Nickel-Cobalt-Manganese Precursor Particle Size Control
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Solution Overview
Problem
Conventional nickel-cobalt-manganese-based compound particles for lithium ion secondary batteries suffer from inadequate suppression of very fine particles and lack a sharp particle size distribution, which affects the thermal stability and cycle characteristics of the batteries.
Innovation Solution
The development of nickel-cobalt-manganese-based compound particles with a controlled volume-based average secondary particle diameter and half value width, along with a specific molar ratio of Ni:Co:Mn, and a process involving continuous precipitation and concentration to produce particles with uniform size and high crystallinity, which are then mixed with lithium and subjected to heat treatment to form lithium composite oxide particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional nickel-cobalt-manganese-based compound particles are used for lithium ion secondary batteries, then the batteries can achieve high charge/discharge voltage and capacity, but the batteries suffer from poor thermal stability and inadequate suppression of very fine particles generation
Solution Approach 1:
The invention changes the chemical composition parameters of the nickel-cobalt-manganese-based compound particles by controlling the molar ratios of Ni, Co, and Mn within specific ranges (Ni: 30-70 mol%, Co: 5-40 mol%, Mn: 5-40 mol%). This parameter optimization resolves the contradiction by achieving both uniform particle size distribution and high thermal stability simultaneously, eliminating very fine particles while maintaining reliability.
2Quantity of substance
If LiNiO2 is used as positive electrode active substance to achieve high charge/discharge capacity, then the capacity increases, but the material deteriorates in thermal stability and durability upon charging and discharging
Solution Approach 1:
The invention creates a composite nickel-cobalt-manganese-based compound particle system that combines the high capacity特性 of Ni with the thermal stability of Co and Mn. The specific molar ratio composition (Ni: 30-70 mol%, Co: 5-40 mol%, Mn: 5-40 mol%) forms a composite structure that simultaneously achieves high charge/discharge capacity and excellent thermal stability and durability, resolving the contradiction between capacity and reliability.
3Temperature
If nickel-cobalt-manganese-based compound particles with high Co content are used to achieve high charge/discharge voltage, then the voltage increases, but the cost increases due to expensive Co
Solution Approach 1:
The invention optimizes the compositional parameters by limiting Co content to 5-40 mol% while maintaining Ni at 30-70 mol% for high voltage characteristics. This parameter adjustment achieves the desired charge/discharge voltage while controlling material cost, as the Co content is sufficient for voltage enhancement but not excessive to cause cost problems.
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 resulting lithium composite oxide particles exhibit improved thermal stability, high capacity, excellent rate characteristics, and enhanced cycle performance at both room and high temperatures, reducing battery swelling and maintaining performance over multiple charge-discharge cycles.
Implementation Method 1
nickel-cobalt-manganese-based compound particles which can be said to be produced through precipitation
Implementation Method 2
the resulting mixture is subjected to heat treatment to form lithium composite oxide particles
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
The present invention relates to nickel-cobalt-manganese-based compound particles which have a volume-based average secondary particle diameter (D50) of 3.0 to 25.0 µm, wherein the volume-based average secondary particle diameter (D50) and a half value width (W) of the peak in volume-based particle size distribution of secondary particles thereof satisfy the relational formula: W ≤ 0.4 x D50, and can be produced by dropping a metal salt-containing solution and an alkali solution to an alkali solution at the same time, followed by subjecting the obtained reaction solution to neutralization and precipitation reaction. The nickel-cobalt-manganese-based compound particles according to the present invention have a uniform particle size, a less content of very fine particles, a high crystallinity and a large primary particle diameter, and therefore are useful as a precursor of a positive electrode active substance used in a non-aqueous electrolyte secondary battery.