Battery Cathode Pretreatment for Adhesion and Corrosion

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Solution Overview

Problem

Lithium-ion battery electrodes face challenges in achieving optimal adhesive strength and anti-corrosive properties without increasing binder amounts, which can reduce battery performance.

Innovation Solution

A pretreatment composition comprising a Group IIIB and/or Group IV metal compound and an electropositive metal is applied to a conductive substrate, followed by a coating composition with a lithium-containing compound, enhancing adhesive strength and anti-corrosive properties without requiring excessive binder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If increased amounts of binder are used to improve adhesive strength, then adhesive strength between active material and conductive substrate is improved, but battery performance is reduced due to decreased electrode capacity

Engineering Contradiction:
Improveadhesive strengthVSAvoidelectrode capacity
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The conductive substrate undergoes preliminary treatment with a pretreatment composition containing Group IIIB and/or Group IV metal compound and electropositive metal before the active material is applied. This preliminary action modifies the substrate surface to enhance adhesion, eliminating the need for excessive binder material while maintaining strong bonding between the active material and substrate.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the chemical and physical parameters of the conductive substrate surface by depositing a layer containing Group IIIB and/or Group IV metal compound and electropositive metal. This parameter change in the substrate surface properties improves adhesive strength without requiring increased binder amounts, thus preserving electrode capacity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If chromium-containing passivation layers are used to improve anti-corrosive properties, then corrosion resistance is improved, but environmental and health concerns arise due to chromium toxicity

Engineering Contradiction:
Improveanti-corrosive propertiesVSAvoidchromium toxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces toxic chromium-containing passivation layers with a chromium-free pretreatment composition containing Group IIIB and/or Group IV metal compound and electropositive metal. This substitution eliminates chromium toxicity while maintaining effective corrosion protection, using environmentally safer materials that achieve the same protective function.

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

Solution Approach 2:

The invention converts the harmful effect of chromium toxicity into a benefit by developing a chromium-free alternative that provides equivalent or superior corrosion resistance. The pretreatment composition with Group IIIB and/or Group IV metal compound and electropositive metal creates a protective layer that eliminates environmental and health hazards while maintaining reliability.

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

3Reliability

If conventional single-layer passivation is applied to conductive substrate, then some corrosion protection is achieved, but adhesive strength is insufficient without excessive binder

Engineering Contradiction:
Improvecorrosion protectionVSAvoidadhesive strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention uses a composite pretreatment composition containing both Group IIIB and/or Group IV metal compound and electropositive metal deposited on the conductive substrate. This composite approach creates a multi-functional layer that simultaneously provides corrosion protection and enhances adhesive strength, eliminating the need for excessive binder material.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention merges the functions of corrosion protection and adhesion enhancement into a single integrated pretreatment step. The pretreatment composition containing Group IIIB and/or Group IV metal compound and electropositive metal performs both functions simultaneously, eliminating the need for separate treatments and excessive binder material.

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 method significantly improves the adhesion and corrosion resistance of battery electrodes, leading to enhanced battery performance and longevity.

Implementation Method 1

a first layer covering at least a portion of the conductive substrate deposited from a pretreatment composition comprising a Group IIIB and/or Group IV metal compound dissolved or dispersed in a carrier and an electropositive metal

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Implementation Method 2

a second layer covering at least a portion of the first layer, the second layer is deposited from a a coating composition comprising a lithium-containing compound

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Data Source

PatentEP2971235B1Pretreatment compositions and methods for coating a battery electrode
Publication Date: 2019.12.25 PPG INDUSTRIES OHIO INC
  • EP2971235B1 patent drawingFigure 1~2

AI summary

Disclosed is a cathode (10) of a lithium-ion battery having a conductive substrate (12), a first layer (14) covering at least a portion of the conductive substrate (12) comprising a pretreatment composition comprising a Group 1MB and/or Group IV metal, and a second layer (16) covering at least a portion of the conductive substrate (12) and the first layer (14), the second layer (16) comprising a coating composition comprising a lithium-containing compound. Also disclosed is method for treating a battery cathode and a battery having the treated cathode.