Multilayer Battery Current Collector for Internal Short-Circuit Safety

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Solution Overview

Problem

Lithium-ion batteries face safety hazards due to internal short circuits, which are exacerbated by poor conductivity and high resistance in current collectors, leading to potential fires or explosions under abnormal conditions.

Innovation Solution

A composite current collector with a support layer and conductive layer, where the conductive material is filled in holes extending through both layers, enhancing safety and conductivity by creating a three-dimensional conductive network and reducing short circuit resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a resin layer is used as current collector to improve safety, then safety performance is improved, but conductivity deteriorates due to high resistance

Engineering Contradiction:
Improvesafety performanceVSAvoidconductivity
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent uses a composite current collector structure consisting of a resin layer (for safety) combined with conductive material (for conductivity). The resin layer provides thermal stability and prevents short circuits, while the conductive material embedded within it ensures adequate electrical conductivity, thus resolving the contradiction between safety and conductivity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The conductive material is selectively distributed within the resin layer at specific locations where conductivity is needed, rather than making the entire structure conductive. This localized approach maintains the insulating and safety properties of the resin while providing conductivity only where required for battery operation.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If conductive material is added to improve conductivity, then conductivity is improved, but device complexity increases due to multilayer structure

Engineering Contradiction:
ImproveconductivityVSAvoidstructure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines the resin layer and conductive material into a single integrated current collector component rather than treating them as separate layers. The conductive material is embedded within the resin matrix to form a unified structure that simultaneously provides both safety and conductivity functions, reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 solution significantly improves the safety and electrochemical performance of lithium-ion batteries by reducing short circuit current and heat generation, while maintaining high-rate charge and discharge performance and cycle life.

Implementation Method 1

the conductive material is filled in the plurality of holes... creating a three-dimensional conductive network

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a support layer, a conductive layer located on two opposite surfaces of the support layer... The positive current collector is provided with a plurality of holes extending through the support layer

Methodology Applied
Scientific EffectMechanical support:

Data Source

PatentEP3547425B1Lithium ion battery comprising a current collector with a multilayer structure
Publication Date: 2024.02.14 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP3547425B1 patent drawingFigure 1~3
  • EP3547425B1 patent drawingFigure 4~6
  • EP3547425B1 patent drawingFigure 7~9

AI summary

The present disclosure relates to the field of batteries and, specifically, to a current collector comprising a support layer, a conductive layer and a conductive material. The conductive layer is located on two surfaces of the support layer. A plurality of holes extending through the support layer and the conductive layer is provided in the current collector and is filled with the conductive material. The current collector of the present disclosure can improve the short circuit resistance of the battery using the current collector when a short circuit occurs under abnormal conditions, so that the short circuit current can be greatly reduced, and thus heat generated by the short circuit can be greatly reduced, thereby improving the safety performance of the battery.