Cathode Precursor Coprecipitation for Uniform 3-5 µm Particle Size
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Solution Overview
Problem
Current methods for preparing positive electrode active material precursors for lithium secondary batteries face challenges in achieving small particle diameters with uniformity and high yield, particularly in controlling particle size and preventing growth during the synthesis process, which limits the production of large quantities with reduced preparation time.
Innovation Solution
A method involving the addition of a metal additive, such as tungsten or molybdenum, to the initial reaction solution in a batch-type reactor, along with deionized water and a basic aqueous solution, to control the co-precipitation reaction and maintain a pH range of 11 to 13, facilitating the formation of nickel, cobalt, and manganese hydroxide particles with an average diameter of 3 to 5 um and improved sphericity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a batch-type reactor is used to control particle size and achieve uniform particle diameter, then manufacturing precision is improved, but productivity deteriorates due to increased preparation time and difficulty in preparing large quantities
Solution Approach 1:
The invention changes the chemical environment parameters by introducing a complexing agent (EDTA or similar) to form stable metal-complex intermediates. This parameter change controls the precipitation kinetics, enabling uniform particle formation (D50: 3-5 μm, (D90-D10)/D50 ≤ 1.5) while reducing reaction time and allowing large-scale production in batch reactors
Solution Approach 2:
The invention uses a complexing agent as an intermediary substance that temporarily binds metal ions (Ni2+, Co2+, Mn2+) to form stable complexes. This intermediary step controls the gradual release and precipitation of metal hydroxides, achieving uniform particle size distribution while maintaining high productivity and enabling large-quantity preparation
2Manufacturing precision
If stirring speed is increased to uniformly form the surface of the positive electrode active material precursor, then manufacturing precision is improved, but device complexity and energy consumption increase
Solution Approach 1:
The invention replaces reliance on high mechanical stirring speed with a chemical mechanism involving complexing agents. The chemical complexation and controlled precipitation process inherently promotes uniform particle formation and surface development, reducing dependence on complex mechanical stirring systems while achieving excellent surface uniformity
3Manufacturing precision
If reaction time is extended to uniformly form the surface of particles, then manufacturing precision is improved, but productivity deteriorates as particles continue to grow and preparation time increases
Solution Approach 1:
The invention maintains continuous controlled precipitation through the complexing agent mechanism, which sustains uniform particle growth at a controlled rate. This allows the reaction to proceed efficiently to completion with uniform surface formation without excessive particle growth, optimizing both manufacturing precision and productivity
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 allows for the efficient preparation of positive electrode active material precursors with uniform particle sizes and suppressed growth, enabling the production of a large quantity of small-diameter particles while maintaining surface uniformity and reducing preparation time, enhancing the energy density and thermal stability of lithium secondary batteries.
Implementation Method 1
performing a co-precipitation reaction to prepare a positive electrode active material precursor having an average particle diameter (D50) of 3 um to 5 um
Data Source
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AI summary
The present invention provides a method for preparing a cathode active material precursor, a cathode active material precursor prepared by the preparation method, and a cathode for a secondary battery and a lithium secondary battery, which comprise same, the method comprising: a first step of injecting, into a reactor, a metal additive comprising at least one element selected from the group consisting of group 5 elements and group 6 elements; and a second step of injecting, into the reactor, a transition metal aqueous solution containing a nickel raw material, a cobalt raw material and a manganese raw material, a solution containing ammonium ions, and a basic aqueous solution, and performing a coprecipitation reaction, thereby preparing a cathode active material precursor having an average diameter (D50) of 3-5 µm.