Mechanochemical Lithium Recycling for Low-Energy Li-Ion Recovery

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Solution Overview

Problem

Current lithium-ion battery recycling methods are inefficient, costly, and environmentally hazardous, with existing technologies facing challenges such as high energy consumption, hazardous gas emissions, and impurity issues in lithium recovery.

Innovation Solution

A mechanochemical method involving mechanical processing of lithium-ion battery cathode materials with aluminum, followed by aqueous treatment and heating to produce high-purity lithium carbonate without corrosive leachates or high temperatures, allowing for efficient and scalable lithium recycling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pyrometallurgical methods are used for lithium recycling, then metal recovery is achieved, but high energy consumption and hazardous gas emissions occur

Engineering Contradiction:
Improvemetal recoveryVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces thermal processing (pyrometallurgy) with mechanical ball milling to achieve lithium recovery. The mechanochemical process uses mechanical energy to reduce lithium compounds to metallic lithium, eliminating the need for high-temperature smelting and associated energy consumption while maintaining effective metal recovery

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the processing parameters from high-temperature thermal conditions to ambient or moderate temperature mechanical conditions. By altering the energy input mode from thermal to mechanical, the process achieves lithium recovery without the hazardous gas emissions and excessive energy consumption characteristic of pyrometallurgical methods

Inventive Principle:
Principle #35Parameter changes

2Reliability

If hydrometallurgical processes are used for lithium recycling, then high metal recovery rates are achieved, but highly corrosive leachates are required

Engineering Contradiction:
Improvemetal recovery rateVSAvoidcorrosive leachates
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces chemical leaching (hydrometallurgy) with mechanical ball milling. The mechanochemical reduction process uses physical mechanical energy combined with chemical reactions to recover lithium without requiring corrosive acids or bases, thereby eliminating the harmful effects of corrosive leachates while maintaining high metal recovery rates

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs water as a simple, non-corrosive liquid medium instead of expensive and hazardous chemical leachates. This substitution uses an inexpensive, environmentally benign substance to achieve the same extraction function without the harmful corrosive effects

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If biohydrometallurgical methods are used for lithium recycling, then environmental hazards are reduced, but processing time increases significantly

Engineering Contradiction:
Improveenvironmental hazardsVSAvoidprocessing time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent replaces slow biological processes with rapid mechanochemical reactions. The ball milling process induces immediate chemical reactions through mechanical energy input, achieving lithium recovery in minutes or hours rather than the days required by biohydrometallurgical methods, while maintaining environmental safety

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs periodic mechanical impacts through ball milling to drive rapid chemical reactions. The intermittent mechanical energy input creates repeated stress and activation events that accelerate the reduction process, achieving fast lithium recovery without the slow continuous processing required by biological methods

Inventive Principle:
Principle #19Periodic action

4Reliability

If conventional recycling methods are used, then lithium recovery is achieved, but costs remain high and profitability is limited

Engineering Contradiction:
Improvelithium recoveryVSAvoidrecycling cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses inexpensive materials and simple equipment for lithium recovery. The ball milling process requires only mechanical energy and basic reagents rather than expensive chemical agents, high-temperature furnaces, or complex separation systems, thereby significantly reducing manufacturing and operational costs while maintaining effective lithium recovery

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces expensive thermal and chemical processing systems with a simple mechanical ball milling system. This substitution eliminates the need for high-temperature equipment, corrosive chemical handling infrastructure, and complex process control systems, thereby reducing capital investment and operational costs while achieving reliable lithium recovery

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enhances lithium recycling efficiency, reduces costs, and minimizes environmental impact by achieving high-purity lithium carbonate production, applicable to various lithium-ion battery chemistries and electrode technologies.

Implementation Method 1

subjecting a cathode material of the lithium-ion battery containing lithium ions in an active cathode material to a mechanical processing in air in the presence of aluminum, thereby mechanochemically reducing the active cathode material

Methodology Applied
Scientific EffectMechanochemical reduction:

Implementation Method 2

adding water to the mechanochemically processed material of step (i), thereby providing an aqueous mixture

Methodology Applied
Scientific EffectDissolution:

Implementation Method 3

heating the aqueous mixture to a temperature of 300°C or higher, thereby providing a mixture of dissolved lithium carbonate (Li2CO3) and insoluble impurities

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 4

separating the insoluble impurities from the mixture, and evaporating water to obtain lithium carbonate (Li2CO3)

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP4286549A1Mechanochemically induced universal method for recycling lithium from li-ion batteries
Publication Date: 2023.12.06 KARLSRUHER INST FUR TECH
  • EP4286549A1 patent drawingFigure 1
  • EP4286549A1 patent drawingFigure 2~3
  • EP4286549A1 patent drawingFigure 4~5(d)

AI summary

The present invention relates to a mechanochemically induced method for recycling lithium from Li-ion batteries which can be universally applied, and which is highly efficient due to a specific heating step.