Empowering the Potassium-Sulfur Battery with Commendable Reaction Kinetics and Capacity Output by Localized...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Potassium-sulfur (K-S) batteries offer high energy density but face challenges from polysulfide dissolution and shuttle effects.
• Conventional electrolytes in K-S cells lack effective anode protection, limiting battery performance and lifespan.

Purpose of the Study:

• To engineer an ether-based localized high-concentration electrolyte (LHCE) for K-S batteries.
• To mitigate polysulfide dissolution and shuttle effects while improving anode-electrolyte interface properties.

Main Methods:

• Formulation of an ether-based LHCE using a nonsolvating, polysulfide-stable fluoroether cosolvent.
• Investigation of the electrolyte's effect on polysulfide solubility and anode-electrolyte interface formation.
• Electrochemical testing of K-S cells with the designed LHCE to evaluate capacity, lifespan, and kinetics.

Main Results:

• The LHCE significantly reduced polysulfide solubility and shuttle, enhancing interfacial kinetics.
• Anion-derived solid electrolyte interphase (SEI) enriched in inorganic components was formed at the anode.
• K-S cells demonstrated unlocked theoretical capacity and achieved a reversible capacity of 448 mA h/g_s after 80 cycles with specific cathode design.

Conclusions:

• Electrolyte engineering with LHCE is a viable strategy for high-energy-density K-S batteries.
• The developed LHCE effectively suppresses parasitic reactions and improves interfacial properties.
• Further research on anode corrosion and byproduct management is needed for complete K-S battery utilization.