Lithium Mixed Oxide Spray Pyrolysis Throughput

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Solution Overview

Problem

Existing spray pyrolysis processes for producing lithium-containing mixed oxides suffer from low throughput, making large-scale implementation economically unfeasible and unsuitable for scaling up, and are affected by thermophoresis leading to energy loss due to wall covering.

Innovation Solution

A process involving atomizing a solution containing lithium and metal compounds into an aerosol with an average droplet size less than 100 μm, using a flame from a fuel gas and air mixture with sufficient oxygen for complete conversion, followed by cooling and separation of the solid product, which can be thermally treated to achieve desired surface areas and particle distributions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional spray pyrolysis processes are used to produce lithium-containing mixed oxides, then the production method is simple, but the throughput is low making large-scale implementation economically unfeasible

Engineering Contradiction:
ImprovethroughputVSAvoideconomic feasibility
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The process segments the reaction into distinct zones: atomization zone, combustion zone, and cooling zone. The aerosol is divided into fine droplets that travel through different regions of the reactor, each performing a specific function. This segmentation enables efficient heat transfer and rapid reaction while maintaining high throughput capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes critical parameters including droplet size (reducing to less than 100 μm), temperature profiles (using flame temperatures for rapid heating), and residence time (optimizing for complete conversion). These parameter changes enable the process to achieve high throughput while maintaining product quality and economic feasibility.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high-temperature spray pyrolysis is used to produce lithium-containing mixed oxides, then the reaction conversion is complete, but thermophoresis occurs leading to wall covering and energy loss

Engineering Contradiction:
Improvereaction conversionVSAvoidenergy loss due to wall covering
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention introduces a controlled atmosphere as an intermediary medium that facilitates complete reaction conversion while preventing direct contact between the aerosol and reactor walls. The controlled atmosphere acts as a buffer that enables high-temperature reaction without the harmful thermophoretic effects that cause wall covering and energy loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If conventional spray pyrolysis processes are used, then the equipment structure is simple, but the process cannot be scaled up to higher throughputs

Engineering Contradiction:
ImprovescalabilityVSAvoidequipment structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The reactor is designed with multi-functionality, serving as atomization chamber, combustion zone, and cooling region simultaneously. This universal design enables the single piece of equipment to handle high throughput while maintaining product quality, eliminating the need for multiple separate units and reducing overall system complexity despite the advanced process capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 allows for high throughput and scalability, producing high-purity mixed oxides with adjustable particle size distributions and BET surface areas, suitable for use in secondary batteries, with good sintering properties.

Implementation Method 1

a stream of a solution, which contains at least one lithium compound and at least one metal compound of one or more mixed oxide components in the required stoichiometric ratio, is atomized using an atomizer gas to form an aerosol which has an average droplet size of less than 100 μm

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

the aerosol in a reaction chamber with a flame which is obtained from a mixture of fuel gas and air, the total amount of oxygen being at least sufficient for complete conversion of the fuel gas and the metal compounds

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

cooling the reaction stream

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 4

then the solid product separated from the reaction stream

Methodology Applied
Scientific EffectSeparation:

Implementation Method 5

the solid product can be thermally treated after separation from the reaction stream at temperatures of 500 to 1200 ° C, preferably 800 to 1100 ° C, particularly preferably 900 to 1050 ° C, over a period of 2 to 36 hours

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP2399867B1Method for producing mixed oxides containing lithium
Publication Date: 2013.08.21 EVONIK OPERATIONS GMBH

AI summary

A process for producing a lithium-containing mixed oxide powder, in which a) a stream of a solution containing at least one lithium compound and at least one metal compound of one or more mixed oxide components in the required stoichiometric ratio is atomized by means of an atomizing gas to form an aerosol having a mean droplet size of less than 100 µm, b) the aerosol is reacted in a reaction chamber with a flame obtained from a mixture of fuel gas and air, wherein the total amount of oxygen is sufficient at least for the complete conversion of the fuel gas and the metal compounds, c) the reaction stream is cooled, and d) the solid product is subsequently separated from the reaction stream.