket compression.
2Reliability
If the external terminal is pressed with a large pressing force, then the hermeticity is improved, but the welding quality deteriorates
Solution Approach 1:
The external terminal incorporates a localized reinforcement structure (raised portion or rib) at the pressing area, which isolates the deformation to this local region. This ensures that the flat plate portion, where the bus bar is welded, remains free from deformation-induced gaps, thereby maintaining both hermeticity through adequate pressing force and high welding quality without compromise.
3Weight of moving object
If the external terminal is made thinner to reduce weight, then the weight is reduced, but the deformation resistance decreases
Solution Approach 1:
The external terminal is designed with a localized reinforcement structure (raised portion or rib) only at the critical pressing area, rather than increasing the thickness of the entire terminal. This allows the terminal to maintain thin overall dimensions for weight reduction while providing localized strength and rigidity to resist deformation during the riveting process, optimizing the weight-to-strength ratio.
Data Source
AI summary
A sealed battery includes a battery case including a mounting hole, an internal terminal disposed in the battery case and including a shaft portion inserted through the mounting hole, an external terminal disposed on an outside of the battery case and including an insertion hole through which the shaft portion of the internal terminal is inserted, and a gasket and an insulator interposed between the battery case and the internal terminal and between the battery case and the external terminal to insulate the internal terminal and the external terminal from the battery case. The shaft portion of the internal terminal is fastened to the insertion hole of the external terminal. The external terminal includes a raised portion provided around a portion of the external terminal onto which the shaft portion of the internal terminal is fastened.