Niobium Titanium Oxide Electrode Moisture Control for Crack Resistance

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Solution Overview

Problem

The electrode material using niobium titanium oxide tends to harden and crack when the density is increased, leading to defects like cracking, chipping, and peeling, which reduces the energy density and increases self-discharge due to inadequate binder content and moisture levels.

Innovation Solution

The moisture content of the electrode material is controlled between 2000 ppm and 10,000 ppm, with a preferred range of 3000 ppm to 10,000 ppm, and a method involving applying a slurry containing niobium titanium oxide or titanium dioxide to a current collector, drying it, and storing it in an atmosphere with a dew point of 30 °C to 50 °C to form an active material-containing layer, which enhances flexural strength and reduces defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the electrode density is increased to improve energy density, then the energy density is improved, but the mixture layer hardens and cracking occurs

Engineering Contradiction:
Improveenergy densityVSAvoidflexural strength
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The invention changes the moisture content parameter of the electrode material from a dry state (below 2000 ppm) to a controlled moist state (2000-10000 ppm). This parameter change softens the electrode material, improving flexural strength and preventing cracking during handling and processing, while allowing high density to be achieved without compromising structural integrity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces moisture content control as a preventive measure before the electrode material is subjected to high-density processing. By pre-conditioning the material with appropriate moisture levels, the electrode gains inherent flexibility and resistance to cracking that would otherwise occur during density enhancement processes

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If the binder content is reduced to improve flexural strength, then the flexural strength is improved, but the binding property degrades causing powder fall and self-discharge

Engineering Contradiction:
Improveflexural strengthVSAvoidbinding property
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the moisture content parameter to compensate for reduced binder content. The added moisture (2000-10000 ppm) provides plasticity and binding properties that replace the mechanical bonding function of binders, allowing the electrode to maintain both high flexural strength and adequate binding properties without excessive binder content

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces moisture as an intermediary substance that mediates between the electrode particles and provides binding properties. The moisture acts as a plasticizer and binding agent, filling the role traditionally performed by organic binders while enabling reduced binder content and improved flexural strength

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

This approach results in an electrode with improved flexural strength, reduced defects during handling, and lower self-discharge, achieving a high-density electrode material with enhanced performance.

Implementation Method 1

When the moisture content of an electrode material is low, the electrode material tends to harden, and the electrode material may be broken when the electrode density is increased. By setting the moisture content of the electrode material to 2000 ppm or more and 10,000 ppm or less, the flexural strength can be improved.

Methodology Applied
Scientific EffectPlasticizer effect of moisture:

Implementation Method 2

a mixture layer formed on a current collector tends to harden, and cracking tends to occur

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4297123A1Electrode material
Publication Date: 2023.12.27 KK TOSHIBA
  • EP4297123A1 patent drawingFigure 1~2
  • EP4297123A1 patent drawingFigure 3~4
  • EP4297123A1 patent drawingFigure 5

AI summary

In general, according to one approach, an electrode material (101) is provided. The electrode material (101) includes at least one of niobium titanium oxide or titanium dioxide. A moisture content measured by a Karl Fischer method is in a range of 2000 ppm or more and 10,000 ppm or less.