Lithium-Ion Cathode Recycling via Gravity Separation and Delamination
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Solution Overview
Problem
Conventional recycling methods for cathode active materials in lithium-ion batteries are inefficient, costly, and environmentally harmful, failing to achieve high purity separation of cathode active material from binders and often requiring additional synthesis steps.
Innovation Solution
A method involving agitation at different speeds to delaminate electrode materials from current collectors, followed by gravity separation using water and multiple sieves/filters to separate cathode active material from binders, minimizing solvent use and achieving high purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional solvent-based methods are used to separate cathode active material from binder, then separation can be achieved, but the process becomes expensive and environmentally harmful
Solution Approach 1:
The invention changes the fundamental parameter of separation mechanism from chemical dissolution (solvent-based) to physical separation (gravity-based). By utilizing density differences between cathode active material particles and binder fibers, the process eliminates the need for expensive and environmentally harmful organic solvents while achieving effective separation and high purity recovery of cathode active material
2Ease of manufacture
If conventional solvent-based methods are used, then separation can be achieved, but the cost increases significantly
Solution Approach 1:
The invention transitions from chemical separation parameters (solvent selection, dissolution kinetics) to physical separation parameters (gravity, density, particle size). This parameter change eliminates the need for expensive solvents and associated disposal costs, making the recycling process economically viable while maintaining high separation efficiency
Solution Approach 2:
The invention replaces the chemical system (solvents and dissolution reactions) with a mechanical/physical system (gravity separation and filtration). This substitution eliminates the need for expensive chemical reagents and simplifies the overall process, reducing both operational and capital costs
3Productivity
If high speed agitation is used to delaminate cathode material from current collector, then separation efficiency improves, but anode material is also damaged
Solution Approach 1:
The invention employs dynamic control of agitation speed as a key parameter. By adjusting the rotation speed of the agitation blade, the process optimizes the balance between delamination efficiency and selectivity. The dynamic adjustment allows sufficient force to detach cathode material from the current collector while maintaining gentler conditions that preserve anode material integrity
Solution Approach 2:
The invention creates different local conditions within the processing system. The agitation blade generates high shear stress zones near the cathode/current collector interface for effective delamination, while other regions of the mixing chamber provide gentler conditions that prevent excessive damage to the anode material. This spatial variation in mechanical stress achieves selective separation
4Manufacturing precision
If gravity separation is used to separate cathode active material from binder, then purity increases, but multiple separation devices are required
Solution Approach 1:
The invention segments the gravity separation process into multiple stages, each handling a specific size fraction or density range of materials. By dividing the separation into sequential steps (e.g., coarse separation followed by fine separation), the system achieves high purity cathode active material recovery while using simpler, more manageable separation devices rather than requiring a single complex high-capacity separator
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 recovers high purity cathode active material with reduced environmental impact and cost, eliminating the need for expensive and hazardous solvents.
Implementation Method 1
agitating the anode sheet and the cathode sheet at a first speed to delaminate the anode material from the anode current collector
Implementation Method 2
performing gravity separation on the cathode material to separate the cathode active material from the binder
Data Source
AI summary
A method is provided for producing a cathode active material. The method includes shredding an anode sheet including an anode material disposed on an anode current collector with a cathode sheet including a cathode material disposed on a cathode current collector, rinsing the sheets with an organic solvent, agitating the sheets to delaminate the anode material from the anode current collector, separating the anode material from the anode current collector using a filter and/or a sieve, and blending the anode current collector and the cathode sheet to delaminate the cathode material from the cathode current collector. The method further includes performing size reduction and deagglomeration on the cathode material, which includes the cathode active material and a binder, separating the cathode material from the cathode current collector using a filter and/or a sieve, and performing gravity separation to separate the cathode active material from the binder.