Flexible Graphite Anode Material for High-Capacity Lithium-Ion Batteries
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Solution Overview
Problem
Current lithium ion battery anode materials, such as natural and artificial graphite, face limitations in achieving high energy density and rapid charge/discharge rates due to their inherent properties, which restrict their capacity and efficiency, especially when used in high-performance applications like portable electronics and electric vehicles.
Innovation Solution
A method involving the production of anode material using flexible graphite powder, involving pulverization, ball-grinding with a solvent, and rolling onto a metal foil to create a high-capacity and high-conductivity anode electrode plate, enhancing lithium ion storage and charge/discharge rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If natural graphite or artificial graphite is used as anode material, then the battery structure is simple and manufacturing is easy, but the capacity cannot exceed the theoretical capacity of 372 mAh/g and charge/discharge rate is limited
Solution Approach 1:
The invention changes the fundamental parameter of anode material from traditional graphite to flexible graphite powder, which has different structural characteristics including larger specific surface area and porous structure. This parameter change enables the material to achieve capacity exceeding 372 mAh/g while maintaining ease of manufacture through the described processing steps.
2Quantity of substance
If flexible graphite powder is used to increase capacity and charge/discharge rate, then energy density is improved, but the material is brittle and difficult to process
Solution Approach 1:
The invention uses binder and conductive agent as intermediary materials to bridge the brittle flexible graphite powder particles. The binder holds the powder particles together to form a cohesive electrode structure, while the conductive agent ensures electrical connectivity, thereby enabling processing of the otherwise difficult-to-handle flexible graphite powder.
Solution Approach 2:
The invention creates a composite material system consisting of flexible graphite powder, binder, and conductive agent. This composite approach combines the high capacity benefits of flexible graphite with the processing advantages of traditional electrode materials, achieving both high capacity and ease of manufacture.
3Area of stationary object
If flexible graphite powder is used, then specific surface area and porosity are increased for better lithium ion diffusion, but the material is brittle and yield is low
Solution Approach 1:
The invention performs preliminary actions including pulverization to obtain uniform particle size distribution, ball-grinding to improve dispersibility, and optimization of powder properties before electrode fabrication. These preliminary treatments reduce brittleness and improve processability, thereby increasing yield while maintaining the high specific surface area and porosity characteristics.
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 significantly increases the capacity and charge/discharge rate of lithium ion batteries, achieving up to 400 mAh/g at 5 C-Rate, surpassing traditional graphite materials by 15-20%, while ensuring high yield and quality.
Implementation Method 1
performing a ball-grinding step for the uniform flexible graphite powder by mixing with a solvent to obtain a liquid containing flexible graphite
Implementation Method 2
coating the liquid containing flexible graphite on a metal foil, and performing a rolling step to obtain an anode material
Data Source
AI summary
A method for producing the anode material of a lithium ion battery from flexible graphite powder, comprising (A) providing a dry flexible graphite, and pulverizing the dry flexible graphite by a pulverizing step, and filtering the dry flexible graphite with a sieve screen to obtain a uniform flexible graphite powder, (B) performing a ball-grinding step for the uniform flexible graphite powder by mixing with a solvent to obtain a liquid containing flexible graphite; (C) coating the liquid containing flexible graphite on a metal foil, and performing a rolling step to obtain an anode material. Then, the anode material is processed in its shape and is formed into an anode electrode plate. Thereafter, the anode electrode plate is stacked with a lower cover of the battery, a separating paper, a cathode electrode plate, a spring sheet and an upper cover of the battery to assemble the lithium ion battery.