Lithium Manganate Particles for High-Temperature Battery Stability
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Solution Overview
Problem
Current lithium manganate materials for non-aqueous electrolyte secondary batteries fail to provide satisfactory high-temperature storage characteristics and output performance, despite improvements in crystallinity and other properties.
Innovation Solution
Lithium manganate particles with a specific composition (Li1+xMn2-x-yY1yO4+Y2) and structure, where Y1 is selected from Mg, Fe, Al, Cr, and Ti, and Y2 is a phosphorus compound, are produced through a calcination process, resulting in improved high-temperature stability and output characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium manganate particles are used as positive electrode active substance, then high voltage and high energy density are achieved, but charge/discharge cycle characteristics deteriorate due to crystal lattice expansion and contraction
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size of lithium manganate particles to 3-8 μm and adjusting the chemical composition parameters (Li1+xMn2-x-yO4) to optimize both energy density and cycle stability. This parameter optimization resolves the contradiction by finding the optimal balance point where high energy density is maintained while cycle characteristics are improved.
Solution Approach 2:
The patent uses composite materials by combining lithium manganate particles with specific additives and coating materials to form a composite positive electrode. This composite structure enhances the base material's properties, allowing high energy density to be maintained while improving charge/discharge cycle characteristics through the synergistic effects of the composite components.
2Reliability
If lithium manganate particles with high crystallinity are obtained by controlling calcining temperature, then charge/discharge cycle characteristics improve, but manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by establishing a specific calcining temperature range and holding time that achieves high crystallinity and improved cycle characteristics. By optimizing these thermal parameters, the patent resolves the contradiction between improving reliability and reducing manufacturing complexity, as the defined parameter range provides a clear, reproducible manufacturing process.
3Stability of the object's composition
If particle size and particle size distribution of lithium manganate particles are controlled, then packing property improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by defining a specific particle size range (3-8 μm) and optimizing the particle size distribution to achieve improved packing properties. This parameter specification resolves the contradiction by providing clear manufacturing targets that balance packing efficiency with achievable precision levels.
4Reliability
If surface treatment or additives are added to lithium manganate particles to suppress Mn elution, then charge/discharge cycle characteristics improve, but manufacturing complexity increases
Solution Approach 1:
The patent uses composite materials by incorporating surface treatment layers and additives into the lithium manganate particle structure. This composite approach resolves the contradiction by integrating multiple functions (Mn elution suppression, conductivity enhancement) into the material itself, improving reliability while managing manufacturing complexity through material design rather than complex processing steps.
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 lithium manganate particles exhibit high output power and excellent high-temperature stability, making them suitable for use as a positive electrode active substance in non-aqueous electrolyte secondary batteries with enhanced charge/discharge cycle characteristics.
Implementation Method 1
an anti-sintering agent having a melting point of not higher than 800°C, in particular, phosphorus, a phosphorus oxide or a phosphorus compound, is added to the lithium manganate particles upon calcination of the particles to impart thereto the effect of preventing elution of Mn therefrom
Implementation Method 2
mixing a manganese compound and a lithium compound at a predetermined mixing ratio and then calcining the resulting mixture in the temperature range of 700 to 800°C
Implementation Method 3
the crystal lattice of the lithium manganate particles used therein is expanded and contracted owing to desorption and insertion behavior of lithium ions in the crystal structure to cause change in volume of the crystal
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to lithium manganate particles having a primary particle diameter of 1 to 8 µm and forming substantially single-phase particles, which have a composition represented by the following chemical formula: Li1+xMn2-x-yY1yO4 + Y2 in which Y1 is at least one element selected from the group consisting of Ni, Co, Mg, Fe, Al, Cr and Ti; Y2 is P and is present in an amount of 0.01 to 0.6 mol% based on Mn; and x and y satisfy 0.03 ≤ x ≤ 0.15 and 0.05 ≤ y ≤ 0.20, respectively, and which lithium manganate particles have a specific surface area of the lithium manganate particles of 0.3 to 0.9 m2/g (as measured by BET method); and have an average particle diameter (D50) of the lithium manganate particles of 3 to 10 µm. A positive electrode active substance of a lithium ion secondary battery using the lithium manganate particles of the present invention has a high output and is excellent in high-temperature stability.