Aqueous Cathode Slurry Stabilization for Nickel-Rich Li-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The preparation of cathode slurries for lithium-ion batteries using nickel-containing cathode active materials is hindered by metal leaching and pH-related issues in aqueous solutions, leading to performance degradation and environmental concerns with organic solvents.
Innovation Solution
A method involving the dispersion of a binder and conductive agent in water, followed by the addition of a lithium compound and cathode active material, with homogenization and application to a current collector, using lithium borate or other soluble lithium compounds to stabilize the slurry and prevent metal leaching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water-based slurry is used instead of organic solvent, then environmental friendliness and ease of handling are improved, but metal leaching and pH-related issues occur leading to performance degradation
Solution Approach 1:
A pH modifier is introduced as an intermediary substance to mediate between the aqueous slurry environment and the nickel-containing cathode active material. The pH modifier controls the slurry pH to prevent metal leaching while maintaining environmental benefits of water-based processing, thus resolving the contradiction between environmental friendliness and electrochemical performance reliability
Solution Approach 2:
The pH parameter of the slurry is actively controlled and adjusted using a pH modifier. By changing the pH parameter to an optimal range, the adverse reactions between water and nickel-containing materials are prevented, thereby maintaining high electrochemical performance while using environmentally friendly aqueous solvents
2Reliability
If conventional organic solvents are used, then electrochemical performance is maintained, but environmental harm and handling difficulty increase
Solution Approach 1:
The solvent type parameter is changed from organic to aqueous. By adjusting the slurry composition and processing parameters specifically for water-based systems, the invention maintains electrochemical performance while eliminating the environmental and handling disadvantages of organic solvents
Solution Approach 2:
A pH modifier serves as an intermediary that enables the use of environmentally friendly aqueous solvents while preventing the adverse reactions that would otherwise occur. This mediator allows the system to achieve both environmental benefits and electrochemical performance
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 enhances electrochemical performance and stability of nickel-containing cathode materials while transitioning to environmentally friendly aqueous processing, reducing the need for organic solvents and improving battery capacity retention.
Implementation Method 1
the lithium compound is selected from the group consisting of lithium borate, lithium bromide, lithium chloride, lithium hydrogen carbonate, lithium hydroxide, lithium iodide, lithium nitrate, lithium sulfate, lithium acetate, lithium lactate, lithium citrate, lithium succinate and combinations thereof
Implementation Method 2
The outer layer contains a fluorine-containing polymer that prevents the pH-raising ion exchange reaction with water by reducing surface coverage of water
Implementation Method 3
dispersing a binder material and a conductive agent in water to form a first suspension; adding an aqueous solution containing at least one lithium compound into the first suspension to form a second suspension; adding a cathode active material into the second suspension to form a third suspension; homogenizing the third suspension by a homogenizer
Implementation Method 4
drying the coated film on the current collector to form the cathode
Data Source
AI summary
A method for preparing a cathode based on an aqueous slurry is provided. The cathode slurry with improved stability in water comprises a cathode active material, especially a nickel-containing cathode active material. Treatment of nickel-containing cathode active materials with lithium compounds may improve stability of the cathode by preventing undesirable decomposition of the material. In addition, battery cells comprising the cathode prepared by the method disclosed herein exhibit impressive electrochemical performances.