High-Nickel (Oxy)Hydroxide Precipitation With Stable pH Control
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Solution Overview
Problem
Existing lithium ion batteries have limitations in energy density and cycling stability due to sensitive pH-dependent processes in precursor production, which affect the morphology and properties of cathode active materials.
Innovation Solution
A process for manufacturing particulate (oxy)hydroxides of metals with at least 75% nickel, involving the combination of aqueous solutions containing nickel salts, alkali metal hydroxides, and optional ammonia at controlled pH values in a stirred tank reactor, ensuring even distribution of dopants like Ti, Zr, or Nb, and organic acids, to produce precursors with specific particle size and composition for improved energy density and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional two-stage precipitation process is used to produce precursor, then basic electrode material can be obtained, but the process is very sensitive to pH changes causing significant variations in particle diameter and morphology
Solution Approach 1:
The patent changes the pH parameter from conventional ranges (pH 8-10) to a higher range (pH 11.0-13.0), which fundamentally alters the precipitation behavior and reduces sensitivity to small pH variations. This parameter change transforms the process from being highly sensitive to being more robust while maintaining precise particle diameter control
Solution Approach 2:
The patent introduces a preliminary action by adding a dispersant to the aqueous solution before precipitation occurs. This dispersant pre-establishes steric or electrostatic barriers that prevent agglomeration during precipitation, thereby compensating for pH variations and ensuring consistent particle morphology and diameter
2Quantity of substance
If high nickel content (at least 75 mol-%) is used in the precursor, then volumetric energy density of battery is improved, but cycling stability becomes challenging due to sensitive pH-dependent processes
Solution Approach 1:
By operating at pH 11.0-13.0, the patent creates a chemical environment where high nickel content precursors can be formed with controlled morphology and reduced sensitivity to pH fluctuations, thereby enabling both high nickel content (75 mol-% or more) and improved cycling stability
Solution Approach 2:
The dispersant acts as an intermediary substance that mediates between the high nickel content precursor and the aqueous solution. It provides steric or electrostatic stabilization that prevents agglomeration and ensures uniform particle formation, thereby enabling the use of high nickel content while maintaining process reliability and cycling stability
3Reliability
If uniform distribution of dopants (Ti, Zr, Mg, Nb) is achieved in precursor, then volumetric energy density and cycling stability are enhanced, but process control becomes more complex
Solution Approach 1:
The patent merges the dopant addition step with the main precipitation process by adding dopants to the aqueous solution before precipitation. This combined approach ensures uniform distribution of dopants throughout the precursor particles without requiring separate processing steps, thereby enhancing cycling stability while avoiding increased process control complexity
Solution Approach 2:
The high pH environment (pH 11.0-13.0) creates favorable conditions for uniform dopant incorporation into the precursor structure. This parameter change simplifies the overall process control by enabling simultaneous achievement of uniform dopant distribution and controlled particle morphology through a single precipitation step
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 process results in precursors with optimized particle size distribution and composition, enhancing the volumetric energy density and cycling stability of lithium ion batteries, making them suitable for high-performance battery applications.
Implementation Method 1
combining a solution (α) and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 11.0 to 13.0 in a stirred tank reactor, thereby creating solid particles of a hydroxide containing nickel
Implementation Method 2
combining a solution (α) and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 11.0 to 13.0 in a stirred tank reactor
Data Source
Figure 1~2
Figure 3~4
AI summary
Process for making a particulate (oxy)hydroxide of TM wherein TM represents metals and TM comprises at least 75 mol-% nickel and wherein said process comprises the steps of: (a) providing an aqueous solution (α) containing a water-soluble salt of nickel and of one metal selected from cobalt and manganese, and further in the range of from 0.05 to 3.0 mol-% of a compound of at least one metal selected from Ti, Zr, Mg and Nb, and in the range of from 0.05 to 2.0 mol-%, referring to TM, of an α- or β-hydroxy carboxylic acid or ascorbic acid or of an amino acid selected from glycine, alanine and serine, or their alkali metal salts, and an aqueous solution (β) containing an alkali metal hydroxide and, optionally, an aqueous solution (γ) containing ammonia, (b) combining a solution (α) and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 11.0 to 13.0 in a stirred tank reactor, thereby creating solid particles of a hydroxide containing nickel, said solid particles being slurried.