Waste Battery Active Material Recovery Without Shredding
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Solution Overview
Problem
Current methods for recycling lithium-ion battery active materials face challenges such as safety risks from residual voltage, difficulty in separating components due to mechanical shredding, high energy consumption, contamination risks, and environmental hazards from high-temperature pyrolysis, which hinder effective recovery and recycling.
Innovation Solution
A method involving the use of carbon tetrachloride and chlorine to desorb active materials from current collectors, followed by water soaking and nitric acid treatment to separate and recover cathode and anode materials without shredding, allowing for the production of valuable aluminum chloride and copper nitrate solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical shredding is performed multiple times to reduce particle size and improve recovery rate of active material powder, then the recovery rate increases, but the recovery grade of separated components deteriorates and sorting difficulty increases
Solution Approach 1:
The patent replaces the mechanical shredding system with a chemical dissolution system. Instead of using mechanical force to separate components, the invention uses selective chemical dissolution where alkaline solution dissolves the aluminum current collector and organic solvent dissolves the PVDF binder, enabling separation without mechanical particle size reduction. This substitution resolves the contradiction by achieving both high recovery rate and high recovery grade through chemical selectivity rather than mechanical force.
Solution Approach 2:
The patent changes the separation parameter from mechanical particle size to chemical solubility. By controlling the chemical properties (pH for alkaline solution, solvent type for organic solution) rather than mechanical parameters (shredding intensity, particle size), the process achieves effective separation that maintains both recovery rate and recovery grade. The active material powder is recovered intact because the separation mechanism is based on differential chemical dissolution of other components.
2Use of energy by stationary object
If alkaline solution is used to dissolve current collector aluminum foil for separation, then the separation of cathode powder and current collector is achieved with low energy consumption, but the aluminum foil enters solution as ions requiring further recycling and neutralization treatment is necessary
Solution Approach 1:
The patent converts the harmful effect of alkaline solution contamination into a beneficial separation mechanism. The alkaline solution's ability to dissolve aluminum is utilized to separate the current collector from the active material, while the organic solvent's ability to dissolve PVDF is used to further separate the binder. By using sequential dissolution with different chemicals, the process transforms what would be contamination into selective separation, recovering pure active material powder without requiring neutralization or further treatment.
3Reliability
If organic solvents are used to dissolve binder PVDF for recovering current collector metal wound core, then the current collector can be recovered in solid form, but the organic solvents are expensive and not suitable for large-scale industrial applications
Solution Approach 1:
The patent applies discarding and recovering by using inexpensive alternatives to expensive organic solvents. Instead of using costly solvents like NMP for PVDF dissolution, the invention employs a two-step process: first alkaline solution dissolves aluminum, then a cheaper organic solvent or alternative method removes the binder. The active material powder is recovered and can be directly reused, making the process economically viable for large-scale applications while maintaining reliable solid form recovery of components.
4Ease of operation
If direct heating to high temperature is applied to deactivate binder for separating current collector aluminum foil, then the binder is deactivated and separation is achieved, but toxic and harmful gases such as HF are produced requiring additional exhaust gas purification
Solution Approach 1:
The patent replaces the thermal treatment system with a chemical dissolution system. Instead of using high-temperature heating to decompose and deactivate the binder, the invention uses selective chemical dissolution where alkaline solution dissolves aluminum and organic solvent dissolves PVDF at ambient or moderate temperatures. This substitution eliminates the need for high-temperature pyrolysis and the associated production of toxic gases like HF, while still achieving effective separation of the current collector and active material through chemical selectivity.
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 safe and efficient recovery of lithium-ion battery active materials without shredding, reducing equipment investment and environmental impact, while producing high-value products like anhydrous aluminum chloride and recyclable carbon tetrachloride, and preserving the structure of lithium iron phosphate for regeneration.
Implementation Method 1
introducing chlorine into the reaction device in step (1) for reaction
Implementation Method 2
obtain a solution of aluminum chloride in carbon tetrachloride
Implementation Method 3
soaking the wound cores and the first desorption powder of cathode in water, removing the soaked wound cores, and performing solid-liquid separation on the remaining material to obtain a lithium salt solution
Implementation Method 4
reacting the soaked wound cores in step (4) with a nitric acid solution and performing solid-liquid separation to obtain a copper nitrate solution
Data Source
AI summary
The present disclosure discloses a method for recovering active material from waste battery by desorption, comprising steps of: reacting wound cores of cathode and anode current collectors of waste battery with carbon tetrachloride and chlorine to obtain remaining wound cores, a solution of aluminum chloride in carbon tetrachloride and a first desorption powder of cathode; soaking the remaining wound cores and the first desorption powder of cathode in water to obtain soaked wound cores, a lithium salt solution and a second desorption powder of cathode; and reacting the soaked wound cores with nitric acid to obtain a copper nitrate solution and a desorption powder of anode. The waste lithium-ion battery only needs to be discharged and disassembled, and no shredding process is required, which avoids steps of shredding and sorting, reduces equipment investment. In addition, cathode and anode materials can be effectively recovered, and the product has high economic value.