In Situ Construction of Mo<sub>2</sub>C Quantum Dots‐Decorated CNT Networks as a Multifunctional Electrocatalyst for Advanced Lithium–Sulfur Batteries
Bo Yu, Aijian Huang, Dongjiang Chen, Katam Srinivas, Xiaojuan Zhang, Xinqiang Wang, Bin Wang, Fei Ma, Chunlin Liu, Wanli Zhang, Jiarui He, Zegao Wang, Yuanfu Chen
Abstract
Abstract The slow redox kinetics during cycling process and the serious shuttle effect caused by the solubility of lithium polysulfides (LiPSs) dramatically hinder the practical application of Li‐S batteries. Herein, a facile and scalable spray‐drying strategy is presented to construct conductive polar Mo 2 C quantum dots‐decorated carbon nanotube (CNT) networks (MCN) as an efficient absorbent and electrocatalyst for Li‐S batteries. The results reveal that the MCN/S electrode exhibits a high specific capacity of 1303.3 mAh g −1 at 0.2 C, and ultrastable cycling stability with decay of 0.019% per cycle even at 1 C. Theoretical simulation uncovers that Mo 2 C exhibits much stronger binding energies for S 8 and Li 2 S n . The energy barrier for the conversion between Li 2 S 4 and Li 2 S 2 decreases from 1.02 to 0.72 eV when hybriding with Mo 2 C. Furthermore, in situ discharge/charge‐dependent Raman spectroscopy shows that long‐chain Li 2 S 8 configuration is generated via S 8 ring opening near the first plateaus at ≈2.36 V versus Li/Li + and the S 6 2− configuration in CNT/S electrode is maintained below the potential of ≈2.30 V versus Li/Li + , indicating that the shuttle of soluble LiPSs happens during the whole discharge process. This work provides deep insights into the polar nanoarchitecture design and scalable fabrication for advanced Li‐S batteries.