Solid/Quasi-Solid Phase Conversion of Sulfur in Lithium-Sulfur Battery

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical specific energy, making them promising for rechargeable applications.
• The conventional "solid-liquid-solid" mechanism is hindered by the "shuttle" phenomenon, caused by soluble polysulfide intermediates, leading to capacity fade and reduced lifespan.

Purpose of the Study:

• This review focuses on the fundamental chemistry of "solid-solid" and "quasi-solid" phase transformations in sulfur cathodes.
• It aims to explore strategies that circumvent the limitations of the traditional "solid-liquid-solid" mechanism.

Main Methods:

• The review introduces sulfur immobilization strategies within "solid-liquid-solid" conversions.
• It summarizes various approaches to achieve "solid-solid" and "quasi-solid" redox mechanisms in sulfur cathodes.

Main Results:

• Alternative phase transformation mechanisms, "solid-solid" and "quasi-solid" modes, are presented as solutions to the polysulfide dissolution issue.
• These alternative mechanisms offer pathways to overcome the inherent limitations of the "solid-liquid-solid" process.

Conclusions:

• Shifting from "solid-liquid-solid" to "solid-solid" or "quasi-solid" conversion is crucial for enhancing Li-S battery performance.
• Further research into these mechanisms provides perspectives for developing high-energy-density Li-S batteries.