Battery Top Cover Pole Sealing Structure for Short-Circuit Prevention

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Solution Overview

Problem

In existing secondary batteries, poor sealing between the lower plastic component and the pole leads to metal debris falling off, causing short circuits and affecting operation performance.

Innovation Solution

A top cover assembly with a seal ring that seals against both the top cover plate and the pole, ensuring insulation and sealing in both axial and radial directions, preventing metal debris from entering the gap and causing short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lower plastic component is mounted to the top cover plate without additional sealing structures, then the device complexity is reduced, but sealing between the lower plastic component and the pole deteriorates, causing metal debris to fall off and create short circuits

Engineering Contradiction:
Improvesealing performanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A seal ring is introduced as an intermediary component between the lower plastic component and the pole. The seal ring includes a sealing surface that contacts the pole and another sealing surface that contacts the lower plastic component, effectively preventing metal debris from falling off while maintaining structural clarity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing function is segmented from the lower plastic component itself and transferred to a dedicated seal ring component. This allows the sealing function to be independently optimized while keeping the main component structure simple

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If a seal ring is added to improve sealing between the lower plastic component and the pole, then metal debris prevention is improved, but the device complexity increases

Engineering Contradiction:
Improvemetal debris preventionVSAvoidcomponent quantity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The seal ring serves multiple functions simultaneously: it provides sealing between the lower plastic component and the pole, prevents metal debris from falling off, and maintains the positional relationship between components. This multi-functionality reduces the need for additional separate components

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the second pole hole has a greater diameter than the first pole hole to accommodate the seal ring, then sealing performance is improved, but the insulation performance may deteriorate due to larger gap

Engineering Contradiction:
Improvesealing performanceVSAvoidshort circuit risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The seal ring acts as an intermediary insulating component between the conductive pole and the larger second pole hole. The seal ring material provides both sealing and electrical insulation, allowing the second pole hole to have a larger diameter for sealing purposes without compromising insulation performance

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4553971B1Top cover assembly, secondary battery, battery module, and electricity-consumption device
Publication Date: 2026.02.18 HITHIUM TECH HK LTD
  • EP4553971B1 patent drawingFigure 1~3
  • EP4553971B1 patent drawingFigure 4~5
  • EP4553971B1 patent drawingFigure 6~7

AI summary

Provided are a top cover assembly, a secondary battery, a battery module, and an electricity-consumption device. The top cover assembly includes a top cover plate, a lower plastic component, a pole, an upper plastic component, a press ring, and a seal ring. A first pole hole is formed at the top cover plate. A second pole hole is defined in the lower plastic component. In a thickness direction of the top cover plate, a surface of the seal ring sealingly abuts against the top cover plate, and another surface of the seal ring sealingly abuts against the press ring. An inner side wall of the seal ring sealingly abuts against an outer peripheral wall of the pole or a side wall of an insertion portion, and an outer wall sealingly abuts against a hole wall of the second pole hole.