Electrode Slurry Stabilization for High-Solids Li-Ion Cathode Coating
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Solution Overview
Problem
Existing methods for producing lithium-ion battery electrodes face issues such as thickening and gelation of the electrode slurry due to alkaline constituents, leading to non-uniform coatings, increased battery resistance, and environmental and operational challenges.
Innovation Solution
Incorporating a stabilizing ingredient composed of a heterocycle-containing compound and a compound that chemically reacts with it into the electrode slurry, forming a protective film that suppresses reactions between alkaline constituents and the binder, thereby preventing thickening and gelation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-nickel positive electrode active materials are used to achieve high discharge capacity, then battery capacity is improved, but alkaline constituents form on the surface causing slurry thickening and gelation
Solution Approach 1:
A stabilizing ingredient is introduced as an intermediary substance that selectively reacts with alkaline constituents (LiOH, Li2O, LiHCO3, Li2CO3) on the surface of high-nickel positive electrode active materials. This stabilizing ingredient prevents these alkaline constituents from reacting with the binder and causing gelation, while allowing the high-nickel material to maintain its high capacity function. The intermediary substance thus resolves the contradiction by neutralizing the harmful effect without compromising the beneficial property.
2Stability of the object's composition
If alkaline constituents are removed or suppressed to prevent gelation, then slurry stability is improved, but battery capacity decreases
Solution Approach 1:
The harmful alkaline constituents (LiOH, Li2O, LiHCO3, Li2CO3) are selectively extracted or neutralized from the surface of the positive electrode active material through reaction with the stabilizing ingredient. This extraction removes the gelation-causing components while preserving the bulk high-nickel material that provides battery capacity, thus resolving the contradiction between slurry stability and battery capacity.
3Stability of the object's composition
If strict pH control and water dispersion treatment are implemented to prevent gelation, then slurry stability is improved, but operational complexity and production cost increase
Solution Approach 1:
The stabilizing ingredient is added to the slurry formulation in advance, performing preliminary neutralization of alkaline constituents before they can cause gelation during storage or processing. This preliminary action eliminates the need for subsequent complex pH control measures, water dispersion treatments, and filtration steps, thereby simplifying the overall production process while maintaining slurry stability.
4Quantity of substance
If alkaline constituents are present to enable high capacity, then battery capacity is improved, but battery resistance increases due to corrosion of aluminum foil and reaction with electrolyte
Solution Approach 1:
The stabilizing ingredient converts the harmful effect of alkaline constituents into a beneficial outcome by selectively reacting with and neutralizing these constituents. The alkaline constituents that would otherwise cause corrosion of aluminum foil and degradation of electrolyte are transformed into stable salts through reaction with the stabilizing ingredient, thereby maintaining both high battery capacity and low battery resistance.
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 solution enhances shelf stability, allows for higher solids concentration, reduces manufacturing costs, and improves battery characteristics by preventing corrosion and reaction with electrolytes, resulting in improved electrode uniformity and reduced environmental impact.
Implementation Method 1
a stabilizing ingredient, a positive electrode active material, a binder and a solvent, wherein the stabilizing ingredient comprises: a heterocycle-containing compound which has a nitrogen-containing five-membered ring, does not include an oxygen atom in the nitrogen-containing five-membered ring and has a reactive group (first constituent) and a compound which chemically reacts with the heterocycle-containing compound (second constituent)
Data Source
AI summary
The present invention provides, as a composition for electrode formation having improved storage stability and higher solid content concentration, while suppressing thickening and gelation by a simple method, a composition for electrode formation, the composition containing a stabilization component, a positive electrode active material, a binder and a solvent, wherein the stabilization component contains: (first component) a heterocycle-containing compound which has a reactive group and a nitrogen-containing five-membered ring without containing an oxygen atom in the nitrogen-containing five-membered ring, and (second component) a compound which is chemically reactive with the heterocycle-containing compound; the first component, the second component, and a reaction product that is obtained by having the first component and the second component react with each other; or the reaction product that is obtained by having the first component and the second component react with each other.