MoP QDs@graphene as highly efficient electrocatalyst for polysulfide conversion in Li-S batteries

Bo Yu ¹Fei Ma ¹Dongjiang Chen ²Katam Srinivas ¹Xiaojuan Zhang ¹Xinqiang Wang ¹Bin Wang ¹Wanli Zhang ¹Zegao Wang ³Weidong He ²Yuanfu Chen⁴

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作者信息

1. School of Electronic Science and Engineering,and State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China;School of Science,and Institute of Oxygen Supply,Tibet University,Lhasa 850000,China
2. School of Physics,University of Electronic Science and Technology of China,Chengdu 611731,China;School of Science,and Institute of Oxygen Supply,Tibet University,Lhasa 850000,China
3. College of Materials Science and Engineering,Sichuan University,Chengdu 610065,China;School of Science,and Institute of Oxygen Supply,Tibet University,Lhasa 850000,China
4. School of Electronic Science and Engineering,and State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China;School of Physics,University of Electronic Science and Technology of China,Chengdu 611731,China;School of Science,and Institute of Oxygen Supply,Tibet University,Lhasa 850000,China
折叠

Abstract

The shuttle effect of lithium polysulfides (LiPSs) and sluggish redox conversion significantly hinder prac-tical implementation of lithium-sulfur batteries (LSBs).To overcome these issues,herein,we present MoP quantum dots anchored N,P-doped graphene (MPQ@G) as a multifunctional LSB cathode.The N,P-doped graphene layers serve as a conductive skeleton to support the MoP QDs which can accelerate the electron transfer,physically hinder the polysulfide migration and thus enhance the electrochemical performance.More importantly,as a polar and conductive catalyst,MoP QDs provide catalytically active sites for the conversion of LiPSs.As a result,the LSBs with MPQ@G/S cathodes deliver an elevated initial capacity of 1220.2 mAh g-1 at 0.2 C and remain 98.9％ after rate cycles,signifying its exceptional cycling stability.Moreover,it displays a large capacity of 681.2 mAh g-1 even at a high rate of 1 C.The Li-S pouch cell also presents high specific capacities and preeminent cycling stabilities,confirming its great potential for high-rate applications.Density functional theory calculations demonstrate the improved absorptivity and redox conversion reversibility of LiPSs.This work provides an efficient strategy to improve composite with highly adsorptive and catalytic properties for high-performance Li-S batteries.

Key words

MoP quantum dots/Graphene/Electrocatalyst/Shuttle effect/Li-S batteries

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基金项目

National Natural Science Foundation of China(52002254)

National Natural Science Foundation of China(21773024)

Sichuan Science and Technology program(2020YJ0324)

Sichuan Science and Technology program(2020YJ0262)

Reformation and Development Funds for Local Re-gion Universities from China Government in 2020(ZCKJ 2020-11)

China Postdoctoral Science Foundation(2019M653376)

Chunhui plan of Ministry of Education of China,Fundamental Research Funds for the Central Universities,China(YJ201893)

State Key Lab of Advanced Metals and Materials,China(2019-Z03)

出版年

2021

材料科学技术(英文版)

中国金属学会中国材料研究学会中国科学院金属研究所

材料科学技术(英文版)

CSTPCDCSCDSCI

影响因子：0.657

ISSN：1005-0302

参考文献量58

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