Ti/Mg-Doped Lithium Nickel Oxide for High-Density Cathode Rolling
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Solution Overview
Problem
Existing lithium secondary battery positive electrode materials face issues with particle breakage during high-pressure rolling, leading to increased specific surface area and accelerated side reactions with the electrolyte, resulting in gas generation and reduced lifespan characteristics.
Innovation Solution
A lithium nickel-based oxide doped with specific amounts of titanium or magnesium, or a combination thereof, to minimize particle breakage and reduce side reactions, improving the electrode's stability and lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If rolling pressure is increased to increase electrode density, then electrode density is improved, but particle breakage occurs leading to increased specific surface area and accelerated side reactions
Solution Approach 1:
The patent applies parameter changes by doping the lithium nickel-based oxide particles with aluminum at controlled concentrations (0.01-0.1 atomic ratio of Al to Ni). This doping modifies the crystal structure parameters and physical properties of the particles, enhancing their mechanical strength and resistance to breakage during rolling, thereby enabling high electrode density without particle fragmentation.
Solution Approach 2:
The patent creates a composite material system by incorporating aluminum-doped lithium nickel-based oxide particles into the electrode structure. The aluminum doping creates a composite crystal structure that combines the high capacity characteristics of lithium nickel oxide with the structural stability of aluminum-doped phases, resulting in particles that maintain integrity under high rolling pressure while achieving high electrode density.
2Strength
If particle breakage is prevented during rolling, then specific surface area is controlled, but electrode density may be reduced
Solution Approach 1:
The patent modifies particle parameters through aluminum doping to achieve optimal balance between integrity and density. The doping concentration (0.01-0.1 atomic ratio) is precisely controlled to enhance particle strength without excessive growth or aggregation, allowing the particles to maintain integrity during rolling while still achieving high electrode density through controlled packing.
3Strength
If aluminum doping is applied to prevent particle breakage, then particle strength is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by incorporating aluminum doping during the precursor synthesis stage or initial particle formation process. This preliminary doping ensures that the protective aluminum phase is already integrated into the particle structure before the rolling process, eliminating the need for additional post-synthesis treatment steps and simplifying the overall manufacturing process while maintaining particle strength.
Data Source
AI summary
The present disclosure provides a positive electrode active material for a secondary battery, comprising: a lithium nickel-based oxide doped with a doping element (M′),wherein the doping element (M′) is at least one selected from the group consisting of titanium (Ti) and magnesium (Mg),wherein when the doping element (M′) is Ti, the doping content of Ti is 3000 ppm to 5000 ppm based on the total amount of the lithium nickel-based oxide excluding the doping element,wherein when the doping element (M′) is Mg, the doping content of Mg is 500 ppm to 5000 ppm based on the total amount of the lithium nickel-based oxide excluding the doping element, andwherein when the doping element (M′) is Ti and Mg, the total doping content of Ti and Mg is 3500 ppm to 5000 ppm based on the total amount of the lithium nickel oxide excluding the doping elements.