Coated Lithium-Nickel Cathode Material for Battery Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-nickel-based positive electrode active materials for lithium secondary batteries face challenges due to the presence of lithium derivatives and moisture on their surface, leading to gelation and degradation of battery performance, which complicates manufacturing and reduces battery lifespan.
Innovation Solution
A lithium-nickel-based transition metal oxide with a coating layer comprising a metal oxalate compound, potentially including boron, is developed to reduce the amount of lithium derivatives on the surface and inhibit moisture adsorption, thereby preventing gelation and enhancing battery stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a water washing process is performed to remove lithium derivatives from the surface, then the amount of lithium carbonate and lithium hydroxide remaining on the surface is reduced, but the manufacturing process becomes complicated and manufacturing costs increase
Solution Approach 1:
The patent extracts and removes lithium derivatives (lithium carbonate and lithium hydroxide) from the surface of the positive electrode active material through a water washing process, separating the harmful surface contaminants from the bulk material to achieve clean surfaces without complicating the overall manufacturing flow
Solution Approach 2:
The water washing process is performed as a preliminary step before electrode manufacturing to pre-clean the positive electrode active material surface, removing lithium derivatives in advance to prevent subsequent gelation issues and performance degradation
2Reliability
If a water washing process is performed to remove lithium derivatives, then surface activation is suppressed, but manufacturing time is increased and large quantities of powder cannot be washed in a short time
Solution Approach 1:
The patent replaces prolonged mechanical washing operations with a chemically-assisted washing approach using dilute acid solutions, which accelerates the removal of lithium derivatives and enables efficient processing of large quantities of powder in shorter times while maintaining surface stability
3Manufacturing precision
If the water washing process is prolonged to wash large quantities of powder, then more lithium derivatives are removed, but lithium and transition metal are eluted from the inside as well as from the surface
Solution Approach 1:
The patent optimizes the washing parameters including using dilute acid solutions (controlled concentration), limiting washing time to 1-6 hours, and controlling temperature to achieve effective removal of surface lithium derivatives while preventing elution of lithium and transition metals from the bulk material
Solution Approach 2:
The patent introduces dilute acid solutions as an intermediary washing medium that selectively removes lithium derivatives from the surface while the controlled acidity prevents penetration and elution of metals from the interior, acting as a selective barrier in the washing process
4Ease of manufacture
If lithium precursors remain on the surface of the positive electrode active material, then the manufacturing process is simpler, but gelation phenomenon occurs making it difficult to manufacture electrodes and battery performance deteriorates
Solution Approach 1:
The patent extracts and removes lithium precursors (lithium carbonate and lithium hydroxide) from the surface of the positive electrode active material through water washing, eliminating the gelation-causing substances that would otherwise interfere with electrode manufacturing operations
Solution Approach 2:
The patent performs preliminary washing to prevent gelation phenomenon before electrode manufacturing, removing lithium precursors in advance to avoid subsequent processing difficulties and performance degradation, thereby enabling smooth electrode fabrication
5Device complexity
If lithium precursors remain on the surface, then no additional processing is needed, but moisture adsorption increases causing surface fading and battery performance deterioration
Solution Approach 1:
The patent extracts and removes lithium precursors from the surface through water washing, eliminating the substances that would otherwise adsorb moisture and cause surface fading, thereby protecting battery performance stability without requiring excessive additional processing steps
Solution Approach 2:
The patent performs preliminary washing to remove moisture-adsorbing lithium precursors before electrode manufacturing and battery assembly, preventing subsequent moisture-related degradation and surface fading issues that would compromise battery reliability
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 coated positive electrode active material effectively reduces lithium derivative and moisture-related issues, resulting in improved capacity and extended lifespan of lithium secondary batteries, making them suitable for high-capacity and long-lifetime applications.
Implementation Method 1
a coating layer which can reduce the amount of a lithium compound remaining on a surface
Implementation Method 2
suppress surface activation
Data Source
AI summary
The present disclosure relates to a positive electrode active material for a lithium secondary battery and a method of preparing the same, and more particularly, to a positive electrode active material for a lithium secondary battery comprising a lithium-nickel-based transition metal oxide; and a coating layer formed on the lithium-nickel-based transition metal oxide, the coating layer comprising a metal oxalate compound, and a method of preparing the same.