Graphite Anode Pore Ratio Control for Rate and Processability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Graphite anode materials face limitations in lithium ion diffusion rates and safety issues due to their layered structure, leading to poor rate performance and potential safety hazards like short circuits and thermal runaway, despite efforts to optimize pore volume and specific surface area.
Innovation Solution
A method to prepare anode materials by controlling the pore volume, specific surface area, and tap density within specific ranges (2≤V*S/T≤10) through precise mixing and heat treatment processes, creating controlled defect structures that enhance lithium ion diffusion pathways and electrochemical reaction interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the layered structure of graphite is used, then the anode material has wide sources and stable electrochemical performance, but the lithium ion diffusion rate is low and rate performance is poor
Solution Approach 1:
The patent introduces a porous structure into the graphite anode material, creating channels and cavities that allow lithium ions to diffuse more efficiently throughout the material. The porous architecture provides multiple diffusion pathways, reducing the reliance on slow solid-state diffusion through the layered graphite structure while maintaining the stable electrochemical performance of graphite.
2Speed
If pore volume and specific surface area are increased to enhance lithium ion diffusion, then the diffusion pathway is improved, but the anode material processability deteriorates
Solution Approach 1:
The patent optimizes the pore volume, specific surface area, and tap density parameters within specific ranges to achieve the best balance between lithium ion diffusion and processability. By carefully controlling these parameters, the material maintains sufficient porosity for fast ion transport while preserving the density and mechanical properties needed for effective electrode manufacturing and electrodeposition.
3Productivity
If defects in graphite structure are increased to create more diffusion pathways, then the rate performance is improved, but the structural stability deteriorates
Solution Approach 1:
The patent introduces defects and porous structures locally within the graphite material rather than uniformly throughout. This creates concentrated diffusion pathways and active sites in specific regions while preserving the overall structural integrity and stability of the graphite lattice. The localized defects provide enhanced rate performance without compromising the global structural stability needed for long-term cycling.
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 improves the rate performance and processability of graphite anode materials, ensuring stable structure and high energy density, while reducing concentration polarization and enhancing cycle performance.
Implementation Method 1
a special layered structure of graphite determines that Li+ can only be embedded from the end plane of the material and gradually diffused into particles, resulting in a low diffusion rate of lithium ions
Implementation Method 2
A method to prepare anode materials by controlling the pore volume, specific surface area, and tap density within specific ranges (2≤V*S/T≤10) through precise mixing and heat treatment processes
Data Source
AI summary
An anode material and a battery. The anode material includes graphite, an interior and/or a surface of the graphite has pores, a pore volume of the anode material is V (cm3/kg), a specific surface area is S (m2/g), a tap density is T (g/cc), wherein, 2≤V*S/T≤10. By constructing the ratio relationship of the specific surface area of the anode material, the pore volume and the tap density of the anode material, the overall distribution condition of defects such as pore pathways, crystal lattices and micro cracks in the graphite particles can be reflected. Within the limited range, when the anode material is made into an electrode to be applied to a battery, the defect distribution in the anode material is uniform.