Continuous Electrode Manufacturing via Suction Filtration
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Solution Overview
Problem
Conventional methods for manufacturing electrodes for metal-ion batteries, such as lithium-ion batteries, are limited in producing thick electrodes with high active material load and conductivity due to solvent evaporation and binder migration issues, which restricts energy density and production rate.
Innovation Solution
A continuous manufacturing process involving a current collector with through holes and a filter to suction the solvent through, ensuring homogeneous distribution and retention of active material, eliminating the need for solvent evaporation and preventing binder migration, allowing for higher active material load and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional slot die coating with solvent evaporation is used, then the manufacturing process is simple and continuous, but the electrode thickness is limited to around 100 μm and production rate is limited to 0.1-10 m/min
Solution Approach 1:
The patent extracts the solvent removal function from thermal evaporation to mechanical filtration. The suction system with filter physically separates and removes solvent through the current collector, eliminating the bottleneck of solvent evaporation rate that limited both electrode thickness and production speed in conventional processes.
Solution Approach 2:
The patent introduces a suction system that uses negative pressure (pneumatic principle) to draw solvent through the current collector and filter. This pneumatic approach enables rapid solvent removal without thermal constraints, allowing both thicker electrodes and higher production rates to be achieved simultaneously.
2Volume of moving object
If solvent evaporation is used to form thick electrodes, then electrode thickness can be increased, but binder migrates to the electrode surface causing composition inhomogeneity
Solution Approach 1:
The patent extracts the solvent removal mechanism from thermal evaporation to mechanical filtration through suction. This prevents the binder migration phenomenon that occurs during evaporation, as the solvent is mechanically pulled through the structure rather than volatilized, maintaining homogeneous distribution of active material and binder throughout the electrode.
Solution Approach 2:
The patent replaces the thermal field (evaporation) with a mechanical field (suction and filtration). This substitution eliminates the compositional inhomogeneity caused by thermal evaporation while enabling the formation of thick electrodes with uniform material distribution.
3Volume of moving object
If foam current collector is used to enable solvent flow through, then thick electrodes can be formed, but it is difficult to achieve high gram-percentage due to challenges in filling foam pores
Solution Approach 1:
The patent employs a porous current collector structure that allows solvent to flow through while providing sufficient surface area for active material deposition. The controlled porosity enables both thick electrode formation and high gram-percentage by facilitating complete pore filling with active material during the suction process.
Solution Approach 2:
The suction system uses pneumatic pressure to force solvent and suspended active material through the porous current collector. This ensures complete and uniform filling of the porous structure, achieving high gram-percentage that was difficult to obtain with passive foam impregnation methods.
4Volume of moving object
If paper substrate with cellulose fibers is used for filtration, then thick electrodes can be formed, but electrical conductivity remains low due to non-conductive cellulose fibers
Solution Approach 1:
The patent uses a composite current collector structure combining porous substrate with conductive materials (such as metal foams or carbon-based materials). This composite approach maintains the filtration and thick electrode formation capabilities while ensuring sufficient electrical conductivity for battery operation.
Solution Approach 2:
The patent introduces a conductive intermediary layer or material within the current collector structure that mediates between the filtration function and electrical conductivity requirement. This intermediary ensures that the porous structure can both filter solvent and conduct electricity effectively.
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 process enables the production of thick electrodes with improved conductivity and energy density, increasing production speed and reducing energy costs, while maintaining mechanical properties and safety.
Implementation Method 1
continuous suction of the deposited ink, through the current collector, from the first face to the second face of the current collector, by a suction system located on the second face of the current collector, to remove the solvent
Implementation Method 2
a filter being disposed between the current collector and the suction system, the filter having pore sizes ranging from 0.1μm to 50μm, so as to retain the solid constituents of the ink, and, in particular, the active material
Data Source
Figure 1a~2
Figure 3~4
Figure 5
AI summary
A method for the continuous manufacture of an electrode comprising the following steps carried out simultaneously and continuously: a) Continuously moving a current collector (10), the current collector having at least one undeburred through hole, b) Continuously depositing an ink (30) onto the first face of the current collector (10), the ink (30) comprising at least one solvent and an active electrode material (20), c) Continuously aspirating the deposited ink (30) through the current collector (10) by a suction system (50) to remove the solvent, so as to form an electrode, the thickness of the electrode being greater than the radius of the through hole, a filter (40) being disposed between the current collector (10) and the suction system (50), the filter (40) having pore sizes ranging from 0.1 µm to 50 µm, and preferably from 0.2 µm to 5 µm, so as to retain the active material (20).