Conductive Material Dispersion for Low-Viscosity Battery Electrodes

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Solution Overview

Problem

Conductive materials in electrode slurry compositions for secondary batteries face issues with high viscosity when the content of conductive materials increases, limiting electrical conductivity and processability, and existing dispersants either cause rapid viscosity increase or degrade in storage stability.

Innovation Solution

A conductive material dispersion using a nitrile-based copolymer as the main dispersant, combined with an auxiliary dispersant containing an oxyalkylene unit and/or styrene unit, reduces viscosity and enhances dispersibility, allowing for higher solid content and improved electrode manufacturing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the content of conductive material in electrode slurry composition is increased, then electrical conductivity is improved, but viscosity increases rapidly

Engineering Contradiction:

Improveelectrical conductivityVSAvoidviscosity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent uses a composite dispersant system combining polyvinyl pyrrolidone (PVP) as the main dispersant with acrylonitrile-butadiene rubber (NBR) as the auxiliary dispersant. This composite approach allows the dispersants to work synergistically, with PVP providing primary dispersion and NBR preventing aggregation, thereby maintaining low viscosity even at high conductive material content (3-10 parts by weight per 100 parts electrode active material).

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent optimizes the molecular weight parameters of the dispersants, specifically using PVP with molecular weight of 10,000-1,000,000 and NBR with molecular weight of 10,000-500,000. It also optimizes the content ratio of conductive material (3-10 parts per 100 parts electrode active material) to achieve the desired balance between conductivity and viscosity.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If a dispersant with low weight average molecular weight is used to lower viscosity, then viscosity is reduced, but storage stability degrades due to gelation

Engineering Contradiction:

ImproveviscosityVSAvoidstorage stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent combines two dispersants with different molecular weight characteristics and functional properties. PVP (molecular weight 10,000-1,000,000) provides good solubility and initial dispersion, while NBR (molecular weight 10,000-500,000) provides steric stabilization and prevents gelation. This composite system achieves low viscosity without compromising storage stability.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The NBR dispersant acts as an intermediary that prevents the PVP dispersant from causing gelation at low molecular weights. The NBR molecules intercalate between PVP chains and conductive material particles, preventing excessive cross-linking and gel formation, thereby maintaining storage stability while allowing the use of lower molecular weight dispersants for reduced viscosity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If the solid content of conductive material dispersion is increased, then productivity is improved, but viscosity increases affecting processability

Engineering Contradiction:

Improvesolid contentVSAvoidprocessability

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent employs a composite dispersant system that enables high solid content (3-10 parts conductive material per 100 parts electrode active material) to be achieved while maintaining acceptable viscosity. The synergistic action of PVP and NBR dispersants prevents aggregation and maintains fluidity, allowing high productivity without sacrificing processability.

Inventive Principle:

Principle #40Composite materials

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 conductive material dispersion achieves lower viscosity, enabling increased solid content, improved productivity, enhanced electrode drying efficiency, and stronger adhesion forces, thus optimizing the manufacturing process.

Implementation Method 1

a copolymer including an oxyalkylene unit and at least one selected from the group consisting of a styrene unit and an alkylene unit is used as an auxiliary dispersant

Methodology Applied

Scientific EffectSteric stabilization:

Implementation Method 2

the auxiliary dispersant is a copolymer including an oxyalkylene unit and at least one selected from the group consisting of a styrene unit and an alkylene unit

Methodology Applied

Scientific EffectSolvation: Solvation

Implementation Method 3

a nitrile-based copolymer is used as a main dispersant

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 4

a copolymer having a nitrile unit and a conjugated diene unit, in which the conjugated diene unit is partially or fully hydrogenated

Methodology Applied

Scientific EffectSteric hindrance:

Data Source

PatentUS20260094837A1Conductive Material Dispersion, and Electrode and Lithium Secondary Battery Manufactured Using the Same

Publication Date: 2026.04.02 LG ENERGY SOLUTION LTD

AI summary

A conductive material dispersion includes a carbon-based conductive material, a main dispersant, an auxiliary dispersant, and a dispersion medium, wherein the main dispersant is a nitrile-based copolymer and the auxiliary dispersant is a copolymer including an oxyalkylene unit and at least one selected from the group consisting of a styrene unit and an alkylene unit.