Corrosion-Resistant Plating on Lithium Battery Terminals

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Solution Overview

Problem

Lithium secondary batteries face corrosion issues with aluminum positive electrode terminals, especially in salty environments, leading to increased contact resistance and potential contact failures due to the formation of oxide layers.

Innovation Solution

The electrode terminals are plated with corrosion-resistant metals such as cobalt, copper, nickel, platinum, manganese, zinc, iron, silver, or gold, which have higher corrosion resistance than aluminum or copper, to prevent corrosion and enhance the adhesion and strength of the welding portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If aluminum is used to form a positive electrode terminal, then workability, conductivity, and material costs are improved, but corrosion resistance deteriorates in salty environments

Engineering Contradiction:
ImproveworkabilityVSAvoidcorrosion resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies composite materials by combining aluminum base material with corrosion-resistant metal plating layers. The electrode terminal consists of an aluminum substrate that provides good workability and conductivity, covered with a plating layer of corrosion-resistant metal (such as nickel, zinc, or their alloys) that provides protection against corrosion in salty environments. This composite structure resolves the contradiction by integrating the advantages of both materials.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The corrosion-resistant metal plating acts as an intermediary layer between the aluminum electrode terminal and the corrosive salty environment. This plating layer serves as a protective barrier that prevents direct contact between the aluminum and corrosive substances, thereby maintaining both the workability of aluminum and the corrosion resistance needed for reliable operation in salty conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If aluminum is used to form a positive electrode terminal, then material costs are reduced, but contact resistance increases due to oxide layer formation

Engineering Contradiction:
Improvematerial costVSAvoidcontact resistance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent uses a composite structure where an aluminum base material (providing cost-effectiveness) is combined with a corrosion-resistant metal plating layer. This plating layer prevents oxide formation on the aluminum surface, thereby maintaining low contact resistance while keeping material costs low through the use of aluminum as the base material.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The corrosion-resistant metal plating serves as an intermediary protective layer that prevents direct oxidation of the aluminum electrode terminal. By blocking oxygen and moisture from reaching the aluminum surface, this plating layer maintains electrical conductivity and low contact resistance, while the aluminum base material keeps overall material costs low.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the electrode terminal is exposed to connect to an electrode lead, then electrical connection is enabled, but corrosion by salty material accelerates

Engineering Contradiction:
Improveelectrical connectionVSAvoidcorrosion by salty material
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing corrosion-resistant metal plating specifically on the exposed portions of the electrode terminal that come into contact with salty environments and need to connect to electrode leads. This localized protection maintains electrical connection functionality while providing targeted corrosion resistance where it is most needed, without requiring complete coverage of the entire terminal structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The corrosion-resistant metal plating acts as an intermediary protective barrier on the exposed surfaces of the electrode terminal. This plating layer enables the terminal to maintain electrical connection functionality while protecting the underlying aluminum from direct contact with corrosive salty materials in the operating environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 plating of electrode terminals with these metals significantly improves corrosion resistance by 5-20% compared to standard terminals, reducing contact failures and maintaining discharge voltage, thereby enhancing the battery's anti-fatigue performance and design.

Implementation Method 1

aluminum is stable at the electric potential of a positive electrode... aluminum tends to form an oxide thin layer... the corrosion of a positive electrode terminal is accelerated

Methodology Applied
Scientific EffectOxidation resistance: Oxidation

Implementation Method 2

the electrode terminal is plated with a corrosion resistant metal... the electrode terminal is plated with the metal having the higher corrosion resistance

Methodology Applied
Scientific EffectPlating: Electroplating

Data Source

PatentEP2602846B1Electrode terminal for secondary battery and lithium secondary battery comprising same
Publication Date: 2017.08.02 LG CHEM LTD
  • EP2602846B1 patent drawingFigure 1
  • EP2602846B1 patent drawingFigure 2~3
  • EP2602846B1 patent drawingFigure 4

AI summary

The present invention relates to a lithium secondary battery, in which an electrode assembly that can be charged/discharged is sealed inside a exterior member, and electrode terminals (positive electrode terminal/negative electrode terminal), which are electrically connected to the electrode assembly, partially protrude out of the exterior member, wherein the portion of the electrode terminals that is exposed out of exterior member of the lithium secondary battery is plated with a corrosion-resistant metal. According to the present invention, corrosion-resistant metals, such as cobalt, copper, nickel, and platinum, are directly plated onto the electrode terminals so as to enhance corrosion resistance of the electrode terminals, thereby improving performance of the lithium secondary battery.