Ion-Conducting Polymeric Binder for Solid-State Battery Electrolytes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polymeric binders used in lithium batteries are insulators for ionic conduction, limiting discharge capacity, and require binders dispersible in hydrophobic solvents for manufacturing all-solid-state secondary batteries with sulfide-based compounds.
Innovation Solution
A polymeric binder containing an ion-conducting polymer with aliphatic polycarbonate and a metal ion, such as lithium, enhances mobility of a metal ion, and improves adhesion and dispersibility in hydrophobic solvents, reducing interface resistance and improving ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional polymeric binder (insulator) is used to bind inorganic solid electrolyte particles, then the binder provides binding function, but the ionic conductivity is poor and discharge capacity does not reach target
Solution Approach 1:
The invention changes the chemical composition parameters of the polymeric binder by incorporating ion-conducting groups (such as carboxylate, sulfate, or phosphonate groups) into the polymer structure. This transforms the binder from an insulating material to an ion-conducting material, enabling it to simultaneously provide both binding strength and ionic conductivity pathways for lithium ion transport.
Solution Approach 2:
The invention creates a composite polymeric binder system that combines organic polymer matrix with ion-conducting functional groups and metal ion complexes. This composite structure integrates the mechanical binding properties of the polymer with the ionic conduction capabilities of the functional groups and metal ions, achieving both binding and ion transport functions in a single material.
2Ease of manufacture
If a polymeric binder dispersible in hydrophobic solvent is required for manufacturing all-solid-state secondary battery with sulfide-based compound, then the binder can be processed with hydrophobic solvents, but conventional binders are not dispersible in hydrophobic solvents
Solution Approach 1:
The invention modifies the solubility parameters of the polymeric binder by selecting polymer backbones and functional groups with appropriate hydrophobicity. The polymeric binder contains hydrophobic segments that are compatible with hydrophobic solvents used in sulfide-based solid electrolyte processing, enabling effective dispersion and coating during manufacturing.
3Quantity of substance
If area and capacity of all-solid-state secondary battery are increased, then the battery provides higher energy density, but brittle fracture occurs in inorganic solid electrolyte layer
Solution Approach 1:
The invention introduces a polymeric binder network that forms a flexible matrix surrounding and binding the rigid inorganic solid electrolyte particles. This polymer matrix acts as a flexible shell that can accommodate mechanical deformation and prevent brittle fracture propagation, enabling the battery to maintain structural integrity at larger sizes and higher capacities.
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 polymeric binder enhances ionic conductivity and dispersibility in hydrophobic solvents, forming a thin and firm inorganic solid electrolyte layer, and improves the mobility of a metal ion, and improves the efficacy of the all-solid-state secondary battery.
Implementation Method 1
a polymeric binder containing an ion-conducting polymer with aliphatic polycarbonate and a metal ion, such as lithium, enhances mobility of a metal ion, and improves adhesion and dispersibility in hydrophobic solvents, reducing interface resistance and improving ionic conductivity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A polymeric binder includes an ion-conducting polymer containing a polymer and a metal ion. The polymer is preferably selected from the group consisting of polyester, polyether, anionic polymer, polycarbonate, and silicone. An all-solid-state secondary battery includes an inorganic solid electrolyte, and the inorganic solid electrolyte in at least an electrode mixture layer or an inorganic solid electrolyte layer is bound together by the polymeric binder.