Solvent-Free Composite Electrode Process Using Solid Binder Pellets
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Solution Overview
Problem
Existing processes for producing composite materials for electrodes in solid-state polymer electrolyte batteries often result in the formation of pores and require high amounts of solvents or binders, leading to reduced energy density and potential damage to sensitive materials.
Innovation Solution
A solvent-free process that involves mixing particulate materials with a polymeric binder and a process auxiliary, which reduces mechanical and chemical interaction, allowing for a high proportion of particulate material and minimizing the binder content, using a weight ratio of process auxiliary to polymeric binder between 3:10 to 0.1:20, and mechanical processing such as kneading, extruding, or calendering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If large amounts of solvent are used to suspend particulate constituents, then the composite material can be processed, but unwanted voids form in the composite material
Solution Approach 1:
The invention changes the physical state parameter of the binder from liquid/dissolved to solid/pellet form. This parameter change eliminates the need for solvent suspension while maintaining processability through direct mechanical mixing and extrusion, thereby avoiding void formation while preserving ease of manufacture
Solution Approach 2:
The invention extracts and removes the solvent component from the traditional suspension process. By using solid binder pellets directly in a dry mixture, the harmful solvent is completely taken out of the system, eliminating void formation while maintaining composite material processability through alternative mechanical processing methods
2Stability of the object's composition
If large amounts of binder are used to bind active material particles, then the composite material structure is stable, but the proportion of active material decreases leading to reduced energy density
Solution Approach 1:
The invention changes the binder form parameter from liquid solution to solid pellets, enabling ultra-low binder content (0.1-10 wt%). This parameter change allows achieving stable composite structure with minimal binder quantity, thereby maximizing active material proportion and energy density
Solution Approach 2:
The invention uses a minimal (partial) amount of binder compared to conventional methods. By applying just enough binder (0.1-10 wt%) to achieve basic binding function through extrusion processing, the active material proportion is maximized while maintaining sufficient structural stability
3Ease of manufacture
If shear forces are applied to fibrillate binder in dry mixture, then a polymer matrix forms to bind particles, but sensitive coated particles are damaged
Solution Approach 1:
The invention performs preliminary action by pre-forming the binder into pellets with controlled physical properties before mixing. This preliminary preparation allows the binder to form a matrix through gentler extrusion processing rather than intense shear forces, protecting sensitive particles while achieving polymer matrix formation
Solution Approach 2:
The invention introduces an intermediary substance (liquid or gas phase additive) that facilitates binder matrix formation without requiring direct high-shear mechanical action on the particles. This intermediary mediates between the binder and particles, enabling matrix formation while protecting sensitive particle coatings from damage
4Ease of operation
If solvent is used to suspend particulate constituents, then mixing is facilitated, but additional operating steps are required for solvent removal
Solution Approach 1:
The invention extracts and eliminates the solvent from the process entirely. By using solid binder pellets in a solvent-free system, the mixing step is simplified to direct mechanical mixing followed by extrusion, completely removing the time-consuming solvent removal step and reducing production cycle time
Solution Approach 2:
The solid binder pellets are self-sufficient and do not require solvent for activation or processing. The binder performs its binding function directly in the dry mixture during extrusion, making the system self-service and eliminating the need for solvent addition and subsequent removal operations
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 enables the production of pore-free composite materials with a high active material content, increasing energy density and reducing production costs and environmental impact, while being gentle on sensitive materials and allowing for conventional processing without solvent use.
Implementation Method 1
at least one process auxiliary which reduces the mechanical and/or chemical interaction between the surfaces of the at least one particulate material and of the at least one polymeric binder
Implementation Method 2
mechanical processing, especially kneading, extruding and/or calendered
Data Source
AI summary
A process for producing a composite material comprising at least one particulate material and at least one polymeric binder, wherein the at least one particulate material and the at least one polymeric binder are mixed with one another and mechanically processed in the presence of at least one process auxiliary which reduces the mechanical and/or chemical interaction between the surfaces of the at least one particulate material and of the at least one polymeric binder, essentially dispensing with the use of solvents, characterized in that the weight ratio of process auxiliary to polymeric binder is within a range from 3:10 to 0.1:20.