Lithium Hydroxide Recovery via Li-Selective Membrane Crystallization

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Solution Overview

Problem

Current methods for producing lithium hydroxide are energy-intensive and limited in their ability to efficiently recover lithium from various lithium-containing solutions, particularly in the context of lithium secondary battery recycling, where the demand for lithium is increasing and energy consumption needs to be reduced.

Innovation Solution

A method involving the use of a Li permselective membrane to recover Li ions from a lithium ion extract in a lithium secondary battery, with temperature control at 50° C. or higher, followed by crystallization, either cooling or evaporative, to produce high-purity lithium hydroxide while minimizing energy consumption, and utilizing inert gases to suppress impurity formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If heating concentration is used to obtain lithium hydroxide, then lithium hydroxide can be produced from aqueous solution, but energy consumption increases significantly

Engineering Contradiction:

Improvelithium hydroxide productionVSAvoidenergy consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The invention utilizes the phase transition of lithium hydroxide from dissolved state to crystalline solid state through cooling crystallization. By controlling temperature reduction, lithium hydroxide crystallizes directly from the aqueous solution without requiring heating concentration, thereby achieving product separation with minimal energy input.

Inventive Principle:

Principle #36Phase transitions

Solution Approach 2:

The invention replaces the thermal field (heating concentration) with a thermal gradient field (cooling crystallization). Instead of applying heat to concentrate and then cool to crystallize, the process directly applies controlled cooling to achieve crystallization, substituting a high-energy thermal process with a lower-energy thermal gradient process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If conventional electrolysis method is used, then lithium hydroxide can be produced from lithium carbonate, but raw material selection is limited

Engineering Contradiction:

Improvelithium hydroxide productionVSAvoidraw material flexibility

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The Li permselective membrane serves multiple functions: it selectively transports lithium ions from various sources, separates lithium hydroxide from impurities, and enables direct crystallization. This multi-functional membrane technology allows the process to handle diverse lithium-containing solutions (recycled battery electrolytes, brine, industrial wastewater) without requiring pre-treatment or specific raw material forms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The Li permselective membrane acts as an intermediary that selectively facilitates lithium ion transport while blocking other ions and impurities. This intermediary component enables the system to process various lithium-containing solutions by providing a universal interface that converts diverse input streams into purified lithium hydroxide product.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If lithium recovery efficiency is increased to meet growing demand, then more lithium can be recovered from batteries, but current methods require energy-intensive processing

Engineering Contradiction:

Improvelithium recovery efficiencyVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention establishes a continuous process where lithium ions are selectively transported through the membrane and simultaneously crystallize as lithium hydroxide in the permeate stream. This continuous operation eliminates batch processing steps and energy-intensive intermediate concentration stages, maintaining high recovery efficiency while minimizing energy input through sustained low-temperature crystallization.

Inventive Principle:

Principle #20Continuity of useful 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 approach enables the efficient production of high-purity lithium hydroxide at lower energy costs, reducing the need for energy-intensive dewatering steps and allowing for the use of a broad range of lithium-containing solutions without specific raw material selection.

Implementation Method 1

recovering Li ions alone in a recovery liquid from a lithium ion extract extracted from a processed member of a lithium secondary battery, using a Li permselective membrane

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

lithium hydroxide is separated from the recovery liquid... the crystallization is cooling crystallization

Methodology Applied

Scientific EffectCooling crystallization: Crystallisation

Data Source

PatentUS20230406718A1Method for producing lithium hydroxide

Publication Date: 2023.12.21 IDEMITSU KOSAN CO LTD

AI summary

Provided is a lithium hydroxide production method for producing high-purity lithium hydroxide efficiently and at a lower energy, wherein Li ions alone are recovered in a recovery liquid from a lithium ion extract extracted from a processed member of a lithium secondary battery, using a Li permselective membrane, and lithium hydroxide is produced from the recovery liquid.