• 文献标题:   A Surface Modification Strategy Towards Reversible Na-ion Intercalation on Graphitic Carbon Using Fluorinated Few-Layer Graphene
  • 文献类型:   Article
  • 作  者:   SARBAPALLI D, LIN YH, STAFFORD S, SON J, MISHRA A, HUI JS, NIJAMUDHEEN A, ROMO AIB, GOSSAGE ZT, VAN DER ZANDE AM, MENDOZACORTES JL, RODRIGUEZLOPEZ J
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF THE ELECTROCHEMICAL SOCIETY
  • ISSN:   0013-4651 EI 1945-7111
  • 通讯作者地址:  
  • 被引频次:   2
  • DOI:   10.1149/1945-7111/ac9c33
  • 出版年:   2022

▎ 摘  要

Na-ion batteries (NIBs) are proposed as a promising candidate for beyond Li-ion chemistries, however, a key challenge associated with NIBs is the inability to achieve intercalation in graphite anodes. This phenomenon has been investigated and is believed to arise due to the thermodynamic instability of Na-intercalated graphite. We have recently demonstrated theoretical calculations showing it is possible to achieve thermodynamically stable Na-intercalated graphene structures with a fluorine surface modifier. Here, we present experimental evidence that Na+ intercalation is indeed possible in fluorinated few-layer graphene (F-FLG) structures using cyclic voltammetry (CV), ion-sensitive scanning electrochemical microscopy (SECM) and in situ Raman spectroscopy. SECM and Raman spectroscopy confirmed Na+ intercalation in F-FLG, while CV measurements allowed us to quantify Na-intercalated F-FLG stoichiometries around NaC14-18. These stoichiometries are higher than the previously reported values of NaC186 in graphite. Our experiments revealed that reversible Na+ ion intercalation also requires a pre-formed Li-based SEI in addition to the surface fluorination, thereby highlighting the critical role of SEI in controlling ion-transfer kinetics in alkali-ion batteries. In summary, our findings highlight the use of surface modification and careful study of electrode-electrolyte interfaces and interphases as an enabling strategy for NIBs. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.