Nickel-Based Lithium Metal Composite Oxide Particle Segmentation
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Solution Overview
Problem
The existing methods for preparing nickel-based lithium metal composite oxides for lithium secondary batteries involve complex and costly processes due to the need for separate heat treatments of large and small secondary particles, which can lead to inconsistent performance and increased manufacturing costs.
Innovation Solution
A method of simultaneously heat-treating large and small nickel-based lithium metal hydroxides with specific manganese and aluminum content distributions, ensuring optimal particle strength and composition to enhance structural stability and energy density, while reducing the number of heat treatment steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If large and small secondary particles are separately heat-treated, then calcination performance is improved, but process complexity and manufacturing cost increase
Solution Approach 1:
The patent segments the secondary particles into large particles (≥14 μm) and small particles (≤5 μm) with distinct compositional characteristics. Large particles contain Al in their core region while small particles contain Mn in their core region, allowing each size fraction to be optimized independently through separate heat treatment processes while maintaining overall particle strength and preventing disintegration during electrode fabrication
Solution Approach 2:
The patent combines the separately heat-treated large and small secondary particles into a mixed particle composition for the positive active material. This merging approach allows the benefits of size-specific optimization to be realized while creating a composite particle system that maintains structural integrity and prevents disintegration during pressing and electrode formation
2Strength
If large and small secondary particles are separately heat-treated, then particle strength is improved, but manufacturing cost increases
Solution Approach 1:
The patent segments the heat treatment process by particle size, applying different thermal histories to large particles (≥14 μm) and small particles (≤5 μm). This segmentation allows each particle size fraction to achieve optimal crystallinity and structural strength tailored to its specific requirements, preventing disintegration during subsequent processing while avoiding the need for overly conservative heat treatment conditions that would increase manufacturing costs
Solution Approach 2:
The patent implements local quality optimization by creating compositional gradients within particles - large particles have Al-enriched cores while small particles have Mn-enriched cores. This local compositional differentiation allows each particle to exhibit enhanced strength and stability in its specific size range, with the core composition providing structural support while the shell composition provides surface stability
3Quantity of substance
If mixed particle sizes are used, then energy density is improved, but particle disintegration occurs
Solution Approach 1:
The patent segments the particle population into distinct size fractions with optimized compositions - large particles (≥14 μm) provide structural stability and prevent disintegration, while small particles (≤5 μm) increase surface area and energy density. The segmentation allows each fraction to fulfill its specific functional role without compromising the other
Solution Approach 2:
The patent creates a composite particle system by combining large Al-containing particles and small Mn-containing particles in a mixed composition. This composite approach leverages the structural stability of large particles to prevent disintegration while incorporating small particles to increase energy density, achieving both goals simultaneously through synergistic particle interaction
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
This approach results in nickel-based lithium metal composite oxides with improved structural stability, high energy density, and extended lifespan characteristics for lithium secondary batteries, while simplifying the manufacturing process and reducing costs.
Implementation Method 1
In a process of preparing the lithium metal composite oxide, heat treatment may be performed. Particularly, a Ni-based lithium metal composite oxide using nickel as one of metal elements may have improved performance via appropriate heat treatment.
Data Source
AI summary
A nickel-based lithium metal composite oxide including secondary particles including aggregates of primary particles. The secondary particles include i) large secondary particles having a particle size of at least about 14 μm and including aluminum and ii) small secondary particles having a particle size of no more than about 5 μm and including manganese, and a manganese content by mole percent of each of the large secondary particles is smaller than a manganese content by mole percent of each of the small secondary particles and manganese is included on a surface of each of the large secondary particles and aluminum is included on a surface of each of the small secondary particles.