Cathode Scrap Thermal Recovery for Direct Active Material Reuse
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Solution Overview
Problem
Existing methods for reusing positive electrode active materials from lithium secondary battery scrap involve acid-based processes that are not eco-friendly, fail to collect lithium, and require additional treatment steps, leading to increased costs and environmental impact.
Innovation Solution
A method involving thermal treatment of positive electrode scrap at 300 to 650°C to separate the current collector from the active material layer, followed by annealing with a lithium precursor to recover the active material, allowing for direct reuse without dissolving the materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If acid-based extraction methods are used to collect active material elements, then pure raw materials can be obtained, but the process becomes non-eco-friendly and requires additional neutralization and waste water treatment steps
Solution Approach 1:
The patent changes the chemical parameters of the extraction process by replacing strong acids with a milder alkaline solution (sodium hydroxide) and controlling the pH and temperature parameters to achieve effective extraction without harmful environmental impacts. The active material elements are extracted by dissolving the binder in alkaline solution, allowing recovery of cobalt, nickel, manganese and lithium without requiring neutralization or waste water treatment.
Solution Approach 2:
The patent uses a simple, inexpensive alkaline solution that can be easily disposed of or regenerated, replacing the complex acid-based system that requires neutralization. The alkaline extraction solution serves its purpose effectively and can be filtered and reused, eliminating the need for additional treatment steps while maintaining extraction efficiency.
2Quantity of substance
If acid-based extraction methods are used, then active material elements can be extracted, but lithium cannot be collected and additional treatment steps are required
Solution Approach 1:
The alkaline extraction solution performs multiple functions simultaneously: it dissolves the binder to release active material elements, extracts cobalt, nickel, manganese and lithium together in a single step, and creates a filtrate that can be directly used for lithium compound recovery without additional treatment steps. This multi-functional approach eliminates the need for separate lithium recovery processes.
Solution Approach 2:
The patent establishes a continuous process where the alkaline extraction solution is filtered and the filtrate is directly used to precipitate lithium compounds. This continuous utilization of the extraction solution without interruption or additional treatment steps maintains the flow of useful action throughout the process, recovering all active material elements in sequence without breaking the process chain.
3Ease of manufacture
If thermal treatment is used to separate current collector from active material layer, then direct reuse of active material is enabled, but energy consumption increases
Solution Approach 1:
The patent utilizes phase transitions of the binder material through controlled thermal treatment. By heating to specific temperature ranges, the binder undergoes decomposition and phase changes that allow separation from the active material layer. This phase transition approach enables clean separation and direct reuse of active material while minimizing energy consumption by targeting specific temperature windows where the binder transitions.
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 the eco-friendly reuse of positive electrode active materials, reducing process costs and environmental impact by avoiding acid use and additional treatment steps, while maintaining the performance of fresh active materials.
Implementation Method 1
thermally treating positive electrode scrap comprising a lithium composite transition metal oxide positive electrode active material layer on a current collector in air at 300 to 650° C. for 1 hour or less, for thermal decomposition of a binder and a conductive material in the active material layer
Implementation Method 2
annealing the collected active material with an addition of 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 positive electrode active material reuse method of the present disclosure includes (a) thermally treating positive electrode scrap comprising a lithium composite transition metal oxide positive electrode active material layer on a current collector in air at 300 to 650° C. for 1 hour or less for thermal decomposition of a binder and a conductive material in the active material layer, to separate the current collector from the active material layer, and collecting an active material in the active material layer, and (b) annealing the collected active material with an addition of a lithium precursor to obtain a reusable active material.