Waste Cathode Material Separation by Heat Treatment and Water Leaching

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Solution Overview

Problem

Current methods for separating transition metals from waste positive electrode materials in lithium secondary batteries often result in environmental pollution due to the use of chemical solvents, necessitating a more sustainable and pollution-free approach.

Innovation Solution

A dry method involving heat treatment of the waste positive electrode material in an inert or oxygen atmosphere to phase separate lithium oxide and metal oxide, followed by cooling and leaching with distilled water to extract the transition metal, effectively avoiding chemical solvent use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If chemical solvents are used to extract transition metals from waste positive electrode material, then metal recovery efficiency is improved, but environmental pollution occurs

Engineering Contradiction:
Improvemetal recovery efficiencyVSAvoidenvironmental pollution
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical and chemical parameters of the extraction process by replacing chemical solvents with a thermal treatment approach. The waste positive electrode material undergoes heat treatment at specific temperatures (700-900°C) in controlled atmospheres, transforming the extraction mechanism from chemical dissolution to thermal decomposition and phase separation, thereby eliminating solvent-related environmental pollution while maintaining effective metal recovery

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions during thermal treatment to separate components. The waste positive electrode material undergoes phase changes at different temperature stages, where the binder and conductive agent decompose and volatilize, while the active material transforms into distinct phases that can be easily separated through simple filtration, replacing the need for chemical solvents and reducing environmental impact

Inventive Principle:
Principle #36Phase transitions

2Object-affected harmful factors

If thermal treatment is used to separate components, then environmental pollution is reduced, but energy consumption increases

Engineering Contradiction:
Improveenvironmental pollutionVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic thermal treatment with staged temperature increases. The process progresses through distinct temperature phases (700-900°C), where each stage targets specific components for decomposition or transformation. This periodic heating approach optimizes energy utilization by applying thermal energy only when and where needed, rather than continuous high-energy input, thus reducing overall energy consumption while maintaining environmental benefits

Inventive Principle:
Principle #19Periodic action

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 enables efficient separation of transition metals from waste positive electrode materials while preventing environmental pollution, ensuring high purity and economic feasibility by maintaining phase separation and reducing the need for chemical solvents.

Implementation Method 1

heat treating the waste positive electrode material in an inert gas atmosphere or an oxygen atmosphere to phase separate the waste positive electrode material into a lithium oxide and a metal oxide

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 2

cooling an obtained product of Step 2 to room temperature in an inert atmosphere

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

mixing a cooled product cooled to room temperature in Step 3 with distilled water, and then filtering the mixture to leach a transition metal

Methodology Applied
Scientific EffectLeaching: Solvation

Data Source

PatentEP3951979B1Method for separating transition metal from waste cathode material
Publication Date: 2024.02.07 LG CHEM LTD
  • EP3951979B1 patent drawingFigure 1(a)~1(c)
  • EP3951979B1 patent drawingFigure 2(a)~2(c)
  • EP3951979B1 patent drawing

AI summary

The present invention relates to a method for separating a transition metal from a waste positive electrode material, wherein the method includes Step 1 of preparing a waste positive electrode material represented by Formula 1, Step 2 of heat treating the waste positive electrode material in an inert gas atmosphere or an oxygen atmosphere to phase separate the waste positive electrode material into a lithium oxide and a metal oxide, Step 3 of cooling an obtained product of Step 2 to room temperature in an inert atmosphere, and Step 4 of mixing a cooled product cooled to room temperature in Step 3 with distilled water, and then filtering the mixture to leach a transition metal.