Layered Composite Metal Oxide Synthesis at Low-Temperature Calcining
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Solution Overview
Problem
Current methods for producing layered composite metal oxide crystal materials for lithium ion secondary batteries require high temperature calcining processes or hydrothermal synthesis under high pressure, making them costly and unsuitable for large-scale production at atmospheric pressure.
Innovation Solution
A method involving calcining a mixture of monovalent anion salts of lithium, sodium, and transition metals in the presence of water and oxygen at temperatures between 150°C and 400°C, using specific molar ratios and hydrates to produce a layered composite metal oxide crystal material, which can be scaled up at lower costs and pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high temperature calcining process (700-900°C) is used to produce layered crystal of lithium cobaltite, then the crystal structure and battery performance are improved, but energy consumption and production cost increase significantly
Solution Approach 1:
The invention changes the temperature parameter from conventional high temperature (700-900°C) to low temperature (300-600°C) range, and modifies the atmosphere parameter by introducing oxygen-containing atmosphere and water vapor. This parameter transformation enables the formation of layered crystal structure at lower energy input while maintaining battery performance through controlled oxidation and crystal growth conditions.
Solution Approach 2:
The invention introduces oxygen-containing atmosphere and water vapor as intermediary substances that facilitate the crystal formation process at lower temperatures. These intermediaries provide the necessary oxygen for oxide formation and water vapor for controlled hydrothermal environment, enabling low-temperature synthesis without compromising the quality of layered crystal structure.
2Use of energy by moving object
If flux method is used to reduce calcining temperature to 500°C, then energy consumption is reduced, but still requires relatively high temperature compared to ambient conditions
Solution Approach 1:
The invention further reduces the temperature parameter from 500°C (flux method) to 300-600°C range by optimizing the oxygen-containing atmosphere composition and water vapor content. This parameter optimization eliminates the need for flux additives while achieving lower calcining temperatures through controlled oxidative environment and hydrothermal conditions.
3Use of energy by moving object
If hydrothermal synthesis method is used to achieve low temperature (50-150°C) production, then energy consumption is reduced, but requires high pressure (30-35 atm) and long reaction time (2-5 days)
Solution Approach 1:
The invention changes the pressure parameter from high pressure (30-35 atm) to atmospheric pressure or mild pressure conditions, and optimizes the temperature parameter to 300-600°C range. This parameter transformation, combined with oxygen-containing atmosphere and water vapor introduction, enables rapid crystal formation within 1-24 hours, dramatically improving production efficiency while maintaining low energy consumption.
Solution Approach 2:
The invention employs periodic heating and oxygen supply during the calcining process, creating optimal conditions for rapid crystal nucleation and growth. This periodic action pattern, combined with water vapor introduction, accelerates the formation of layered crystal structure, reducing reaction time from days to hours without requiring extreme pressure conditions.
4Temperature
If hydrothermal synthesis under high pressure (30-35 atm) is used, then low temperature production is achieved, but requires specialized high pressure resistant equipment and increases operational complexity
Solution Approach 1:
The invention fundamentally changes the pressure parameter from high pressure (30-35 atm) to atmospheric pressure or mild pressure conditions. This parameter change eliminates the need for specialized high pressure resistant equipment, simplifying the reaction apparatus to conventional calcining furnaces while maintaining low temperature synthesis capability through oxygen-containing atmosphere and water vapor control.
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 method allows for the efficient production of layered composite metal oxide crystal materials at lower temperatures and atmospheric pressure, enabling large-scale synthesis with reduced energy consumption and operational costs, while maintaining high crystallinity and charge-discharge capacity.
Implementation Method 1
calcining a mixture comprising a monovalent anion salt of lithium, a monovalent anion salt of sodium and/or potassium, and a monovalent anion salt of a transition metal at 150° C. or higher and 400° C. or lower in the presence of a water molecule and oxygen
Implementation Method 2
producing a layered composite metal oxide crystal material... maintaining high crystallinity
Data Source
AI summary
The objective of the present invention is to provide a method for producing a layered composite metal oxide crystal material, which can be utilized as a positive electrode material for a lithium ion secondary battery or the like, in a milder condition, and methods for producing a positive electrode and a lithium ion secondary battery using the above method. The method for producing a layered composite metal oxide crystal material according to the present invention, wherein the layered composite metal oxide crystal material comprises a composite metal oxide represented by the formula: LixMOy wherein M is 1 or 2 or more of transition metals, and a part of the M may be substituted with Al and/or Mg, x is the number of 1 or more and 2 or less, y is the number of 2 or more and 3 or less, a value of x+n is 2×y, wherein n is an average valence of the transition metal M, is characterized in comprising the step of calcining a mixture comprising a monovalent anion salt of lithium, a monovalent anion salt of sodium and/or potassium, and a monovalent anion salt of the transition metal at 150° C. or higher and 400° C. or lower in the presence of a water molecule and oxygen.