Cathode Active Material Production via Polymer-Modified Precursor
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Solution Overview
Problem
Current methods for producing cathode active materials for lithium ion secondary batteries do not effectively reduce particle size, leading to high battery resistance.
Innovation Solution
A method involving the use of a precursor with a water-soluble polymer introduced into secondary particles, which is then burned to produce a composite oxide with a specific particle size distribution, resulting in a cathode active material with reduced particle size and improved dispersibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional methods are used to produce cathode active material, then the production process is simple, but the particle size is large leading to high battery resistance
Solution Approach 1:
The water-soluble polymer is introduced into the secondary particles during the precursor preparation stage, before the burning step. This preliminary action ensures that the polymer is already positioned within the particle structure, enabling it to effectively control particle growth during subsequent heating and achieve small final particle sizes with reduced battery resistance.
Solution Approach 2:
The water-soluble polymer acts as an intermediary substance that mediates between the precursor materials and the final composite oxide product. During the burning step, the polymer decomposes and influences the particle formation process, controlling particle size and morphology to reduce battery resistance without requiring complex post-processing.
2Object-affected harmful factors
If particle size is reduced to decrease battery resistance, then battery performance improves, but the production process becomes more complex
Solution Approach 1:
The invention changes the chemical composition parameter by introducing water-soluble polymer into the precursor mixture. This parameter change enables control over particle size during the burning process, achieving small particle sizes that reduce battery resistance while maintaining a relatively simple production process that uses conventional ceramic processing steps.
3Length of stationary object
If water-soluble polymer is introduced into secondary particle, then particle size is reduced, but the preparation process becomes more complex
Solution Approach 1:
The water-soluble polymer is introduced into the secondary particles during the precursor preparation stage, before the burning step. This preliminary action ensures that the polymer is already positioned within the particle structure, enabling it to effectively control particle growth during subsequent heating and achieve small final particle sizes with reduced battery resistance.
Solution Approach 2:
The water-soluble polymer is specifically introduced into the secondary particles rather than being uniformly distributed throughout the entire precursor mixture. This localized introduction allows the polymer to exert its particle size control effect precisely where needed, while minimizing the overall complexity of the preparation 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 method achieves a cathode active material with small particle size, leading to lithium ion secondary batteries with low resistance and improved energy density.
Implementation Method 1
a polymer-containing aqueous solution in which a water-soluble polymer is dissolved is used to introduce the water-soluble polymer into a secondary particle
Implementation Method 2
a burning step of burning the precursor to obtain the composite oxide
Data Source
AI summary
A main object of the present disclosure is to provide a method for producing a cathode active material capable of obtaining a cathode active material with small particle size. The present disclosure achieves the object by providing a method for producing a cathode active material including a composite oxide, the method comprising: a preparing step of preparing a precursor containing Li, and Me, which is at least one kind of Ni, Co, Mn, Al and Fe; and a burning step of burning the precursor to obtain the composite oxide; wherein in the preparing step, a polymercontaining aqueous solution in which a water-soluble polymer is dissolved is used to introduce the water-soluble polymer into a secondary particle configured in the precursor.