Battery Cell Guard Structure for Controlled Liquid Leakage

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Solution Overview

Problem

Existing batteries suffer from poor safety due to liquid leakage at the connecting portion between the case and the end lid, which can lead to short-circuit fires or ignitions, especially when used upside down.

Innovation Solution

A guard is arranged on the outer surface of the can to cover at least part of the connecting portion between the case and the end lid, featuring a liquid outlet hole and an accommodating space to guide and contain leaked liquid, reducing leakage speed and preventing fires.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the connecting portion between case and end lid is used for liquid ejection, then battery structure is simplified, but liquid leakage speed increases causing safety issues

Engineering Contradiction:
Improvebattery structureVSAvoidbattery safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a guard as an intermediary component positioned between the connecting portion and the external environment. The guard includes a liquid outlet hole that controls liquid ejection, acting as a mediator that maintains the simplified structure benefit while preventing uncontrolled leakage. The guard's accommodating space temporarily holds liquid before controlled release, ensuring safety without adding complex sealing mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If liquid flows out quickly from the connecting portion, then liquid ejection efficiency is improved, but liquid spreads causing short-circuit fires

Engineering Contradiction:
Improveliquid ejection speedVSAvoidshort-circuit fire risk
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful rapid liquid flow into a beneficial controlled ejection process. The guard's accommodating space temporarily contains the liquid, and the liquid outlet hole provides a controlled release path. This transforms the dangerous uncontrolled leakage into a managed liquid ejection that maintains efficiency while preventing fire hazards by directing liquid away from sensitive components.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If guard structure is added to cover connecting portion, then liquid leakage is controlled, but battery energy density decreases

Engineering Contradiction:
Improvebattery safetyVSAvoidbattery energy density
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The guard is designed as a thin-walled structure that provides effective liquid control functionality while minimizing volume occupation. The thin wall design allows the guard to cover the connecting portion and control liquid leakage without significantly reducing the battery's active material volume, thus maintaining energy density while achieving the required safety improvement.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP4648187A1Battery cell, battery, and electrical device
Publication Date: 2025.11.12 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4648187A1 patent drawingFigure 1~2
  • EP4648187A1 patent drawingFigure 3
  • EP4648187A1 patent drawingFigure 4~5

AI summary

This application provides a cell, a battery, and an electric device, and relates to the field of batteries. The cell includes a can and a guard. The can includes a case and an end lid. The case has an opening. The end lid is connected to the case and closes the opening. The end lid is connected to the case to form a connecting portion. The guard is arranged on an outer surface of the can and covers at least a part of the connecting portion. The cell has the guard arranged thereon, where the guard covers at least a part of the connecting portion. The guard can prevent liquid from leaking from the connecting portion to some extent, and lower a liquid leakage speed, thereby improving safety of the cell to some extent.