Positive Electrode Material Washing for Residual Lithium Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for preparing nickel-based positive electrode active materials result in residual lithium and by-products on the surface, leading to battery performance deterioration, stability issues, and gelation during electrode slurry preparation, necessitating a method to effectively control residual lithium and minimize surface deterioration.
Innovation Solution
A method involving the preparation of lithium transition metal oxides, followed by a two-step water-washing and filtering process using specific ratios of water-washing solutions, and optionally forming a coating layer to enhance surface stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a large amount of water-washing solution is used to effectively control residual lithium, then residual lithium is reduced, but surface deterioration of positive electrode active materials occurs and battery performance degrades
Solution Approach 1:
The water-washing process is divided into multiple sequential steps (first water-washing, second water-washing, third water-washing) with each step using a controlled amount of water-washing solution. This segmentation allows effective removal of residual lithium while limiting surface deterioration that would occur with a single large-volume washing step.
Solution Approach 2:
The patent employs periodic water-washing actions with intermittent filtering steps. Between water-washing steps, the slurry is filtered to remove by-products, creating a periodic cycle of washing and filtering that maintains effectiveness while reducing overall water consumption and surface damage.
2Quantity of substance
If a large amount of water-washing solution is used to effectively control residual lithium, then residual lithium is reduced, but the amount of water-washing solution increases causing process issues
Solution Approach 1:
The water-washing process is divided into multiple sequential steps (first water-washing, second water-washing, third water-washing) with each step using a controlled amount of water-washing solution. This segmentation allows effective removal of residual lithium while limiting surface deterioration that would occur with a single large-volume washing step.
Solution Approach 2:
The patent implements a filtering step after water-washing to remove by-products from the slurry. This allows the water-washing solution to be more efficiently used, as the filtering removes contaminants that would otherwise require additional washing, effectively recovering the washing process efficiency.
3Quantity of substance
If conventional water-washing process is used, then residual lithium is removed, but surface deterioration occurs leading to increased resistance and reduced lifespan
Solution Approach 1:
The water-washing process is divided into multiple sequential steps (first water-washing, second water-washing, third water-washing) with each step using a controlled amount of water-washing solution. This segmentation allows effective removal of residual lithium while limiting surface deterioration that would occur with a single large-volume washing step.
Solution Approach 2:
The patent performs water-washing steps at controlled intervals during the preparation process, rather than as a single final step. This preliminary and intermediate washing action prevents excessive accumulation of by-products that would require aggressive final washing, thereby protecting the surface of the active material.
4Quantity of substance
If conventional water-washing process is used, then residual lithium is removed, but by-products remain causing gelation in electrode slurry preparation
Solution Approach 1:
The patent employs periodic water-washing actions with intermittent filtering steps. Between water-washing steps, the slurry is filtered to remove by-products, creating a periodic cycle of washing and filtering that maintains effectiveness while reducing overall water consumption and surface damage.
Solution Approach 2:
The patent implements a filtering step after water-washing to remove by-products from the slurry. This allows the water-washing solution to be more efficiently used, as the filtering removes contaminants that would otherwise require additional washing, effectively recovering the washing process efficiency.
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 reduces the amount of water-washing solution used, minimizes surface deterioration, effectively controls residual lithium, and improves the electrochemical and thermal stability of the positive electrode active material, resulting in enhanced battery performance.
Implementation Method 1
mixing the lithium transition metal oxide with a first water-washing solution to perform a first water-washing
Implementation Method 2
a first filtering on the lithium transition metal oxide
Data Source
AI summary
A method of preparing a positive electrode active material and a positive electrode active material prepared by the same are disclosed herein. The method is capable of reducing an amount of a water-washing solution used, minimizing surface deterioration of the positive electrode active material, and effectively controlling residual lithium. In some embodiments, a method includes: performing a first water-washing of a lithium transition metal oxide in a first water-washing solution, performing a first filtering to separate the lithium transition metal oxide from the first water-washing solution, and performing, concurrently, a second water-washing and a second filtering of the lithium transition metal oxide with a second water-washing solution using a filtering device capable of concurrently water-washing and filtering, wherein the second water-washing solution is in an amount of 10 parts by weight to 50 parts by weight with respect to 100 parts by weight of the first water-washing solution.