Three-Layered Nickel-Copper-Nickel Negative Electrode Tab for Lithium Batteries

Solution Overview

Problem

Rechargeable lithium batteries face issues with high resistance in nickel monolayer negative electrode tabs, which hinder high power characteristics, and copper monolayer tabs can cause short circuits due to copper elution, while double-layered structures may prevent short circuits but still face resistance challenges.

Innovation Solution

A three-layered negative electrode tab structure comprising a nickel layer, a copper layer, and another nickel layer, with a weight percentage of 60-80% nickel and 20-40% copper, which prevents copper elution and minimizes resistance, thereby enhancing power characteristics and avoiding short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a nickel monolayer negative electrode tab is used, then short circuit prevention is achieved, but resistance is high which hinders power characteristics

Engineering Contradiction:

Improveshort circuit preventionVSAvoidpower characteristics

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The negative electrode tab uses a composite structure with a copper layer (providing low resistance and high conductivity) covered by nickel layers (providing corrosion resistance and preventing copper elution). This composite material approach allows the tab to simultaneously achieve low resistance for high power characteristics and protection against short circuits through the nickel barrier layers.

Inventive Principle:

Principle #40Composite materials

2Power

If a copper monolayer negative electrode tab is used, then power characteristics are improved due to low resistance, but copper elution causes short circuits

Engineering Contradiction:

Improvepower characteristicsVSAvoidshort circuit prevention

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The negative electrode tab uses a composite structure with a copper layer (providing low resistance and high conductivity) covered by nickel layers (providing corrosion resistance and preventing copper elution). This composite material approach allows the tab to simultaneously achieve low resistance for high power characteristics and protection against short circuits through the nickel barrier layers.

Inventive Principle:

Principle #40Composite materials

3Reliability

If a double-layered nickel-copper structure is used, then short circuit prevention is achieved, but resistance challenges remain

Engineering Contradiction:

Improveshort circuit preventionVSAvoidresistance

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The negative electrode tab uses a composite structure with a copper layer (providing low resistance and high conductivity) covered by nickel layers (providing corrosion resistance and preventing copper elution). This composite material approach allows the tab to simultaneously achieve low resistance for high power characteristics and protection against short circuits through the nickel barrier layers.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS10205171B2Negative electrode for rechargeable lithium battery and rechargeable lithium battery including same

Publication Date: 2019.02.12 SAMSUNG SDI CO LTD

AI summary

A negative electrode for a rechargeable lithium battery includes a negative current collector; a negative active material layer on the negative current collector; and a negative electrode tab on an uncoated region of the negative current collector, the uncoated region not having a negative active material coated thereon, wherein the negative electrode tab has a three-layered structure of a nickel layer-copper layer-nickel layer. A rechargeable lithium battery includes the negative electrode.