Core-Shell Hydroxide Particles with Taylor Vortex Crystallization
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Solution Overview
Problem
Existing methods for producing nickel composite hydroxide particles for non-aqueous electrolyte secondary batteries are complex, leading to non-uniform particle shapes and poor performance due to the need for frequent pH and atmosphere changes during crystallization, which affects the output and capacity properties of the batteries.
Innovation Solution
A method involving a Taylor vortex reaction field is used to produce particles with a core, gap, and outer portions made of nickel-containing transition metal composite hydroxide, where pH and atmosphere changes are minimized, allowing for controlled crystallization and enhanced particle circularity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If frequent pH and atmosphere changes are made during crystallization to produce nickel composite hydroxide particles, then the crystallization process can be completed, but the particle shape becomes non-uniform and manufacturing precision deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the pH to 12.5 or less before starting crystallization and maintaining it throughout the process. The oxidizing atmosphere is established beforehand and maintained continuously during both nucleation and growth steps, eliminating the need for intermediate pH and atmosphere changes that cause particle shape non-uniformity.
2Productivity
If complex crystallization procedures with multiple pH and atmosphere changes are used, then nickel composite hydroxide particles can be produced, but the process complexity increases
Solution Approach 1:
The patent implements continuity of useful action by maintaining a constant pH (12.5 or less) and continuous oxidizing atmosphere throughout the entire crystallization process from nucleation to growth. This eliminates the need for intermediate adjustments and changes, simplifying the procedure while ensuring complete particle production.
3Productivity
If frequent atmosphere changes are made during crystallization, then the crystallization can proceed through different stages, but the porosity control becomes difficult
Solution Approach 1:
The patent applies preliminary action by establishing the oxidizing atmosphere before crystallization begins and maintaining it continuously throughout both nucleation and growth stages. This preliminary setup eliminates the need for intermediate atmosphere changes, enabling precise control over porosity while ensuring complete crystallization stage progression.
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 particles with high circularity and uniformity, improving packing and capacity properties of the positive electrode active material, thereby enhancing the performance of non-aqueous electrolyte secondary batteries.
Implementation Method 1
A method involving a Taylor vortex reaction field is used to produce particles with a core, gap, and outer portions made of nickel-containing transition metal composite hydroxide
Implementation Method 2
adding an aqueous solution containing a transition-metal-containing compound, an ammonium supplier, and an aqueous alkaline solution to the Taylor vortex reaction field to allow crystallization of a nickel-containing transition metal composite hydroxide to proceed
Implementation Method 3
allow crystallization of a nickel-containing transition metal composite hydroxide to proceed
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The present disclosure relates to a method of producing particles that include first particles (20) each having a core portion (21), a gap portion (22), and an outer portion (23) and each made of a nickel-containing transition metal composite hydroxide. In the method of producing particles according to the present disclosure, a pH of the Taylor vortex reaction field at a liquid temperature of 25°C is 12.5 or less, a first crystallization is performed in which the crystallization is allowed to proceed at an oxygen concentration of the Taylor vortex reaction field of 3.5 vol% or less, a second crystallization is performed in which the oxygen concentration of the Taylor vortex reaction field is changed to a range of 5 vol% to 65 vol% and the crystallization is allowed to proceed, and a duration of the first crystallization is from 40% to 90% of a total crystallization duration.