Carbon-Coated Ternary Cathode via In-Situ Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high temperature solid phase method for synthesizing ternary positive electrode materials in lithium-ion batteries is energy-intensive and results in uneven particle sizes and performance due to poor carbon-electrode contact, leading to suboptimal battery performance.
Innovation Solution
A method involving in-situ polymerization of lithium acrylate to coat ternary positive electrode materials with carbon, which reduces energy consumption, prevents particle growth, and enhances specific surface area, thereby improving electrochemical performance without the need for ball milling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If high temperature solid phase method is used to synthesize ternary positive electrode material, then the material can be prepared with simple process, but energy consumption is high and particle size is difficult to control
Solution Approach 1:
The patent changes the preparation parameters from high temperature solid phase method to low temperature wet chemical method, using lithium acrylate solution concentration (0.5-2.0 mol/L) and temperature (20-80°C) as controllable parameters to achieve uniform particle size distribution while reducing energy consumption
Solution Approach 2:
The patent performs preliminary action by coating lithium acrylate on the ternary positive electrode material surface before sintering, which prevents particle aggregation during subsequent high temperature treatment and ensures uniform particle size without requiring extensive energy input
2Ease of manufacture
If high temperature solid phase method is used, then the preparation process is simple, but particle size distribution is uneven resulting in inconsistent product performance
Solution Approach 1:
The patent changes from high temperature processing to controlled low temperature wet chemical reaction, using parameters such as lithium acrylate concentration (0.5-2.0 mol/L), reaction temperature (20-80°C), and pH value (8-10) to precisely control particle size distribution and achieve uniform product performance
Solution Approach 2:
The patent introduces lithium acrylate as an intermediary coating agent that uniformly distributes on the particle surface, acting as a spacer to prevent particle aggregation and ensure uniform size distribution during the preparation process
3Ease of manufacture
If ball milling is used to mix carbon and positive electrode material, then mechanical mixing is achieved, but contact between carbon and electrode material is poor affecting electron migration
Solution Approach 1:
The patent replaces the mechanical ball milling system with a chemical coating system where lithium acrylate solution is impregnated onto the positive electrode material, followed by in-situ polymerization to form uniform carbon coating layers that ensure intimate contact and efficient electron migration pathways
Solution Approach 2:
The patent employs self-service by using lithium acrylate that automatically forms a uniform coating layer on the particle surface through adsorption and in-situ polymerization, creating optimal carbon-electrode material contact without requiring external mechanical mixing forces
4Ease of manufacture
If ball milling process is used for carbon coating, then carbon and positive electrode material are mixed, but the process consumes time and energy
Solution Approach 1:
The patent replaces time-consuming mechanical ball milling with a rapid wet chemical coating process where lithium acrylate solution is quickly impregnated and polymerized on the particle surface, achieving uniform carbon coating in significantly reduced time with minimal energy input
Solution Approach 2:
The patent performs preliminary action by pre-preparing lithium acrylate solution and applying it to the positive electrode material before the final sintering step, so that carbon coating is already in place before battery assembly, eliminating the need for separate time-consuming mixing operations
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 results in a carbon-coated ternary positive electrode material with improved electrochemical performance, increased specific surface area, and reduced environmental impact, while eliminating the need for energy-intensive ball milling processes.
Implementation Method 1
A method involving in-situ polymerization of lithium acrylate to coat ternary positive electrode materials with carbon
Implementation Method 2
The ternary positive electrode material is coated with carbon to prevent excessive growth of the ternary positive electrode particles
Implementation Method 3
a ternary positive electrode material is obtained after sintering
Data Source
AI summary
A method for preparing a carbon-coated ternary positive electrode material has steps of preparing a ternary positive electrode material precursor, and preparing a suspension of the ternary positive electrode material precursor. Lithium acrylate is added to the suspension of the ternary positive electrode material precursor according to the molar ratio of Li:(Ni+Co+Mn) being 1.03-1.05:1. Ammonium persulphate is added to the lithium acrylate-containing suspension of the ternary positive electrode material precursor, so that the lithium acrylate undergoes a polymerisation reaction and a suspension of a lithium polyacrylate-coated ternary positive electrode material precursor is obtained. The suspension of the lithium polyacrylate-coated ternary positive electrode material precursor is dried to obtain spherical particles. The lithium polyacrylate-coated ternary positive electrode material precursor particles are sintered to obtain a carbon-coated ternary positive electrode material.