Sulfate-Treated Li-Ion Cathode Material for Low-Gas Dense Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cathode active materials for lithium-ion batteries face issues such as gas generation during charging due to residual alkaline components and challenges in achieving high density and excellent filling properties.
Innovation Solution
A method involving the use of a treatment solution containing sulfate ions to wash lithium transition metal composite oxides, forming secondary particles with specific diameters, and controlling the content of sulfate and sodium ions to improve dispersibility and filling properties, thereby reducing gas generation and enhancing cathode density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium-nickel-based composite oxide is used to increase charge-discharge capacity, then capacity per unit weight is improved, but residual alkaline components cause gas generation during charging
Solution Approach 1:
The patent converts the harmful residual alkaline components into beneficial sulfate ions through treatment with sulfate-containing solution. The sulfate ions replace the harmful alkaline residues and form a protective layer that prevents gas generation during charging, while maintaining the high capacity properties of lithium-nickel-based composite oxide
Solution Approach 2:
The patent changes the chemical composition parameters of the cathode active material surface by controlling sulfate ion content (500-6500 ppm) and sodium ion content (50-1500 ppm). This parameter adjustment eliminates gas generation while preserving high charge-discharge capacity
2Volume of stationary object
If secondary particles with volume-average particle diameter greater than 3 μm and less than 5 μm are formed, then filling property is improved, but particle size control becomes more difficult
Solution Approach 1:
The patent performs preliminary aggregation of primary particles into secondary particles with controlled size range (3-5 μm) before electrode fabrication. This preliminary size control enables improved filling properties in the final electrode structure while making the manufacturing process more manageable through staged particle formation
3Object-generated harmful factors
If sulfate ion concentration is controlled in range of 1 mass % to 9 mass %, then gas generation is reduced, but treatment solution composition control becomes more complex
Solution Approach 1:
The patent establishes specific parameter ranges for sulfate ion concentration (1-9 mass %) and sodium ion concentration (0.1-2 mass %) in the treatment solution. By defining these parameter boundaries, the patent simplifies the control process while achieving effective elimination of gas generation through systematic composition control
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 effectively reduces gas generation and improves the filling property of cathode active materials, leading to increased density and charge-discharge capacity in lithium-ion batteries.
Implementation Method 1
a treatment solution containing a sulfate ion and a liquid medium, a concentration of the sulfate ion being in a range of 1 mass % to 9 mass %; and removing the treatment solution from the mixture
Implementation Method 2
brought into contact with a solution containing sodium ions, followed by mixing with a boron compound and subjecting the mixture to heat treatment
Implementation Method 3
containing secondary particles formed by aggregation of a plurality of primary particles, the secondary particles having a volume-average particle diameter greater than 3 μm and less than 5 μm
Data Source
AI summary
Provided is a cathode active material for a lithium-ion battery that can reduce gas generation in the cathode and exhibits an excellent filling property. Also provided is a method of producing a cathode active material for a lithium-ion battery, the method including preparing a mixture comprising a lithium transition metal composite oxide having a layered structure, containing lithium and nickel in a composition, and containing secondary particles formed by aggregation of a plurality of primary particles, the secondary particles having a volume-average particle diameter greater than 3 μm and less than 5 μm, and a treatment solution containing a sulfate ion and a liquid medium, a concentration of the sulfate ion being in a range of 1 mass % to 9 mass %; and removing the treatment solution from the mixture.