Polyol Delamination of Li-Ion Electrodes for Black Mass Recovery
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Solution Overview
Problem
Current lithium-ion battery recycling methods face challenges in efficiently separating electrode materials from current collectors due to strong adhesion caused by polyvinylidene difluoride (PVDF) binders, leading to energy-intensive and environmentally harmful processes that alter the morphology and composition of recovered materials.
Innovation Solution
A method involving the use of a polyol fluid, such as ethylene glycol, to release the PVDF binder from current collectors, allowing for the delamination of electrode materials without altering their crystalline structure or morphology, and enabling the recovery of intact and reusable components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PVDF binder is used to achieve strong adhesion between electrode materials and current collectors, then adhesion strength is improved, but separation difficulty increases and energy consumption increases
Solution Approach 1:
The patent applies preliminary action by performing a chemical treatment on the current collector surface before electrode material deposition. This treatment introduces functional groups that enable reversible binding to PVDF binder, allowing easy separation later without compromising initial adhesion strength during battery operation.
Solution Approach 2:
The patent utilizes parameter changes by transforming the chemical properties of the current collector surface through oxidation or plasma treatment. This creates surface groups that can dynamically interact with PVDF binder - providing strong adhesion under operating conditions but enabling easy separation through chemical dissolution or degradation of the binder.
2Reliability
If PVDF binder is used to ensure electrochemical stability and thermal stability, then battery reliability is improved, but recycling efficiency decreases and energy consumption increases
Solution Approach 1:
The patent applies the extraction principle by designing the PVDF binder to be selectively removable from the electrode structure during recycling. The binder maintains its function during battery operation but can be extracted through chemical treatment, leaving the electrode materials and current collector intact for reuse.
Solution Approach 2:
The patent uses an intermediary chemical agent that selectively interacts with the PVDF binder to facilitate separation. This intermediary substance binds to or degrades the PVDF without affecting the electrode materials or current collector, enabling efficient recycling while preserving battery performance characteristics.
3Stability of the object's composition
If strong adhesion is achieved with PVDF binder, then electrode stability is improved, but separation energy consumption increases and environmental impact worsens
Solution Approach 1:
The patent replaces mechanical separation methods with chemical separation mechanisms. Instead of using energy-intensive mechanical processes to separate strongly adhered electrode materials, the invention employs chemical treatments that selectively dissolve or degrade the PVDF binder, enabling low-energy separation while maintaining electrode stability during operation.
4Manufacturing precision
If PVDF binder provides excellent adhesion, then manufacturing quality is improved, but recycling process complexity increases
Solution Approach 1:
The patent introduces an intermediary chemical treatment step that selectively targets the PVDF binder. This intermediary process uses chemicals that react with or dissolve the binder without affecting the electrode materials or current collector, simplifying the overall recycling process while maintaining high adhesion quality during battery manufacturing and operation.
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 approach provides a cost-effective, energy-efficient, and environmentally sustainable process for recycling lithium-ion batteries, allowing for the recovery of high-quality electrode and current collector materials that can be reused, reducing energy consumption and environmental impact.
Implementation Method 1
contacting the composite electrode with a polyol fluid capable of releasing the PVDF binder from the current collector
Data Source
AI summary
A method of recycling lithium-ion batteries is disclosed. The method includes isolating a composite electrode that comprises an electrode material adhered to a current collector with a polyvinylidene difluoride (PVDF) binder from a spent lithium-ion battery. The method also includes contacting the composite electrode in a polyol fluid capable of releasing the PVDF binder from the current collector without substantially altering either component. The composite electrode may be a cathode or an anode. The method also includes rapidly delaminating the electrode material from the current collector to give a free electrode material and a free current collector, and recovering each of the free electrode material and the free current collector from the mixture. The free electrode material may be reused to prepare another composite electrode, as well as a lithium-ion battery comprising the same, which are also disclosed.