Nickel (Oxy)Hydroxide Precipitation With pH-Robust Particle Control
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Solution Overview
Problem
Existing lithium ion batteries have potential for improvement in energy density and cycling stability, particularly due to sensitivity to pH value changes during the process of making precursors, which are crucial for cathode active materials.
Innovation Solution
A process for producing particulate (oxy)hydroxides of metals, primarily nickel, with optional cobalt and manganese, using a stirred tank reactor to create solid particles with controlled pH and composition, resulting in precursors with specific particle sizes and structures suitable for high volumetric energy density and cycling stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional precipitation processes are used to make precursor salts, then the process is simple and straightforward, but the process is very sensitive to pH value changes which significantly impact precursor properties such as particle diameter
Solution Approach 1:
The patent introduces a complexing agent as an intermediary substance that binds to metal ions in the precipitation solution. This complexing agent acts as a buffer that maintains stable metal ion availability during pH changes, thereby decoupling the precipitation process from pH sensitivity. The complexing agent serves as a mediator between the pH environment and the metal ion precipitation, ensuring consistent particle formation despite pH fluctuations.
Solution Approach 2:
The patent changes the chemical parameters of the precipitation system by introducing complexing agents that alter the metal ion speciation and reactivity. This parameter change transforms the precipitation process from being pH-sensitive to being complexation-controlled, thereby stabilizing particle diameter against pH variations while maintaining manufacturing precision.
2Quantity of substance
If high nickel content (at least 60 mol-%) is used in the precursor to achieve high energy density, then the energy density improves, but the process complexity increases due to the need for precise composition control
Solution Approach 1:
The patent uses complexing agents to change the chemical parameters of metal ion availability, enabling precise control of nickel content in the precursor. The complexing agent selectively binds to different metal ions based on their complexation constants, allowing the process to achieve high nickel content (at least 60 mol-%) while maintaining simple mixing operations without requiring complex separation or purification steps.
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 produces precursors that enable lithium ion batteries with high energy density and excellent cycling stability, being robust against pH value changes and efficient for lithiation.
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 10.0 to 13.0 in a stirred tank reactor, thereby creating solid particles of a hydroxide containing nickel
Data Source
AI summary
Described herein is a process for making a particulate (oxy)hydroxide of TM, where TM are metals and TM includes at least 60 mol-% nickel, and where said process includes the steps of:(a) providing an aqueous solution (α) including water-soluble salts of Ni and of at least one metal selected from the group consisting of Co and Mn, and, optionally, at least one further metal selected from the group consisting of Ti, Zr, Mo, W, Al, Mg, Nb, and Ta, and an aqueous solution (β) an alkali metal hydroxide and, optionally, an aqueous solution (γ) including ammonia,(b) combining the solution (α) and the solution (β) and, if applicable, the solution (γ) at a pH value in a 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.