Kinetically Enhanced Electrochemical Redox of Polysulfides on Polymeric Carbon Nitrides for Improved Lithium–Sulfur Batteries

• DOI: 10.1021/acsami.6b05647
• Publication Date: 2016-09-06T20:56:15Z
• Authors: Ji Liang; Lichang Yin; Xiaonan Tang; Huicong Yang; Wensheng Yan; Li Song; Hui-Ming Cheng; Feng Li
• Keywords: Electrochemical kinetics; Carbon fibers; Half-reaction

The kinetics and stability of the redox lithium polysulfides (LiPSs) fundamentally determine overall performance lithium-sulfur (Li-S) batteries. Inspired by theoretical predictions, we herein validated existence a strong electrostatic affinity between polymeric carbon nitride (p-C3N4) LiPSs, that can not only stabilize cycling but also enhance their kinetics. As result, utilization p-C3N4 in Li-S battery has brought much improved aspects high capacity low fading over prolonged cycling. Especially upon application p-C3N4, kinetic barrier LiPS reactions been significantly reduced, which thus resulted better rate performance. Further density functional theory simulations have revealed origin such enhancement was from distortion molecular configurations LiPSs anchored on p-C3N4. Therefore, this proof-of-concept study opens up promising avenue to improve batteries accelerating fundamental electrochemical processes, potential be applied other energy storage/conversion systems.