Core-Shell Lithium-Ion Anode Material for High Energy Density
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Solution Overview
Problem
Current lithium-ion battery anode materials with high nickel content face issues such as surface reduction, capacity degradation, and safety hazards due to high surface activity and the need for additional calcination steps, which result in non-uniform coating and reduced performance.
Innovation Solution
A novel anode material structure comprising a core, transition layer, and shell layer, where the shell layer is Li1+xNi1−y−zCoyMnzO2 and the transition layer is selected from Al2O3, ZrO2, or other oxides, with a manufacturing method that deposits these layers before sintering, reducing nickel surface content and enhancing stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high nickel content material is used to increase capacity, then energy density is improved, but surface activity increases causing reduction and capacity degradation
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the core contains high nickel content (0.8-0.95) for high capacity, while the shell contains low nickel content (0.1-0.5) for surface stability. This spatial differentiation allows the high-nickel core to provide energy density while the low-nickel shell prevents surface reduction and capacity degradation, resolving the contradiction between bulk performance and surface stability.
2Reliability
If coating process is applied to sintered material, then protective layer is formed, but additional secondary calcination is required increasing process complexity
Solution Approach 1:
The patent applies preliminary action by forming the low-nickel shell layer on the precursor particles before sintering. This pre-coating approach allows the protective shell to be in place before the high-temperature sintering process, eliminating the need for subsequent secondary calcination steps that would be required if coating were applied after sintering. The shell is formed during the sintering process itself, simplifying the overall manufacturing流程.
3Reliability
If coating is performed on sintered material, then surface protection is achieved, but coating layer is non-uniform and has small content
Solution Approach 1:
By forming the shell layer on the precursor before sintering, the coating has a better opportunity to uniformly cover the particle surface when the particles are in their precursor state with more uniform morphology. The subsequent sintering process then densifies both the core and shell together, ensuring uniform thickness and composition throughout the shell layer, avoiding the non-uniformity that would result from post-sintering coating.
4Object-affected harmful factors
If oxide coating is applied to reduce nickel contact, then harmful factors are reduced, but deintercalation capacity for lithium ions is lost
Solution Approach 1:
The patent applies parameter changes by carefully controlling the nickel content in the shell layer (0.1-0.5) to strike a balance between protection and electrochemical activity. This optimized composition allows the shell to provide sufficient protection against nickel reduction while maintaining enough nickel content to preserve lithium ion deintercalation capacity. The thin shell design also ensures that the protective function is achieved without excessive material that would block ion transport.
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 proposed solution results in an anode material with improved energy density, reduced nickel surface content, and enhanced cycle stability, overcoming the limitations of existing high-nickel materials by forming a stable and active shell layer that inhibits nickel diffusion and supports high-voltage operation.
Implementation Method 1
the transition layer and the shell layer can be used to reduce the nickel element content of the material surface, so that the surface activity is reduced and the harm of nickel element diffusion to the surface is avoided
Implementation Method 2
the cladding layer is not electrochemically active material and do not possess deintercalation capacity for the lithium ions
Data Source
AI summary
The present invention relates to a modified lithium ion battery anode material having high energy density, and a manufacturing process thereof, the anode material comprising, from inside to outside, a core, a transition layer and a shell layer. The anode material of the present invention has the advantages of high energy density, low surface activity, good storage performance, and a simple manufacturing process, and is suitable for large scale application.