Highlighting the Implantation of Metal Particles into Hollow Cavity Yeast-Based Carbon for Improved Electrochemical Performance of Lithium–Sulfur Batteries

Abstract

The introduction of metal particles into microbe-based carbon materials for application to lithium–sulfur (Li–S) batteries has the three major advantages of pore formation, chemisorption for polysulfides, and catalysis of electrochemical reactions. Metal particles and high specific surface area are often considered to enhance the properties of Li–S batteries. However, there are few data to support the claim that metal particles implanted in microbe-based carbon hosts can improve Li–S battery performance without interfering with the specific surface area. In this work, hollow-cavity cobalt-embedded yeast-based carbon (HC–Co–YC) with low specific surface area was successfully produced by impregnating yeast cells with a solution containing 0.075 M CoCl2 (designated as HC–Co–YC–0.075M). Cobalt particles implanted in yeast carbon (YC) could improve the conductive properties, lithium-ion diffusion, and cycling stability of the sulfur cathode. Compared to previously reported counterpart electrodes without metal particles, the HC–Co–YC–0.075M/S electrode in this study had a high initial specific capacity of 1061.9 mAh g−1 at 0.2 C, maintained a reversible specific capacity of 504.9 mAh g−1 after 500 cycles, and showed a capacity fading rate of 0.1049% per cycle. In conclusion, the combination of cobalt particles and YC with low specific surface area exhibited better cycle stability, emphasizing the importance of implantation of metal particles into carbon hosts for improving the electrochemical properties of Li–S batteries.