Cathode Active Material Manufacturing via Chelated Aqueous Precursor
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Solution Overview
Problem
Current methods for manufacturing cathode active materials for lithium secondary batteries face challenges in achieving uniform composition, high capacity, and environmental sustainability, with issues such as impurity inclusion, energy consumption, and pollution in solid phase reactions, and compositional non-uniformity in coprecipitation methods.
Innovation Solution
A method involving a precursor aqueous solution with a lithium precursor, a transition metal precursor, and an organic acid containing a carboxyl group, heat-treated to satisfy specific FTIR spectroscopy conditions, allowing for uniform chelation and easy insertion and desorption of lithium ions, using a spray pyrolysis process for mass production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solid phase reaction method is used, then manufacturing process is simple, but compositional uniformity is poor and impurities are generated
Solution Approach 1:
The invention changes the physical state parameter from solid phase to aqueous solution phase for the reaction medium. By dissolving metal precursors in water and using ammonia water as a precipitating agent, the method achieves molecular-level mixing and uniform composition distribution, resolving the compositional uniformity issue while maintaining process simplicity through a single-step precipitation reaction.
Solution Approach 2:
The invention introduces ammonia water as an intermediary substance that mediates the precipitation reaction. The ammonia water serves as both the precipitating agent and the medium for uniform distribution of metal ions, enabling controlled formation of homogeneous cathode material particles without the need for complex solid phase mixing and repeated heat treatments.
2Ease of manufacture
If solid phase reaction method is used, then manufacturing process is simple, but energy consumption and time are significantly consumed
Solution Approach 1:
The invention performs preliminary dissolution of metal precursors in water before the precipitation reaction, ensuring complete dispersion and uniform distribution of metal ions in advance. This preliminary action eliminates the need for repeated solid phase mixing and multiple heat treatment cycles, significantly reducing the total manufacturing time while maintaining process simplicity.
Solution Approach 2:
The invention utilizes the phase transition from dissolved state to precipitated solid state by adding ammonia water to the aqueous precursor solution. This phase transition occurs rapidly and uniformly throughout the solution, forming homogeneous cathode material particles in a single step, thereby dramatically reducing the time required compared to gradual solid phase diffusion processes.
3Manufacturing precision
If coprecipitation method is used, then compositional uniformity is improved, but pollution and waste liquid are generated
Solution Approach 1:
The invention employs a ammonia water-based precipitation system where the byproduct is ammonia gas that can be easily separated and recovered. The precipitated cathode material can be filtered and washed with minimal waste liquid generation, and the filtrate containing excess ammonia can be reused or treated efficiently, significantly reducing pollution compared to traditional coprecipitation methods using other reagents.
4Manufacturing precision
If coprecipitation method is used, then compositional uniformity is improved, but precise control in processes is required
Solution Approach 1:
The invention simplifies process control by changing the precipitating agent to ammonia water, which provides gradual and controlled pH increase during addition. This parameter change in the chemical system naturally buffers the precipitation process, reducing sensitivity to addition rate variations and eliminating the need for complex real-time control systems while maintaining excellent compositional uniformity.
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 results in a cathode active material with excellent crystallinity and compositional uniformity, enabling efficient lithium ion insertion and desorption, while being environmentally friendly and cost-effective, with improved charge and discharge properties.
Implementation Method 1
a precursor aqueous solution containing a lithium precursor, a transition metal precursor, and an organic acid containing a carboxyl group
Implementation Method 2
heat-treating a precursor aqueous solution containing a lithium precursor, a transition metal precursor, and an organic acid containing a carboxyl group
Implementation Method 3
Lithium ions in the electrolyte moves toward the anode at the time of charging, and moves toward the cathode at the time of discharging
Data Source
AI summary
Provided is a method for manufacturing a cathode active material for a lithium secondary battery, the method including heat-treating a precursor aqueous solution containing a lithium precursor, a transition metal precursor, and an organic acid containing a carboxyl group, and having a chelation index (C.I) value less than 1 and 0.5 or more, wherein the chelation index value is defined by transmittance of a peak located in a wavenumber from 1,700 to 1,710 cm−1 and transmittance of a peak located in a wavenumber from 1,550 to 1,610 cm−1 in Fourier transform infrared (FTIR) spectroscopy spectrum.