Revisiting N, S co-doped carbon materials with boosted electrochemical performance in sodium-ion capacitors: The manipulation of internal electric field

被引：0

作者：

Li S. ^{[1
]}

Zhang J. ^{[2
]}

Li Y. ^{[3
]}

Fan P. ^{[4
]}

Wu M. ^{[3
]}

机构：

[1] Shandong Institute of Petroleum and Chemical Technology, Dongying

[2] School of Chemical Engineering, The University of Adelaide, North Terrace, Adelaide

[3] State key laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum, (East China), Qingdao

[4] Shandong Hi-tech Spring Material Technology Co., Ltd, Dongying

来源：

Nano Research Energy | 2024年 / 3卷 / 01期

基金：

中国国家自然科学基金;

关键词：

internal electric field; N/S co-doped carbon; Na[!sup]+[!/sup] adsorption; sodium-ion capacitors; sodium-ion storage;

D O I：

10.26599/NRE.2023.9120098

中图分类号：

学科分类号：

摘要：

Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials. However, the underlying mechanism governing the performance enhancement remains undisclosed. Herein, we fabricated N/S co-doped carbon beaded fibers (S-N-CBFs), which exhibited glorious rate performance and durableness in Na+ storage, showcasing no obvious capacity decay even after 3500 cycles. Furthermore, when used as anodes in sodium-ion capacitors, the S-N-CBFs delivered exceptional results, boasting a high energy density of 225 Wh·kg–1, superior power output of 22500 W·kg–1, and outstanding cycling stability with a capacity attenuation of merely 0.014% per cycle after 4000 cycles at 2 A·g–1. Mechanistic investigations revealed that the incorporation of both pyridinic N and pyrrolic N into the carbon matrix of S-N-CBFs induced internal electric fields (IEFs), with the former IEF being stronger than the latter, in conjunction with the doped S atom. Density functional theory calculations further unveiled that the intensity of the IEF directly influenced the adsorption of Na+, thereby resulting in the exceptional performances of S-NCBFs as sodium-ion storage materials. This work uncovers the pivotal role of IEF in regulating the electronic structure of carbon materials and enhancing their Na+ storage capabilities, providing valuable insights for the development of more advanced electrode materials. © The Author(s) 2024.

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