Li-Ion Battery Pyrolysis Recycling With Water-Based Lithium Separation

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Solution Overview

Problem

The existing dry smelting process for recycling waste lithium ion batteries is economically inefficient, requires extensive equipment and time, and results in a high presence of impurities, reducing the extraction ratio of valuable components and causing environmental issues.

Innovation Solution

A recycling method involving the pyrolysis of waste lithium ion batteries, followed by a separation process using water, to recover electrode raw materials such as lithium, nickel, cobalt, and iron, while minimizing environmental impact and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the dry smelting process is used to recover valuable metals from waste batteries, then the processing capacity is large and recovery efficiency is high, but the process requires extensive equipment, time, and complex procedures making it economically inefficient

Engineering Contradiction:
Improveprocessing capacityVSAvoidequipment and process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention extracts and removes the electrolyte from waste lithium-ion batteries before pyrolysis treatment. This preliminary extraction step simplifies the overall process by eliminating the need for complex disassembly equipment and reduces interference during subsequent thermal treatment, thereby reducing device complexity while maintaining processing capacity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention performs preliminary discharge and electrolyte removal actions before the main pyrolysis process. By pre-processing the batteries to remove flammable and interfering components, the system reduces the complexity of equipment needed during the main processing stage and shortens the overall processing time

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If high temperature heating is applied in the dry smelting process, then organic compounds and polymer components are effectively removed, but a large amount of impurities are generated reducing the extraction ratio of valuable components

Engineering Contradiction:
Improveremoval efficiency of organic compoundsVSAvoidextraction ratio of valuable components
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The invention performs preliminary extraction of the electrolyte and discharge of the battery before pyrolysis. This removes organic compounds and active materials in advance, so that subsequent low-temperature pyrolysis (300-500°C) is sufficient to decompose remaining polymers without generating excessive impurities, thus maintaining manufacturing precision while reducing substance loss

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter from high temperature (traditional dry smelting) to low temperature (300-500°C) pyrolysis. This parameter change, combined with preliminary electrolyte removal, achieves effective decomposition of organic compounds while minimizing the formation of impurities that would reduce the extraction ratio of valuable metal components

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the waste battery is processed in bulk state through dry smelting, then large-scale processing is achieved, but pulverization and strong acid treatment are required again reducing economic efficiency

Engineering Contradiction:
Improvelarge-scale processing capabilityVSAvoideconomic efficiency
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The pyrolysis process itself serves to pulverize and transform the battery materials into a fine powder state suitable for direct wet chemical processing. The thermal decomposition and expansion during pyrolysis naturally breaks down the bulk structure, eliminating the need for separate mechanical pulverization equipment and reducing overall manufacturing complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention merges the pyrolysis step with the pulverization function. The thermal treatment process simultaneously achieves decomposition, phase change, and physical breakdown of materials, combining multiple functions into one operation. This eliminates the need for separate pulverization equipment and reduces the number of processing stages, improving economic efficiency while maintaining large-scale processing capability

Inventive Principle:
Principle #5Merging (Combining)

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 achieves an economical and eco-friendly recovery of electrode raw materials, increasing recycling efficiency and reducing environmental problems associated with traditional recycling processes.

Implementation Method 1

increasing the internal temperature of the pyrolysis furnace to induce self-heating of the waste lithium ion secondary battery

Methodology Applied
Scientific EffectPyrolysis: Pyrolysis

Implementation Method 2

induce self-heating of the waste lithium ion secondary battery, (c) maintaining a self-heating reaction

Methodology Applied
Scientific EffectSelf-heating: Exothermic Reaction

Implementation Method 3

injecting the first powder into water, dissolving a lithium component included in the first powder

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 4

separating and recovering a lithium aqueous solution, a powder settled in the lithium aqueous solution

Methodology Applied
Scientific EffectSedimentation: Sedimentation

Data Source

PatentEP4509621A1Recycling method for waste lithium ion secondary batteries and electrode raw materials obtained therefrom
Publication Date: 2025.02.19 AK TREE CO LTD
  • EP4509621A1 patent drawingFigure 1
  • EP4509621A1 patent drawingFigure 2
  • EP4509621A1 patent drawingFigure 3

AI summary

An object of the invention is to provide a method for economically and eco-friendly recovering an electrode raw material for a positive electrode and a negative electrode from a waste lithium ion secondary battery, which is formed by the pyrolysis of a waste lithium ion secondary battery, and an electrode raw material for a positive electrode and a negative electrode, obtained therefrom. To accomplish the object, a recycling method of a waste lithium ion secondary battery according to the invention may include (a) loading a waste lithium ion secondary battery into a pyrolysis furnace, (b) increasing the internal temperature of the pyrolysis furnace to induce self-heating of the waste lithium ion secondary battery, (c) maintaining a self-heating reaction of the waste lithium ion secondary battery, (d) discharging a first powder formed after completing the self-heating reaction of the waste lithium ion secondary battery, and (e) injecting the first powder into water, dissolving a lithium component included in the first powder, and separating and recovering a lithium aqueous solution, a powder settled in the lithium aqueous solution, and a floating material on the surface of the lithium aqueous solution, separately.