Cathode Material Mixing for Uniform Carbon Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for preparing cathode materials for secondary batteries face challenges in achieving uniformity of ingredients, leading to adverse effects on battery performance such as nonuniform energy density and charging/discharging performance.
Innovation Solution
A method involving the mechanical mixing of lithium metal phosphate with conductive carbon using a mechanofusion method to create a composite material with uniformly arranged conductive carbon, followed by mixing with additional conductive carbon, binder, and solvent to enhance the uniformity and loading density of the cathode material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mixing methods are used to prepare cathode material, then the preparation process is simple, but the uniformity of ingredients is poor
Solution Approach 1:
The patent applies preliminary action by pre-mixing lithium metal phosphate with conductive carbon using mechanofusion method before the main mixing process. This preliminary preparation ensures uniform distribution of conductive carbon in interparticle spaces, which then improves the overall uniformity of the cathode material during subsequent mixing with binder and solvent.
Solution Approach 2:
The patent uses mechanofusion method as an intermediary process between material preparation and final mixing. This intermediate step creates a composite material with improved uniformity, acting as a mediator that bridges the gap between simple mixing and high uniformity requirements.
2Reliability
If more conductive carbon is added to improve conductivity, then the charging and discharging performance is improved, but the viscosity of slurry increases and solid content decreases
Solution Approach 1:
The patent uses preliminary action by pre-distributing conductive carbon through mechanofusion before final mixing. This ensures maximum utilization of conductive carbon in critical interparticle spaces, allowing reduced overall carbon content while maintaining performance, thus controlling slurry viscosity and solid content.
Solution Approach 2:
The patent applies parameter changes by optimizing the amount and distribution of conductive carbon. Through mechanofusion, the carbon is more efficiently distributed, allowing reduction in total carbon content while maintaining conductivity performance, which in turn controls slurry rheological properties.
3Reliability
If conventional mixing is used, then the preparation method is simple, but the interface impedance is high and adhesion strength is low
Solution Approach 1:
The patent applies preliminary action by performing mechanofusion treatment before final mixing and coating. This preliminary step reduces interface impedance and improves adhesion strength by ensuring uniform conductive carbon distribution in interparticle spaces, addressing performance issues before the main manufacturing 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
This method improves the uniformity of the cathode material, increasing its loading density and adhesion strength, resulting in high capacity and excellent fast charging performance at high charging and discharging rates.
Implementation Method 1
A mechanofusion method uses strong compression and shear forces to induce mechano-chemical reactions between multiple particles and form new particles
Data Source
AI summary
A preparation method of a cathode material for a secondary battery is provided. First, a lithium metal phosphate material and a first conductive carbon are provided. The lithium metal phosphate material is made of a plurality of secondary particles. Each of the secondary particles is formed by the aggregation of a plurality of primary particles. An interparticle space is formed between the plurality of primary particles. Next, the lithium metal phosphate material and the first conductive carbon are mixed by a mechanical method, and a composite material is prepared. The first conductive carbon is uniformly arranged in the interparticle space. After that, a second conductive carbon, a binder and a solvent are provided. Finally, the composite material, the second conductive carbon, the binder and the solvent are mixed, and a cathode material for preparing a positive plate is prepared.