Dry Conductive Composite via Expandable Microspheres
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy storage device electrodes require hazardous and flammable solvents for manufacturing, which poses safety risks and limits their porosity and electrolyte wettability, hindering their cycling and recharge capabilities.
Innovation Solution
The formation of electrically conductive porous composites using expandable microspheres and a material composition with electrical conductivity properties, which are compressed and heated to create interconnected pores, allowing for high porosity and wettability without the need for solvent-based processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solvent-based slurry coating process is used to manufacture electrodes, then the electrochemically active material can be coated onto current collector, but hazardous and flammable solvents are required which pose safety risks
Solution Approach 1:
The invention extracts and eliminates the solvent component from the traditional slurry coating process. Instead of using a solvent-based slurry, the patent employs a dry powder mixture that is compressed and sintered to form the electrode coating, completely removing the hazardous solvent from the manufacturing process.
Solution Approach 2:
The invention replaces the chemical bonding mechanism (solvent-based adhesion) with a mechanical-thermal process. Dry powder materials are compressed under pressure and then sintered through controlled heating, creating mechanical and metallurgical bonds that eliminate the need for organic solvents.
2Quantity of substance
If electrode is calendered to densify the electrochemically active material, then the packing fraction increases, but the porosity of the electrode is reduced
Solution Approach 1:
The invention changes the fundamental parameters of the coating process by eliminating the drying and calendering steps entirely. Instead of starting with a slurry and removing solvent, the dry powder metallurgy approach allows direct compression and sintering, achieving both high packing fraction and controlled porosity through pressure and temperature parameter optimization.
Solution Approach 2:
The invention creates a composite structure where electrochemically active materials are combined with binder materials in a controlled ratio. This composite approach allows the formation of a dense yet porous structure through the sintering process, where the binder creates interconnected pores while maintaining mechanical integrity.
3Ease of manufacture
If traditional drying oven process is used to remove solvent, then the slurry can be converted to solid electrode, but the process requires hazardous solvents and reduces porosity
Solution Approach 1:
The invention extracts and eliminates the drying oven process entirely by never introducing a solvent in the first place. The dry powder metallurgy method proceeds directly from powder mixing through compression to sintering, completely removing the solvent removal step and its associated hazards and porosity reduction.
Solution Approach 2:
The invention replaces the thermal evaporation process (drying oven) with a mechanical compression followed by controlled sintering process. Instead of heating to evaporate solvent, the material is compressed and then sintered at lower temperatures to form the solid electrode structure.
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 resulting composites exhibit excellent porosity and electrolyte wettability, enhancing the cycling and recharge capabilities of energy storage devices while eliminating the use of hazardous solvents, thereby improving the manufacturability and performance of batteries and ultracapacitors.
Implementation Method 1
When heated, the internal pressure from the fluid increases and the thermoplastic shell softens. Accordingly, with the fluid trapped inside the spheres, the volume of the microspheres increases.
Implementation Method 2
Compression and heat are preferably used to form the porous composites. The material composition having electrical conductivity properties is preferably mixed with expandable microspheres and then heated in a confined volumetric space, such as a mold.
Data Source
AI summary
An electrically conductive porous composite composed of an expanded microsphere matrix binding a material composition having electrical conductivity properties to form an electrically conductive porous composite is disclosed herein. An energy storage device incorporating the electrically conductive porous composite is also disclosed herein.