LFP Cathode Paste Recycling via 5 μm Recyclate Grinding
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Solution Overview
Problem
Current methods for recycling lithium-ion battery cathode materials, particularly lithium iron phosphate (LFP), are energy- and resource-intensive, and there is a lack of economical processes for recycling used LFP from spent lithium-ion batteries, leading to significant material wastage and inefficiencies.
Innovation Solution
A method involving the reduction of LFP active material recyclate to an average grain size of 5 μm through grinding, followed by mixing it with cathode paste, allowing for its reuse in lithium-ion battery production, with the option to add lithium to compensate for depletion and adjust the proportion of additives and binders, enabling the production of a cathode paste containing up to 100% LFP active material recyclate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If traditional thermal and chemical processes are used to recycle cathode materials, then individual metals like copper, nickel, and cobalt can be recovered, but the process becomes energy- and resource-intensive
Solution Approach 1:
The patent extracts and recycles the entire LFP active material directly from spent cathodes without breaking it down into individual metals. The process removes LFP from the cathode structure and incorporates it into new cathode materials, avoiding the energy-intensive thermal and chemical processes needed to recover individual metals like copper, nickel, and cobalt separately.
Solution Approach 2:
The patent performs preliminary classification and separation of cathode materials by type (including LFP identification) before recycling. This preliminary action enables direct LFP-to-LFP recycling without needing subsequent complex processing steps, reducing overall energy consumption compared to methods that recover individual metals through multiple thermal and chemical processes.
2Productivity
If cathode material is recycled without purification, then resource efficiency improves, but material quality and battery performance may deteriorate
Solution Approach 1:
The patent changes the purity parameter requirements for recycled LFP material. Instead of requiring high purification levels, the process accepts LFP material with typical impurity levels from spent cathodes and achieves successful recycling by adjusting other parameters such as particle size distribution and chemical composition ratios in the new cathode formulation.
Solution Approach 2:
The patent creates composite cathode materials by combining recycled LFP with fresh LFP and other cathode components. This composite approach allows the recycled material (with its inherent impurities) to be successfully integrated into functional cathodes without requiring complete purification, maintaining both recycling efficiency and battery performance.
3Loss of substance
If LFP active material recyclate is used in high proportions, then resource conservation improves, but cathode paste quality and electrode performance may be compromised
Solution Approach 1:
The patent adjusts multiple parameters of the cathode paste formulation when using high proportions of recyclate, including particle size distribution (reducing to 5 μm average), chemical composition ratios (adding lithium to compensate for depletion), and binder content. These parameter changes enable the use of up to 100% LFP recyclate while maintaining cathode paste quality and electrode performance.
4Stability of the object's composition
If LFP recyclate is ground to fine particle size, then mixing homogeneity improves, but energy consumption and processing time increase
Solution Approach 1:
The patent performs preliminary size reduction of LFP recyclate to a fine particle size distribution (average 5 μm) before mixing into the cathode paste. This preliminary action ensures that the LFP particles are already optimized for homogeneous mixing and electrode fabrication, reducing the need for extended mixing times and improving overall process efficiency.
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 enables the efficient recycling and reuse of LFP active material, reducing material wastage, conserving resources, and improving the energy storage device's performance by potentially increasing energy density and rapid charging capabilities without significant loss of performance.
Implementation Method 1
The LFP active material recyclate is reduced to an average grain size of 5 μm by grinding in a comminution device
Implementation Method 2
before being mixed with the cathode paste
Data Source
Figure 1~4
AI summary
A method for producing a cathode paste (8) incorporates LFP active material recyclate (2) during the production process for a lithium-ion battery for the reuse of the LFP active material recyclate in the lithium-ion battery. The LFP active material recyclate (2) is reduced to an average particle size of 5 µm by grinding in a comminution device (3) before being mixed with the cathode paste (8).