LMNO Cathode Coating for Low-Water Aqueous Electrode Processing
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Solution Overview
Problem
The manufacturing of lithium-manganese-nickel oxide spinel cathodes for lithium-ion cells is hindered by the use of expensive and toxic organic solvents, which require lengthy drying processes to remove water traces, affecting electrolyte stability and integrity.
Innovation Solution
Applying a coating of specific oxides around lithium-manganese-nickel oxide particles to reduce their water affinity, improving electrolyte stability and adhesion to current collectors, using an aqueous medium and a method involving lithium salts, titanium ions, and heat treatment to achieve a coating with reduced water content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an aqueous solvent is used to replace organic solvent in the ink, then the toxicity and cost are reduced, but the drying time increases and water content remains high
Solution Approach 1:
The patent extracts the harmful organic solvent from the ink formulation and replaces it with an aqueous solvent system. The water removal function is extracted and performed by the hydrophobic coating on the cathode, which actively repels and excludes water molecules from the electrode structure during the drying process, enabling faster water evacuation without requiring prolonged drying times.
Solution Approach 2:
The hydrophobic coating acts as an intermediary layer between the aqueous ink and the environment. This coating mediates the water removal process by providing a water-repelling interface that facilitates rapid water evacuation from the electrode while maintaining the integrity of the aqueous-based ink formulation, thus enabling fast drying without using organic solvents.
2Object-affected harmful factors
If an aqueous solvent is used in the ink, then the cost and toxicity are reduced, but the water content in the electrode increases, affecting electrolyte stability
Solution Approach 1:
The patent extracts excess water from the electrode through the hydrophobic coating mechanism. The coating actively removes water molecules from the electrode structure during and after the drying process, ensuring that the final electrode contains minimal water content despite being manufactured with an aqueous ink, thereby preserving electrolyte stability.
Solution Approach 2:
The hydrophobic coating serves as an intermediary that protects the electrolyte from water contamination. By creating a water-repelling barrier on the cathode surface, the coating prevents residual water from migrating into the electrolyte, thus maintaining electrolyte stability while allowing the use of safe aqueous solvents in the ink formulation.
3Loss of time
If a coating of specific oxides is applied around LMNO particles, then water affinity is reduced and residual water content decreases, but the manufacturing process complexity increases
Solution Approach 1:
The patent modifies the surface properties of LMNO particles by applying a hydrophobic oxide coating, which changes the surface energy parameters to reduce water affinity. This parameter change in surface hydrophobicity enables rapid water removal during drying without requiring complex manufacturing equipment or multi-step processes, achieving fast drying through material property modification alone.
4Ease of manufacture
If organic solvent is used in the ink, then the binder compatibility is ensured, but the cost increases and toxicity increases
Solution Approach 1:
The patent replaces expensive and toxic organic solvents with a cheap and safe aqueous solvent system. The hydrophobic oxide coating on the LMNO particles compensates for any potential binder compatibility issues that might arise from the solvent change, enabling the use of water as a disposable, safe medium that evaporates completely without leaving harmful residues.
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 particles exhibit significantly reduced residual water content, enhanced electrolyte stability, and improved adhesion to current collectors, shortening manufacturing time and increasing the safety and thermal stability of lithium-ion cells.
Implementation Method 1
the application of a coating consisting of certain oxides around the lithium-manganese-nickel oxide LMNO particles makes it possible to reduce the affinity of these particles for water
Implementation Method 2
The elimination of traces of water makes it necessary to subject the electrode to a drying step which is long
Data Source
AI summary
A compound of formula LixMn2-y-zNiyMO4-d-cFc (LMNO) where M is one or more elements chosen from the group consisting of B, Mg, Al, Si, Ca, Ti, V, Cr, Fe, Co, Cu, Zn, Y, Zr, Nb, Ru, W and Mo; and 1≤x≤1.4; 0<y≤0.6; 0≤z≤0.2; 0≤d≤1; 0≤c≤1 and the surface of which is at least partially covered with a coating of an oxide or of a lithium oxide. The oxygen of the oxide is partially substituted with fluorine. In the lithium oxide, either the lithium is partially substituted with Na, K or Mg, or the oxygen is partially substituted with fluorine, or the lithium is partially substituted with Na, K or Mg, and the oxygen is partially substituted with fluorine. The creation of the coating makes it possible to reduce the affinity of the LMNO compound for water.