Lithium Composite Oxide Baking Without Molded Body Collapse
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Solution Overview
Problem
Existing methods for producing lithium-containing composite oxides result in the generation of water during baking, leading to collapsed molded bodies with insufficient particle-to-particle contact, reduced heat conductivity, and non-homogeneous baked bodies with varying crystallinity.
Innovation Solution
A method involving the preparation of lithium hydroxide and a composite oxide through heating, mixing, compression-molding, and baking at specific temperatures to suppress water generation and maintain contact between compounds, ensuring homogeneous and high-crystallinity lithium-containing composite oxides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a molded body including a hydroxide containing nickel is baked, then a lithium-containing composite oxide can be produced, but water is generated during baking causing the molded body to collapse
Solution Approach 1:
The patent applies preliminary action by pre-heating the hydroxide-containing molded body to 300-800°C before the main baking process to convert hydroxides to oxides in advance. This preliminary conversion removes the water-generating hydroxide groups before the actual lithium-containing composite oxide formation, preventing water generation during the critical baking stage that would cause collapse.
Solution Approach 2:
The patent skips the water-generating transformation step by directly converting hydroxides to oxides through pre-heating before the main reaction. Instead of allowing the slow, water-generating decomposition during baking, the process rushes through the transformation in a controlled pre-heating stage, eliminating the harmful water generation phase.
2Quantity of substance
If the molded body collapses during baking, then less dense portions increase, but this results in insufficient particle-to-particle contact and reduced heat conductivity
Solution Approach 1:
The pre-heating treatment at 300-800°C before main baking serves as a preliminary action that stabilizes the molded body structure by converting hydroxides to oxides and removing volatile components in advance. This preliminary stabilization prevents the collapse that would otherwise create voids and reduce particle contact, maintaining both density and heat conductivity.
3Shape
If the molded body collapses, then the difference between less dense and dense portions increases, but this causes variation in the degree of baking and non-homogeneous baked body
Solution Approach 1:
The pre-heating step acts as a preliminary uniformization process that converts all hydroxide phases to oxide phases uniformly throughout the molded body before the main baking reaction. This preliminary uniform transformation eliminates the density variations that would otherwise develop during baking, ensuring homogeneous composition and structure in the final product.
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 method produces a lithium-containing composite oxide with improved crystallinity and reactivity, achieving a homogeneous baked body with controlled crystallite size and reduced variation.
Implementation Method 1
heating a hydroxide containing nickel and a metal M1 other than lithium and nickel to 300° C. or higher and 800° C. or lower, to obtain a composite oxide containing the nickel and the metal M1
Implementation Method 2
baking the molded body at 600° C. or higher and 850° C. or lower, to obtain a baked body
Implementation Method 3
obtain a homogeneous lithium-containing composite oxide having high crystallinity
Data Source
AI summary
A method for producing a lithium-containing composite oxide, the method including: a first step of preparing a lithium hydroxide; a second step of heating a hydroxide containing nickel and a metal M1 other than lithium and nickel to 300° C. or higher and 800° C. or lower, to obtain a composite oxide containing the nickel and the metal M; a third step of mixing the lithium hydroxide and the composite oxide, to obtain a mixture; a fourth step of compression-molding the mixture, to obtain a molded body; and a fifth step of baking the molded body at 600° C. or higher and 850° C. or lower, to obtain a baked body.