Enabling Durable Quasi-Solid-State Li-S Batteries with an Organic Nitrate Additive for Anode Protection and...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Poly(1,3-dioxolane) (PDOL) electrolytes show promise for lithium-sulfur (Li-S) batteries due to high conductivity and low cost.
• Poor interfacial compatibility with lithium metal and inhibition of DOL polymerization by conventional nitrate additives hinder SEI formation.

Purpose of the Study:

• To introduce isosorbide dinitrate (ISDN) as a novel additive for PDOL-based electrolytes in Li-S batteries.
• To investigate ISDN's ability to promote DOL polymerization and form a stable, inorganic-rich SEI.
• To evaluate the impact of ISDN on lithium deposition, polysulfide shuttle effect, and overall battery performance.

Main Methods:

• Synthesis and characterization of PDOL-based electrolytes with ISDN additive.
• X-ray photoelectron spectroscopy (XPS) to analyze SEI composition.
• Density functional theory (DFT) calculations to study interfacial interactions and polysulfide adsorption.
• Electrochemical testing of Li|PDOL@ISDN|Li symmetric cells and quasi-solid-state Li-S batteries.

Main Results:

• ISDN promotes DOL polymerization and forms a hybrid SEI rich in Li3N and LiNxy, verified by XPS and DFT.
• The reinforced SEI ensures uniform, dendrite-free lithium deposition and enhanced interfacial ion transport.
• DFT calculations confirm strong ISDN-PDOL interactions, suppressing the polysulfide shuttle effect.
• Symmetric cells cycled over 1000 hours without failure; Li-S batteries retained 84.7% capacity after 100 cycles at 0.2C.

Conclusions:

• ISDN is a multifunctional additive that effectively addresses SEI instability and polysulfide shuttling in PDOL-based Li-S batteries.
• The developed strategy offers a promising route for high-performance solid-state Li-S batteries.