Polysulfide regulation by defect-modulated Ta_(3)N_(5-x) electrocatalyst toward superior room-temperature sodium-sulfur batteries  

作　　者：Zhen Zhang Dan Luo Jun Chen Chuyin Ma Matthew Li Haoze Zhang Renfei Feng Rui Gao Haozhen Dou Aiping Yu Xin Wang Zhongwei Chen 

机构地区：[1]Department of Chemical Engineering,Waterloo Institute for Nanotechnology,University of Waterloo,Waterloo N2L 3G1,Canada [2]Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [3]South China Academy of Advanced Optoelectronics&International Academy of Optoelectronics at Zhaoqing,South China Normal University,Guangzhou 510006,China [4]Chemical Sciences and Engineering Division,Argonne National Laboratory,Lemont 60439,USA [5]Canadian Light Source,Saskatoon S7N 2V3,Canada

出　　处：《Science Bulletin》2024年第2期197-208,共12页科学通报（英文版）

基　　金：support from University of Waterloo,Waterloo Institute for Nanotechnology,and Natural Sciences and Engineering Research Council of Canada(NSERC).This work was also supported by the Outstanding Youth Project of Guangdong Natural Science Foundation(2021B1515020051);Department of Science and Technology of Guangdong Province(2019JC01L203 and 2020B0909030004);the Natural Science Foundation of Ningxia(2023AAC01003);the Foundation of State Key Laboratory of High Efficiency Utilization of Coal and Green Chemical Engineering(2022-K79).

摘　　要：Resolving low sulfur reaction activity and severe polysulfide dissolution remains challenging in metalsulfur batteries.Motivated by a theoretical prediction,herein,we strategically propose nitrogenvacancy tantalum nitride(Ta3N5-x)impregnated inside the interconnected nanopores of nitrogendecorated carbon matrix as a new electrocatalyst for regulating sulfur redox reactions in roomtemperature sodium-sulfur batteries.Through a pore-constriction mechanism,the nitrogen vacancies are controllably constructed during the nucleation of Ta3N5-x.The defect manipulation on the local environment enables well-regulated Ta 5d-orbital energy level,not only modulating band structure toward enhanced intrinsic conductivity of Ta-based materials,but also promoting polysulfide stabilization and achieving bifunctional catalytic capability toward completely reversible polysulfide conversion.Moreover,the interconnected continuous Ta3N5-x-in-pore structure facilitates electron and sodium-ion transport and accommodates volume expansion of sulfur species while suppressing their shuttle behavior.Due to these attributes,the as-developed Ta3N5-x-based electrode achieves superior rate capability of 730 mAh g-1 at 3.35 A g-1,long-term cycling stability over 2000 cycles,and high areal capacity over 6 mAh cm-2 under high sulfur loading of 6.2 mg cm-2.This work not only presents a new sulfur electrocatalyst candidate for metal-sulfur batteries,but also sheds light on the controllable material design of defect structure in hopes of inspiring new ideas and directions for future research.

关 键 词：Tantalum nitride Nitrogen defects Sodium-sulfur batteries ELECTROCATALYSTS Polysulfide conversion 

分 类 号：O643.36[理学—物理化学] TM912[理学—化学]