Dry Electrode Film Lamination for Stronger Energy Storage Cells
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Solution Overview
Problem
Current methods for producing dry electrode films for energy storage devices face challenges in achieving the required mechanical strength and thickness, leading to inefficiencies and environmental concerns associated with wet electrode processes.
Innovation Solution
A dry film manufacturing process involving a shear force to fibrillate a mixture of active materials and binders, followed by hot roll-pressing into a free-standing film, trimming, and winding onto a spool, with optional cooling and tensioning to form laminated electrodes, which are then layered with separators to create energy storage devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet electrode application process is used, then electrode material can be applied to foil, but considerable energy is consumed due to drying ovens and solvent recovery systems
Solution Approach 1:
The patent removes the drying and solvent recovery steps from the electrode manufacturing process by using a dry electrode material instead of a wet slurry. The dry material is applied directly to the foil without requiring energy-intensive drying ovens or solvent recovery systems, thereby eliminating the harmful thermal processing step while maintaining ease of manufacture.
Solution Approach 2:
The patent replaces the thermal drying mechanism with a mechanical application process. Dry electrode material is applied to the foil using mechanical means (such as dry coating or lamination) instead of applying a wet slurry that requires thermal evaporation, substituting a mechanical system for a thermal system to reduce energy consumption.
2Ease of manufacture
If wet electrode application process is used, then electrode material can be applied to foil, but solvents are used which are toxic, costly and flammable
Solution Approach 1:
The patent extracts and removes the solvent component from the electrode application process. By using dry electrode material composed of active material particles and binder in a dry state, the process eliminates the need for toxic, costly, and flammable solvents entirely, thereby removing the harmful factors while maintaining the ability to apply electrode material to foil.
Solution Approach 2:
The patent uses a disposable dry electrode material that can be applied directly without requiring solvent-based processing. The dry material serves its function during application and can be discarded or processed without the need for expensive solvent recovery systems, replacing a complex solvent-based system with a simpler dry system.
3Ease of manufacture
If current dry film production methods are used, then dry electrode films can be produced, but films do not have the required mechanical strength and thickness
Solution Approach 1:
The patent changes the parameters of the dry film production process, specifically the composition ratios of active material to binder and the application pressure, to achieve films with both adequate thickness and mechanical strength. By optimizing these parameters, the process produces films that meet the required specifications for both manufacturability and structural integrity.
Solution Approach 2:
The patent uses a composite material composition consisting of active material particles combined with a specific binder material in optimized ratios. This composite structure provides both the functional properties of the active material and the mechanical strength provided by the binder, creating a film that satisfies both production ease and strength requirements.
4Ease of manufacture
If current dry film production methods are used, then dry electrode films can be produced, but films do not achieve the desired thickness required to complete assembly
Solution Approach 1:
The patent adjusts the parameters of the dry film production process, including the amount of material applied, the application pressure, and the composition ratios, to achieve films of the desired thickness. These parameter changes enable the production of sufficiently thick films that can complete the assembly process without compromising mechanical strength or manufacturability.
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
The process produces dry electrode films with improved mechanical strength and thickness, reducing environmental impact and enabling efficient assembly of energy storage devices.
Implementation Method 1
a fibrillating process using reduced speed and/or increased process pressure such that fibrillating of the binder material can be increased. Increasing fibrillating of the binder material may facilitate formation of thinner electrode films
Implementation Method 2
The powder mixture is subjected to a shear force in order to be fibrillated
Implementation Method 3
The fibrillated mixture is hot roll-pressed into a free-standing film, which is then trimmed and wound
Implementation Method 4
Optionally the film is cooled immediately after coming out of the hot-press rollers
Implementation Method 5
The film tension is relatively low after coming out of the hot-press rollers and before trimming. At, before, or after trimming, the tension is increased in order to wind the film onto a spool without tearing
Implementation Method 6
the dry film is pressed and bound to a first side of a current collector foil to form a laminated electrode
Data Source
AI summary
Electrical energy storage devices made using a wet electrode application technique are associated with high energy consumption. Herein, a dry electrode or electrolyte application process involves mixing activated carbon with a binder and then fibrillating the mixture. The mixture is roll-pressed into a film, which is then actively cooled. Optionally, tension in the cooled portion of the film is increased for spooling the film. The film is adhered to a pre-treated current collector and then wound into a jelly roll for the manufacture of an electrical energy storage device.