Cathode Active Material Recycling via Carboxylic Acid Digestion

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Solution Overview

Problem

Current battery recycling methods for cathode active material (CAM) are unsustainable due to the formation of sodium sulfate and require high temperatures and pressures, leading to metal losses and inefficiencies in recovering valuable metals like lithium, nickel, manganese, and cobalt.

Innovation Solution

A method involving the digestion of black mass from depleted batteries with a carboxylic acid to form delithiated cathode active material precursors, followed by the addition of virgin lithium salt and calcination, allowing for the recovery of recycled CAM without sulfate formation and at ambient temperatures, thereby maintaining metal ratios and reducing waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydrothermal digestion at high temperatures and pressures is used to recycle cathode active material, then the digestion process can effectively break down the battery materials, but it results in formation of sodium sulfate and metal losses

Engineering Contradiction:

Improvedigestion efficiencyVSAvoidmetal loss

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent changes the digestion parameters by using carboxylic acids at ambient temperatures instead of high-temperature hydrothermal conditions. This parameter change eliminates the formation of sodium sulfate and prevents metal losses while maintaining effective digestion of the cathode active material.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces carboxylic acids as intermediary substances to facilitate the digestion process. These intermediaries enable effective breakdown of battery materials without requiring extreme conditions that cause metal loss and sodium sulfate formation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If hydrothermal digestion is used to recycle cathode active material, then the process can recover metals, but it requires high temperatures and pressures leading to process inefficiency

Engineering Contradiction:

Improvemetal recoveryVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent fundamentally changes the temperature and pressure parameters of the digestion process, operating at ambient conditions rather than high temperatures and pressures. This maintains reliable metal recovery while dramatically reducing energy consumption.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If conventional recycling processes are used, then cathode active material can be recovered, but sodium sulfate is formed rendering the process unsustainable

Engineering Contradiction:

Improvemetal recovery quantityVSAvoidsodium sulfate formation

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of conventional digestion methods that produce sodium sulfate waste into a beneficial process by using carboxylic acids that do not form harmful byproducts. This enables sustainable recycling while maintaining effective metal recovery.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Carboxylic acids serve as intermediary substances that enable metal recovery without generating sodium sulfate. These intermediaries facilitate the chemical reactions needed for digestion while producing environmentally benign byproducts.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If filtration of black mass is required in the recycling process, then metal separation can be achieved, but it increases process complexity and metal losses

Engineering Contradiction:

Improvemetal separationVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the digestion step as a standalone process using carboxylic acids that directly produces recoverable metal salts without forming problematic black mass requiring filtration. This eliminates complex separation steps while maintaining reliable metal recovery.

Inventive Principle:

Principle #2Taking out (Extraction)

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 process effectively recovers valuable metals with minimal loss, forming recycled CAM suitable for battery reuse, with improved metal ratios and reduced environmental impact, and demonstrates scalable and efficient recycling without the need for high-temperature hydrothermal processes.

Implementation Method 1

digesting the black mass with a carboxylic acid to form delithiated cathode active material precursor

Methodology Applied

Scientific EffectChemical dissolution: Solvation

Implementation Method 2

calcining the cathode active material precursor to form the recycled cathode active material

Methodology Applied

Scientific EffectThermal decomposition: Pyrolysis

Data Source

PatentUS20240097225A1Process for Efficient Recycling of Cathode Active Materials

Publication Date: 2024.03.21 NANO ONE MATERIALS

AI summary

A process of forming recycled cathode active material, particularly from depleted cathode active material from a battery, comprising:forming black mass from the depleted cathode active material;digesting the black mass with a carboxylic acid to form delithiated cathode active material precursor;adding virgin lithium salt to the delithiated cathode active material precursor to form cathode active material precursor; andcalcining the cathode active material precursor to form the recycled cathode active material.