Particles, positive electrode active material particles, method of producing the same, and non-aqueous electrolyte secondary battery
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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 oxygen concentration are controlled to facilitate crystallization without frequent changes, resulting in particles with high circularity and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If frequent pH and atmosphere changes are made during crystallization to produce nickel composite hydroxide particles, then the crystallization can proceed through different stages, but the particle shape becomes non-uniform and manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by controlling pH within a specific range (10.0-12.5) and oxygen concentration (5-65 vol%) during crystallization to achieve uniform particle shapes with circularity of 0.90 or more, eliminating the need for frequent parameter adjustments while maintaining manufacturing precision
Solution Approach 2:
Instead of changing pH and atmosphere frequently to control crystallization stages, the patent inverts the approach by maintaining stable pH and oxygen concentration conditions throughout the crystallization process, achieving uniform particles without complex procedure changes
2Manufacturing precision
If frequent atmosphere changes are made during crystallization to control particle formation, then different particle structures can be formed, but productivity decreases due to extended processing time
Solution Approach 1:
The patent implements continuity of useful action by maintaining continuous crystallization under stable pH (10.0-12.5) and oxygen concentration (5-65 vol%) conditions without interruption or frequent changes, achieving both particle structure control and improved productivity by eliminating downtime for atmosphere changes
3Manufacturing precision
If pH is maintained at high levels during crystallization to ensure complete reaction, then particle uniformity improves, but energy consumption increases due to pH control requirements
Solution Approach 1:
The patent optimizes the pH parameter by maintaining it within the specific range of 10.0-12.5 during crystallization, which is sufficient to ensure complete reaction and particle uniformity without requiring excessive energy input for pH control, achieving energy-efficient manufacturing of uniform particles
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 method enables the production of particles with enhanced circularity and uniformity, improving packing and capacity properties of the secondary battery, thereby enhancing its output and capacity.
Implementation Method 1
a crystallization step that involves generating a Taylor vortex reaction field
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
AI summary
The present disclosure relates to a method of producing particles that include first particles each having a core portion, a gap portion, and an outer portion 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.