Graphite Anode Material with Bimodal Particle Size Distribution

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing lithium secondary cells face challenges in achieving high-temperature storage characteristics and cycle characteristics, particularly in applications requiring rapid charging.

Innovation Solution

The anode material precursor is formulated with a controlled particle size distribution of graphite, featuring two distinct peaks at 2-8 µm and 10-25 µm, and bound with a binder, enhancing packing density through optimized particle size and shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional graphite-based anode materials are used, then the battery achieves basic energy density, but high-temperature storage characteristics and cycle characteristics deteriorate

Engineering Contradiction:

Improvehigh-temperature storage characteristicsVSAvoidhigh-temperature performance

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent changes the particle size parameters of graphite, specifically controlling the D50 value to 6-23 μm with peaks at 2-8 μm and 10-25 μm. This parameter optimization improves packing density and enhances high-temperature storage characteristics while maintaining good cycle performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite graphite particles formed by aggregating fine graphite particles (2-8 μm) with coarser graphite particles (10-25 μm). This composite structure creates a synergistic effect where fine particles fill voids between larger particles, improving both packing density and high-temperature stability

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If carbon-based active materials with low discharge voltage are used, then energy density improves, but high-temperature cycle characteristics worsen

Engineering Contradiction:

Improveenergy densityVSAvoidhigh-temperature cycle characteristics

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent optimizes the particle size parameters of graphite to balance energy density and cycle characteristics. By controlling D50 to 6-23 μm with specific peak distributions, the anode achieves high packing density for energy density while the optimized structure maintains integrity during high-temperature cycling

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs spherical graphite particles which provide better packing efficiency and uniform stress distribution during lithium insertion/extraction cycles. The spherical morphology with controlled size distribution reduces mechanical stress concentration, improving high-temperature cycle characteristics while maintaining high energy density

Inventive Principle:

Principle #14Spheroidality (Curvature)

Data Source

PatentEP4636842A1Anode material for lithium secondary cell, precursor for same, lithium secondary cell, and manufacturing method of anode material

Publication Date: 2025.10.22 POSCO HLDG INC

Figure 1
Figure 2

AI summary

The present invention relates to an anode material for a lithium secondary cell, a precursor for the anode material, a lithium secondary cell, and a manufacturing method of the anode material. A precursor for the anode material according to an aspect of the present invention is an anode material precursor containing graphite, wherein the graphite may have peaks in particle size ranges of 2-8 µm and 10-25 µm, respectively, and a particle size distribution with a D50 of 6-23 µm.