Recycled Li-Ion Electrode Coatings via Solvent-Free Melt Mixing
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Solution Overview
Problem
Current lithium-ion battery recycling methods are complex, energy-intensive, and costly, with high CO2 emissions, and fail to effectively recover binder materials and achieve electrochemical performance comparable to new electrodes.
Innovation Solution
A method involving hot melt mixing without solvents of recycled lithium-ion battery electrode coatings with new ingredients, including a compatible active material, permanent binder, sacrificial binder, and conductive additive, followed by partial elimination of the sacrificial binder, to create a precursor mixture for forming new electrode coatings with comparable electrochemical performance to those made from virgin materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional coating processes using organic solvents like NMP are used to manufacture lithium-ion battery electrodes, then the electrode coating can be applied, but the process becomes environmentally harmful due to toxicity and flammability, requires large amounts of solvent evaporation, and creates safety issues
Solution Approach 1:
The patent changes the fundamental parameter of the coating process by replacing solvent-based dispersion with a water-based slurry system. This parameter change eliminates the harmful organic solvents (NMP) while maintaining the coating functionality, thus resolving the contradiction between ease of manufacture and environmental harm.
Solution Approach 2:
The patent converts the typically harmful organic solvent system into a beneficial water-based system. By using water as the continuous phase instead of flammable organic solvents, the process transforms an environmental hazard into an environmentally friendly solution, eliminating toxicity and flammability issues while preserving coating effectiveness.
2Manufacturing precision
If high mass fraction of solid compounds are dispersed in organic solvent to create electrode coating, then the coating quality can be improved, but the process becomes delicate and difficult due to sedimentation and coagulation problems
Solution Approach 1:
The patent changes the dispersion medium from organic solvent to water-based slurry, fundamentally altering the chemical environment. This parameter change prevents the sedimentation and coagulation issues associated with high solid fractions in organic solvents, enabling simpler processing while maintaining coating quality.
Solution Approach 2:
The patent introduces water as an intermediary medium that facilitates the dispersion of solid electrode compounds without causing sedimentation or coagulation. This water-based intermediary enables stable high-solid-content formulations, simplifying the manufacturing process while ensuring coating uniformity.
3Manufacturing precision
If complex hydrometallurgical purification processes are used to recycle active materials from spent batteries, then the purity of recycled materials can be improved, but the process becomes costly and energy-intensive with high CO2 emissions
Solution Approach 1:
The patent extracts only the necessary purification steps from the complex hydrometallurgical process. By selectively removing and recycling the binder fraction through simple filtration and drying, the process achieves adequate purity without the energy-intensive and costly full hydrometallurgical treatment, thus resolving the contradiction between purity and energy consumption.
Solution Approach 2:
The patent accepts that the binder fraction in recycled electrodes will have reduced service life or performance compared to virgin materials. By deliberately using a simplified purification approach that recovers the binder for immediate reuse rather than achieving maximum purity, the process reduces energy consumption and costs while maintaining functional performance.
4Loss of substance
If conventional recycling methods are used to process spent lithium-ion batteries, then the materials can be recovered, but the process fails to effectively recover binder materials and achieve electrochemical performance comparable to new electrodes
Solution Approach 1:
The patent creates a multi-functional recycling process that simultaneously recovers active material, conductive additive, and binder in a single integrated water-based slurry system. This universal approach recovers all electrode components together, maintaining their original functional relationships and achieving electrochemical performance comparable to new electrodes, unlike conventional methods that treat each component separately.
Solution Approach 2:
The patent merges the recovery of all electrode components (active material, binder, conductive additive) into a single water-based slurry formulation. By combining these components in one unified process rather than separate treatment streams, the method preserves the synergistic relationships between components, enabling effective binder recovery and electrochemical performance comparable to virgin materials.
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 direct and low-cost reuse of anode and cathode coatings with satisfactory electrochemical properties and cyclability, reducing the need for energy-intensive steps and minimizing environmental impact.
Implementation Method 1
eliminating the sacrificial binder to obtain the composition
Data Source
AI summary
The invention relates in particular to a method for recycling a first electrode for a lithium-ion battery, a precursor mixture of an electrode composition obtained through this recycling, and the composition resulting therefrom.The first electrode includes a first collector and a first coating which comprises first ingredients, and the method comprises:a) separating the first coating from the first collector,b) melt mixing, without solvent, the recovered first coating with new second ingredients comprising a second active material, a second binder comprising a permanent binder and a sacrificial binder, and an electrically-conductive second additive to obtain the precursor mixture, thenc) eliminating the sacrificial binder to obtain the composition forming a second electrode coating.