Conglomerated Graphite Processing for Low-Surface-Area Battery Anodes

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Solution Overview

Problem

Existing methods for manufacturing spheroidal graphite as an anode active material for secondary batteries face issues such as non-uniform particle shapes, reduced capacity due to stress and defects, and inefficiencies in charging/discharging rates, particularly when using natural or artificial graphite.

Innovation Solution

A method involving pulverizing flaky natural graphite and pitch, forming a conglomerated precursor with a binder, heat-treating at specific temperatures, and classifying the resulting conglomerated graphite to achieve uniform particle size, low pore volume, and high crystallinity, resulting in conglomerated graphite with excellent initial discharge capacity and high power characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If flaky natural graphite is spheroidized through milling process, then particle shape is improved, but capacity decreases due to stress and defects

Engineering Contradiction:

Improveparticle shapeVSAvoidcapacity

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The flaky natural graphite is divided into fine particles through controlled pulverization, creating numerous small crystalline domains within each spheroidal particle. This segmentation reduces internal stress concentration while maintaining overall spherical shape, thereby improving both shape uniformity and capacity retention.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention creates a composite structure where pulverized natural graphite particles are coated with carbonaceous material and binder, forming a reinforced spherical composite. This composite structure protects the internal graphite crystallites from stress-induced defects while maintaining spheroidal shape, resolving the contradiction between shape improvement and capacity preservation.

Inventive Principle:

Principle #40Composite materials

2Shape

If artificial graphite is coated with binder material and carbonized, then spheroidal shape is achieved, but shape uniformity is poor

Engineering Contradiction:

Improvespheroidal shapeVSAvoidshape uniformity

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The natural graphite is pulverized into fine particles before coating and spheroidization processes. This preliminary size reduction ensures uniform particle behavior during subsequent coating and heat treatment, leading to consistent spherical shapes with high uniformity while maintaining the advantages of natural graphite.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention optimizes coating parameters including binder composition, coating thickness, and carbonization temperature to achieve uniform spheroidal shapes. By carefully controlling these parameters, the process produces particles with consistent morphology and size distribution, resolving the shape uniformity issue.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If natural graphite is discarded during spheroidizing processing, then production cost is reduced, but resource utilization is poor

Engineering Contradiction:

Improveproduction costVSAvoidnatural graphite

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The invention converts the discarded fine particles from natural graphite spheroidization into valuable raw material for conglomerated graphite production. These previously wasted particles are reprocessed through coating and controlled spheroidization to create high-performance anode materials, transforming a loss into a benefit while reducing production costs.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Instead of discarding fine natural graphite particles during spheroidization, the invention recovers and reuses them by incorporating them into the coating mixture. This recovery process maximizes resource utilization while maintaining cost-effectiveness, as the fine particles are given a second life as valuable anode material.

Inventive Principle:

Principle #34Discarding and recovering

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 method produces conglomerated graphite with a specific surface area of 2.0 m2/g or less, pore volume of 0.006 cc/g or less, and d002 of 3.36 Å or less, enabling it to serve as an anode active material with excellent initial discharge capacity, efficiency, and high-rate charging/discharging characteristics.

Implementation Method 1

heat-treating at specific temperatures

Methodology Applied

Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

after crystallization of the conglomerated graphite

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Data Source

PatentUS12503368B2Method for manufacturing conglomerated graphite, the conglomerated graphite manufactured using the method, and secondary battery including the conglomerated graphite as an anode active material

Publication Date: 2025.12.23 EGMATERIALS CO LTD

AI summary

Provided are a method for manufacturing conglomerated graphite, the conglomerated graphite manufactured using the method, and a secondary battery including the conglomerated graphite as an anode active material. Particularly, provided are a method for producing conglomerated graphite having a small specific surface area for excellent initial efficiency and excellent high power of a secondary battery using natural graphite, the conglomerated graphite produced using the method, and a secondary battery including the conglomerated graphite as an anode active material.