Cathode Active Material Rinsing with Thiol Compounds
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Solution Overview
Problem
Lithium secondary batteries face issues with residual lithium on the surface of cathode active materials, leading to swelling and reduced stability due to reactions with the electrolyte, and existing manufacturing methods do not effectively minimize residual lithium and sulfur content.
Innovation Solution
A method for manufacturing cathode active materials with a specific chemical structure (Lix1Ni1-y1M1y1O2-αXα or Lix1Ni1-y2-z2Coy2M2z2O2-αXα) involves rinsing with a solution containing a compound with a thiol group, followed by drying, to reduce residual lithium and sulfur content, using compounds like 1,3,4-thiadiazole-2,5-dithiol and maintaining a reactor temperature between 5 to 50°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional manufacturing methods are used to produce cathode active materials, then production efficiency is maintained, but residual lithium on the surface remains high causing swelling and reduced stability
Solution Approach 1:
The patent applies preliminary action by performing a rinsing treatment with thiol-containing solution immediately after the cathode active material is formed but before battery assembly. This preliminary removal of residual lithium prevents subsequent harmful reactions with electrolyte that would cause swelling and stability issues, addressing the problem at the source rather than after damage occurs.
Solution Approach 2:
The patent introduces a thiol-containing solution as an intermediary substance to facilitate the removal of residual lithium. The thiol group in the solution acts as a mediator that selectively binds to and removes residual lithium and sulfur compounds from the cathode material surface through chemical interaction, enabling effective cleaning without damaging the active material structure.
2Reliability
If conventional rinsing methods are used, then processing simplicity is maintained, but residual sulfur content remains high affecting battery performance
Solution Approach 1:
The thiol-containing solution serves as a specialized intermediary agent that selectively removes sulfur compounds from the cathode material surface. The thiol groups in the solution have high affinity for sulfur, enabling effective removal of residual sulfur that would otherwise degrade battery performance, while the solution itself can be recovered and reused.
Solution Approach 2:
The patent applies parameter changes by controlling the temperature of the rinsing process between 5 to 50°C and adjusting the concentration of thiol-containing solution. These parameter optimizations enhance the effectiveness of sulfur removal while maintaining process efficiency and enabling solution reuse, thereby improving charge/discharge efficiency without excessive complexity.
3Reliability
If additional rinsing steps are added to reduce residual lithium, then battery stability improves, but manufacturing complexity increases
Solution Approach 1:
The thiol-containing solution acts as a multi-functional intermediary that simultaneously removes both residual lithium and sulfur compounds in a single treatment step. This consolidates what would otherwise require multiple separate rinsing operations into one efficient process, improving high temperature stability without proportionally increasing manufacturing complexity.
Solution Approach 2:
The patent implements resource recovery by collecting and reusing the thiol-containing rinsing solution after it has removed residual lithium and sulfur. This recovery approach reduces waste and minimizes the need for fresh solution, thereby improving battery stability through effective cleaning while reducing the overall complexity and cost of the manufacturing 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 significantly decreases residual lithium to 0.3% by weight or less and sulfur to 500 ppm, enhancing the stability and performance of lithium secondary batteries by improving charge/discharge efficiency and cycle life.
Implementation Method 1
rinsing the cathode active material using a solution including a compound including a thiol group
Implementation Method 2
rinsed by a compound including thiol group, such that it may include residual sulfur on a surface
Implementation Method 3
drying the rinsed cathode active material
Data Source
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AI summary
Disclosed are a method of manufacturing a cathode active material and a cathode active material manufactured by the same, and more particularly, a cathode active material which is rinsed by a compound including thiol group, includes residual sulfur on a surface, and has decreased residual lithium and a method of manufacturing the same.