Modified Green Coke for Higher-Graphitization Anode Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional raw green coke materials used for producing graphite negative electrode materials have low graphitization degree, low gram capacity, and low compaction density, leading to inadequate performance in lithium ion cells, particularly in terms of cycle life and rate performance.
Innovation Solution
A modified green coke material with a higher percentage of long fibrous and broad-domain structures and reduced volatile components, achieved through a treatment process involving low-temperature heat treatment of raw green coke particles, which enhances graphitization, gram capacity, and compaction density without causing agglomeration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional raw green coke material is used, then the production cost is low, but the graphitization degree, gram capacity, and compaction density are low
Solution Approach 1:
The patent applies preliminary action by performing a low-temperature heat treatment (calcination) on the green coke material before the main graphitization process. This pre-treatment removes volatile components and develops the micaceous structure, creating a more favorable starting condition for subsequent high-temperature graphitization, thereby improving graphitization degree without requiring excessive energy in the main process
Solution Approach 2:
The patent applies parameter changes by optimizing the low-temperature heat treatment parameters (temperature range of 200-400°C, holding time of 1-6 hours) to achieve the desired micaceous structure development and volatile component removal. By carefully controlling these parameters, the process improves graphitization degree while managing energy consumption and production cost
2Quantity of substance
If conventional raw green coke material is used, then the material structure is simple, but the gram capacity and compaction density are low
Solution Approach 1:
The low-temperature heat treatment performs preliminary action by developing the micaceous structure and removing volatile components before graphitization. This pre-development of the layered structure provides better prerequisites for lithium ion insertion and improves the final gram capacity of the graphite material
Solution Approach 2:
The patent applies local quality by creating a specific micaceous structure with long fibrous and broad-domain structures through controlled low-temperature heat treatment. This localized structural transformation in specific regions of the material improves overall gram capacity and compaction density without requiring complete restructuring of the entire material
3Ease of manufacture
If raw green coke material with high volatile components is used, then the material is easy to process, but agglomeration or caking occurs during heat treatment
Solution Approach 1:
The patent applies preliminary action by performing low-temperature heat treatment to remove volatile components before subsequent high-temperature processing. This pre-removal of volatiles prevents agglomeration and caking during later heat treatment stages, maintaining material uniformity while preserving ease of processing
Solution Approach 2:
The patent applies skipping by rapidly passing through the temperature range where agglomeration occurs by first removing volatiles at low temperature, then quickly proceeding to high-temperature graphitization. This avoids prolonged exposure to conditions that would cause caking, maintaining material uniformity throughout the process
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 modified green coke material improves the graphitization degree, gram capacity, and compaction density of graphite negative electrode materials, resulting in enhanced performance, including higher energy density and improved cycle life and rate performance in lithium-ion cells.
Implementation Method 1
a low-temperature heat treatment is performed to obtain the modified green coke material
Implementation Method 2
low-temperature heat treatment of raw green coke particles
Data Source
AI summary
A modified green coke material, a method for preparing the modified green coke material, and an application of the modified green coke material are provided. A sum of percentages of a long fibrous structure and a broad-domain structure in a polarized microstructure of the modified green coke material is in a range of 55˜99%, and a percentage of volatile components in the modified green coke material is in a range of 1%≤volatile components matter<5%.