Mixed Oxide Powder Multimodal Particle Size Distribution
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Solution Overview
Problem
Existing mixed oxide powders for secondary batteries exhibit limitations in capacity and discharge cycles, necessitating an improved material and production process.
Innovation Solution
A mixed oxide powder with the composition Li x Mn 0.5-a Ni 0.5-b Co a+b O 2 is produced using a spray pyrolysis process, involving a solution with metal compounds atomized into an aerosol, reacted in a flame, and thermally treated, achieving a multimodal particle size distribution and high crystallinity, which enhances battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing mixed oxide powders are used for secondary batteries, then the basic battery function is achieved, but the capacity and discharge cycles are limited
Solution Approach 1:
The patent changes the particle size distribution parameters by using spray pyrolysis to create a multimodal distribution with specific d10, d50, and d90 values. This parameter change in particle morphology directly improves both capacity and charge/discharge cycle performance by optimizing surface area and structural stability
Solution Approach 2:
The patent creates a composite particle structure through spray pyrolysis where particles exhibit multimodal size distribution characteristics. The composite nature of the particle size distribution (combining fine and coarse particles) enables simultaneous improvement of capacity and cycle life
2Manufacturing precision
If a spray pyrolysis process is used to produce mixed oxide powder, then multimodal particle size distribution and high crystallinity are achieved, but the process complexity increases
Solution Approach 1:
The patent replaces traditional mechanical grinding and classification methods with a spray pyrolysis process. This substitution uses chemical and thermal fields instead of mechanical fields to achieve precise particle size control and high crystallinity in a single integrated process
Solution Approach 2:
The patent utilizes phase transitions during spray pyrolysis - the solution transitions from liquid aerosol droplets to solid particles through rapid evaporation and decomposition. This phase transition mechanism enables precise control over particle formation, size distribution, and crystalline structure
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 process results in mixed oxide powders with improved capacity and extended charge/discharge cycles, characterized by a higher ratio of X-ray signal intensities and increased BET surface area, leading to enhanced battery performance.
Implementation Method 1
a process for producing a mixed oxide with the composition Li x Mn 0.5-a Ni 0.5-b Co a+b O 2, with a) 0.8 ≤ x ≤ 1.2, 0.05 ≤ a ≤ 0.3, 0.05 ≤ b ≤ 0.4 and 0.1 ≤ a+b ≤ 0.5, by spray pyrolysis a solution or dispersion which contains compounds with the metal components of the mixed oxide
Implementation Method 2
by spray pyrolysis a solution or dispersion which contains compounds with the metal components of the mixed oxide in the required stoichiometric ratio is atomized into an aerosol using an atomizer gas, b) the aerosol in a reaction space with a flame consisting of a fuel gas and an oxygen-containing gas
Data Source
AI summary
Mixed oxide with the composition Lix Mn0,5-a Ni0,5-b COa+b O2, with 0.8 ≤ x ≤ 1,2, 0.05 ≤ a ≤ 0.3, 0.05 ≤ b < 0.3, -0.1 ≤ ab ≤ 0.02 and a + b < 0.5, which has a BET surface area of 3 to 20 m2/g, a multimodal particle size distribution and a d50 value of less than or equal to 5 µm. Mixed oxide with the composition Lix Mn0,5-a Ni0,5-b Coa+b O2, with 0.8 ≤ x ≤ 1.2, 0.05 ≤ a ≤ 0.3, 0.05 ≤ b < 0.3, -0.1 ≤ ab ≤ 0.02 and a + b < 0.5, which has a BET surface area of 0.05 to 1 m2/g, a d50 value of less than or equal to 10 µm and in the X-ray diffractogram a ratio of the intensities of the signals at 2Θ = 18.6 ±1° to 2Θ = 44.1±1° of greater than or equal to 2.4.