Graphite Flake Rounding with Zoned Tools and Flow Guidance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing rounded graphite flakes are costly and inefficient, failing to produce graphite powder with uniform, rounded particles suitable for battery applications.

Innovation Solution

A device and method involving a rotating disk with rounding tools, a guide device, and a separating device to fold and separate graphite flakes, ensuring multiple contacts and optimal flow for rounding graphite flakes into spherical particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional methods are used to produce rounded graphite flakes, then graphite powder can be produced, but the production process is costly and inefficient, and the particles are not uniformly rounded

Engineering Contradiction:
Improverounding uniformity of graphite particlesVSAvoidproduction efficiency and cost-effectiveness
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The device segments the rounding process into distinct zones: a first rounding zone with rounding tools for initial rounding, and a second rounding zone with additional rounding tools for further rounding. This segmentation allows different stages of rounding to occur in separate areas, improving uniformity while maintaining efficiency through continuous processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a vertical dimension to the rounding process by arranging rounding tools at different heights and positions in space. The graphite material is conveyed vertically through multiple rounding zones, allowing rounding to occur from multiple spatial perspectives simultaneously, which enhances rounding uniformity without increasing processing time.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If graphite material is conveyed through the device, then rounding can occur, but coarse graphite material may be thrown upwards by pressure waves and circulate without contact with rounding tools

Engineering Contradiction:
Improvematerial flow guidanceVSAvoidcontact frequency with rounding tools
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

A cover ring is introduced as an intermediary element between the rounding tools and the graphite material. This cover ring acts as a mediator that redirects pressure waves and guides material flow, ensuring that graphite particles are directed toward the rounding tools rather than being thrown upward and lost from the processing zone.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The device utilizes process air flow as a pneumatic medium to convey graphite material through the rounding zones. The cover ring works in conjunction with this pneumatic system to control air flow patterns, preventing pressure waves from throwing material upward while maintaining effective material circulation and contact with rounding tools.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Manufacturing precision

If multiple rounding zones are implemented, then rounding uniformity improves, but device complexity increases

Engineering Contradiction:
Improverounding uniformityVSAvoiddevice structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The rounding tools are designed with multi-functionality, serving both as rounding elements and as flow guidance elements. The same structural components that perform rounding also help guide material flow and manage pressure distribution, reducing the need for additional separate elements and thereby limiting the increase in device complexity despite having multiple rounding zones.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the functions of material conveyance, pressure wave management, and rounding into integrated structural elements. The cover ring and guide elements are combined with the rounding tool assembly, creating a unified structure that performs multiple functions simultaneously, thus reducing overall device complexity while maintaining multiple rounding zones.

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

Produces rounded graphite particles with minimized porosity and increased density, suitable for lithium-ion batteries, with high separation accuracy and low abrasion, enhancing battery performance.

Implementation Method 1

The graphite material is imparted with a swirl by single or multiple active contact with at least one rounding tool

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the natural crystalline graphite flakes are processed by impact, cutting, and friction in the air stream

Methodology Applied
Scientific EffectImpact Force: Impact Force

Implementation Method 3

guides the graphite material to the rounding tools and/or a separating device

Methodology Applied
Scientific EffectAir Entrainment: Air Entrainment

Implementation Method 4

The at least one guide device redirects the swirled graphite material in a largely vertically upward direction

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 5

a separating device for separating fine material and ultrafine material that would interfere with subsequent processing steps

Methodology Applied
Scientific EffectCyclone Separation: Cyclone Separation

Data Source

PatentEP3851194B1Device and method for rounding graphite flakes of a graphite material
Publication Date: 2025.07.23 NETZSCH TROCKENMAHLTECHNIK GMBH
  • EP3851194B1 patent drawingFigure 1
  • EP3851194B1 patent drawingFigure 2A~2E
  • EP3851194B1 patent drawingFigure 3A~3D

AI summary

The invention relates to a device and a method for rounding a graphite material. The device comprises a feeding unit for supplying the graphite material to the device; a plurality of rotating rounding tools arranged on the outer circumference of a disk rotating about an axis of rotation and in one direction; at least one guide apparatus; a separating device for separating fine and ultrafine material; and a product outlet. Furthermore, a cover ring is arranged above the rounding tools.