Single-Crystal Cathode Material for Lithium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The development of lithium secondary batteries with high energy density faces challenges in safety and increased manufacturing costs due to the use of flux in preparing single-crystal cathode active materials, which requires a washing process and high-temperature heat treatment, leading to particle agglomeration and reduced productivity.
Innovation Solution
A nickel-based lithium metal oxide cathode active material with single-crystal particles of specific size distribution is developed without using flux, achieved through a method involving co-precipitation reactions, heat treatments, and pulverization to enhance structural and morphological stability, thereby improving cycle characteristics and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a flux is used to prepare single-crystal cathode active material, then single-crystal structure is achieved, but washing process is required and residual salt remains
Solution Approach 1:
The patent removes the flux component from the preparation process entirely. By using a solid-state reaction method without flux, the need for washing processes to remove residual salt is eliminated, while still achieving single-crystal cathode active material with controlled particle size distribution.
Solution Approach 2:
The patent replaces the flux-based method with a simpler solid-state reaction approach that uses common precursors and eliminates the need for expensive washing and drying processes to remove flux residues, simplifying the manufacturing workflow.
2Stability of the object's composition
If high-temperature heat treatment is applied for single-crystallization, then single-crystal structure is formed, but particle agglomeration occurs and productivity is reduced
Solution Approach 1:
The patent performs preliminary particle size control during the precipitation step, creating uniformly sized precursor particles before the solid-state reaction. This preliminary sizing prevents agglomeration during subsequent heat treatment, maintaining high productivity while achieving single-crystal structure.
Solution Approach 2:
The patent changes the heating rate parameter during heat treatment, using a controlled heating rate that allows single-crystal formation without excessive particle agglomeration. This parameter optimization maintains both structural quality and manufacturing efficiency.
3Manufacturing precision
If washing process is implemented to remove residual salt, then purity is improved, but manufacturing cost increases and process complexity increases
Solution Approach 1:
The patent extracts the flux component from the process, which eliminates the source of residual salt that would require washing. This removes the entire washing and drying sequence from the manufacturing process, reducing both complexity and cost while maintaining purity through the inherent cleanliness of the flux-free solid-state reaction.
4Stability of the object's composition
If flux-based single-crystal preparation is used, then single-crystal cathode active material is obtained, but energy consumption increases due to high-temperature heat treatment
Solution Approach 1:
The patent performs preliminary particle formation and size control at lower temperatures during the precipitation step. This preliminary action reduces the subsequent heat treatment temperature and time required for single-crystal formation, thereby reducing energy consumption while maintaining structural quality.
Solution Approach 2:
The patent optimizes the heating rate and temperature parameters during heat treatment, using a controlled approach that achieves single-crystal structure at lower energy input compared to conventional flux-based methods that require prolonged high-temperature treatment.
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 solution results in a lithium secondary battery with improved cycle characteristics, reduced aggregation, and enhanced safety, allowing for mass production with increased energy density and prolonged lifespan.
Implementation Method 1
obtaining a nickel-based metal precursor having pores therein by a co-precipitation reaction of a nickel precursor and at least one compound selected from the group consisting of an M1 precursor and an M2 precursor
Implementation Method 2
performing a first heat treatment of the mixture to obtain porous oxide particles
Implementation Method 3
pulverizing the porous oxide particles
Data Source
AI summary
Provided are a cathode active material for a lithium secondary battery, a method of preparing the same, and a lithium secondary battery containing a cathode including the cathode active material, in which the cathode active material includes nickel-based lithium metal oxide containing single-crystal particles, and a particle size of the single-crystal particles is about 1 μm to about 8 μm, and a particle size distribution of the single-crystal particles expressed by (D90-D10)/D50 is 1.4 or less.