Solid-State Cell Electrolyte Layering to Suppress Li Dendrites
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Solution Overview
Problem
All-solid-state cells using a deposition-dissolution reaction of metallic lithium as an anode reaction face challenges in reducing the risk of short circuits, which affects their reliability and performance.
Innovation Solution
The all-solid-state cell incorporates a first solid electrolyte layer with a specific proportion of a metal phase containing Sn, Mg, and Ag, which is 2.50 vol % or less, and a second solid electrolyte layer without the metal phase, to reduce the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a commonly used anode active material layer is not provided and an anode active material layer is formed by initial charge, then the manufacturing process can be easily simplified and the energy density can be easily improved, but the risk of a short circuit increases
Solution Approach 1:
The patent applies preliminary action by incorporating a metal phase (containing Li, Mg, Al, Mn, Zn, Ca, or Ba) into the solid electrolyte layer before cell assembly. This pre-prepared metal phase serves as a controlled anode reaction site that prevents uncontrolled Li deposition during initial charge, thereby reducing short circuit risk while maintaining manufacturing simplicity and high energy density.
Solution Approach 2:
The patent applies local quality by creating a non-uniform distribution of metal phase within the solid electrolyte layer. The metal phase is dispersed at specific concentrations (0.01-5 wt%) to create localized regions that guide Li deposition, preventing uniform dendrite formation across the entire electrode surface and reducing short circuit risk in critical areas.
2Reliability
If metal phase is added to solid electrolyte layer, then the risk of short circuit is reduced, but the device complexity increases
Solution Approach 1:
The patent applies merging by combining the metal phase directly into the solid electrolyte layer to form a composite structure. This integration eliminates the need for separate anode active material layers and additional components, reducing overall device complexity while maintaining the short circuit prevention function through the dispersed metal phase.
Solution Approach 2:
The patent applies composite materials by creating a solid electrolyte layer that contains both the base solid electrolyte matrix and dispersed metal phase particles. This composite structure provides dual functionality: the solid electrolyte maintains ionic conductivity while the metal phase prevents dendrite formation, achieving short circuit protection without adding complex separate components.
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 configuration effectively suppresses the formation of dendrites and short circuits, improving the cycle characteristics and charge capacity of the all-solid-state cell while maintaining a reduced risk of short circuits.
Implementation Method 1
All-solid-state cells using a deposition-dissolution reaction of metallic lithium as an anode reaction
Data Source
AI summary
An all-solid-state cell using a deposition-dissolution reaction of metallic lithium as an anode reaction includes: an anode current collector, a first solid electrolyte layer, a second solid electrolyte layer, and a cathode active material layer in this order in a thickness direction. The first solid electrolyte layer contains a solid electrolyte phase containing a first solid electrolyte, and a metal phase containing at least one of the following: Sn, Mg, and Ag. A proportion of the metal phase in the first electrolyte layer is 2.50 vol % or less. The second solid electrolyte layer contains a second solid electrolyte and does not contain the metal phase.