Lithium Battery Precursor FWHM Control for High Packing Density
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Solution Overview
Problem
Existing methods for manufacturing positive electrode active materials for lithium secondary batteries face challenges in balancing productivity and electrochemical properties, particularly due to high manufacturing costs and instability of the layered structure, which can lead to increased unreacted lithium and degradation.
Innovation Solution
A method involving the preparation of a metal oxide precursor through a first heat treatment of a metal hydroxide mixture, followed by a second heat treatment of a molded body to produce a sintered body, which is then crushed and classified, ensuring specific properties like FWHM, crystallite size, and tap density are within optimal ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the filling amount in a saggar is increased to improve productivity, then productivity is improved, but the amount of unreacted residual lithium increases and electrochemical properties degrade
Solution Approach 1:
The patent applies preliminary action by pre-forming molded bodies with controlled density and shape before calcination. The molded bodies are prepared with specific physical properties (density of 2.0-2.4 g/cm³, spherical or ellipsoidal shape) that enable optimal packing in the saggar while ensuring complete reaction during subsequent heat treatment, thus allowing high filling amounts without residual lithium
Solution Approach 2:
The patent changes physical parameters of the precursor material to resolve the contradiction. By controlling the density of molded bodies within 2.0-2.4 g/cm³ and maintaining specific surface area between 0.5-2.0 m²/g, the process enables high packing density in saggar while ensuring complete reaction and stable electrochemical properties of the final product
2Ease of manufacture
If the calcination temperature and holding time are optimized to reduce manufacturing costs, then manufacturing cost is reduced, but the quality of positive electrode active material may be compromised
Solution Approach 1:
The patent performs preliminary heat treatment at 500-700°C to convert hydroxide to oxide precursor before the main calcination step. This preliminary transformation reduces the temperature and time required for the subsequent calcination process, lowering manufacturing costs while ensuring complete reaction and high-quality product with stable layered structure
Solution Approach 2:
The patent implements a continuous two-stage heat treatment process where the first stage (500-700°C) transforms hydroxide to oxide, and the second stage (900-1000°C) completes the calcination. This continuous process ensures complete reaction at optimized temperatures, reducing energy consumption and manufacturing cost while maintaining high product quality
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 enhances electrochemical properties and increases yield, minimizing manufacturing costs by allowing higher filling amounts during calcination, thus improving economic efficiency and performance.
Implementation Method 1
performing a first heat treatment on a mixture of the metal hydroxide and an additive to prepare a metal oxide precursor
Implementation Method 2
performing a first heat treatment on a mixture of the metal hydroxide and an additive to prepare a metal oxide precursor
Implementation Method 3
performing a second heat treatment to prepare a sintered body
Implementation Method 4
a full width at half maximum (FWHM) of a diffraction peak of the (200) plane measured by X-ray diffraction
Data Source
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AI summary
The present disclosure relates to a precursor of a positive electrode active material for a lithium secondary battery, a method for manufacturing a positive electrode active material using the same, and a lithium secondary battery including the positive electrode active material manufactured thereby. In one embodiment, the precursor of a positive electrode active material for a lithium secondary battery may have a full width at half maximum (FWHM) of a diffraction peak of the (200) plane measured by X-ray diffraction in a range from 0.28° to 1.30°.