Lithium Cathode Recovery via Hydrophilic Separation

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Solution Overview

Problem

Current lithium-ion battery recycling methods are expensive and inefficient, failing to recover the full value of lithium-containing materials, particularly lithium metal oxides, which are lost during the process, leading to a scarcity of these materials and increased costs.

Innovation Solution

A method involving the crushing, screening, heat treatment, and froth flotation separation of lithium-ion batteries to isolate and regenerate lithium metal oxides, achieving high purity levels suitable for direct reuse in new lithium-ion batteries, while also recovering copper, aluminum, and carbon.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If electric furnace processing with molten steel is used to recover metals, then cobalt, nickel and manganese are recovered for stainless steel alloy, but lithium is lost in the slag and requires expensive extra processing steps to recover

Engineering Contradiction:
Improverecovery of cobalt, nickel, manganeseVSAvoidloss of lithium
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The recycling process is divided into distinct stages: mechanical disassembly, hydrophilic separation to isolate cathode material, and selective metal recovery. This segmentation allows lithium to be recovered in a separate stream from the steelmaking process, preventing its loss in the slag while still enabling cobalt, nickel, and manganese recovery for stainless steel production.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts lithium-containing cathode material from the battery assembly using hydrophilic separation before the electric furnace processing occurs. This extraction removes lithium from the material stream that would otherwise be sent to the electric furnace and lost in the slag, allowing it to be processed separately through evaporation and crystallization to recover lithium hydroxide or lithium carbonate.

Inventive Principle:
Principle #2Taking out (Extraction)

2Quantity of substance

If hammer mill processing with screening is used to separate metals, then copper and aluminum foils are recovered, but the full value of lithium metal oxide cathode material is lost and no lithium recovery is achieved

Engineering Contradiction:
Improverecovery of copper, aluminumVSAvoidloss of lithium metal oxide
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The patent introduces water as an intermediary medium to create a slurry that enables hydrophilic separation. The cathode material's affinity for water allows it to be selectively separated from the anode material and foils through filtration. This intermediary approach preserves the lithium metal oxide in a recoverable form while still allowing copper and aluminum foils to be recovered through the screening process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical state of the battery materials by converting them into a slurry form through addition of water. This parameter change enables the cathode material to be separated based on its hydrophilic properties through filtration, whereas in the hammer mill process alone, all materials would be mixed together and lithium would be lost. The slurry formation is the key parameter change that enables subsequent lithium recovery through evaporation and crystallization.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If roasting process is used for lithium-ion battery recycling, then some materials are recovered, but the full value of recoverable materials is not achieved and the process is expensive

Engineering Contradiction:
Improverecovery of some materialsVSAvoidloss of full value of recoverable materials
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The patent replaces the thermal roasting process with a hydrophilic separation mechanism using water and filtration. Instead of using high-temperature roasting to separate materials, the invention uses the differential water affinity of cathode and anode materials to achieve separation at ambient or moderate temperatures. This substitution eliminates the expensive roasting step while still enabling recovery of lithium, cobalt, nickel, and other valuable materials through subsequent selective processing.

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

The method enables the efficient recovery and regeneration of lithium cathode materials at 95% purity, reducing material scarcity and production costs by utilizing the full value of lithium-containing materials, and maintaining the original fine particle size of the cathode material.

Implementation Method 1

passing the slurry through a molecular sieve to adsorb the lithium

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

heating the solution to a temperature sufficient to evaporate the water and leave a solid behind

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentUS8882007B1Process for recovering and regenerating lithium cathode material from lithium-ion batteries
Publication Date: 2014.11.11 CIRBA SOLUTIONS US INC

AI summary

The present invention related to a method for the recycling of batteries by recovering and regenerating the cathode material. The method includes the steps of isolating the cathode particles and then regenerating the cathode particles for use in the same type of battery.