Coated Lithium-Nickel Composite Oxide Particles for Battery Stability
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Solution Overview
Problem
Lithium-nickel composite oxide particles with high nickel content are sensitive to environmental conditions, leading to reactivity with water and carbon dioxide, resulting in impurity deposition and battery instability, which requires costly controlled production environments, and existing coatings fail to provide long-term stability and prevent impurity generation.
Innovation Solution
A method of coating lithium-nickel composite oxide particles with a polymer layer, specifically using modified polyolefin, polyester, polyphenol, polyurethane, or silane-modified resins that provide both adsorption and ionic conductivity, ensuring the coating adheres and prevents moisture and carbon dioxide permeation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium-nickel composite oxide particles with high nickel content are used to achieve higher capacity, then the theoretical capacity is improved, but the reactivity with water and carbon dioxide increases, leading to impurity deposition and safety problems
Solution Approach 1:
The patent applies composite materials by combining lithium-nickel composite oxide particles with a polymer coating layer. The polymer component (acrylic resin, styrene resin, or their copolymers) forms a protective composite structure around the high-nickel core particles, enabling the system to maintain high theoretical capacity while reducing reactivity with water and carbon dioxide through the barrier properties of the polymer shell.
Solution Approach 2:
The patent uses a flexible polymer coating shell made of acrylic resin, styrene resin, or their copolymers to encapsulate the lithium-nickel composite oxide particles. This thin film barrier prevents direct contact between the reactive particle surface and environmental moisture and carbon dioxide, thereby suppressing impurity generation while allowing the high-capacity nickel-based material to function effectively.
2Object-affected harmful factors
If existing coating agents such as inorganic materials or fluorine-containing polymers are used, then moisture adsorption is suppressed, but the coating layer redissolves in NMP during slurry production, causing detachment and failure to prevent impurity generation
Solution Approach 1:
The patent changes the chemical composition parameters of the coating material by selecting acrylic resins, styrene resins, or their copolymers with specific molecular weight ranges (10,000-1,000,000). These parameter selections ensure the coating has sufficient chemical stability to resist redissolution in NMP during slurry production while maintaining effective moisture and carbon dioxide barrier properties.
Solution Approach 2:
The patent employs a coating material that is stable and durable under processing conditions, replacing the previously used unstable fluorine-containing polymer coatings. The acrylic or styrene-based polymer coating provides long-term stability during slurry preparation and battery operation, preventing both detachment and impurity generation throughout the battery lifecycle.
3Object-generated harmful factors
If a dry (low humidity) environment in a decarbonated atmosphere is maintained during production, then impurity generation is prevented, but the facility introduction cost and running cost increase significantly
Solution Approach 1:
The patent applies preliminary action by pre-coating the lithium-nickel composite oxide particles with a stable polymer layer before positive electrode production. This pre-protective coating enables the particles to be handled and processed in standard atmospheric conditions without requiring costly dry and decarbonated environments, as the coating prevents impurity generation during subsequent production steps.
Solution Approach 2:
The patent introduces a polymer coating intermediary layer that acts as a barrier between the lithium-nickel composite oxide particles and the production environment. This intermediary coating allows production to proceed in standard atmospheric conditions by preventing direct reaction between the particles and environmental moisture and carbon dioxide, thereby eliminating the need for expensive controlled atmosphere facilities.
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 improved environmental stability, allowing for handling and storage in standard conditions, reducing production costs, and maintaining battery performance by suppressing impurity generation and gelation in the electrode slurry.
Implementation Method 1
a polymer or copolymer coating a particle surface that includes at least one kind selected from the group consisting of a modified polyolefin resin, a polyester resin, a polyphenol resin, a polyurethane resin, an epoxy resin, a silane-modified polyether resin, a silane-modified polyester resin, a silane-modified polyphenol resin, a silane-modified polyurethane resin, a silane-modified epoxy resin, and a silane-modified polyamide resin
Implementation Method 2
having both the adsorption between particle and polymer and the ionic conductivity
Implementation Method 3
ensuring the coating adheres and prevents moisture and carbon dioxide permeation
Data Source
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AI summary
Provided are excellent coated lithium-nickel composite oxide particles which are capable of suppressing the occurrence of impurities produced by absorbing water and carbonic acid gas as a result of the high environmental stability thereof, have strong adhesion properties, do not result in easy coating layer detachment, and also exhibit lithium ion conductivity. The surface of the lithium-nickel composite oxide particles is coated with a polymer or copolymer comprising one or more types selected from a group consisting of a modified polyolefin resin, a polyester resin, a polyphenol resin, a polyurethane resin, an epoxy resin, a silane-modified polyether resin, a silane-modified polyester resin, a silane-modified polyphenol resin, a silane-modified polyurethane resin, a silane-modified epoxy resin, and a silane-modified polyamide resin. As a result, the coated lithium-nickel composite oxide particles exhibit conductivity, and said compound is capable of suppressing the transmission of water and carbonic acid gas. Consequently, it is possible to provide coated lithium-nickel composite oxide particles for use in a lithium-ion battery positive electrode active material which is excellent for use in a lithium-ion battery.