Organic Sulfonic Acid Stripping Agent for Battery Electrode Recovery
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Solution Overview
Problem
Current methods for recovering active materials from secondary batteries, such as lithium-ion batteries, face challenges in efficiently separating the active material from the current collector, resulting in long treatment times, impurity contamination, and increased costs due to the use of organic solvents and harsh chemicals.
Innovation Solution
An aqueous solution containing organic sulfonic acid or its derivatives is used as a stripping agent to efficiently separate the active material from the current collector, reducing treatment time and minimizing impurity contamination, with a preferred concentration range of 5 to 50 mass% and specific aromatic sulfonic acids like benzenesulfonic acid, which suppresses metal constituent elution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If organic solution of alkyl phosphoric acid is used as stripping agent, then active material can be separated from current collector, but treatment time becomes long (10 to 180 minutes) and organic solvent recovery is required
Solution Approach 1:
The patent changes the chemical parameters of the stripping agent by using aqueous solutions of organic sulfonic acids (such as benzenesulfonic acid, toluenesulfonic acid, xylenesulfonic acid, naphthalenesulfonic acid) instead of organic solutions of alkyl phosphoric acid. This parameter change enables the stripping process to be completed in significantly shorter time (5 to 60 minutes) while maintaining effective separation of active material from current collector, and eliminates the need for organic solvent recovery.
2Manufacturing precision
If acid solution (sulfuric acid) is used as stripping agent, then active material and metal foil can be separated, but aluminum foil dissolves and impurities increase
Solution Approach 1:
The patent applies local quality by using organic sulfonic acids that selectively interact with the interface between active material and current collector without causing bulk dissolution of the aluminum foil. The stripping action is localized to the adhesive interface, preserving the integrity of the current collector while achieving effective separation.
Solution Approach 2:
The organic sulfonic acid acts as an intermediary substance that facilitates the separation process by targeting the adhesive bonding between active material and current collector. It mediates the separation without directly attacking or dissolving the metal foil, thus preserving current collector integrity while enabling effective separation.
3Manufacturing precision
If alkali metal hydroxide solution is used as stripping agent, then active material and aluminum foil can be separated, but aluminum foil corrodes to generate large amount of aluminum hydroxides requiring additional separation treatment
Solution Approach 1:
The patent converts the potentially harmful corrosive action of stripping agents into a beneficial selective interface reaction. By using organic sulfonic acids, the harmful bulk corrosion of aluminum foil is avoided, and only the adhesive interface is targeted for separation. This eliminates the generation of harmful aluminum hydroxides and the need for additional separation treatments.
4Ease of manufacture
If water-insoluble organic solvent medium is used to dissolve alkyl phosphoric acid, then stripping can be performed, but solvent recovery is required and flammability concerns arise
Solution Approach 1:
The patent fundamentally changes the solvent parameter from water-insoluble organic solvents to water-based aqueous solutions. This parameter change eliminates the need for complex solvent recovery systems and removes flammability concerns, while maintaining the stripping process capability through the use of aqueous organic sulfonic acids.
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 method significantly reduces the stripping time, enhances the purity of the recovered active material, and simplifies the refinement process, making the recycling of valuable resources more efficient and cost-effective.
Implementation Method 1
an aqueous solution containing at least one of an organic sulfonic acid and derivative thereof is used as a stripping agent to strip an electrode material from a current collector
Data Source
AI summary
An electrode of a secondary battery is treated to remove an electrode material adhering to the current collector of the electrode. The electrode is treated by exposing to a stripping agent, which is constituted as an aqueous solution containing at least one of an organic sulfonic acid and derivative thereof, and the electrode exposure to each other to strip the electrode material from the current collector constituting the electrode.