Amorphous-Coated Natural Graphite Anodes for Fast-Charging Batteries

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Solution Overview

Problem

Carbon materials with an orientation parameter intensity ratio I(002)/I(110) greater than 1200 in negative electrodes of secondary batteries exhibit high diffusion resistance and poor rapid charging characteristics.

Innovation Solution

A carbon material composed of natural graphite coated with an amorphous carbonaceous substance, with an orientation parameter intensity ratio I(002)/I(110) ranging from 200 to 1200, is used in the negative electrode, along with specific manufacturing steps to form an active material layer on a metal current collector, optimizing the electrode structure for improved lithium ion diffusibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a carbon material with high orientation parameter intensity ratio I(002)/I(110) (>1200) is used in negative electrode, then structural order is improved, but diffusion resistance increases and rapid charging characteristics deteriorate

Engineering Contradiction:

Improvestructural orderVSAvoidrapid charging characteristics

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent changes the orientation parameter intensity ratio from a high value (>1200) to a controlled range (200-1200) to optimize both structural order and lithium ion diffusibility. This parameter adjustment resolves the contradiction by finding an optimal balance point that maintains structural stability while enabling rapid charging.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses natural graphite coated with amorphous carbonaceous substance to create a composite structure. The crystalline graphite core provides structural order while the amorphous carbon coating enhances lithium ion diffusibility, resolving the contradiction between structural stability and charging speed.

Inventive Principle:

Principle #40Composite materials

2Strength

If the orientation parameter intensity ratio I(002)/I(110) is increased to improve crystal structure, then structural integrity is improved, but lithium ion diffusibility perpendicular to current collector decreases

Engineering Contradiction:

Improvestructural integrityVSAvoidlithium ion diffusibility

Core Design Contradiction:

StrengthVSSpeed

Solution Approach 1:

The patent applies different properties to different parts of the carbon material: the core maintains high crystallinity for structural integrity, while the surface coating provides amorphous structure for enhanced lithium ion diffusibility. This local differentiation resolves the contradiction between strength and speed.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent addresses lithium ion transport in the direction perpendicular to the current collector by optimizing the orientation parameter ratio. By controlling the crystallite orientation and size in this specific dimension, the patent achieves both structural integrity and improved diffusibility in the critical transport direction.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 carbon material suppresses diffusion resistance and enhances rapid charging characteristics of the secondary battery by ensuring excellent lithium ion diffusibility perpendicular to the current collector.

Implementation Method 1

the diffusion resistance of the secondary battery is suppressed, and the rapid charging characteristics of the secondary battery are improved

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

an orientation parameter intensity ratio represented by I(002)/I(110) is from 200 to 1200, where I(110) is a peak intensity corresponding to a lattice plane (110) and I(002) is a peak intensity corresponding to a lattice plane (002), and both I(110) and I(002) are obtained by a wide-angle X-ray diffraction measurement

Methodology Applied

Scientific EffectX-ray diffraction: X-Ray

Data Source

PatentUS20260005234A1Carbon material, negative electrode, secondary battery, method for manufacturing carbon material, method for manufacturing negative electrode, and method for manufacturing secondary battery

Publication Date: 2026.01.01 MITSUBISHI CHEM CORP

AI summary

A carbon material containing graphite particles. The graphite particles are natural graphite coated with an amorphous carbonaceous substance. When the carbon material is included in an electrode fabricated by adding a binder resin and a dispersion medium to the carbon material to form a slurry, applying the slurry to a metal current collector, drying the applied slurry to form an active material layer on the metal current collector, and then pressing the active material layer such that the active material layer has a density of 1.65 g/cm3, the carbon material has an orientation parameter intensity ratio I(002)/I(110) of from 200 to 1200, where I(110) is a peak intensity corresponding to a lattice plane (110) and I(002) is a peak intensity corresponding to a lattice plane (002), and both I(110) and I(002) are obtained by a wide-angle X-ray diffraction measurement.