Dry Powder Electrode Fabrication for Uniform Current Collector Coating
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Solution Overview
Problem
Current dry powder electrode manufacturing processes face challenges in achieving uniform thickness and particle distribution due to electrostatic deposition methods, leading to non-uniform current distribution and reduced cycle life in batteries, along with safety and containment issues.
Innovation Solution
A method involving mixing dry particles of electrode active materials, conductive additives, and binder materials to form a binder-coated dry powder electrode material, which is then deposited onto a current collector using a dry powder dispensing device and uniformly spread using doctor blades, counter-rotating rollers, and conditioning rollers before compaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electrostatic deposition is used to spray active material particles onto the current collector, then the particles are easier to handle prior to compaction, but the resulting electrode layer is non-uniform in thickness and particle distribution
Solution Approach 1:
The patent replaces the electrostatic field-based deposition system with a mechanical powder delivery system. A powder dispenser delivers dry powder electrode material onto the current collector, and rolling elements mechanically spread and compact the powder to form a uniform electrode layer, eliminating the non-uniformity issues caused by electrostatic forces.
Solution Approach 2:
The patent introduces rolling elements (such as rollers or drums) as intermediary mechanical components between the powder dispenser and the current collector. These rolling elements serve as mediators that receive the delivered powder and mechanically process it into a uniform layer, bridging the gap between simple powder delivery and uniform layer formation.
2Productivity
If forced air gas flow is used to carry fluidized particles through the electrostatic applicator, then the particles can be deposited onto the current collector, but the surface thickness becomes non-uniform with wave or stripe patterns
Solution Approach 1:
The patent replaces the forced air gas flow system with a dry powder delivery mechanism. Instead of using gas flow to transport and deposit particles, the system uses a powder dispenser to deliver dry powder directly onto the current collector, followed by mechanical rolling elements to spread and compact the powder uniformly, eliminating wave and stripe patterns.
Solution Approach 2:
The patent extracts and removes the forced air gas flow component from the deposition system. By eliminating the gas flow mechanism entirely and replacing it with direct powder delivery and mechanical spreading, the source of non-uniform surface thickness and patterning is removed.
3Ease of manufacture
If wet coating process with solvent is used to form electrode layers, then the electrode structure can be formed, but large manufacturing footprint and energy consumption are required for drying and solvent recovery
Solution Approach 1:
The patent changes the physical state parameter of the coating process from wet (liquid slurry with solvent) to dry (powder form). By using dry powder electrode material instead of solvent-based slurry, the process eliminates the need for drying and solvent recovery operations, dramatically reducing energy consumption while still forming the required electrode structure through mechanical compaction.
Solution Approach 2:
The patent extracts and removes the solvent component from the electrode manufacturing process. By using a solvent-free dry powder approach, the entire drying and solvent recovery infrastructure is eliminated, reducing manufacturing footprint and energy consumption while maintaining electrode structure formation capability through alternative mechanical means.
4Productivity
If electrostatic deposition is used to form the electrode layer, then the active material can be deposited, but containment and safety issues arise due to use of forced air powder spray
Solution Approach 1:
The patent replaces the forced air powder spray system with a contained dry powder delivery system. A powder dispenser delivers dry powder electrode material in a controlled manner onto the current collector, eliminating the need for forced air flow. This mechanical delivery approach contains the powder within a controlled environment, preventing safety issues associated with airborne powder and improving containment.
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 results in a uniform and cohesive electrode layer with improved electrochemical performance, enhanced ionic conductivity, and reduced manufacturing costs by eliminating the need for solvents and associated energy consumption.
Implementation Method 1
mixing dry particles of one or more electrode active materials, conductive additives, and one or more binder materials to form a binder-coated dry powder electrode material
Implementation Method 2
The dry powder electrode material is a loose powder that can be poured from the dispensing device onto a moving current collector web
Implementation Method 3
the loose dry powder electrode material is uniformly spread across the width of the moving current collector web by one or more spreading devices
Implementation Method 4
the dry powder electrode material is compacted against the moving current collector web using a calender configured to apply at least one of pressure or heat
Implementation Method 5
the dry powder electrode material is compacted against the moving current collector web using a calender configured to apply at least one of pressure or heat to the dry powder electrode material to activate the binder
Data Source
AI summary
A method for manufacturing a battery electrode includes mixing particles of active electrode materials, conductive additives, and binder to form a dry powder electrode material. The dry powder is then deposited onto a moving electrode current collector using a dry powder dispensing device. The dry powder is a loose powder continuously poured from the dispensing device onto a moving current collector in a roll-to-roll system where the powder remains loose on the current collector as it travels towards a compaction stage. After being poured onto the current collector, the loose dry powder is uniformly spread across the width of the moving current collector web by one or more spreading devices, such as smoothing rollers and conditioning rollers. Finally, the dry powder is compacted using a calender configured to apply pressure and/or heat to the dry powder electrode material to activate the binder and form a battery electrode.