Battery Positive Electrode Thermit Recycling Without External Heating
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Solution Overview
Problem
Current methods for recovering valuable materials like nickel and cobalt from non-aqueous electrolyte secondary batteries are costly due to requirements for magnetic separation, acid fusion, and the use of reducing agents, as well as the need for pulverizing and high-temperature external heating in the thermit method.
Innovation Solution
A treating method for a non-aqueous electrolyte secondary battery positive electrode involving a foil with aluminum and a metal composite oxide active material, where a heating treatment promotes a thermit reaction to melt the electrode, separating it into metal and slag without external heating, thus reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional recovering methods (roasting, magnetic separation, acid fusion) are used, then valuable materials like cobalt can be recovered, but the cost for recycling increases due to multiple required steps
Solution Approach 1:
The patent combines roasting and reduction steps into a single integrated process by adding a reducing agent during the roasting phase. This merging eliminates the need for separate magnetic separation and acid fusion steps, reducing the total number of processing steps while maintaining effective recovery of valuable materials like cobalt and nickel.
Solution Approach 2:
The roasting step is designed to serve multiple functions simultaneously: it performs oxidation of organic materials, prepares the metal oxide structure, and enables in-situ reduction when the reducing agent is added. This multi-functional approach replaces multiple specialized steps with a single versatile process.
2Reliability
If a reducing agent is mixed into recovered materials, then valuable materials like Ni and Co can be recovered, but the operation for mixing and cost for the reducing agent are inevitably required
Solution Approach 1:
The reducing agent is added during the initial roasting step rather than in a separate subsequent step. This preliminary action allows the reducing agent to be distributed throughout the material during the roasting process itself, eliminating the need for separate mixing operations and simplifying the overall process flow.
3Reliability
If the positive electrode metal foil is pulverized before thermit method, then the thermit reaction can proceed, but the cost increases due to additional pulverizing step and high-temperature external heating
Solution Approach 1:
The patent extracts and removes the aluminum foil current collector from the positive electrode structure before applying the thermit method. This extraction creates a loose, powder-like structure of the active material that can undergo thermit reaction without requiring additional pulverizing steps, while the removed aluminum foil serves as the reducing agent in the thermit reaction.
Solution Approach 2:
The aluminum foil current collector itself is utilized as the reducing agent for the thermit reaction. By removing the foil and using it as the reductant, the system becomes self-sufficient, eliminating the need to add external reducing agents or perform separate pulverizing operations. The structure of the electrode provides the necessary components for the reaction.
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 effectively promotes a reduction reaction at a lower cost by eliminating the need for external heating and pulverizing, improving yield and reducing operational costs in recycling valuable materials.
Implementation Method 1
melting the positive electrode using heat of reaction of the foil and the active material to obtain a molten material
Data Source
AI summary
The treating method for a positive electrode for a non-aqueous electrolyte secondary battery is a treating method for a positive electrode for a non-aqueous electrolyte secondary battery which comprises a positive electrode having a foil containing Al and an active material which is a metal composite oxide, the method comprising: conducting a heating treatment for heating the positive electrode (heating step); melting the positive electrode using heat of reaction of the foil and the active material to obtain a molten material (melting step); and separating the molten material into a metal material containing a metal constituting the metal composite oxide and a slag (separating step). By subjecting the positive electrode to heating treatment, a reduction reaction of the positive electrode can be promoted at a low cost.