Phosphorus and Nitrogen Codoped Porous Carbon-Based Sulfur Host for High-Loading Lithium/Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium/sulfur (Li/S) batteries offer high theoretical energy density and low cost, making them promising for next-generation applications.
• Commercialization requires high-loading sulfur cathodes with stable, high-rate cycling performance and lean electrolytes.

Purpose of the Study:

• To develop a stable sulfur host material for high-loading Li/S batteries.
• To evaluate the electrochemical performance of Li/S batteries using a novel codoped porous carbon sulfur host.

Main Methods:

• Synthesis of phosphorus and nitrogen codoped porous carbon.
• Fabrication of high-loading sulfur electrodes using the synthesized carbon host.
• Electrochemical testing of Li/S cells at various sulfur loadings and cycling rates.

Main Results:

• Li/S batteries with 4 mg cm^-2 sulfur loading demonstrated stable cycling at 1 C for 200 cycles (553 mAh g^-1), with a low degradation rate of 0.068% per cycle.
• At a higher loading of 7 mg cm^-2, batteries showed an initial capacity of 1207 mAh g^-1, retaining 736 mAh g^-1 after 100 cycles at 0.1 C.
• The codoped carbon host facilitated stable performance under lean electrolyte conditions.

Conclusions:

• Phosphorus and nitrogen codoped porous carbon is a viable sulfur host for high-loading Li/S electrodes.
• The material enables stable, high-rate cycling crucial for practical Li/S battery commercialization.
• This advancement supports the development of efficient and cost-effective next-generation batteries.