S/N-co-doped graphite nanosheets exfoliated via three-roll milling for high-performance sodium/potassium ion batteries  

作　　者：Xin Wang Zhicong Luo Juntong Huang Zhi Chen Tong Xiang Zhijun Feng Jing Wang Sinong Wang Yongcun Ma Huiyong Yang Xibao Li 

机构地区：[1]School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China

出　　处：《Journal of Materials Science & Technology》2023年第16期47-55,共9页材料科学技术（英文版）

基　　金：supported by the Natural Science Foundation of China(Nos.51862024 and 51962023);the Key Research and Development Program of Jiangxi Province(No.20203BBE53066).

摘　　要：Due to its larger ionic radius,further studies are needed before graphite can be used as an anode for sodium/potassium-ion batteries(SIBs/KIBs).It is believed that doping and increasing the layer spacing can improve the Na+/K+storage.Herein,S/N co-doped graphite nanosheets(GNS)with an enlarged interlayer spacing of 0.39 nm were prepared via exfoliation with three-roll milling(TRM)combined with thiourea heated at different temperatures.This method generates abundant defects and active sites for GNS,as well as facilitates rapid access and transport of electrolytes and electrons/ions.The electrochemical results show that the S/N-doped GNS exfoliated 15 times and heated at 600°C(SNGNS15-600)with thiourea as the electrode delivers a discharge capacity of 94 mAh g–1 over 6000 cycles at 10 A g–1 with an enhanced rate capability and stable performance for application in SIBs.Calculations using density functional theory show that the increased interlayer spacing by TRM and S,N co-doping enhances the adsorption energies of Na+on graphite,thus improving the Na+storage.As the anode for KIBs,the SNGNS15-600 electrode has a capacity of 142 mAh g–1 after 5000 cycles at 0.5 A g–1.This study provides an essential theoretical basis for the effective exfoliation of layered graphite-based materials and their applications in energy storage.

关 键 词：Graphite nanosheets S/N doping Three-roll milling Sodium-ion batteries Potassium-ion batteries 

分 类 号：TQ426[化学工程] TQ116.2[一般工业技术—材料科学与工程] TB383.1