Artificial Graphite Surface Roughness for Longer-Life Battery Anodes

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Solution Overview

Problem

Existing artificial graphite materials for secondary batteries fail to achieve high energy density and long service life, leading to suboptimal performance in terms of energy storage and durability.

Innovation Solution

Development of artificial graphite materials with specific surface roughness, true density, median particle size, and graphitization degree, along with a preparation method involving crushing, shaping, granulation, graphitization treatment, and surface roughening, to enhance binding forces and acting forces between graphite particles and binders, thereby increasing energy density and prolonging service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing artificial graphite materials are used, then manufacturing simplicity is maintained, but energy density and service life requirements cannot be satisfied

Engineering Contradiction:
Improveservice lifeVSAvoidpreparation process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The preparation process is divided into distinct sequential steps: crushing, shaping, granulation, graphitization treatment, and surface roughening. Each step transforms the material to specific parameters, allowing precise control over the final graphite properties to achieve both high reliability and controlled complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention systematically controls multiple parameters including surface roughness (6≤η≤12), true density (ρ≥2.20 g/cm³), median particle size (Dv50≥10 μm), specific surface area (1.5-4.0 m²/g), and graphitization degree (>92%). By optimizing these parameters through the multi-step process, the graphite achieves enhanced service life and performance

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If surface roughness is increased to enhance binding forces, then energy density improves, but manufacturing complexity increases

Engineering Contradiction:
Improveenergy densityVSAvoidmanufacturing ease
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The surface roughening treatment is performed as a preliminary step before graphitization, preparing the surface morphology in advance. This preliminary action ensures that when graphitization occurs, the rough surface structure is already established, facilitating better binding forces and higher energy density without requiring complex post-processing

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Surface roughness is controlled within the specific range of 6≤η≤12 through the surface roughening treatment. This parameter optimization enhances the binding forces between graphite particles and binders, directly improving energy density while maintaining manufacturing feasibility through controlled process parameters

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If particle size is increased to reduce specific surface area, then service life improves, but energy density may be compromised

Engineering Contradiction:
Improveservice lifeVSAvoidenergy density
Core Design Contradiction:
Duration of action of stationary objectVSUse of energy by moving object

Solution Approach 1:

The invention optimizes the median particle size to Dv50≥10 μm while controlling the specific surface area to 1.5-4.0 m²/g. This parameter combination achieves the right balance: larger particles reduce the specific surface area and improve service life, while the controlled surface roughness and graphitization degree ensure sufficient energy density is maintained

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If graphitization degree is increased to improve structural stability, then service life extends, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvestructural stabilityVSAvoidgraphitization process complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The graphitization degree is controlled to be greater than 92% through optimized graphitization treatment parameters including temperature, time, and atmosphere. This parameter optimization achieves high structural stability and service life while avoiding excessive complexity by establishing clear process boundaries and control points

Inventive Principle:
Principle #35Parameter changes

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 optimized artificial graphite materials result in higher energy density and extended service life for secondary batteries, improving safety performance and reducing bounce during cold pressing, while maintaining structural stability and suppressing side reactions.

Implementation Method 1

enhance binding forces and acting forces between graphite particles and binders

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

enhance binding forces and acting forces between graphite particles and binders

Methodology Applied
Scientific EffectCohesion: Cohesion

Data Source

PatentEP4231390B1Artificial graphite and preparation method thereof, secondary battery containing such artificial graphite, and electric apparatus
Publication Date: 2025.01.01 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4231390B1 patent drawingFigure 1~3
  • EP4231390B1 patent drawingFigure 4~5
  • EP4231390B1 patent drawing

AI summary

This application provides an artificial graphite material A. The artificial graphite material A is secondary particles, where a surface roughness ηA of the artificial graphite material A satisfies 6≤ηA≤12. This application further provides an artificial graphite material B. The artificial graphite material B is primary particles, where a surface roughness ηB of the artificial graphite material B satisfies 2.5≤ηB≤5. This application further provides a secondary battery containing the artificial graphite material A and/or the artificial graphite material B and an electric apparatus. The secondary battery provided by this application can have high energy density and long service life.