Layered Sulfide Solid Electrolyte Film for Dendrite Suppression
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Solution Overview
Problem
Sulfide solid electrolytes used in solid state batteries face issues with low conductivity, poor interface contact, and stability when combined with lithium metal negative electrodes, leading to lithium dendrite growth and internal short circuits.
Innovation Solution
A solid electrolyte film composed of a lithium metal stable layer, lithium dendrite inhibition layer, and high-conductivity layer, all made of sulfide solid electrolytes, with specific coatings and crystallinity indices to enhance stability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a third component is introduced to improve adaptability between sulfide solid electrolyte and lithium metal negative electrode, then stability and interface contact are improved, but conductivity decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the sulfide solid electrolyte by introducing specific elements (Al, Si, Ge, Sn, Pb from Group 13-14; or B, Al, Ga, In from Group 13; or P, As, Sb from Group 15) to modify the electrolyte's properties. This allows improving stability and interface contact with lithium metal while maintaining acceptable conductivity through controlled compositional adjustment.
Solution Approach 2:
The patent creates a composite sulfide solid electrolyte material by combining base sulfide electrolyte with additional metallic elements. This composite structure improves interface compatibility and stability with lithium metal negative electrode while the specific composition design maintains ionic conductivity through optimized phase structure and grain boundary characteristics.
2Reliability
If a third component is introduced to improve adaptability, then interface contact is improved, but material strength and mechanical properties cause poor interface contact
Solution Approach 1:
The patent adjusts mechanical and physical parameters of the sulfide solid electrolyte through compositional modification. By controlling the content and type of additional elements, the electrolyte's mechanical strength and softness are optimized to achieve good interface contact and adaptability with lithium metal while maintaining structural integrity.
3Quantity of substance
If sulfide solid electrolyte is used with lithium metal negative electrode, then high capacity is achieved, but lithium dendrites penetrate gaps between particles causing short circuits
Solution Approach 1:
The patent modifies the microstructural parameters of the sulfide solid electrolyte through compositional control. By adjusting the electrolyte's composition, grain size, and density, the material achieves better particle packing and reduced porosity, which suppresses lithium dendrite nucleation and growth while maintaining high ionic conductivity for lithium metal operation.
Data Source
AI summary
The present application relates to the technical field of battery materials, in particular to a solid state electrolyte film, preparation method and use thereof and solid state battery. The solid electrolyte film includes a lithium metal stable layer, a lithium dendrite inhibition layer and a high-conductivity layer that are stacked in sequence; in particular, the lithium metal stable layer contains a first sulfide solid electrolyte, and a surface of the first sulfide solid electrolyte is coated with a lithium sulfide protective layer; the lithium dendrite inhibition layer contains a second sulfide solid electrolyte, and the lithium dendrite inhibition layer has a porosity of less than 8%; the high-conductivity layer contains a third sulfide solid electrolyte, the third sulfide solid electrolyte has a Hinckley crystallinity index of greater than 1.1, and a particle size of greater than 20 μm.