Composite Solid Electrolyte Layer for Dendrite-Resistant Li Deposition
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Solution Overview
Problem
All-solid secondary batteries face issues with dendrite formation leading to electron paths that cause short circuits and degrade the solid electrolyte layer, resulting in reduced performance and durability.
Innovation Solution
A composite solid electrolyte layer is developed with an electron blocking layer on one surface and a lithiophilic layer on the electron blocking layer, preventing electron movement from the negative electrode to the electrolyte layer, thereby delaying lithium metal nucleus generation and preventing short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If dendrites grow on the negative electrode surface, then charging capacity increases temporarily, but cracks form in the solid electrolyte causing short circuits
Solution Approach 1:
The lithiophilic first solid electrolyte layer is prepared in advance to provide a favorable interface for lithium deposition. This preliminary preparation ensures uniform Li ion distribution and controlled nucleation during charging, preventing the formation of dendritic structures that would cause cracks. The layer is designed with specific composition and structure to guide Li deposition before dendrites can form.
Solution Approach 2:
The buffer layer with electron-blocking properties is positioned beforehand to prevent electron migration that would lead to lithium metal nucleus formation within the electrolyte. By blocking electrons at the interface, the layer prevents the creation of electron paths that would enable lithium deposition inside the electrolyte, thereby preventing internal dendrite formation and subsequent cracking.
2Productivity
If high current density is applied to achieve faster charging, then productivity increases, but critical current density of the electrolyte is exceeded causing degradation
Solution Approach 1:
The composite solid electrolyte layer changes the critical current density parameter by introducing the electron-blocking buffer layer and lithiophilic first layer. These layers modify the interfacial properties and electron transport characteristics, effectively increasing the critical current density threshold. This allows the battery to operate at higher current densities for faster charging without exceeding the degraded threshold that would cause electrolyte breakdown.
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 composite solid electrolyte layer enhances long-term cycle stability and durability by effectively blocking electrons, maintaining high critical current density and specific capacity over multiple cycles.
Implementation Method 1
an electron blocking layer disposed on at least one surface of the solid electrolyte layer
Implementation Method 2
a lithiophilic layer disposed on the electron blocking layer
Data Source
AI summary
Provided is a composite solid electrolyte layer having excellent power performance and long-term cycle stability. An embodiment of the present invention provides a composite solid electrolyte layer including a solid electrolyte layer containing a solid electrolyte, an electron blocking layer disposed on at least one surface of the solid electrolyte layer, and a lithiophilic layer disposed on the electron blocking layer.