Core-Shell Carbonaceous Anode Material for Lithium-Ion Batteries
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Solution Overview
Problem
Lithium-ion batteries using graphite as an anode material face limitations due to insufficient intercalation sites and long lithium ion diffusion paths, resulting in suboptimal charge/discharge characteristics.
Innovation Solution
A carbonaceous material with a core-shell structure, comprising a graphite core and an amorphous carbonaceous shell, is developed, which enhances lithium ion diffusion and includes micropores and nanoholes to improve electron conductivity and charging rates, prepared by adding graphite to an alkaline aqueous solution and excluding thermal treatment to minimize etchant residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If graphite is used as anode material, then the battery structure is simple and manufacturing is easy, but the intercalation sites are insufficient and diffusion path is long resulting in poor charge/discharge characteristics
Solution Approach 1:
The patent applies composite materials by combining graphite particles with amorphous carbonaceous material to form a core-shell structured composite anode material. The graphite core provides structural stability while the amorphous carbon shell introduces additional intercalation sites and shortens lithium ion diffusion paths, thereby improving charge/discharge characteristics without compromising manufacturing simplicity
Solution Approach 2:
The patent utilizes porous materials by incorporating amorphous carbonaceous material with micropores and nanoholes into the anode structure. This porous structure increases the surface area and provides numerous intercalation sites for lithium ions, significantly enhancing charge/discharge rates while maintaining ease of manufacture through conventional mixing and coating processes
2Stability of the object's composition
If graphite with narrow interplanar spacing is used, then the structure is stable, but the diffusion region between graphite interlayers is long resulting in limited capacity
Solution Approach 1:
The patent applies dimensionality change by transitioning from the limited two-dimensional interlayer diffusion path in graphite to a three-dimensional porous network structure. The amorphous carbon shell with micropores and nanoholes creates multiple diffusion pathways and intercalation sites throughout the particle volume, dramatically increasing lithium ion capacity while maintaining structural stability
Solution Approach 2:
The patent implements nesting by creating a core-shell structure where the amorphous carbonaceous material with micropores and nanoholes is nested around the graphite core. This nested configuration allows lithium ions to access intercalation sites both in the graphite core and the surrounding amorphous carbon, effectively increasing total capacity while preserving the stable graphite framework
3Manufacturing precision
If thermal treatment is applied to prepare carbonaceous material, then the carbonization is complete, but etchant residues remain on the surface
Solution Approach 1:
The patent applies extraction by removing the thermal treatment step from the preparation process. Instead of using high-temperature carbonization that leaves etchant residues, the invention uses a mild chemical treatment followed by washing to convert graphite to amorphous carbonaceous material, achieving complete carbonization without residual harmful substances
Solution Approach 2:
The patent substitutes thermal treatment (thermal system) with chemical treatment and washing (chemical system). By replacing the high-temperature thermal carbonization process with controlled chemical conversion followed by solvent washing, the invention achieves complete carbonization while eliminating etchant residues from the material surface
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 carbonaceous material significantly improves the capacity and charge/discharge characteristics of lithium batteries, including enhanced rate characteristics and extended lifetime, as demonstrated by increased specific surface area and reduced potassium hydroxide residues on the surface.
Implementation Method 1
adding graphite to an alkaline aqueous solution and stirring a resulting solution to obtain a mixture; and washing the mixture with a solvent and drying a resulting mixture
Implementation Method 2
the carbonaceous material having a core-shell structure, comprising a graphite core and an amorphous carbonaceous shell, which enhances lithium ion diffusion
Data Source
AI summary
A carbonaceous material, an anode active material including the carbonaceous material, a lithium battery including the anode active material, and a method of preparing the carbonaceous material are provided. The carbonaceous material includes: a core including graphite; and a shell on the core and including an amorphous carbonaceous material, wherein the carbonaceous material is a single body.