Improved lithium-ion battery performance by introducing oxygen-containing functional groups by plasma treatment.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metal sulfides are promising cathode materials for lithium-ion batteries (LIBs) due to high theoretical capacity.
• However, their practical application is hindered by rapid capacity decay and material shedding during cycling.

Purpose of the Study:

• To develop a cobalt sulfide-carbon nanofiber (CoS-CNF) composite using plasma treatment and solvothermal methods.
• To enhance the electrochemical performance of LIBs by improving cathode material stability and conductivity.

Main Methods:

• Plasma treatment of carbon nanofibers (CNFs) to introduce oxygen-containing polar groups and defects.
• Solvothermal synthesis to grow cobalt sulfide (CoS) onto the modified CNFs, forming a CoS-CNF composite.
• Electrochemical testing of the composite as a cathode material in LIBs.

Main Results:

• The CoS-CNF composite electrode exhibited a high discharge specific capacity of 839 mAh g⁻¹ at 100 mA g⁻¹.
• Excellent cycle stability was observed, with nearly 100% capacity retention after 500 cycles at 2000 mA g⁻¹.
• Plasma treatment improved CNF hydrophilicity, facilitating uniform CoS growth and enhancing conductivity.

Conclusions:

• Plasma treatment combined with solvothermal synthesis is an effective strategy for preparing high-performance LIB cathode materials.
• The developed CoS-CNF composite demonstrates significant potential for advanced lithium-ion battery applications.
• This approach addresses key challenges in metal sulfide cathode stability and performance.