Lithium Nickel Composite Oxide Surface Layer for Residual Lithium Removal
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Solution Overview
Problem
Lithium secondary batteries face issues with residual lithium on the surface of positive electrode active materials, leading to deteriorated cycle characteristics and stability, which affects their capacity and safety.
Innovation Solution
A positive electrode active material with a core of lithium nickel composite oxide and a surface layer containing water-soluble ammonium-based or amine-based organic compounds is developed, along with a method involving heat treatment and washing processes to prevent residual lithium formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water washing and drying are performed to remove residual lithium, then residual lithium on the surface is reduced, but capacity and cycle-life of the battery decrease and surface resistance increases
Solution Approach 1:
The patent extracts and removes residual lithium from the surface of the positive electrode active material through water washing and drying processes. This directly addresses the harmful factor by extracting the unwanted substance (residual lithium) from the material surface, preventing its negative effects on battery performance.
Solution Approach 2:
The patent applies parameter changes by controlling washing conditions (water temperature, washing time, drying temperature) to optimize the removal of residual lithium while minimizing damage to the active material. By adjusting these parameters, the patent seeks to achieve effective lithium removal without causing excessive capacity loss or surface resistance increase.
2Object-affected harmful factors
If water washing and drying are performed to remove residual lithium, then residual lithium on the surface is reduced, but surface resistance of the active material increases
Solution Approach 1:
The patent extracts residual lithium from the surface through controlled water washing, removing the harmful substance that causes both cycle-life degradation and surface resistance increase. The extraction process is optimized to remove lithium without causing excessive surface damage.
Solution Approach 2:
The patent controls washing and drying parameters (water temperature, washing duration, drying temperature) to minimize surface resistance increase while effectively removing residual lithium. By optimizing these parameters, the patent reduces the harmful effects on surface resistance.
3Object-affected harmful factors
If water washing and drying are performed to remove residual lithium, then residual lithium on the surface is reduced, but capacity of the battery decreases
Solution Approach 1:
The patent extracts residual lithium from the positive electrode active material surface through water washing, removing the harmful substance that degrades battery performance. This extraction targets only the surface residual lithium while preserving the bulk material capacity.
Solution Approach 2:
The patent optimizes washing and drying parameters (water temperature, washing time, drying temperature) to minimize capacity loss while effectively removing residual lithium. By carefully controlling these parameters, the patent reduces the negative impact on battery capacity.
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 approach enhances the cycle characteristics and safety of lithium secondary batteries by preventing residual lithium on the surface, improving thermal stability and maintaining passivation while maintaining high capacity and binding force.
Implementation Method 1
a surface layer present on the core and including at least one of a water-soluble ammonium-based organic compound and a water-soluble amine-based organic compound
Implementation Method 2
forming a positive electrode active material through a heat treatment process
Data Source
AI summary
The present disclosure relates to a positive electrode active material, a preparing method therefor, and a lithium secondary battery including same. A positive electrode active material according to an embodiment comprises: a core including a lithium nickel composite oxide represented by Chemical Formula 1; and a surface layer present on the core and including at least one of a water-soluble ammonium-based organic compound and a water-soluble amine-based organic compound. The details of Chemical Formula 1 are as defined in the specification.