Nickel Oxyhydroxide Precipitation for Bimodal Cathode Precursors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing cathode active materials for lithium-ion batteries, particularly those rich in nickel, face challenges in achieving high energy density and efficient manufacturing processes, with existing precursors often resulting in reduced cycle life and capacity loss.
Innovation Solution
A process for creating a particulate (oxy)hydroxide of transition metals, specifically nickel and optionally cobalt and manganese, with a bimodal particle diameter distribution, which serves as a precursor for electrode active materials, involving controlled pH adjustments and residence times in aqueous solutions to optimize particle formation and growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high nickel content is used in cathode active materials to increase energy density, then energy density is improved, but cycle life is reduced and capacity loss increases
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the particle core contains high nickel content (≥80 mol-%) for high energy density, while the particle shell contains lower nickel content and different transition metal ratios for stability. This spatial differentiation of composition allows the high-nickel core to provide energy density while the protective shell maintains cycle life and reduces capacity loss.
2Manufacturing precision
If complex multi-step precipitation processes are used to control particle size distribution, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent employs periodic action by conducting the precipitation process in distinct sequential stages with different pH conditions. The process includes an initial precipitation stage at high pH (12.1-13.0) to form nuclei, followed by a growth stage at lower pH (9.0-12.1) to control particle size. This staged approach with periodic pH adjustment achieves precise bimodal particle size distribution while maintaining manageable process complexity.
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 yields electrode active materials with improved energy density and high pressed density, enabling enhanced performance and longevity of lithium-ion batteries through precise control of particle size and composition.
Implementation Method 1
combining a solution (α) - or solution (α-b) - and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 12.1 to 13.0, thereby creating solid particles of hydroxide containing nickel
Data Source
AI summary
Process for making a particulate (oxy)hydroxide of TM wherein TM comprises nickel wherein said process comprises the steps of: (a) Providing an aqueous solution (α) containing water-soluble salts of Ni and of at least one transition metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, and Ta, 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 12.0 to 13.0, thereby creating solid particles of hydroxide containing nickel, (c) continuing combining solutions (α) and (β) and, if applicable, (γ) at a pH value in the range of from 9.0 to 12.0 and in any way below the pH value in step (b), (d) adding a solution (α) and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 12.0 to 12.7 and in any way above the pH value in step (c), (e) continuing combining such solutions (α) and (β) and, if applicable, (γ) at a pH value in the range of from 9.0 to 12.0 and in any way below the pH value in step (d), wherein step (d) has a duration in the range of from rt-0.01 to rt-0.15 and wherein rt is the average residence time of the reactor in which steps (b) to (e) are carried out.