Solid-State Battery Wet-on-Wet Electrolyte Layers for Low-Resistance Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solid-state battery production methods face challenges in achieving high surface-to-surface contact between layers while minimizing ionic and electronic resistance, as increasing binder concentration to enhance contact also increases resistance.
Innovation Solution
A process involving the coating of wet slurries to create a binder concentration gradient, where the binder concentration is highest at the surface interface between layers, achieved by coating a first electrochemical cell layer slurry on a surface, followed by a second slurry while the first is still wet, and then drying to form a multilayer stack, allowing binder migration and densification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If binder concentration is increased to enhance surface-to-surface contact between layers, then contact quality is improved, but ionic and electronic resistance increases
Solution Approach 1:
The patent applies local quality by creating a binder concentration gradient where the binder concentration varies spatially across the layer thickness. The binder concentration is highest at the interface between layers (where contact is needed) and decreases toward the outer surfaces. This localized concentration of binder at the interface improves surface-to-surface contact without requiring high binder concentration throughout the entire layer, thereby minimizing the increase in ionic and electronic resistance.
Solution Approach 2:
The patent changes the concentration parameter of the binder from being uniform throughout the layer to being non-uniform with a gradient distribution. By controlling the drying process and using wet-on-wet coating methodology, the binder concentration parameter is transformed from a homogeneous value to a spatially varying profile, with maximum concentration at the interface and lower concentrations elsewhere, resolving the contradiction between contact quality and resistance.
2Reliability
If total binder concentration is increased to ensure optimal contact, then electrochemical performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by coating multiple layers in a wet state before any drying occurs. The wet-on-wet coating process allows the binder to be distributed throughout the layers while they are still in a plastic, workable state. Subsequent controlled drying then creates the desired concentration gradient as solvent evaporates and binder redistributes. This preliminary wet coating approach simplifies the process compared to attempting to create gradient structures after drying.
Solution Approach 2:
The patent utilizes self-service by allowing the binder to naturally migrate and concentrate at the interfaces during the drying process through capillary action and evaporation-driven redistribution. The system self-organizes the binder concentration profile without requiring external intervention or complex control mechanisms. The drying process itself serves to create the desired gradient distribution, eliminating the need for additional processing steps.
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 enhances surface-to-surface contact between layers without increasing total binder concentration, thereby reducing ionic and electronic resistance, leading to improved electrochemical performance.
Implementation Method 1
at least 1% of the binder in the first coated layer migrates across the interface into the second coated layer during drying
Implementation Method 2
The slurry is then dried to remove the solvent, leaving behind a solid layer
Implementation Method 3
assembling a negative electrode layer (anode), one or more separator layers (solid electrolyte layers), and a positive electrode layer (cathode). One or more of these layers may be pressed or laminated together to ensure optimal surface-to-surface contact between the layers
Data Source
AI summary
Described herein are processes for preparing electrochemical cells. The processes are defined by coating a second electrochemical cell layer on top of a first electrochemical cell layer while both electrochemical cell layers are wet. Electrochemical cells produced by this process are also described.