Relithiation of Lithium-Ion Battery Cathodes Using Oxidizing Agents

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Solution Overview

Problem

Lithium-ion battery recycling methods face inefficiencies due to the sensitivity of nickel-containing positive-electrode materials to reducing factors, leading to metal ion reduction and dissolution, which affects electrode performance and requires costly sintering steps.

Innovation Solution

Incorporating an oxidizing agent into the hydrothermal relithiation treatment solution to prevent metal ion reduction and potentially eliminate subsequent sintering steps, thereby enhancing recycling efficiency and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If hydrothermal relithiation treatment is performed without oxidizing agents, then the process is simple and low-cost, but metal ion reduction and dissolution occur, affecting electrode performance

Engineering Contradiction:

Improveprocess simplicityVSAvoidelectrode performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies strong oxidizing agents (such as hydrogen peroxide, sodium chlorate, or sodium percarbonate) to the hydrothermal relithiation treatment solution to prevent metal ion reduction and dissolution. The oxidizing agents maintain metal ions in their proper oxidation states during the relithiation process, thereby preserving electrode performance while enabling effective recycling of lithium-ion battery materials.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

2Device complexity

If conventional hydrothermal treatment is used, then the process avoids complex chemistry, but sintering steps are required to maintain material stability, increasing process complexity and cost

Engineering Contradiction:

Improveprocess complexityVSAvoidmanufacturing cost

Core Design Contradiction:

Device complexityVSEase of manufacture

Solution Approach 1:

By incorporating oxidizing agents into the hydrothermal treatment, the patent eliminates the need for subsequent sintering steps. The oxidizing agents stabilize the crystal structure and prevent phase transformations that would otherwise require high-temperature sintering, thereby simplifying the overall process while reducing manufacturing costs.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

Solution Approach 2:

The patent changes the chemical parameters of the hydrothermal treatment by adding oxidizing agents, which fundamentally alters the reaction environment. This parameter change allows the process to achieve material stability and performance without requiring additional high-temperature sintering steps, thus reducing process complexity and cost.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If nickel-containing positive-electrode materials are treated in reducing conditions, then the hydrothermal treatment proceeds easily, but metal ion dissolution occurs, requiring additional processing steps

Engineering Contradiction:

Improvetreatment easeVSAvoidmetal ion dissolution

Core Design Contradiction:

Ease of operationVSLoss of substance

Solution Approach 1:

The patent uses strong oxidizing agents to counteract the reducing conditions that would otherwise cause metal ion dissolution. The oxidizing agents maintain nickel and other metal ions in stable oxidation states throughout the hydrothermal treatment, preventing dissolution while allowing the treatment to proceed easily under mild conditions.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

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 use of oxidizing agents during hydrothermal treatment stabilizes nickel in the +3 oxidation state, maintaining electrode performance and simplifying the recycling process by avoiding metal ion reduction and the need for sintering, resulting in improved recovery efficiency and cost reduction.

Implementation Method 1

relithiating the positive-electrode material in a solution comprising lithium ions and an oxidizing agent

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

The use of oxidizing agents during hydrothermal treatment stabilizes nickel in the +3 oxidation state, preventing metal ion reduction

Methodology Applied

Scientific EffectRedox Reactions: Redox Reactions

Implementation Method 3

Incorporating an oxidizing agent into the hydrothermal relithiation treatment solution

Methodology Applied

Scientific EffectHydrothermal treatment:

Implementation Method 4

relithiating the positive-electrode material in a solution comprising lithium ions

Methodology Applied

Scientific EffectIon Exchange: Ion Exchange

Data Source

PatentUS20220352572A1Relithiation in oxidizing conditions

Publication Date: 2022.11.03 HULICO LLC

AI summary

Examples are disclosed of methods to recycle positive-electrode material of a lithium-ion battery. One example provides a method including relithiating the positive-electrode material in a solution comprising lithium ions and an oxidizing agent, and after relithiating, separating the positive-electrode material from the solution.