Ternary Precursor Seed-Crystal Growth With Reduced Ammonia Waste
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing ternary lithium-ion battery precursors using ammonia water result in high wastewater treatment costs, environmental harm, and particles with low sphericity and high surface energy, leading to agglomeration issues.
Innovation Solution
A method involving the use of ammonia water for seed crystal preparation followed by acid treatment and subsequent growth in an ammonia-free environment, utilizing pH and temperature control to achieve high sphericity and specific surface area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ammonia water is used as a complexing agent in the co-precipitation method, then precursor particles achieve slow growth, uniform composition, high sphericity, and high tap density, but a large amount of ammonia-nitrogen wastewater is generated, increasing wastewater treatment cost and production cost
Solution Approach 1:
The patent divides the precipitation process into two stages: first using ammonia water to form uniform seed crystals with controlled morphology, then using sodium hydroxide for further growth without additional ammonia. This segmentation allows the system to benefit from ammonia's complexing effect during nucleation while avoiding continuous ammonia addition that generates wastewater.
Solution Approach 2:
The patent performs preliminary action by forming seed crystals with ammonia water first, establishing the desired particle morphology and uniform composition before the main growth stage. This preliminary structuring allows subsequent growth to proceed without ammonia, reducing wastewater generation while preserving the benefits of controlled nucleation.
2Stability of the object's composition
If ammonia water is used as a complexing agent, then nickel, cobalt, and manganese are homogeneously precipitated, but ammonia water is easy to volatilize, causing harm to the environment and human health
Solution Approach 1:
The patent extracts the harmful volatilization issue by limiting ammonia water use to only the seed crystal formation stage under controlled conditions, then completely replacing it with sodium hydroxide for the main precipitation process. This extraction removes the continuous source of ammonia volatilization while preserving the homogeneous composition benefit during the critical nucleation phase.
Solution Approach 2:
The patent changes the chemical parameter from ammonia water to sodium hydroxide after the seed crystal stage, transitioning from a system prone to volatilization to one that is stable and non-volatile. This parameter change eliminates harmful emissions while maintaining compositional homogeneity through controlled precipitation conditions.
3Loss of substance
If a method prepares high-performance LIB ternary cathode material at low ammonia concentration (≤0.1 mol/L), then ammonia-nitrogen wastewater problem is reduced, but production cost increases due to introduction of ammonium salt as raw material
Solution Approach 1:
The patent discards the continuous ammonia water addition approach that generates wastewater, instead using a brief initial ammonia treatment followed by sodium hydroxide. This eliminates the need for expensive ammonium salts while avoiding wastewater generation, achieving both environmental and economic goals.
4Loss of substance
If ammonia water is not used as a complexing agent, then wastewater treatment cost is reduced, but particles are rapidly precipitated out with inconsistent compositions and high surface energy, leading to agglomeration and low sphericity
Solution Approach 1:
The patent performs preliminary action by using ammonia water to form well-structured seed crystals with consistent composition and controlled surface energy before the main growth stage. This preliminary structuring ensures that subsequent growth without ammonia occurs on pre-formed spherical nuclei, preventing agglomeration and maintaining high sphericity while avoiding continuous ammonia use.
Solution Approach 2:
The patent segments the precipitation process into a nucleation stage with ammonia water (for uniform composition and morphology) and a growth stage with sodium hydroxide (for continued growth without ammonia). This segmentation allows the system to achieve both low wastewater treatment cost and high particle quality by assigning different functions to different stages.
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 reduces wastewater treatment costs, maintains high sphericity, and enhances the uniformity and activity of the cathode material, improving its output capacity.
Implementation Method 1
ammonia water is used as a complexing agent. That is, materials are continuously pumped into a reactor, and a stirring speed, a reaction temperature, a pH value, an ammonia concentration, and a solid content each are controlled within a specified range, such that a ternary precursor is obtained through continuous nucleation and gradual crystal growth
Implementation Method 2
NaOH is used as a precipitating agent and ammonia water is used as a complexing agent. That is, materials are continuously pumped into a reactor, and a stirring speed, a reaction temperature, a pH value, an ammonia concentration, and a solid content each are controlled within a specified range, such that a ternary precursor is obtained through continuous nucleation and gradual crystal growth
Implementation Method 3
A method involving the use of ammonia water for seed crystal preparation followed by acid treatment and subsequent growth in an ammonia-free environment
Data Source
AI summary
The present disclosure discloses a preparation method of a ternary precursor, including: S1: mixing a first metal salt solution with a soluble nickel salt, a soluble cobalt salt, and a soluble manganese salt, ammonia water, and a sodium hydroxide solution, adjusting a pH, and heating and stirring a resulting mixture to allow a reaction; and aging and filtering a resulting slurry to obtain a precursor seed crystal; S2: adding the precursor seed crystal to a dilute acid solution, and stirring and filtering a resulting mixture to obtain an acidified seed crystal; and S3: mixing a second metal salt solution with a soluble nickel salt, a soluble cobalt salt, and a soluble manganese salt, a sodium hydroxide solution, and the acidified seed crystal, adjusting a pH, and heating and stirring a resulting mixture to allow a reaction; and aging, filtering, and drying a resulting slurry to obtain the ternary precursor.