Battery Cell Current Collector Fuse Bridge for Rapid Overcurrent Cutoff

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Solution Overview

Problem

Current secondary battery cell safety devices, such as PTC thermistors and TCOs, fail to promptly cut off overcurrent, leading to potential safety issues like ignition or explosion due to delayed response in high-current environments.

Innovation Solution

A battery cell design featuring a current collector with a bridge portion having a cross-sectional area of 5% or less, which quickly fuses to disconnect electrical connections when an overcurrent occurs, ensuring rapid safety cutoff.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional safety devices (PTC thermistors, TCOs) are used, then the battery cell can operate normally under standard conditions, but the response time is delayed when overcurrent occurs in high-current environments

Engineering Contradiction:
Improvesafety response timeVSAvoidovercurrent cutoff delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The current collector is designed with a bridge portion that has a smaller cross-sectional area than other portions, creating a localized weak point with higher resistance. This local structural differentiation enables the bridge portion to heat up and fuse faster than conventional uniform structures when overcurrent occurs, achieving rapid safety cutoff in high-current environments

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bridge portion is pre-designed with specific geometric characteristics (smaller cross-sectional area) before operation, preparing it to act as a sacrificial element that will fuse first under overcurrent conditions. This preliminary structural arrangement ensures that the safety cutoff action occurs automatically and rapidly when needed, without requiring external detection or control systems

Inventive Principle:
Principle #10Preliminary action

2Reliability

If PTC thermistors or TCOs are repeatedly operated, then they can block overcurrent, but their resistance increases leading to higher overall circuit resistance

Engineering Contradiction:
Improveovercurrent protection capabilityVSAvoidcircuit resistance increase
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The bridge portion is designed as a disposable sacrificial element that fuses quickly during overcurrent events to切断 the circuit. Unlike reusable PTC thermistors or TCOs that degrade with repeated operation, the bridge portion performs its safety function once and is replaced, ensuring consistent low-resistance electrical connection during normal operation without the resistance increase problem

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If thermal-based safety devices are used, then they can block overcurrent after temperature rise, but they cannot prevent ignition or explosion when internal pressure increases due to abnormal temperature rises

Engineering Contradiction:
Improveovercurrent blocking functionVSAvoidignition or explosion risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The bridge portion is strategically designed to fuse before the battery reaches dangerous temperature or pressure levels that could cause ignition or explosion. By creating a controlled failure point with lower fusion temperature, the system performs preliminary protective action that interrupts the harmful sequence of events before they can escalate to catastrophic failure

Inventive Principle:
Principle #9Preliminary anti-action

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

The design effectively prevents ignition by quickly cutting off overcurrent, enhancing safety in high-current conditions.

Implementation Method 1

the above devices are all operated by heat generated due to overcurrent. That is, the above devices operate to block the flow of current only when overcurrent flows through the circuit current path due to overcharge or the like so that the temperature rises according thereto.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4661199A1Battery cell, battery pack, and vehicle comprising same
Publication Date: 2025.12.10 LG ENERGY SOLUTION LTD
  • EP4661199A1 patent drawingFigure 1~2
  • EP4661199A1 patent drawingFigure 3~4
  • EP4661199A1 patent drawingFigure 5~6

AI summary

A battery cell according to an embodiment of the present disclosure may include: an electrode assembly; a battery housing having an opening on one side thereof and configured to accommodate the electrode assembly through the opening; a battery terminal configured to be electrically connected to the electrode assembly through a closed portion provided opposite the opening of the battery housing; and a current collector comprising a first coupling portion configured to be electrically coupled to the electrode assembly, a second coupling portion configured to be electrically coupled to the battery terminal, and a bridge portion configured to electrically connect the first coupling portion and the second coupling portion, wherein a cross-sectional area of the bridge portion may be configured to be 5% or less of an entire cross-sectional area of the current collector.