Nickel Hydroxide Crystallization With Low Dissolved Oxygen
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Solution Overview
Problem
Lithium-ion secondary batteries require a positive electrode active material that is resistant to crushing and has excellent battery capacity, which is not adequately addressed by existing methods that fail to suppress porosity in nickel-containing hydroxides used as precursors.
Innovation Solution
A method of producing nickel-containing hydroxides by preparing a pre-reaction aqueous solution with a low dissolved oxygen concentration, using a neutralizing agent and a complexing agent, to suppress porosity and density issues in the resulting active material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional methods are used to produce nickel-containing hydroxides, then the production process is simple, but porosity in the resulting active material is high leading to poor resistance to crushing
Solution Approach 1:
The invention changes the dissolved oxygen concentration parameter in the pre-reaction aqueous solution from conventional levels to 0.1 mg/L or less. This parameter change fundamentally alters the crystallization process, resulting in nickel-containing hydroxide with suppressed porosity and improved resistance to crushing without complicating the manufacturing process
Solution Approach 2:
The invention performs preliminary deoxygenation of the pre-reaction aqueous solution before adding metal salts and initiating crystallization. By removing dissolved oxygen in advance (through nitrogen purging, vacuum treatment, or other deoxygenation methods), the crystallization process proceeds without oxygen interference, producing dense, low-porosity particles with superior mechanical strength
2Quantity of substance
If conventional crystallization methods are used, then the process is straightforward, but porosity suppression is insufficient leading to reduced battery capacity
Solution Approach 1:
The invention modifies the dissolved oxygen concentration parameter to 0.1 mg/L or less in the pre-reaction aqueous solution, which fundamentally changes the crystallization mechanism. This produces nickel-containing hydroxide with suppressed porosity, leading to higher density and improved battery capacity without complicating the manufacturing process
Solution Approach 2:
The invention replaces conventional mechanical mixing and crystallization approaches with a chemically-controlled process where dissolved oxygen concentration is precisely managed. By controlling the chemical environment (low oxygen conditions) rather than relying on mechanical parameters alone, the invention achieves superior porosity suppression and particle density
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 method effectively reduces porosity in nickel-containing hydroxides, leading to improved resistance to crushing and enhanced battery capacity when used as a positive electrode active material in lithium-ion secondary batteries.
Implementation Method 1
a neutralizing agent that reacts with the metal salt to form a metal hydroxide
Implementation Method 2
a complexing agent to the pre-reaction aqueous solution
Data Source
AI summary
A method of producing a nickel-containing hydroxide includes a pre-reaction aqueous solution preparation step of preparing a pre-reaction aqueous solution, and a crystallization step of obtaining the nickel-containing hydroxide by adding at least a nickel salt as a metal salt, a neutralizing agent that reacts with the metal salt to form a metal hydroxide, and a complexing agent to the pre-reaction aqueous solution while stirring the pre-reaction aqueous solution, wherein the pre-reaction aqueous solution contains water and the neutralizing agent, and a concentration of dissolved oxygen in the pre-reaction aqueous solution is 0.1 mg/L or less when the crystallization step starts.