Conductive Composite Particles for Uniform Battery Electrode Coatings
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Solution Overview
Problem
Current conductive materials used in lithium ion rechargeable batteries face challenges with poor dispersibility and uniformity, leading to inadequate electron conductivity and reduced battery performance, along with environmental concerns due to high organic solvent usage and sedimentation issues.
Innovation Solution
Development of conductive material composite particles with specific particle size distribution, incorporating a dispersant to enhance dispersibility and uniformity, and a method for manufacturing these particles that involves dispersion medium removal to produce a dried powder, reducing environmental impact and improving long-term stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive carbon black is used as a fine powder with small primary particle size, then conductivity is improved, but dispersibility deteriorates due to strong cohesive force
Solution Approach 1:
The conductive material is segmented into primary particles (10-50 nm) that are further aggregated into secondary particles (5-50 μm) with controlled structure. This segmentation allows the fine primary particles to provide conductivity while the larger secondary particle structure reduces cohesive force and improves dispersibility in the electrode paste.
Solution Approach 2:
The invention creates a composite structure where conductive carbon black primary particles are aggregated into secondary particles with controlled morphology and size distribution. This composite structure combines the high conductivity of fine particles with the improved dispersibility of larger aggregated structures, resolving the contradiction between conductivity and dispersibility.
2Ease of manufacture
If conductive material dispersed paste is produced by dispersing in organic solvent, then dispersibility is improved, but environmental impact worsens due to high solvent usage
Solution Approach 1:
The invention changes the physical parameters of the conductive material by controlling primary particle size (10-50 nm) and secondary particle structure, enabling effective dispersion without requiring large amounts of organic solvent. The optimized particle morphology allows efficient electron conduction pathways to form with minimal solvent usage.
Solution Approach 2:
The invention minimizes the use of organic solvents by optimizing the dispersion process and particle structure, effectively discarding the harmful solvent component while maintaining dispersibility through controlled particle morphology and size distribution.
3Object-affected harmful factors
If conductive material dispersed paste is dried to remove solvent, then environmental impact is reduced, but uniformity deteriorates due to sedimentation and re-cohesion
Solution Approach 1:
The invention performs preliminary action by optimizing the particle size distribution and secondary particle structure before drying. The controlled aggregation into secondary particles (5-50 μm) with specific morphology prevents sedimentation and re-cohesion during drying, maintaining uniformity while removing solvents to reduce environmental impact.
Solution Approach 2:
Instead of dispersing fine particles and then drying (which causes sedimentation), the invention inverts the approach by pre-forming stable secondary particle aggregates with optimized structure before dispersion. This inverted structure prevents re-cohesion during drying and maintains uniform distribution.
4Device complexity
If conductive material is used alone in the positive electrode, then simplicity is maintained, but conductivity deteriorates due to poor electron conductivity of electrode active material
Solution Approach 1:
The invention creates a composite conductive material structure where primary carbon black particles (10-50 nm) are aggregated into secondary particles (5-50 μm) with controlled morphology. This composite structure provides superior electron conductivity compared to using electrode active material alone, while maintaining relatively simple electrode formulation and processing.
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 composite particles achieve improved charge and discharge capacity, reduced risk of short-circuiting, and enhanced battery performance with long-term stability, while minimizing environmental impact through reduced solvent usage.
Implementation Method 1
conductive material composite particles containing at least a conductive material and a dispersant, characterized by: the particles having a particle size distribution D50 of 15 μm or more and a sieved particle size of 150 μm or less
Implementation Method 2
a method for manufacturing conductive material composite particles that involves dispersion medium removal to produce a dried powder
Data Source
AI summary
[Problem] To provide a novel conductive material and manufacturing method thereof, which is in dry powder form effective in reducing environmental impact and improving long-term stability, and has high dispersibility and uniformity in an electrode coating that improves battery performance.[Resolution Means] Conductive material composite particles containing at least a conductive material and a dispersant, characterized by: the particle size distribution D50 being 20 μm or more and the sieved particle size being 150 μm or less; the DBP oil absorption of the conductive material being 550 ml/100 g or less; and including the dispersant at 1 to 10 parts by weight to 100 parts by weight of the conductive material.