O2-Type Cathode Material Composition for Higher Li-Ion Battery Capacity
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Solution Overview
Problem
Conventional positive electrode active materials with an O2-type structure have limited capacity.
Innovation Solution
A positive electrode active material comprising a Li-containing oxide with specific X-ray diffraction peak intensity ratios and chemical composition, including Mn, Ni, and Co, is developed to enhance the O2-type structure, reducing the intensity of the T#2-type structure peaks and stabilizing the O2-type structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional positive electrode active materials with an O2-type structure are used, then the material structure is established, but the capacity is limited
Solution Approach 1:
The patent applies parameter changes by precisely controlling the X-ray diffraction peak intensity ratio (I1/I2) to be 0.30 or less, and by optimizing the chemical composition parameters (Li content, Mn content, Ni content, Co content) to achieve both high capacity and structural stability. This quantitative parameter control resolves the contradiction between capacity improvement and structure stability.
Solution Approach 2:
The patent uses composite materials by combining multiple transition metal elements (Mn, Ni, Co) with Li to form a Li-containing oxide with an O2-type structure. This composite approach enables the material to achieve enhanced capacity while maintaining structural stability through synergistic effects of different elements.
2Stability of the object's composition
If the intensity ratio I1/I2 is increased to enhance T#2-type structure, then structural variation occurs, but O2-type structure stability decreases
Solution Approach 1:
The patent applies parameter changes by setting a specific threshold (I1/I2 ≤ 0.30) to control the relative intensities of X-ray diffraction peaks. This precise parameter control ensures the dominance of the O2-type structure while minimizing T#2-type structure formation, thereby maintaining structural stability.
Solution Approach 2:
The patent employs feedback by using X-ray diffraction analysis to measure the I1/I2 ratio and adjusting the synthesis conditions accordingly. This feedback mechanism enables precise control of the crystal structure composition to achieve the target I1/I2 ratio and ensure O2-type structure stability.
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 Li-containing oxide material achieves a higher capacity and improved performance in lithium-ion secondary batteries by optimizing the X-ray diffraction peak intensities and maintaining a stable O2-type structure.
Implementation Method 1
An X-ray diffraction pattern of the Li-containing oxide satisfies 0 ≤ I 1 /I 2 ≤ 0.30, the I1 is an intensity of an X-ray diffraction peak originating from (002) plane of a T#2-type structure, and the I2 is an intensity of an X-ray diffraction peak originating from (002) plane of the O2-type structure.
Data Source
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AI summary
Disclosed is a positive electrode active material having an O2-type structure and having a large capacity. The positive electrode active material of the present disclosure comprises a Li-containing oxide. The Li-containing oxide has an O2-type structure. The Li-containing oxide at least comprises, as constituent elements, at least one element among Mn, Ni, and Co; Li; and O. An X-ray diffraction pattern of the Li-containing oxide satisfies 0 ≤ I1/I2 ≤ 0.30. The I1 is an intensity of an X-ray diffraction peak originating from (002) plane of a T#2-type structure, and the I2 is an X-ray diffraction peak intensity originating from (002) plane of the O2-type structure.