Positive Electrode Scrap Reuse via Basic Separation and Relithiation
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Solution Overview
Problem
Existing methods for recycling positive electrode active materials from lithium secondary batteries are non-eco-friendly, costly, and inefficient, particularly due to the use of acids for elemental extraction, and fail to recover lithium, while residual electrolyte solutions complicate the process.
Innovation Solution
A method involving immersion in a basic solution to separate the active material from the current collector, followed by thermal treatment to decompose the binder and conductive material, washing with a lithium compound solution, and annealing with a lithium precursor to recover the active material, without using acids or toxic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If acid dissolution is used to extract active material elements, then pure raw materials can be collected, but the process becomes non-eco-friendly and requires neutralization and waste water treatment, increasing process cost
Solution Approach 1:
Instead of using acid dissolution to extract elements, the patent inverts the approach by directly recovering the active material in its original compound form through basic solution treatment, eliminating the need for element extraction and subsequent synthesis, thereby avoiding environmental harm and additional process steps
Solution Approach 2:
The patent extracts the active material layer from the current collector using a basic solution, separating the valuable active material (containing lithium, cobalt, nickel, manganese) from the aluminum current collector without dissolving the active material itself, enabling direct reuse
2Quantity of substance
If acid dissolution and element extraction are used, then active material elements can be recovered, but lithium cannot be collected and the process becomes complex and costly
Solution Approach 1:
The active material layer serves itself by being directly recovered in its original functional form through basic solution treatment, eliminating the need for external extraction and synthesis processes. The material essentially recovers itself without complex chemical transformations
Solution Approach 2:
The patent changes the chemical environment from acidic to basic, which fundamentally alters the recovery mechanism. The basic solution selectively dissolves the aluminum current collector while leaving the active material intact, enabling direct separation without complex extraction processes
3Quantity of substance
If conventional recycling methods are used, then some active material can be recovered, but the process is time-consuming and requires multiple steps including dissolution, extraction, and synthesis
Solution Approach 1:
The active material layer is directly extracted from the current collector using basic solution treatment, obtaining the active material in a reusable form without requiring subsequent synthesis steps, thereby significantly reducing process time
Solution Approach 2:
The patent combines multiple functions into a single treatment step: the basic solution simultaneously dissolves the aluminum current collector, removes binder materials, and preserves the active material in its functional form, eliminating the need for separate extraction and synthesis processes
4Ease of operation
If residual electrolyte solution is present on positive electrode scrap, then the scrap can be directly processed, but safety issues arise and the process becomes complicated
Solution Approach 1:
The basic solution treatment extracts and removes residual electrolyte solution from the positive electrode scrap during the same process that separates the active material layer, eliminating safety hazards without requiring separate pretreatment steps
Solution Approach 2:
The basic solution acts as an intermediary medium that simultaneously addresses multiple issues: it dissolves the aluminum current collector, removes binder materials, and eliminates residual electrolyte solution, thereby safely preparing the active material for reuse while simplifying the overall process
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 method enables eco-friendly, cost-effective recovery of all metal elements from positive electrode scrap, ensuring excellent resistance and capacity characteristics without electrochemical degradation, suitable for mass production and commercialization.
Implementation Method 1
immersing a positive electrode scrap comprising an active material layer on a current collector into a basic solution to separate the active material layer from the current collector
Implementation Method 2
thermally treating the active material layer in air for thermal decomposition of a binder and a conductive material in the active material layer
Implementation Method 3
annealing the active material washed from the step (b) with a lithium precursor to obtain a reusable active material
Data Source
AI summary
There is provided a method for collecting and reusing an active material from positive electrode scrap. The method of reusing a positive electrode active material of the present disclosure includes (a-1) immersing a positive electrode scrap comprising an active material layer on a current collector into a basic solution to separate the active material layer from the current collector, (a-2) thermally treating the active material layer in air for thermal decomposition of a binder and a conductive material in the active material layer, and collecting an active material in the active material layer, (b) washing the active material collected from the step (a-2) with a lithium compound solution which is basic in an aqueous solution and drying, and (c) annealing the active material washed from the step (b) with a lithium precursor to obtain a reusable active material.